Insect Child Care

As humans, we take the care of children for granted.  If you have a kid, you take care of it until it is old enough to move out and live on its own.  Lots of other mammals care for their children in similar ways, teaching their offspring how to survive in the world without their parents.  But this sort of parental care behavior is very rare in insects.  The insects I study, the giant water bugs, have a very special form of parental care and I’ll talk about that in my next post.  Today, I want to go over some of the different insects that use parental care so that you might learn a bit about the different ways that insects can care for their young.

This is a carrion beetle (also known as a burying beetle):

carrion beetle

Carrion beetle

If you follow my blog, I’ve talked about this beetle before in my post about my mold problem in my insect collection, so it should be familiar.  Carrion beetles are some of the more disgusting animals in the world, at least as far as most people are concerned, so please skip on to the next photo if you have a weak stomach.

So how exactly do carrion beetles care for their young?  Let’s go through the process, keeping in mind that it works a little differently from species to species.   First, the male-female pair finds a dead animal.  This could be a mouse, a snake, a bird, a small opossum – anything that’s in the size range a pair of beetles can handle.  Let’s say the beetle above has found a mouse.  The beetle and its mate will pull all of the fur off, roll the mouse into a ball (often colorfully called “mouse balls” in entomological circles), and bury it to prepare the carrion.  The pair will mate and then the female will lay her eggs near or on the carrion.  When the eggs hatch, the larvae will feed on the rotting carcass and the parents often help them feed.  The parents also help make the carrion last longer by eating fly larvae (maggots) that compete with their young for food.  Some carrion beetles spit digestive enzymes on the carrion to keep it fresher longer and others will carry mites that provide this service for them.  In fact, the parents are so busy taking care of the carrion that it requires both of them to keep molds, maggots, and other organisms from completely taking it over and depriving their children of food.  If the parents are successful, the larvae will feed for several days to a few weeks and go through all of their larval instars, then drop off the carcass to pupate.  At this time, the parents abandon the nest and leave their offspring to fend for themselves.  So, carrion beetles care for their young from the egg stage until pupation.  They are also among the very few insect species that have this sort of bi-parental (two parent) care. It is very unusual for both the father and the mother to care for the young.

A more common parental care behavior is the sort you find in the webspinners.  This lovely creature is a webspinner:

Webspinner

Webspinner

Isn’t he gorgeous?  These are actually rather unusual insects that aren’t common most non-tropical (i.e. temperate) locations.  Many entomologists will actually never see one of these alive in their lives!  Luckily for me, Arizona just happens to be one of the places where they are very common, so I was able to get some photos of this webspinner on my back porch one afternoon.

Take a look at the forelegs and look at the tarsi, those little segments near the end of the leg.  See that one big oval shaped tarsus where the arrow is pointing?  This is a specialized tarsal segment.  Were you curious why these are called webspinners?  If so, here’s the reason: that specialized tarsal segment contains a silk gland.  Webspinners are actually able to make webs!  They don’t make webs like most spiders though.  They make long, tube-like webs, called galleries, underground or in a food source.  The galleries are where the parental care takes place.  A male and female webspinner mate in a female’s gallery.  The male leaves right away and the female lays her eggs in her gallery.  As the nymphs hatch, they live within the gallery of their mother under her care.  When they reach the adult stage, they may leave the nest to find another place to live (especially if they are males – they don’t stick around in their mother’s nest very long) or continue to live in the gallery, expanding it so that it fits more and more individuals.  This sort of parental care should sound very familiar, even if you know very little about insects.  If it’s not coming to you right away, I’ll give you a hint: ever see an ant farm?  Webspinner galleries are a lot like ant nests and the sort of care that they exhibit is very ant-like.  One female establishes a nest that can end up containing several generations of offspring.  Paternal care by a single adult female is relatively common among insects, especially in the social insects like ants, bees, and wasps.  But webspinners are rather different from the ants, bees, and wasps too – they don’t have one single female who produces all of the offspring in the nest.  The female who establishes the gallery originally produces a second generation and might produce several more, but the other females in the nest are all able to produce their own offspring as well.  So, to recap, webspinners use maternal parental care (the female parent cares for the young) and care for their offspring from the egg stage through adulthood, and even sometimes beyond!  This is very different than what we saw in the carrion beetles where both parents were necessary for the survival of the offspring and care ended as soon as the larvae pupated.

