Urban Dragon Hunters

Review: Dragonflies and Damselflies of the East

2012-01-18T08:35:00.000-05:00

If you live in the eastern United States or Canada, be sure to pick up a copy of Dragonflies and Damselflies of the East by Dennis Paulson. This book is a must for any odonata enthusiast.

It covers 336 species in 538 pages. Some of these are the same species Paulson covered in his earlier release, Dragonflies and Damselflies of the West. If you own that book, you may want to pick up the eastern guide anyway; Paulson notes in his preface that in the two years or so since the western guide was published he has learned so much that some material in the eastern guide will "modify, perhaps even contradict" the previous book.

That caveat reflects how rapidly our understanding of Odonata distribution, ecology, and identification is evolving. Putting together a field guide to any taxa is a daunting task, much less authoring one on a moving target like Odonata. Paulson has pulled together reams of data from many sources to make this book an essential step forward from the first broad field guide to Odonata, Dunkle's Dragonflies through Binoculars, published in 2000. And of course, unlike Dunkle, it contains damselflies -- a huge and exciting plus.

Field use

Although it is in a standard roughly 8.5 by 5.5 inch field-guide size, it will weigh down your field pack by 2 pounds, 5 ounces. The type size doesn't seem smaller than other field guides, but it is very dense -- a lot of text with characters spaced very closely. For those of us in middle age, it can be difficult to wade through, especially in the field.

There are two aspects of the layout that could make field use a bit frustrating from some people. Although we strongly prefer photo/illustration, text, and maps for each species to be all together (as they are in this book) rather than separated into plates and text (as they are in Dunkle), the variable amount of material for each species in this book means a species account could start anywhere on a page. You have to scan each page for the name of the species you are looking for. This layout is unavoidable given the amount of material in the book; thoroughness won out over user-friendly.

Second, the species are arranged in taxonomic order. In most lists of Odonata (including the Checklist of North American Odonata¹), the species are listed in alphabetical order within each genus. Perhaps for most folks, who don't know the scientific names of many odonates in the first place, this will start them out on the right foot: learning the correct order and relationships. For those of us who know just enough Latin to be dangerous, it just sends us to the index. Putting together a quickie index to paste inside the back cover to guide you to your most frequently-used genera/species will be helpful.

Introductory and background material

A good introduction reviews Odonata natural history and anatomy with many great photos adding to the text. Paulson writes clear prose that is easy-to-read without dumbing down, technical and accurate without being pedantic, and which shows his enthusiasm and wonder for odonates. The detailed macro anatomy photos in this section will be extremely helpful to complement the text describing each species, as will the three-page glossary in the back of the book.

Other overview material includes odonate threats and conservation; and finding, photographing, identifying, and collecting Odonata. Paulson outlines the important elements of identification, emphasizing the many pitfalls of trying to ID odes in the field or from photos, and he provides a good section on the hows and whys of collecting voucher specimens.

Species accounts

As one would expect, the majority of the book contains the species accounts. Each species is given similar attention, whether it's widespread and common, or limited in range. Topics for each include identification, similar species, natural history, habitat, flight season, distribution, and a range map. There are typically at least two photos in each account, usually one of each sex but also sometimes various color forms, young individuals, or regional variants.

One of the best features of the book are the illustrations which show differences between similar species' features such as male appendages or female subgenital plates. These usually follow the group of species accounts that they illustrate (pond damsels, common clubtails), but sometimes occur within the species accounts (e.g., some male Aeshna hamules and appendages). We find illustrations like this essential to ID, providing you have the insect in hand (we'd love to have these illustrations included in a small booklet for the field). These are some of the largest and most helpful we've seen, especially helpful since while the photographs of each species are very nice, most cannot adequately portray these key features. Note, however, that the illlustrations are all simple, clear line drawings and depict structural differences. Thus, no page of thoracic patterns of darners, or color patterns of the last few abdominal sections of bluets or dancers. The line drawings are only labeled with common names; scientific names would have been a valuable inclusion, and it seems like space is adequate.

While we haven't read each one, the text for the accounts seems more than adequate. Regional differences are noted if needed. The "Comments" section is often the most interesting, providing information on taxonomic quandaries, distribution mysteries, and/or knotty identification problems. It's worth it to read the introductory material for each genera as well as the accounts of all similar species when you're attacking an ID to get a complete picture. For instance, the account for Slender Baskettail (Epitheca costalis) mentions the intermediate/hybrid individuals (with Common Baskettail, E. cynosura) in the upper Midwest, but this is not brought up in the cynosura account -- even though that account notes it is the most common baskettail in the east with which all others should be compared.

The range maps are not color-coded to indicate early or late flight seasons. That was a nice touch in Dunkle's book, but would have added another layer of complexity to an already complicated task. Constructing range maps for a large region is fraught with pitfalls. These are based on a wide variety of sources and include data through the year 2010. But with a taxa like Odonata where our knowledge of distribution is so dynamic, they should be used, as Paulson notes, to "give a good idea of the known or expected distribution." He provides a further caveat that some records on which the maps are based are old, and some species may now be absent for parts of their former range.

At this particular scale, some range margins need to be taken with a grain of salt. For instance, Flag-tailed Spinyleg (Dromogomphus spoliatus) was first found by us in Michigan in Wayne Co., and has since been found in Monroe and Lenawee counties, all in extreme southeastern Michigan. The range map seems overly generous for the state. We had Michigan's first Band-winged Dragonlets (Erythrodiplax umbrata) in 2007. The record is in Odonata Central, and was published within months, but the range falls short of Michigan (nor is there a dot indicating a vagrant record). And although it was axed from the MOS database -- but not from Odonata Central -- years ago as an error, the Alpena County Russet-tipped Clubtail (Stylurus plagiatus) is shown on its map. It's just not possible for an author to keep up with all of this, and the range maps are surprisingly detailed given the amount of fragmented source data. They are a great jumping off point...and let the errata compilation begin!

In fact, the Princeton University Press web site includes a link to references used in both the eastern and western guides. It only includes papers published through 2007, but will be added to and become a valuable go-to site for serious users wanting updates.

This guide is also available in a Kindle edition. We'd be interested in hearing from people who have this on a Kindle Fire or other color e-reader. How does it look and function?

Our job as reviewers is to critique. Many of our comments are nit-picky, and probably won't be too important to the average user of the book. Though we have critiqued, we are not critical of this absolutely essential book. Get it, study it, and be ready for ode season 2012!

¹Paulson, D. R., and S. W. Dunkle. 2011. A Checklist of North American Odonata, Including English Name, Etymology, Type Locality and Distribution. 2011 Edition. Originally published as Occasional Paper No. 56, Slater Museum of Natural History, University of Puget Sound, June 1999; completely revised March 2009; updated February 2011.