Now we’ve come to the really rare parental care behavior: paternal care, or care only by the father.  This sort of behavior is only known in a VERY few insects, including the golden egg bug (Phyllomorpha laciniata) and the giant water bugs.  I’m going to talk about the giant water bugs in more detail in my next post, so for now, check out the photo of the golden egg bug at this link:

http://www.koleopterologie.de/heteroptera/5pent2/coreidae-phyllomorpha-laciniata-foto-guenther.html

(I apologize for not having my own photo, but these are only found in Europe and I’ve never been there.  I’m also not keen on stealing other peoples’ photos without permission.)  Did you see the gold colored eggs on the back of the male in the photo?  These bugs are, like SO many other insects, named after a characteristic they possess.  These bugs have bright gold eggs, so they’re called golden egg bugs.  So how do they care for their offspring?  This species is probably just evolving their paternal care, so it’s still a bit sloppy compared to the elegant system you find in the giant water bugs, but here’s the general idea of how the system is thought to work.  The eggs of these bugs have traditionally been laid on plants near the ground.  However, the vast majority of the eggs left by themselves are eaten by ants.  The females of this species are therefore starting to deposit their eggs on the back of other members of their own species, mostly the males, gluing them to the backs of these individuals so that they are protected from the ants until they hatch.  The bugs themselves don’t like having ants on them, so they’re inclined to keep the ants away from the eggs they carry as well.  Pretty neat huh?  The offspring thus benefit from the selfishness of the adult that carries them.  I call this a sloppy system because females basically have to ambush a mating pair to be able to lay eggs on their backs.  Most golden egg bugs really don’t want to carry the eggs and will try to get away.  Mating pairs have more important things going on and keep doing what they’re doing while another female lays her eggs on the male.  The male bugs then carry the eggs around with them until they hatch, at which point the egg shells fall off.  Golden egg bugs thus care for young only in the egg stage and then the nymphs are on their own.  Unlike the carrion beetles, only one sex usually cares for the eggs, and unlike the webspinners, the males are usually the caregivers.  In the giant water bugs, the other insects that use paternal parental care, the system is a little different.  The male and female mate, and then the female lays her eggs in a way that ensures that the male cares for his own offspring.  The females mate, lay their eggs, and leave.  The male is left on his own to care for the eggs until the nymphs hatch from them.

Paternal parental care is probably the most rare form of parental care known in insects, but all of the giant water bugs observed to date use this form of parental care.  Tune in next time for more information about the amazing parental care system of the giant water bugs and prepare to be dazzled and amazed!

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Text and images copyright © 2009 DragonflyWoman.wordpress.com

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Identifying American Giant Water Bug Genera

In my last post, I went over what to look for to distinguish a giant water bug (remember: they belong to the family Belostomatidae) from other true bugs.  Today, I’ll go over what to look for to tell the different American genera of water bugs apart by showing you examples ofArizona’s giant water bugs.

This is Abedus herberti:

Abedus herberti

Abedus herberti

This bug is near and dear to my heart since he was the subject of my Master’s thesis.  I think Abedus is definitely the cutest of the giant water bugs (if any of them can be considered cute)!  This is a medium sized water bug, a little over an inch long, and most of the American Abedus are about the same size.  So, how do you tell this bug apart from the other water bugs?  It’s easy!  Take a look at the back end of the bug.  First, you’ll notice that it doesn’t have the long respiratory siphons you find in some water bugs.  If you recall from my last post, these are called air straps, the shorter of the two types of respiratory appendages in the belostomatids.  You should also notice that this bug is broadly rounded, particularly in the back.  The other two American genera of giant water bugs have pointed tips at the end of their abdomens.  So, the combination of the rounded back end and short air straps lets you know that this water bug belongs to the genus Abedus.