Honduras: the odes of Pico Bonito

2011-11-30T16:17:00.019-05:00

We made another trip south this past holiday weekend (November 24-28, 2011). This year we visited Honduras and stayed at The Lodge at Pico Bonito (15.6929, -86.9022) near La Ceiba.

Travel to the location was easy. We flew into San Pedro Sula, then one has two options to arrive at the lodge: fly to La Ceiba or drive 2.5 hours via car. We chose the latter since this gave us a chance to see a bit more of the country. The highway was in amazing condition compared with other roads in Central America, but we soon determined why this was the case. Heading east from the airport, we soon encountered oil palm plantations which have taken over vast areas of land and large variety of issues. We then drove past immense areas of fruit production (bananas and pineapple). Upon arriving in El Pino, we turned onto a nondescript road leading through secondary growth forests and cacao plantations. When the forest became thicker, we knew we were close since the lodge is at the edge of Pico Bonito National Park.

The Lodge at Pico Bonito includes several buildings (lodge, restaurant/bar, cabins) and an outdoor pool. The grounds and gardens between the cabins are a mix of manicured lawn, flower beds, and an old cacao plantation.

These gardens were good areas to find young individuals of a variety of species.

Digiscoped female skimmer (Orthemis sp.).

The porch of our cabin (#2) provided the location of our favorite ode observation.

Megaloprepus caerulatus - our favorite ode in the world.

Megaloprepus caerulatus - close up of wing tips.

The property is situated along a ridge between two rivers (Rio Coloradito to the west and Rio Corinto to the east). These clear, swift-flowing mountain rivers didn't provide much in the way of odonata observations, but they were quite beautiful. The only species observed next to a river was one female Band-winged Dragonlet (Erythrodiplax umbrata). Perhaps this was due to the time of year?

Rio Coloradito.

Rio Corinto.

Each afternoon we took a walk to the Butterfly House since the trail went through an old cacao plantation with a couple of open areas. The clearing between the larval house and the adult houses was a good area to look for odes and leps.

The ubiquitous dragonlet Band-winged Dragonlet (Erythrodiplax umbrata).

Pin-tailed Pondhawk (Erythemis plebeja).


Erythrodiplax fervida. She looks like she is about to do a swan dive.

On our last full day (11/27/11), we hired one of the lodge's guides Elmer Escoto for a morning bird walk. We went to a new trail created west of the Rio Coloradito. The area on the left side of the photo below.

We crossed a small stream in the forest that had a few patches of sunlight. That's all we needed to pull out the net and find a couple more species of odes. We turned our bird guide into a Honduran dragonhunter.

Our guide Elmer Escoto caught the rubyspot for us.

Hetaerina capitalis.

There were also several Argias present. These appeared to be of the Argia oculatus complex, type B.

Finally, that afternoon (11/27/11) we witnessed the large dragonfly movement that the Lodge's naturalist James Adams had mentioned to us when we arrived. On our walk to the Butterfly House, we spied 1000s, if not 10s of 1000s, of odes flying in an easterly direction. Here's a distant photo (click on it to view large...all the small specs are dragonflies):

...and a digiscoped shot through my binoculars:

This flight continued nonstop throughout the afternoon. Anytime we looked up through the trees, the numbers continued. We're not sure how many species were involved, how many days this continued, or the reason for the movement.

List of species observed and locations during our brief visit:
1. Hetaerina capitalis = small forest stream west of Rio Coloradito
2. Megaloprepus caerulatus = cabin #2
3. Argia oculata complex, type B = small forest stream west of Rio Coloradito
4. Telebasis sp. = small forest stream west of Rio Coloradito
5. Black Pondhawk (Erythemis attala) = Butterfly House vicinity
6. Pin-tailed Pondhawk (E. plebeja) = Butterfly House vicinity
7. Great Pondhawk (E. vesiculosa) = the Lodge's gardens
8. Erythrodiplax fervida = Butterfly House vicinity
9. Band-winged Dragonlet (E. umbrata) = any open area
10. Roseate Skimmer (Orthemis ferruginea) = Butterfly House vicinity

Updated Late Dates 2011

2011-11-10T15:36:00.000-05:00

The mild November weather allowed us to check on a special species in Michigan. Great Spreadwing (Archilestes grandis) has only been found in Livonia through the years. Julie saw individuals again a month or so ago, and had noted goldfish swimming in one of the small pools of the creek. (this may not bode well for the odonata species).

On November 6, we waited until the frost thawed and then headed to THE location. Within a minute I found a male Eastern Forktail (Ischnura verticalis) which marks a new late date.

Julie noted that she now saw a bluegill in the same pool that had goldfish previously, and the location where the A. grandis were easiest to find in past years. (uh oh) I walked further down the creek towards I-275 between the newer buildings. In the first sunlit, sheltered location I flushed a coupled pair of Great Spreadwings! Soon after I saw a solo male and either the same or another coupled pair. This marks the new late date for Michigan by 1 day.

These may be the last species the two of us see in Michigan this season, barring Autumn Meadowhawks (Sympetrum vicinum).

Last Odes of the 2011 Season in southeastern MI

2011-11-06T11:00:00.002-05:00

While walking around campus at my workplace in Farmington Hills, Oakland County, MI, during lunch hour on October 24, 2011, I found 3 of the last dragonfly species of the season.

3+ Familiar Bluet (Enallagma civile)
1 Common Green Darner (Anax junius)
4+ Autumn Meadowhawks (Sympetrum vicinum)

Over the following days I kept an eye out for these since the late dates for specimens was approaching.

On October 31, I was able to find a female Eastern Forktail (Ischnura verticalis) for what I believe is a new late date for a MI voucher. The previous late date in the MOS database was an individual I had on 10/07/07.
This image is of a female I found in Monroe County earlier in October:

On November 2, I found one female and one male Familiar Bluet (E. civile)! This, too, is what I believe to be the latest date for a MI voucher. The previous late date in the MOS database was an individual I had on 10/19/10. Here is the male:

Today is one of the truly nice days remaining for this year. We'll head out to look for the last possibilities of flying damsels around here.

Aeshna ID: Canada versus Green-striped

2011-10-19T18:14:00.004-04:00

In our quest for Canada Darner (Aeshna canadensis) in Wayne County, we have come up with a number of locations and specimens of the similar Green-striped Darner (A. verticalis). While there is a historical and possible photo record for Canada (CADA) for the county, we've had no luck finding this species over the last ten years. We've only found one Green-striped (GSDA), in 2003, prior to this year, when we found many.

Most field guides present differentiating these two species as fairly straightforward. We've found ID more problematic, although we are hampered by a lack of live CADA material to work with. This post will go over these two species, and (necessarily) feature the variability of GSDA that would complicate field ID.

Here are the characteristics typically cited to separate the two species.

Field characteristics

Color of thoracic stripes: Usually blue in CADA, green in GSDA. However, male CADA often have stripes that are greenish ventrally or sometimes all green. Meanwhile, the rear stripe in male GSDA is sometimes blue-green dorsally.

Dot on thorax: CADA usually have a yellow dot between the two thoracic stripes. This feature is also sometimes present on GSDA. We have found it present at least half the time in our area.


Male Green-striped Darner. Rear thoracic stripe partly blue, spot between stripes present. Livingston Co., MI

Male Green-striped Darner with very bluish stripes and thoracic
spot absent. Wayne Co., MI

CADA females come in a green-striped form, and some female GSDA are blue (rarely). Cold individuals of either species can be dull and confusing. Many guides agree that green females are probably impossible to tell apart without close examination in the hand.

Female Green-striped Darner with bluish and green abdominal spots;
thoracic spot absent. Wayne Co., MI

Female Green-striped Darner with bluish abdominal spots;
thoracic spot present. Note that both females are missing cerci,
which presents another problem (see below). Wayne Co., MI

Shape of thoracic stripes: Front stripe is supposed to be deeply notched in CADA, not so deeply notched in GSDA. The dorsal "flag" (the part of the front stripe that runs along the base of the wing) of CADA narrows, often becomes wider in GSDA, as is evident in the photos above.


This Aeshna has a "flag"that narrows, which could indicate Canada, but the thoracic stripes are greenish, as in Green-striped. We were unable to collect this one to verify identity. Livingston Co., MI

Males, spot on abdominal segment 1: Usually only slightly pinched in CADA, deeply notched or bifurcated in GSDA. I've added this feature per Reuven's comment below. Here is a composite of GSDAs showing variability, with a red arrow in the first photo pointing out s1.

Certainly variable, but often distinctly "bi-lobed." I hestitate to link to online photos since I don't know if they are always correctly identified, but here are some shots that I believe are of genuine CADA showing s1.

Minnesota, s1 nearly entire.
Montana, s1 notched.
Ontario, s1 notched.
Presumed Montana, s1 deeply notched. This photo, by the way, is worth viewing original size, as there is the head of a hymenopteran latched on to one of the darner's legs!

While apparently variable in both species, this could be reliable, especially in combination with other features.

Face: Black band across the labrum in CADA, brownish edge in GSDA.

Canada Darner, black labrum.

Green-striped Darner, brownish labrum.

This seems like it also might be reliable, but we have not looked at enough CADA to be sure. One thing we've noticed about this feature, at least in GSDA, is the variability of facial markings. Many have random botches and spots. We wonder how prevalent this is in CADA, and if it muddies the diagnosis of labrum color. This photo of a putative CADA, also shows a weird blotchy face. Here are just a few GSDA faces.

In-hand characteristics

We have had more success examining these two species in the hand under very close magnification, but the keys and characteristics can be puzzling without experience or comparative material. Here are some of our experiences.

Males

In males, the shape of the cerci are similar in both species. However, as most keys note, the top margin of the superior claspers of male CADA have tiny teeth; these are absent in GSDA. These usually cannot be seen in the field or a photograph, but are said to detectable by running a finger across the cerci. I'm not sure this would be a slam-dunk even for Helen Keller. These teeth are very tiny.

Arrow pointing to teeth on top margin of CADA male cerci.
Crawford Co., MI

What we have found to be most obvious (once you know what you are looking at) are the "anteromedial process of each anterior hamule," or an aspect of the naughty bits. They are, in much more simple language, pointed in toward the rear in CADA and pointed at each other in GSDA. First, let's look at the diagram from DONA*. The red arrows show these bits, and the orientation is such that the top of the diagram is the direction of the heads of the dragonflies:

And to put this in some context, here is what it looks like. We used a Dino-Lite Digital Microscope to take these photos.

Male CADA, arrow pointing to rightmost anteromedial process. Note that in CADA, these
two paired structures look like open gates, pointing to the head of the insect.

Male GSDA, arrow pointing to rightmost anteromedial process. Note that in GSDA, these
two paired structures look like closed gates, with the tips pointing to each other.

These things are very tiny and hard to see! But if you can get the right look, they are diagnostic.

By the way, although it is not pictured or mentioned consistently in all keys, both species have a little tubercle or bump on the top of abdominal segment 10. It's visible in the photo above of the male CADA cerci.

Females

Most authors acknowledge that green-colored females of these two species can't be separated in the field, or with photos. DONA's key points us to the structure of the ridge of the genital valves, and provides us with this diagram:

These two look pretty similar. The shape of the cerci is different -- but they are often broken off. We haven't caught any candidates that still had their cerci. Those being absent, we weren't sure, even with the little arrows, precisely what structure we were supposed to be examining (in the hand, they have a lot of little ridges and flanges going on in those parts). Another diagram is helpful:

This shows that the genital valves in question are the things that the little hair-like styli come from. Once we saw that, we knew what we had to look at. The key notes that in CADA, the basal third of these valves has a weakly developed ridge, which is well developed in GSDA. We must admit, looking at a single specimen we were still uncertain. It looked kind of like either one of them. For what it's worth, here is a GSDA, with the contrast tweaked to show the ridge.

This winter, I'll try to pull out some specimens at the University of Michigan Museum of Zoology Insect Division and take a look at further material. Even better, maybe I can convince Mark O'Brien to take some digital photos. Even better than that, maybe next year the Urban Dragon Hunters can find some Canada Darners of our own.

*Needham, J.G., M.J. Westfall, Jr. and M.L. May. 2000. Dragonflies of North America, revised edition. Gainesville: Scientific Publishers. The granddaddy of Odonata keys.

Circus of the Spineless

2011-10-04T07:33:00.000-04:00

Way back in the Jurassic period of the Internet, Julie was one of the founders of the blog carnival Circus of the Spineless, a monthly compendium of blog posts on invertebrates. It's high time we start participating once again in CoTS. This month, CoTS #66 is hosted by another long-running blog, Wanderin' Weeta. It includes our post on Striped saddlebag and the value of vouchers, and a bunch of other invert posts, including two more on Odonata. Go take a look, and consider submitting a post to a future issue.

Green-striped Darners

2011-09-17T09:10:00.001-04:00

We saw our first Green-striped Darner (Aeshna verticalis) in October of 2003 at the hawkwatch (formerly SMRR, now the Detroit River Hawkwatch) at Lake Erie Metropark.

Years have gone by without seeing others and now, in the past week, we have found multiple individuals at two more locations in Wayne County.

On August 28th, we visited Crosswinds Marsh in an attempt to confirm Canada Darner (A. canadensis). At one point in the NW area of phase I, a mosaic darner flew across the trail and perched in a small tree. This turned out to be a female Green-striped Darner (A. verticalis). This shot shows the obtuse angle of the anterior lateral thoracic stripe:

This shot shows the dorsal patterning:

This shot shows the frons and the face:

Several days later on September 3rd we visited Maybury State Park. In the northwest area of the park, we found several darners working an open area. We captured a pair of Green-striped Darners (A. verticalis).