You’ve seen him before, but let’s take a look at Lethocerus medius one more time:

Lethocerus medius

Lethocerus medius

You should be able to tell right away that this bug is very different from the cute little Abedus above.  First, you’ll notice the long respiratory siphon at the back end.  This bug has his siphon fully extended (they do look quite a bit shorter when they’re retracted), so the different between the respiratory siphon of this bug and the air straps of Abedus should be immediately obvious.  The shape of Lethocerus is also distinctive.  This bug is robust and strong, so he has huge raptorial forelegs.  He’s also pointed at the back end.  Lethocerus species are BIG bugs.  The biggest true bug in the world is a species of Lethocerus in fact.  L. medius is actually fairly small for a Lethocerus, only about 2 inches long, but it’s still a formidible looking bug.  Some of the biggest members of this genus can be close to 5 inches long!  So, if you find a water bug that is large, pointed at the back end, and has a respiratory siphon instead of air straps, you know you’re looking at a Lethocerus.

The last genus we have in the U.S. is Belostoma.  This is Belostoma flumineum:

Belostoma flumineum

Belostoma flumineum

The American Belostoma tend to be smaller than Abedus and Lethocerus.  This particular species is about 3/4 of an inch long.  It’s a little hard to tell from the photo, but this bug has air straps and not the long respiratory siphon.  Belostoma is more rounded overall than Lethocerus as well, but it is also pointed in the back.  You can tell Belostoma apart from Lethocerus easily by looking at the size of the bug and the presence of air straps.  Belostoma is easy to distinguish from Abedus simply by looking at the shape of the back end: pointed in Belostoma and rounded in Abedus.

While the U.S. species of giant water bugs tend to fall into nice, neat little size categories (Belostoma is smaller than Abedus which is smaller than Lethocerus), the water bugs in other locations show a lot more variation.  For example, in South America you will still find Lethocerus, Abedus, and Belostoma, but the size ranges will be quite different than they are in the U.S.  The South American Belostoma, for example, include some of the smallest and largest species of the genus.  They range in size from a little over 1/4 inch to almost the size of Lethocerus!  In South America, you wouldn’t be able to use the same size characteristics to distinguish the different genera of water bugs.  However, the type of respiratory appendages a bug has and the shape of the tip of the abdomen will still tell you which genus you have, regardless of the size.

Next time, I’ll go over the behavior that has made the belostomatids famous among entomologists, parental care.  Water bugs have some seriously cool behaviors and parental care is one of the best.  Prepare to be shocked and amazed!

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Text and images copyright © 2009 DragonflyWoman.wordpress.com

Meet the giant water bugs!

This time I’m actually going to write about giant water bugs, as promised!  As I write this, I am sitting in a lab at Arizona State University measuring the oxygen consumption of water bug eggs.  I’ll write more about that in another post, but first allow me to introduce you to the giant water bugs!

This gorgeous creature is Lethocerus medius:

Lethocerus medius

Lethocerus medius

Isn’t he a formidible looking insect?  It’s hard to tell from the picture, but this male is about 2.5 inches long from the top of the head to the tip of the abdomen, and that doesn’t include the long, pointy bits sticking out of the back!  The size of these bugs is where they get the “giant” part of their common name.  They get “water” because they are aquatic insects and live in water.  The “bug” portion of the common name comes from the fact that they are true bugs, i.e. they belong to the insect order Hemiptera .  The common name giant water bug thus tells you a lot about these insects – the giant water bugs are really big aquatic insects!

The giant water bugs belong to the family Belostomatidae.  What makes an insect a belostomatid?  First, let’s review why this insect is a true bug.  We can tell he is a bug because there are hemielytra present and, if you flip him on his back and look under his head, his mouthparts are piercing-sucking mouthparts.  These are the characteristics of true bugs.  You can read more about what makes an insect a bug in my post about the true bugs.

You can tell this is a belostomatid, as opposed to any other true bug, because it has the following:

1. Raptorial forelegs.  Predatory insects, such as the giant water bugs, mantids, and assassin bugs, frequently have enlarged forelegs to help them grab and hold their food.  If you eat live animals, it’s important that you are able to subdue them!  Raptorial forelegs help you do that – they’re full of huge, strong muscles.  For a comparison in humans, think of a skinny, nonathletic 10 year old and a professional weight lifter (or Fezzik in The Princess Bride!).  Who is going to be able to lift more and/or hold onto something more tightly?  The weight lifter, of course, because he has bigger, stronger, and better developed muscles than the 10 year old.  The same thing goes with insects.  Big forelegs help you grab and subdue prey so you can eat your food.  (Interesting aside: there is another type of enlarged foreleg, called a fossorial foreleg, that helps insects that live underground!  They need strong muscles in their forelegs to help themdig and move through dirt.  If you’ve ever seen a mole cricket, you know what these look like.)