Side view of the male:

Dorsal view patterning:

Another good feature for confirming ID of A. verticalis is the lack of "teeth" on the dorsal surface of the cerci. I'm not sure one could see "teeth", or bumps, in this photo even if it was a Canada (A. canadensis), but in the hand and under a microscope the "teeth" were absent:

The female lateral view:

It has been fun gaining more experience with the Green-striped Darners (A. verticalis), but we still need to find that elusive Canada Darner (A. canadensis) in Wayne County. In the coming days, we'll add more information about how to differentiate A. verticalis from A. canadensis.

An insect in the hand is worth more than a book cover

2011-09-13T11:18:00.002-04:00

At the risk of sounding like (even more of a) stick-in-the-mud regarding the value of vouchers, here is a great example of not always being able to trust photographic identifications of insects:

This is a real book, thankfully out of print, which has a fly illustrating the cover. It was highlighted on the Scientific American blog of Alex Wild in a post on misidentified insects in the media. Alex has his own excellent blog, Myrmecos, where he has shown that even National Geographic isn't immune to these mistakes (nor The Learning Channel, a Discovery company). Surely they should know better. And so should the "experts" at pest eradication companies around the country, but look at the array of things that are not fire ants displayed on their web sites.

Unfortunately, mislabeled photos online often come back to haunt us, as the misidentifications may be passed on and perpetuated. I'm not going to beat a dead horse here. I'll just say be careful when using photos to ID insects, don't just label something online if you aren't sure (ask for help!), and correct your mistakes in a timely manner.

[stands down from soapbox]

Flag-tailed Spinyleg confirmed for Lenawee County

2011-09-10T10:00:00.001-04:00

We had heard that Flag-tailed Spinylegs (Dromogomphus spoliatus) were observed at Indian Crossing Trails Park in Tecumseh in the mid-August. This is only the third location they've been observed in Michigan so we had to confirm the record. The first record was from Oakwoods Metropark in Wayne County and earlier this August a photograph was obtained of an individual at Pte. Mouillee SGA in Monroe County.

We arrived to the park late in the morning on August 27, 2011 and almost immediately flushed a spinyleg from the rip rap bordering the millpond next to the community center. We obtained several photographs at a distance, but they were very skittish.
Some through binoculars:

and others with Julie's macro lens:

Now the challenge was to net one. We worked the edge of the dam repeatedly, trying to get in a position to approach the individuals without casting a shadow and having room for a swing of the net. After 45 minutes or so, I was able to trap one on a flat piece of concrete with Julie helping to herd it. This male (D. spoliatus) confirms the record for Lenawee county and was one of ~10 individuals present:

...and this photo shows its spiny legs and the flag tail:

While chasing the target species, we found several other great dragonflies. A couple Black-shouldered Spinyleg (Dromogomphus spinosus), such as this male:

A few Royal River Cruisers (Macromia taeniolata), with this male possibly representing the first record for Lenawee County:

Many Smoky Rubyspots (Hetaerina titia), which seem to be everywhere this year:

A few Eastern Amberwings (Perithemis tenera), such as this female:

We also had heard that a Dragonhunter (Hagenius brevistylus) or two had been observed recently, but no luck this day. We had observed a male a few years ago, but couldn't obtain any photos. Indian Crossing Trails Park is a must for a return visit in the future.

Dragonfly Migration, part 2

2011-09-02T07:04:00.003-04:00

Last night there was a strong movement of dragonflies over our house outside of Detroit last night, 1 September. We count migrating Common Nighthawks every evening at dusk, so I was ready with a tally sheet and hand-counter to record the numbers (Darrin was at a meeting, so I was on my own). I may have missed the first part of it, since I went out at the usual time of 0730 PM EDT and stuff was already on the move.

I counted 612 dragonflies -- from what I could tell predominantly green darners, with about 10% saddlebags -- moving south in about 30 minutes. These were mostly what I counted with my naked eye. When I did look up with binoculars, many dozens more visible (as were clouds of flying ants and some other insects that I initially took as wispy clouds!). I estimate that up to 3000 dragonflies passed over the small patch of sky over our yard in a half-hour. Given my inland, urban location, I presume this may have been the fringe of a larger swarm, perhaps along the Rouge River just west of us; much of the ode activity was in the western quadrant of the sky. Large movements often follow a cold front, and/or occur on northwest winds. However, conditions here were a clear/hazy sky, 82F, wind ESE 3, and 69% humidity. The day before was similar, and today is forecast to be the same. I expect the ant/insect swarms played a role.

Animal migrations capture the imagination like few other events the natural world. In 2006, I wrote a brief post about dragonfly migration, and promised a follow-up. I just had to be inspired to finally do it. Last night's observation did the trick. Here is some background and information on dragonfly migration.

Based on observations of mass movements, over a dozen species of North American dragonflies are thought to undergo regular migrations. Two are Aeshnids:

Common Green Darner, Anax junius
Swamp Darner, Epiaeschna heros

and the rest are Libellulids:

Bar-winged skimmer, Libellula axilena
Twelve-spotted Skimmer, L. pulchella
Painted Skimmer, L. semifasciata
Great Blue Skimmer, L. vibrans
Variegated Meadowhawk, Sympetrum corruptum
Wandering Glider, Pantala flavescens
Spot-winged Glider, P. hymenea
Vermilion Saddlebags, Tramea abdominalis
Striped Saddlebags, T. calverti
Carolina Saddlebags, T. carolina
Black Saddlebags, T. lacerata
Red [-mantled] Saddlebags, T. onusta

Another dozen species, also in these families, have been reported as migratory.

Strictly speaking, migration is the seasonal movement of an entire population of animals to a more favorable environment. This doesn’t really seem to be the case with dragonflies. Most of the listed species are usually seen as southbound migrants, and their northbound flights are not as well documented. On the other hand, two species -- the Bar-winged and Great Blue Skimmers -- have not been seen going south in numbers. They may not be true migrants, but move north in response to climatic conditions, such as drought, in order to find suitable places to lay eggs (see the previous post on Striped Saddlebags). Variegated Meadowhawks both apparently migrate along the west coast of the U.S., and move east as vagrants. Meanwhile, Wandering Gliders are well-known for tracking swarms of aerial plankton. They are found worldwide, and are quite nomadic. They are also known to make regular, stunning movements between Africa and India (they are referred to as "Globe Skimmers" in that article).

In North America, green darners are the best-studied migratory odonata, and even they do not make a true, round-trip migration. Instead, it is inter-generational, like Monarch butterflies. So-called resident green darners lay their eggs in mid- to late summer. These take nearly a year to emerge as adults, overwintering as larvae. But in the same pond, there may be another sub-population. Eggs laid by early-arriving migrants from the south take only three months to fully develop, emerge as adults in late summer or early fall, and these adults then move south.

We know so little because dragonfly migration is difficult to study. Since it is often low density, we don’t really notice movements until dramatic events take place. Like birds, dragonflies are influenced by weather. For example, in fall, large movements occur during times of northwest winds following the passage of a cold front. These conditions have triggered dragonfly movements where the insects have been estimated at densities comparable to those of locust swarms. Much of what we surmise about dragonfly migration has come from documentation of these types of mass movements.

Tracking more ordinary movements would involve marking the insects somehow. Wings of larger species can be marked or tagged, but for any worthwhile information to be gleaned, large numbers of insects would have to be captured and then recaptured. The use of miniaturized radio transmitters is extremely intriguing, but is costly – not only do you have to pay for the transmitters, but since ground receivers only grab a signal within a mile, finding the outfitted dragonflies requires a plane, where reception increases to five miles or so.

Another less expensive technique currently being used for linking migratory routes and wintering areas in other taxa: stable isotope analysis. Rainwater at different latitudes has different ratios of stable hydrogen isotopes. This isotopic signature is preserved in plants taking up that water, and consequently in the body parts of organisms that were formed as they consumed those plants or other organisms feeding on them. If you know that a particular body part (feathers in birds, for example) is grown at a particular location (usually, the breeding site), you can sample the body part at another location and after a relatively simple lab analysis, “read” the isotopic signature, matching it with a breeding site. This has been done extensively with birds, and also with Monarch butterflies.

Technology is continually improving, and I expect we will unravel many mysteries of dragonfly migration in the near future.

I have dutifully reported my observation to the Xerces Society, and on this web site.

A whole lot has been written about dragonfly migration since my first post, so I'm late to the party. Here are just a few resources:

Simple rules guide dragonfly migration. 2006. Wikelski, et al. Biology Letters 22(3): 325–329. This open access paper gives the nuts and bolts on findings on movements of green darners using radio transmitters. It's the one I mentioned in the first post.
Christine Goforth's Dragonfly Woman blog has a whole section on her work on dragonfly swarms. This is your one-stop shopping for info on this phenomena.
Overview of Wandering Glider migration, with cool map.
British Dragonfly Society migrant dragonfly project
Dragonfly migration at Journey North

Striped Saddlebags and the value of vouchers

2011-08-29T19:02:00.000-04:00

Craves, J. A., and D. S. O’Brien. 2011. Tramea calverti (Odonata: Libellulidae): new for Michigan with notes on other new reports from the Great Lakes region (pdf). Great Lakes Entomologist 44:78-82. 

Our paper on Striped Saddlebags appears in the most recent issue of the Great Lakes Entomologist. As the title implies, it not only describes our first state record for Michigan in 2010, but also includes reports from the Great Lakes region, all over the eastern U.S., and background on previous northward movements of this species.

In late 2010, this southern species was reported from eight states and Canada north of 38°N. It had never been reported in five of those states and Canada. Some of the locations had multiple sightings over multiple days. Quite a few were photographed.

But the voucher we obtained was the only one obtained in 2010 in this incursion. Not just in Michigan, but anywhere in the eastern U.S., as far as we were able to determine.

We've talked before about the pitfalls of trying to identify Odonata from photographs, one reason most states require a voucher specimen to confirm county or state level records. Of course, many species, including Striped Saddlebags, can be identified from a photo. But concrete ID is only one aspect of the value of specimens, and the lack of vouchers of Striped Saddlebags from 2010 is a good example.

Ohio, for instance, had multiple sightings of Striped Saddlebags in 2010 in at least two locations. However, this wasn't the first time this species had been seen and photographed there. There were reports from 2006, 2007, and 2008. No vouchers have been submitted for this species in Ohio.

There are a number of fundamental questions that cannot be answered by the photographs of Striped Saddlebags in Ohio, such as whether or not this is a breeding population, or if they are repeatedly colonizing the same spots year after year. Nor can we determine where they came from. Because there are no vouchers from Ohio or other states (except ours in Michigan), we can't see if these saddlebags all originated from a particular region or population. Or if there is some subtle morphological difference in these far-wandering saddlebags -- wing shape, flight musculature, etc. -- that helped them make the trip north. And, if breeding populations are being established from such individuals, whether these traits being maintained in the population, representing evolution at work.

Specimens could help answer these questions (and others I have not considered, I'm sure). Molecular work on insects is widely used to look at dispersal, routes of expansion, and colonization; delineate genetic populations and gene flow; and examine evolutionary divergence. Measurements of morphological traits obviously cannot be performed without a physical specimen.

When our paper went through informal and formal peer review, several referees did not want sight or photo reports included at all because they are generally not accepted by the scientific community. Obviously this removed a great deal of context for our record. In the end, we came to the conclusion that describing all the sightings would at least provide some published historical record, given that specimen material is not available.

And publication in some sort of formal journal is important. Usually these are archived in libraries as hard copy and are therefore available to researchers for the long haul. About 70% of the Striped Saddlebags records we referenced in this paper were found on local Internet forums, listservs, or personal web sites. These sources are far too ephemeral and difficult to find to act as historical documentation. Fortunately, quite a few of the records were also submitted to Odonata Central. This is extremely helpful, but does not replace vouchers as valid records in every state, and as a site that relies on donations, it's future is not guaranteed.

For significant records of Odonata, please consider collecting voucher specimens. If you would rather not do it yourself, please let someone who is willing to do so know about your observations. We've listed many resources in the sidebar that will help you find the right people to contact.

Another visit....Another Monroe County Record

2011-08-27T17:28:00.000-04:00

Thinking about the other Stylurus species along the Raisin River, we headed back to Monroe County, MI on August 20th.

We found Russet-tipped Clubtails (S. plagiatus) and Fawn Darners (Boyeria vinosa), but none of the other Stylurus.

The highlight was flushing a young, male Carolina Saddlebags (Tramea carolina) which provides the first record for Monroe County. I had guessed I'd have to wait until the southerly winds in September brought some north, but that wasn't the case.

Here's a lateral view showing the black down the sides of the abdomen and the smaller hamules:

Here's a shot of the purplish frons:

I guess I'll have to make another visit in early September to Monroe County for the other Stylurus species.

Consider a contribution to Odonata Central

2011-08-24T20:23:00.004-04:00

Odonata Central is a great resource for dragonfly information including (as noted on its homepage): "distribution, biogeography, biodiversity, and identification of Odonata (dragonflies and damselflies) world-wide"

We'd encourage all people taking photographs of dragonflies to enter their data in the Odonata Central database. This can help us all understand the distribution and phenology of the various species.

However, the site is also in need of monetary donations. Updates and improvements to the site and database are planned and this requires resources. Thus, John Abbott (the man behind Odonata Central) has added a link on the home page to make secure online donations.

If you haven't done so before, please go and check out the site.

www.odonatacentral.org

...and please consider making a tax-deductible donation.

Stylurus confirmed in Monroe County!

2011-08-08T19:43:00.015-04:00

This weekend we had Russet-tipped Clubtails (Stylurus plagiatus) on the mind.