2. Swimming hairs on the legs.  See all that brushy stuff coming off the legs?  Those are called swimming hairs.  Insects have a hard time moving through water and have all kinds of adaptations that help improve their mobility.  Having thick hairs on your legs helps you swim better than if your legs are smooth.  Think about the way we relatively hairless humans swim.  Which is easier: swimming with flippers or swimming without them?  It’s easier to swim with flippers because the increase your surface area.  By attaching flippers, you are effectively making your feet bigger and flatter.  More of your “body” is coming into contact with the water with each kick, so you move further and with less effort than you would without the flippers.  Swimming hairs work the same way.  They are nature’s swimming flippers!

3.  Retractable respiratory appendages.  Take a second look at those long pointy bits sticking off the back of the Lethocerus in the picture above.  Those are respiratory appendages, called respiratory siphons or air straps depending on which type of water bug you’re looking at.  What makes the water bugs different from other insects with respiratory appendages (such as the water scorpions – I’ll be posting about these sometime as well as they include my very favorite insect!) is they are able to retract theirs, pulling them mostly or entirely within their bodies!  So why do giant water bugs have these structures?  Well, giant water bugs require air to survive, the same air that you and I breathe.  I’ll write more about giant water bug respiration in a future post (this is something I study in my lab), but for now just know that these structures help the giant water bugs collect air.  Not all giant water bugs have the long siphons though.  The giant water bug in the image below is Abedus herberti.  Take a look at the respiratory appendage indicated by the arrow:

air straps

Abedus herberti. Arrow points to the air straps.

Most of the giant water bugs actually have these little short air straps rather than the long respiratory siphons of Lethocerus, but both types of appendages work the same way.  Regardless of the type of appendage, all water bugs are able to pull them into their bodies.

So now we know that belostomatids are true bugs and that they have raptorial forelegs, swimming hairs on their legs, and retractable respiratory appendages.  All giant water bugs share these characteristics, regardless of their subfamily, genus, or species.  Next time I’ll delve a little bit deeper into the different types of water bugs found in the U.S. and then talk a bit about what I’m doing with my resrearch during my visit to ASU.  Stay tuned!

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Text and images copyright © 2009 DragonflyWoman.wordpress.com

My house is overrun with ants!

Okay, okay.  I know I said I’d talk about the giant water bugs next, but I just had to stick in this quick little post first.  Ants have been on my mind quite a bit recently, so I thought I’d share something fun I observed the other day.

Every summer since I’ve lived in my current home, we’ve ended up with a lot of ants in our house.  Mostly, they’ve stayed in the kitchen and in the soil of one potted plant, but they’ve spread out a lot this year and are now in the living room and the bathroom too.  They’re pretty annoying actually because they get on everything – dishes that aren’t absolutely clean, any crumbs on the counter or floor, and they seem to really, really love the metal sink and faucets.  They’re tiny little ants that belong to the genus Brachymyrmex.  (At least I’m pretty sure they are Brachymyrmex.  I have several friends who are serious ant people and if they say my house ants are Brachymyrmex, I don’t question them.)

Ants generally fall into two categories: ants that make and follow trails and ants that do not.  When I teach insect behavior, my students do a lab where they look at two different types of ants and determine which of the two is the trail maker.  Pretty fun activity really, but not when they’re making trails in your kitchen.  My house ants are definitely trail makers.  You can see long lines of them running along the counter and can follow the trail back to the place they are getting into the house.  This makes it easy to watch them because they’re all moving through the same areas in large numbers and make themselves very conspicuous.  This trait was beneficial one day when the ants attacked a dying pinacate beetle (often known as a stink bug – the black beetles that stick their butts up in the air!) that somehow got into my kitchen cabinet.  I could smell the beetle all day (they’re called stink bugs for a reaason!), but I couldn’t find it until I noticed a line of ants flowing into a cabinet that contained only canned foods.  There wasn’t any food available in there, so I popped the door open to see what they were doing.  There was the pinacate beetle, being devoured alive by ants.  It’s the one time I was actually happy the little buggers were in my kitchen.  That beetle smelled really bad!

Last week, my fiancee left an empty birch beer bottle on the kitchen counter.  The ants, being able to find food anywhere (I marvel at their ability to find food in the most random places), ended up discovering the tiny layer of sugary fluid at the bottom of the bottle and were happily sucking it down.  I wouldn’t have noticed they were in the bottle at all except I saw this:

Brachymyrmex ants

Brachymyrmex ants

I know the photo’s a little blurry – the ants were moving REALLY fast, so it was hard to get a good picture – but do you see how swollen they are?  They are so full of sugary birch beer, you can see the soft connective tissue between the hard plates that make up their exoskeleton!  Those sections are stretched so tightly, you can actually see the light passing all the way through the ants and shining onto the metal of the sink below them.  These ants were going back to the nest, completely full of food.  Furthermore, they were tapping ants coming the other way with their antennae.  This was likely a form of communication between the incoming ants and the outgoing ants, one that perhaps told the outgoing ants from the nest where the food was or something about it’s quality and/or abundance.  It’s pretty common to see trail making ants doing an antennal tapping behavior, at least in the trail making ants I’ve observed.

Compare the “full” ants heading back to the nest with their bounty to these “empty” ants that were just leaving the nest:

Brachymyrmex ants

Brachymyrmex ants

The abdomens of these ants are tighly compacted.  You can’t see the soft connective tissues between the plates of the exoskeleton, so they look solid black instead of striped and reddish like the ants in the previous photo.  These ants hadn’t gotten to the birch beer yet, so they haden’t collected food.  Had I left the bottle on the counter, they would have climbed in, drank the liquid at the bottom until they were as full as they could be, and gone back to the nest looking like the ants in the picture above.

Even though I really hate the ants in my home, I couldn’t help but enjoy spending a few minutes watching these swollen, completely stuffed ants lazily returning home after the best meal of their lives.  I don’t know – something about an ant that has eaten so much it can barely move can hold my interest for ages.  If you happen to have ants in your house, especially if you see lines of them traveling back and forth across your kitchen counters, take a look at the ones headed back toward the walls.  Chances are, if you’ve left a sugary liquid out, even only a tiny amount, the ants will find it and you will be able to observe your own entomological gluttons!

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Text and images copyright © 2009 DragonflyWoman.wordpress.com

Dragonflies from the swarm

I’ve already posted twice about the dragonfly swarm my friend and I came across last week on the lake where we work, Lakeside Lake in Tucson.  While we watched the swarm, we also collected some of the dragonflies to add to our insect collections.  Because dragonflies tend to lose their colors VERY quickly in collections, it has become common practice for dragonfly enthusiasts of all levels of expertise to scan their specimens on standard flatbed scanners to preserve the colors as they are in life.  If you would like more information how to make your own dragonfly scans or would like to see some amazing images made using this process, I recommend taking a look at the website Digital Dragonflies.  (This is a great website to consult if you want to try to identify a dragonfly you’ve seen and you don’t have a field guide.)  Or check out the book written by the Digital Dragonfly creators, A Dazzle of Dragonflies. This book is absolutely gorgeous and I recommend it to anyone with even a passing interest in dragonflies, even if you only look at the pictures.

We found 4 species of dragonfly in the swarm, all of which are common in the Tucson area.  We’ve seen all of these at Lakeside many times, just not in the numbers we saw in the swarm.  I only managed to catch three of the four species (and if you know anything about catching dragonflies, especially these particular species, you know that’s pretty good!), so I’ll only go through the ones I have images for.  First, let’s meet the wandering glider, Pantala flavescens:

Wandering glider male (Pantala flavescens)

Wandering glider male (Pantala flavescens)

This handsome dragonfly is my favorite of all the dragonflies.  (If I ever get a tattoo, this is what I’m getting!)  This is a fairly common dragonfly in the Tucson area, though I find they’re much more abundant during the monsoons than at other times of the year.  This might have to do with a behavior they exhibit – they sometimes travel very long distances in front of storms!  I’ll post more about Pantala flavescens in a future post, but for now just know they’re amazing insects.  For a relatively boring looking dragonfly, it’s certainly got some fantastic behaviors.