After checking a couple of previously known locations in Wayne County over the past week and coming up empty (for a variety of reasons), we decided to check the Raisin River near Dundee in Monroe County. Last year I did see one male patrolling the river.

We revisited the site near US-23 first and found very little other than a couple of Lyre-tipped Spreadwings (Lestes unguiculatus). The shoreline and upland habitat had been changed a bit in the last year with more shoreline trees removed and all the upland habitat being mowed.

Our next stop was West County Park. This is a great park bordering a bend in the Raisin River east of Dundee and has many upland acres of native prairie plantings. Upon arrival, this area looked good for Stylurus: tall trees at the water's edge, shrubby (dogwood, viburnum, etc) areas adjacent to the trees, with native or fallow fields upland.

Within minutes of walking the trail nearest the river, a clubtail flew up from the vegetation and perched on a trailside Monarda. A quick view with binoculars confirmed it was a male Russet-tipped Clubtail (S. plagiatus). Here is a shot taken through my binoculars:

... and a better view in the hand:

This is the first confirmed record for Monroe County!

Walking the edge a bit more turned up several more individuals including one coupled pair.

Also, a dark Stylurus clubtail flew up and away from the vegetation without giving time for species ID. It was likely an Arrow (S. spiniceps) or an Elusive (S. notatus) Clubtail.

Checking the river's edge turned up two dark rubyspots (Hetaerina sp.). I didn't even have Smoky Rubyspots (H. titia) on my mind, but there were at least 6 perched along the bank. This is the earliest in the season we've had this species in Michigan. Here is one of the males:

While poking around the edges, I flushed at least 3 Fawn Darners (Boyeria vinosa). These were perched amongst the shaded trees and downfalls:

At one point a Royal River Cruiser (Macromia taeniolata) was observed patrolling the river which turned and flew up over the upland area of the park. Later we found one hunting along the trail near some of the taller grasses.

The trail through the northernmost portion of the park turned a few Lyre-tipped Spreadwings (Lestes unguiculatus). Here is one of the males:

... and the claspers which provide its common name:

While walking back to the car along the road, a female Wandering Glider (Pantala flavescens) was found hovering:

This great little park will require future visits. There is a lot of potential to find additional odonata species, and the prairie plantings provide great opportunities to see a great variety of insects.

Another Andromorphic Female

2011-07-20T07:47:00.011-04:00

Over the past year during my lunch hours, I've walked the grounds at my workplace in Farmington Hills, MI, tallying the various plants and animals. The route back to the building is an enclosed walkway and is quite the collector of various bugs since they get trapped in the glass panels. Each panel is surrounded by a frame that protrudes a few inches and many insects can't determine how to navigate from the enclosure.

Thus, I walk along and pluck out the variety of individuals which gives me a chance for further identifications and release from their "deathtrap". I've found many species in this walkway that I haven't found "out in the field".

On June 28th, 2011, I picked up an Eastern Forktail (Ischnura verticalis) expecting it to be a male based on the coloration, but quickly realized it was a female. In this photo, the ovipositor is visible:

... and a view of the dorsal surface of the abdomen:

Amazingly, this is the second time I've seen an andromorphic female. Here's a link to the account of our first sighting.

There are always interesting things to find... even in an industrial park of metro Detroit.

Tagged Monarch Recovered!

2011-07-08T18:46:00.013-04:00

Monarchs (Danaus plexippus) are not dragonflies, but they are fascinating insects. These migratory butterflies have an incredible life cycle, which can be found at the Monarch Watch website.

Since the eastern population of this species winters in Mexico, it takes a couple generations to make it to the northern US.
We don't see greater numbers in southeast Michigan until mid-summer, although the first individuals make it to our area as early as mid-May. Common Milkweed (Asclepias syriaca) doesn't get large until June, with flowering later in the month. This plant is one of the common host plants for the butterfly eggs and larvae. A generation or two may be produced in the northern US and southern Canada.

In our yard, we offer several host plants including: Common Milkweed, Butterfly Weed (A. tuberosa), Whorled Milkweed (A. verticillata), Swamp Milkweed (A. incarnata), and Tropical Milkweed (A. curassavica). Unlike the others, the latter is non-native and not hardy here, but we pick some up and grow it as an annual if we see it at a nursery. In any given year, we may have 10 to 30 caterpillars. We remove many and raise them in a small tent or enclosure for protection from predators or injury.

In late summer and fall, adults begin the couple thousand mile migration south towards the wintering grounds in Michoacan , Mexico.

Since the mid-1990s, I have tagged southbound migrating Monarchs. Some years I only find a few individuals and other years several dozen are tagged. The organization Monarch Wat ch sells the adhesive, paper tags which have unique ID numbers printed on them. On the right is a Monarch we tagged in our yard a couple years ago.

Earlier this year on a whim, I checked the tag recovery database. To my surprise, there was a recovery of one of my tags! LHA926 was a male we caught on 27 Aug 2008 in our yard in Dearborn. On 3 March 2009, this individual was recovered by Javier Martinez in Sierra Chincua, Michoacan, Mexico. (near N19 36 23 W100 14 30 ) The distance between the two locations is 1,858 miles (in a straight line).

This is the location of one of the Monarch santuaries, west of Mexico City. A detailed look at the sanctuary is here, at the web site of the Monarch Butterfly Fund, one of the partners (Monarch Watch is another) of the Monarch Joint Venture.

One never knows when data will be most useful. Some years we've tagged several dozen, but 2008 was one of the fall seasons when we didn't find many Monarchs. A total of only 12 were tagged, 2 were reared in our yard and the remainder were from multiple locations in SE MI. It's incredible that one of the twelve was refound that winter.

I'd encourage others to order tags from Monarch Watch since the fall migration season isn't far away.

Dragonhunter in Wayne County!

2011-07-04T11:55:00.005-04:00

On July 3, 2011, we went to Fish Hatchery Park in Northville, MI. This was the location of the first federal fish hatchery as noted previously. Our hopes were to capture Black-shouldered Spinyleg (Dromogomphus spinosus) since this was the location we observed a male in 2010.

Upon arrival a large clubtail flew from one of the many perches along Johnson Creek that were bathed in sunlight. Initial thought was spinylegs, but it was big and the abdomen was curled in a distinctive J-shape. Once it landed the small head with green eyes were obvious: Dragonhunter (Hagenius brevistylus)! This was a species we didn't expect to see this day, but we had always had hopes to find one.

Now to catch an individual...vouchers are required for first county records in Michigan. Unfortunately, subsequent visits over the past few days haven't turned up the spinylegs or Dragonhunter.

Spring Mill Pond area - revisited

2011-06-25T21:00:00.004-04:00

I took a partial vacation day to revisit Island Lake SRA on June 13, 2011 in hopes of confirming a new species or two for Livingston County. It was a windy and partly cloudy afternoon, but the area around Spring Mill Pond has the large sand dunes which provide areas of shelter.

Unfortunately, the southeast portion which had the Painted Skimmers (Libellula semifasciata) was fairly windy and all I found were Four-spotted Skimmers (Libellula quadrimaculata). Here is a male:

More than 90% of the bluets I examined were Marsh Bluets (Enallagma ebrium), such as this male:

If you click on the photo, the forked cerci are visible which is a diagnostic field mark for this species.

At one of the "stream" crossings, a male Unicorn Clubtail (Arigomphus villosipes) was found perching on the gravelly edges:

Finally making it to the vicinity of the saddlebags (Tramea sp.) sightings from a couple weeks earlier, I had little hope of finding much since it was quite breezy. Given the large amount of rain in recent times, the location southwest of the parking area was flooded. This helped make the hunt for odes a bit easier since they seemed to be gathered near the little "islands" of vegetation. Within minutes, a male Carolina Saddlebags (T. carolina) flew by and went with the wind. I thought that may be my only sighting, but it ended up circling back to one of the little islands and perched on a small snag. Soon after another male Carolina Saddlebags perched on an adjacent plant. Here is the confirmation of this species for the county, which shows the purplish frons and the black coming down the sides of S8 and S9:

I then followed the flow of water to a little pond which had a patrolling Prince Baskettail (Epitheca princeps). Nearby, perched on a branch over the water was a male Lancet Clubtail (Gomphus exilis):

A second Lancet Clubtail was found a few meters down the shoreline.

Finishing up the visit, I had decided to check the shoreline of Spring Mill Pond itself. Before arriving at the edge, a Springtime Darner (Basiaeschna janata) flew past and landed in vegetation on the hillside. As I approached, it lifted off and flew away, not giving a chance for a photo or further observation. Returning to the pond, I found another patrolling darner so I positioned myself between cattails and came up with this male Springtime Darner (B. janata):

What a way to end a day!

Given the diversity of this area, I have to wonder what other species will be found in the coming visits.

A confirmation & reconfirmation for Wayne County

2011-06-24T21:05:00.001-04:00

Looking to fill in gaps of the Wayne County, Michigan, odonata list, I had decided to visit Crosswinds Marsh, phase I, on June 11, 2011.

There is a nice loop (Blue Heron Trail) that hits a variety of habitats that I was visiting last fall and I was hoping for a missing early season darner or a Spangled Skimmer. No luck for either, but one does have to get into the field to have a chance.

Surprisingly, there were a large number of Aurora Damselflies (Chromagrion conditum), a species we do not see often. Many were coupled:

Here's a closeup of a male showing the yellow area of the thorax:

Hanging out on a culvert for Disbrow Drain was this male Unicorn Clubtail (Arigomphus villosipes):

I find this species very difficult to catch, unless one lands directly in front of the net. Thus, the digiscoped image through my binoculars is the best I can provide.

Pleased with the population of Aurora Damselflies discovered, I was hiking back towards the car and paused at the Mallard Trail boardwalk. A smallish, dark ode flew by that had brilliant, green eyes. Initial thought was baskettail (Epitheca sp.), but the body was looking solidly black and the eyes were like emeralds. Eureka!

I called Julie to tell her of the interesting sighting, and she also asked if it was a baskettail. Just then, the dragonfly flew back near me. Ending the call quickly, I was able to swing the net and capture the individual. It was a male emerald (Family Corduliidae), but I have little experience with any species other than Mocha (Somatochlora linearis). We just don't have bog or fen habitats in our home county.

Identification would have to wait until I returned home and we reviewed our references.
Examining the wing venation and the claspers confirmed the species as Racket-tailed Emerald (Dorocordulia libera). This is the first confirmed record of this species for the county!

Interestingly, Julie thought she had seen an emerald in the same area ~10 years ago, but dismissed it as a baskettail. There was a literature record from the 1870s, but this was to be removed from the county list since there is not voucher available and the records from that time period can be quite confusing. Sometimes locations of "Detroit" in the historical records seem to be related to the ship's port of call (typical transportation in that era), rather than the actual sighting or voucher location.

Anxious for Julie to see a live individual, we returned on June 19. A half hour or more was spent in the area of the original sighting with no luck. (Although, I thought I had an individual fly by at one point.) We slowly worked our way to the western boardwalk, while I tried to flush odes from the adjacent vegetation. We did see our first Halloween Pennants (Celithemis eponina) and Eastern Amberwing (Perithemis tenera) of the year. I pushed farther into the vegetation and flushed a couple female Slaty Skimmers (Libellula incesta), when a coupled pair of smaller, dark dragonflies flew in and perched in front of me. Racket-tailed Emeralds! Julie came over quickly with her good camera and was able to observe and photograph these cooperative individuals.

Mission accomplished and we have confirmation these are breeding in the vicinity. Julie once again has to revise her manuscript on Wayne County species, which she is hoping to submit for publication in the next couple of months.

Acid-loving Odes

2011-06-05T18:21:00.014-04:00

We've been waiting for the right time to visit Island Lake SRA this spring for Elfin Skimmers (Nannothemis bella). Given the weather of June 5th and no commitments, we made the trip to Livingston County, Michigan.

Communications with a fellow insectophile provided additional reasons to investigate the Spring Mill Pond area now. Last year we found a large population of Checkered Whites (Pontia protodice) and a few were found in the past week, along with some reddish saddlebags (Tramea sp.) of which one appeared to be Red Saddlebags (T. onusta). Either reddish Tramea would be a county record.

Soon after arriving, several Four-spotted Skimmers (Libellula quadrimaculata) and a male Spangled Skimmer (Libellula cyanea) "greeted" us. This handsome skimmer (L. cyanea) is a species we can't seem to find in our home county of Wayne:

We initially headed west towards the area in which the saddlebags had been sighted, but had no luck finding these. A number of teneral clubtails (Gomphus sp.) were perching along the sandy dunes. We identified one as Lancet Clubtail (Gomphus exilis).

Turning back to the east was the answer. Much of the area must have been an old gravel pit with sand dunes and a long two-track area that holds water and a nice variety of acid-loving plants and animals.

Arriving back at our starting point, we found a couple pairs of Eastern Red Damselflies (Amphiagrion saucium) making more:

A short distance later was the jackpot for the smallest dragonfly in the USA. There must have been three dozen or more Elfin Skimmers (Nannothemis bella) and many were teneral. This species can be easily overlooked since they are less than an inch long. The following photos are misleading about their visibility since they normally fly very low over the vegetation and blend in quite well. Here's a female:

...and a younger male that doesn't have the typical pruinosity of older individuals:

Dozens of Dot-tailed Whitefaces (Leucorrhinia intacta) were flying about, including one whiteface showing a pruinose patch along the abdomen. We quickly realized that we found several individuals of another whiteface species that we'd normally expect to find up north. Examining the wing venation proved these to be Frosted Whitefaces (Leucorrhinia frigida):

While traipsing around the area, we also spied a few Painted Skimmers (Libellula semifasciata), but none were cooperative for a photo. Interestingly, this would also be a county record for Livingston County.