How can I tell this is a wandering glider?  There are several ways.  This is a fairly big dragonfly with a wingspan of about 2 inches.  When they fly, they tend to appear brightly yellow-orange. There aren’t  many dragonflies with this sort of coloration, so it’s distinctive.  They are also fliers and rarely perch.  When they do perch, they tend to rest vertically (perpendicular to the ground) instead of horizontally (parallel to the ground) like other species.  If you manage to be lucky enough to catch a male, like the one above, and look at it head on, his face will be bright orange.  His eyes, as you can see in the image above, will be reddish.  His abdomen will be yellow to orange with black spots that widen the further down the abdomen you look.  And finally, the cerci (those little pointy bits sticking off the back end) are black.  This dragonfly gets its common name of glider from the shape of its wings.  See how the hindwings are much more broad than the forewings?  This is a flight adaptation that helps make them one of the strongest fliers of all the dragonflies.  There aren’t all that many dragonflies with wing structures like this, so if you see it, you can narrow down your options quickly.

This dragonfly, the spot-winged glider (Pantala hymenaea), is closely related to the wandering glider:

Spot-winged glider male (Pantala hymenaea)

Spot-winged glider male (Pantala hymenaea)

Compare the wings of this dragonfly to the image of Pantala flavescens above and you’ll see they’re about the same shape.  That makes this a glider as well.  These are very easy to tell apart from their other Pantala relatives, even though they do rest vertically, are also fliers, are about the same size, and have very similar shapes.  In flight, these dragonflies will look reddish or brown instead of yellow.  The eyes are grey with a reddish spot on the top, so they’re not red all over as they are in P. flavescens.    Their faces are red instead of yellow.  The easiest way to tell this dragonfly from the previous one, however, is the dark brown, round spot at the base of the hindwings.  It’s visible in the image above and if you look closely, you will be able to see it when these dragonflies are in flight.  In fact, you can see it in one of the photos I posted in my last post.  If you see a dragonfly with very broad hind wings with a dark, rounded spot at their base, you’ve got a spot-winged glider.  However, sometimes in flight they can be difficult to tell apart from the saddlebag dragonflies, the group to which the last species I’ll discuss here belongs, at least to the untrained eye.  This dragonfly is Tramea onusta:

Red saddlebags male (Tramea onusta)

Red saddlebags male (Tramea onusta)

It’s also called the red saddlebags.  All of the saddlebags (we have 6 species of Tramea in the United States) have broad hindwings like the gliders and are likely close relatives.  However, they have dark, broad bands on their wings that run along the base of the wings from the top to the bottom.  These bands can be narrow or wide and the width will help determine which type of saddlebag you have.  For example, here in Arizona, we have four species of saddlbags.  I can tell this is a red saddlebags because the body coloration is distinctly reddish and the band on the wings is wide.  The Antillean saddlebags and striped saddlebags, though reddish, both have narrow bands.  And it’s very easy to tell this dragonfly apart from the black saddlebags, a dragonfly you commonly find in the same locations as the red saddlebags in Tucson, because the red saddlebags are red and the black saddlebags are black.  (Bet you didn’t see that coming!)  The saddlebags are pretty easy to tell apart from most other dragonflies based solely on the dark band on their hindwings.  If you see a dark stripe running along the base of the hindwings, it’s a good bet you’re looking at one of the saddlebags.

The last species we saw was the black saddlebags, Tramea lacerata.  They’re the only black saddlebag species, so they’re very easy to tell apart from the others!

Since I wrote about the swarm last week, I’ve received several comments and e mails about swarms that other people have seen.  The four species we saw in this swarm are known to do this swarming behavior and it’s common for them to swarm in mixed groups like the one we observed.  I’ve been hearing reports of many other dragonfly species forming swarms though.  If you see a swarm, it might include these speices (and hopefully you can identify them now if it does!), but it could include other speices as well.  Regardless, if you happen to see one of these swarms, consider yourself lucky!  It’s an amazing thing to see so many dragonflies flying around together at one time.