This outing provided a nice variety of dragonflies, some of which we don't see regularly in our home county due to the lack of bog or acidic habitat. Followup visits will be necessary to find additional species.

Spiketail record for Lenawee County

2011-06-05T07:03:00.009-04:00

As noted previously, I wanted to find Arrowhead Spiketail (Cordulegaster obliqua) in a county other than Wayne.

Last year I found a Mocha Emeralds (Somatochlora linearis) at Bicentennial Woods County Park in Lenawee County. Black Creek looked like appropriate habitat for the spiketail. (clean, smallish creek, with muddy/silty bottom, running through high quality woods)

On June 4th, I made a visit and walked the southern edge of the woods near the creek. Within 30 minutes I spied an individual perched at waist height, but it flushed before I approached. Another 10 minutes later, a female flew down the path and perched in front of me at chest height. A new county record confirmed!

Also present were Ebony Jewelwing (Calopteryx maculata), Marsh Bluet (Enallagma ebrium), Springtime Darner (Basiaeschna janata), baskettail sp. (Epitheca sp.), Dot-tailed Whiteface (Leucorrhinia intacta), and Eastern Pondhawk (Erythemis simplicicollis).

Next up....which species will we find in another county?

2nd visit to Maybury State Park

2011-05-30T17:59:00.007-04:00

With early dragonflies on the mind that would make new records for the county, I headed to Maybury State Park in northwestern Wayne County on May 30th. My first visit of the year a week ago only provided a female Common Whitetail (Plathemis lydia).

No luck with new species for the county, but I did see a couple new species for the season.

Several Ebony Jewelwings (Calopteryx maculata) were flitting about Sump Drain:

A few baskettails (Epitheca sp.) were patrolling the forest clearings. I caught one male and will try to ID it at a later date. It may be Common (E. cynosura) or Stripe-winged (E. costalis):

A nice surprise was a young male Arrowhead Spiketail (Cordulegaster obliqua) perching in a small Prickly Ash:

Next I'll look for this species in another county.

Slow start to the southeast Michigan ode season

2011-05-29T18:00:00.007-04:00

I was looking forward to making a post on an earlier date, but we've had an extremely cold and wet spring. I believe it's the 2nd wettest spring on record for this area.

Up through today (May 29th), I've only tallied 6 species of odonata of only several individuals. Below is my meager list of first dates:

- Fragile Forktail (Ischnura posita) = emerging individuals mid-May in Farmington Hills

- Eastern Forktail (Ischnura verticalis) = emerging individuals mid-May in Farmington Hills. Here's a fairly teneral female from 5/19:

- Common Green Darner (Anax junius) = one male on 5/5 in Farmington Hills

- baskettail sp. (Epitheca sp.) = 6+ on 5/29 at UM-Dearborn. These were likely Common (E. cynosura), but could have the possibility of being Stripe-winged (E. costalis).

- Dot-tailed Whiteface (Leucorrhinia intacta) = one young male on 5/29 at UM-Dearborn:

- Common Whitetail (Plathemis lydia) = one teneral female at Maybury State Park on 5/22. Here's a teneral male found 5/23 in Farmington Hills:

Don't worry, there is more to come. Although we could see a lower number of river and stream species this year due to the excessive flooding experienced this spring.

New books, with UDH photos

2011-05-17T18:51:00.008-04:00

A couple of books have come out recently that are worth adding to any insect lover's library. Not only that, an Urban Dragon Hunter contributed a photo to each.

First up is the excellent Attracting Native Pollinators: The Xerces Society Guide to Conserving North American Bees and Butterflies and Their Habitat. The Xerces Society, a well-respected invertebrate conservation organization, really went all out in this book. Chapters cover pollination, pollinators, and pollinator conservation, and every aspect of how to manage land, greenspaces, and gardens to provide nest sites, foraging habitat, and wintering sites for pollinators. Another section describes the bees of North America by family and subfamily. The photo illustrating the account of the genus Stelis (a cuckoo bee) was taken by Nannothemis in the Urban Dragon Hunter backyard. For a few years, we have photographed and tried to identify all the Hymenoptera and Diptera in the yard. We were happy to make this contribution to the Xerces Society, especially for such a terrific book. If you have even a passing interest in pollinators or landscaping for wildlife, get this book.

Next up we move on to another taxa with The Complete Book of North American Butterflies. This is a beautiful book that, ironically, does not cover all the butterflies of the continent. The first 60 pages or so provide an overview the Lepidopteran life cycle. Most of the remainder of the volume gives summaries of the six families of butterflies in North America with brief, representative species accounts. There are over 700 species of butterflies in N.A. (there is a list in the back of the book), but fewer than 100 are described. Nonetheless, these accounts are succinct but thorough and each features one or two excellent photos. Nannothemis contributed a shot of a Little Wood Satyr that appears in both the "self-defense" section and on the back cover of the book. This book will be released next month, and would make a great introduction for a new butterfly enthusiast.

Ode habitats at El Jaguar Reserve

2011-04-09T11:20:00.000-04:00

As a followup to the 2011 Nicaraguan ode shots in the previous post, here are habitat shots to help give a sense of the terrain.

Finca Esperanza Verde (FEV) and General Nestor's were highlighted previously here.

This post will focus on our visit to a finca in the department of Jinotega.

EL JAGUAR RESERVE (EJ) -- cloud forest including a sustainable coffee farm, near El Mojon

-- Ariel El Dorado, near Forest MoSI station: 13.234785, -86.054017, 1270+ m
During our first full day (March 9th) we visited the forest MoSI station. A large tree had fallen near the bird banding station which created a sunlit patch in the forest and several teneral or young damselflies were present.

-- Ariel El Dorado, "pond area": 13.23432, -86.05405, ~1270 m
This is a spring-fed stream that begins in the hillside and flows through the forest down to a low, open area that creates a wide spot (almost a pond).

The stream is rocky in the forest area, and the sunny rocks are ode hotspots:

The wide spot downstream was truly the ode hotspot we found at El Jaguar. The edges were quite silty and could "swallow a man alive". With a little caution, one could navigate the edges.

-- Uriel La Pedegrosa: 13.234418, -86.052895, ~1273 m
This is a small stream that runs from the hills through the middle of the reserve. For some reason, I didn't save any photos from this location. In general, it's similar to the Ariel El Dorado forest portion, but a little muddier.

-- Finisterra, below the Coffee MoSI station: 13.233472, -86.051930, ~1273 m
This is also a small stream that runs through the hills, but its origin is in the neighbor's property. This waterway had the fewest dragonflies and may be due to the neighbor's use of chemicals for agriculture and/or soaps for washing.

-- two-tracks in the finca
The roadways throughout the farm also provided areas to find patrolling darners, skimmers or ode hunters.