I’ve been on a big dragonfly kick recently, but next time I’ll be shifting gears to my own research.  I’m making a trip up to Phoenix next week to do some research in a lab at Arizona State University, so it’s time to introduce you to my research study subjects, the amazing giant water bugs!

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Have you seen a dragonfly swarm?

I am tracking swarms so I can learn more about this interesting behavior.  If you see one, I’d love to hear from you!  Please visit my Report a Dragonfly Swarm page to fill out the official report form.  It only takes a few minutes!

Thanks!

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Want more information?

Visit my dragonfly swarm information page for my entire collection of posts about dragonfly swarms!

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Text and images copyright © 2009-2010 DragonflyWoman.wordpress.com

Photos from the swarm

I went out to Lakeside Lake with a friend early this morning to take some photos of the dragonfly swarm that’s been forming there.  (See my previous post for more information about the swarm and a video of the behavior.)  The swarm’s been forming every morning this week!  The dragonflies were flying constantly and darting here and there very unpredictably, so it was nearly impossible to get a good shot, but I got a few I thought were worthy of showing here.  My apologies for the general blurriness – these things are FAST!

Pantala hymenaea

Spot wing glider (Pantala hymenaea)

Pantala hymenaea banking

Spot-winged Glider (Pantala hymenaea) banking during a turn

Pantala flavescens

Wandering glider (Pantala flavescens)

A few things I noticed about the dragonflies in the photos I took:

1) The forewings of the dragonflies move separately from the hindwings.  I already knew this, but it’s hard to see it when they’re flying around because their wings move so fast.  It’s very obvious in the photos though!

2) When the dragonflies turned sharply in flight, they usually kept their heads parallel to the ground.  Even though their bodies were twisting and turning as they glided about, their heads remained in about the same position the whole time. This resulted in some pretty gnarly looking photos where the dragonflies’ heads looked like they were on upside down!  I unfortunately didn’t not get a clear shot of this to show you…

3) Dragonflies can definitely fly backwards.  Dragonflies are among the most agile of flighted animals and part of what makes them so agile is their ability to fly backwards, a very difficult maneuver.  It was frustrating to get a shot all lined up only to have the dragonfly zoom BACKWARDS out of the photo at the last second!

4) Dragonflies at rest are a LOT easier to photograph than flying ones!  Case in point: the photo I posted last week (see myDragonfly Sighting post) was of a dragonfly sitting on a bush branch.  I took 3 photos of the dragonfly before it took off and I considered all 3 good enough to post.  Today I took 377 photos.  About a third of them didn’t end up having any dragonflies in them at all.  Of the 236 that actually contained dragonflies, the vast majority showed the dragonflies as blurry, indistinct blobs of color.  I only got 13 shots I thought were decent at all, and my best one, the wandering glider above, is still far from perfect.  I like the photo more for the contrasting colors than anything else.

Regardless of the difficulty of the photography, it was still really fun!  If nothing else, it was amusing to TRY to get some good photos of these guys.  (I can’t help it – I’m drawn to the difficult photographic subjects, if only so I can practice and improve my skills.)  Even if we hadn’t gotten any good shots, it still would have been worth the trip to the lake just to see so many dragonflies in one place at one time.  This swarm is pretty darned impressive and watching hundreds of dragonflies lazily flying around a hill in the morning sun is a fabulous way to spend a weekend morning.

Be sure to check out the photo my friend posted from this morning’s shooting.  The photo she posted is better than any of mine, so I hope you’ll take a look!

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Have you seen a dragonfly swarm?

I am tracking swarms so I can learn more about this interesting behavior.  If you see one, I’d love to hear from you!  Please visit my Report a Dragonfly Swarm page to fill out the official report form.

    I welcome any information that you’re willing to provide about your swarm!  The more details you’re willing to provide, the more helpful your report will be, but I’ll happily take anything you’re willing to share.  Reports so far have varied from a few words to novellas, and it’s all useful.

    Thanks!

    (Added June 30, 2010)

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