Well-Nigh Wordless Wednesday: First o’ the Year Odonate

I saw my first damselfly of the year yesterday!  A coworker and I went down to the pond to listen to the toads calling and I saw it as we walked along the trail.  It was chilly out and the damselfly had just emerged so it could barely fly, but I was still very excited to see it.  You’ll have to take my word for it that it was a female fragile forktail, Ischnura posita, as I didn’t have my camera with me.  She was beautiful!

In honor of the first damselfly sighting of the year, I give you a photo of a pair of damselflies from last summer:

Damselflies

Damselflies mating

I am super excited the odonates are coming back.  It’s about time!

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Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth
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Well-Nigh Wordless Wednesday: Desert Firetails

I don’t know why exactly, but this has always been one of my favorite damselfly photos:

Desert Firetails

Desert firetails

I took it at the Arizona-Sonora Desert Museum several years ago now, with an older camera with relatively low resolution and depth of field, and it’s not even entirely in focus, but I still like it.  There’s something about the bright red male damselflies peeking out of the front of the photo against the muted greens in the background that just seems right to me.

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Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth

Friday 5: My Favorite Dragonfly Watching Areas

Sympetrum corruptum male

Variegated skimmer

I’ve been so wrapped up in family and work related things recently that I’ve barely had any time to get into nature and experience the world outside.  But I’ve been dreaming about going oding too.  Oding, or odonate watching, has become a popular pastime for a wide variety of people  over the last few years.  Similar to birding, people who participate in oding (calling them “oders” just doesn’t sound right…) visit wild or man-made water bodies, usually toting binoculars or cameras, and see how many different types of odonates they can find.  Many people are keeping life lists of dragonfly species they’ve seen, just like birders.  If the wealth of recently published odonate field guides is any indication, more and more people are joining in on the fun and I expect that the activity will become increasingly popular over the next several years.

Because I have not been able to go oding myself, I thought I would highlight the places I would go if I had the time.  The following are my 5 favorite oding spots in or around Tucson, AZ:

Sweetwater

Sweetwater Wetlands

Sweetwater Wetlands

The Sweetwater Wetlands is a huge constructed wetland on the west side of Tucson.  Wetlands are phenomenally good at filtering nasty stuff out of water and many constructed wetlands are built with the intention of improving water quality.  The Sweetwater Wetlands are no exception and was designed to filter some of the wastewater from the nearby wastewater treatment plant.  While the water smells a little funky (as you might expect in a wetland designed to treat wastewater), the wetlands support a ton of wildlife!  As you can see in the photo, there is a lot of green stuff around the ponds.  There are also a ton of dragonflies and damselflies!  While the diversity of the odonates at Sweetwater is not as high as in some other locations in my area, the sheer number of them at this site is astounding.  I love going to Sweetwater to take photos of odonates because you are bound to get many good shots.  I rarely get to check anything off my life list when I visit, but who can resist seeing thousands upon thousands of dragonflies during a 20-30 minute visit?

Las Cienegas

Las Cienegas

Las Cienegas

Las Cienegas is one of my favorite places to visit in southern Arizona.  It’s always about 10-15 degrees cooler than it is in Tucson, it’s got a lovely spring-fed stream that has water year-round (it’s under the green stuff in the photo – that’s watercress on top!), it’s got the best ancient old cottonwood, and there is hardly ever anyone else there.  Plus, there are dragonflies!  There might not be tons of them and there might not be all that many different species on most visits, but you see some really spectacular ones there.  Besides, few things beat getting out of town and watching dragonflies in the shade of old cottonwoods while trodding on the mint growing along the banks of the creek.  Heaven!

Sabino

Me in Sabino Canyon. Photo by Laura Goforth.

Sabino Canyon

I’ve been going to Sabino Canyon as long as I can remember.  Even when my family lived in Colorado and we only visited Tucson once a year, we always made a trip to Sabino.  It’s a gorgeous place to visit on the northeast side of Tucson and has a cool, clear creek that tumbles down off the Santa Catalina Mountains.  It’s chock full of fabulous aquatic insects (and a whole lot of invasive, awful crayfish) and there are always a lot of dragonflies flying around.  Sabino is where I saw my first giant darner (Anax walsinghami) and my first filigree skimmer (Psuedoleon superbus).  I was blown away by the beauty of each.  It’s also home to the Sabino dancer (Argia sabino), a damselfly listed on the IUCN Red list as a vulnerable species.  Sabino is nearly always crowded, but it’s such a nostalgic place for me and so pretty that I love it anyway.

Madera

Madera Canyon

Madera Canyon

Like Sabino, I’ve been visiting Madera Canyon for as long as I can remember.  It too has a lovely, clear creek flowing down the middle of it.  It too is full of aquatic insects and attracts many odonates.  Madera is a little less crowded though and has some different odonates that you don’t see in Sabino, so it’s still really exciting to go there.  It’s nice to take a camera, a soup strainer, and a lunch.  That way, you can have a picnic by the creek, snap a few photos of any odonates you see, and collect some aquatic insects.  And, you can do this all on one perfect 3 hour trip!  What a great place!

Agua Caliente

Agua Caliente

Agua Caliente

Agua Caliente is another nostalgic place I’ve visited since I was a kid, but it is different from every other place I’ve mentioned so far.  Like Las Cienegas, it is a spring-fed system, but here it fuels a natural oasis in the desert valley east of the city.  The property used to be a cattle ranch and has been significantly modified to create more cattle ponds with a little stream that runs between them, but the whole system still depends on the spring for its water.  Now it’s a county park and is known as a great place to bird (it’s got wood ducks!), but I keep going back for the odonates.  The diversity of habitats within Aqua Caliente Park results in a high diversity of species within a small area, which makes this a great place to go with a pair of binoculars and a camera and knock off several species on your life list in only an hour or two.  It’s really gorgeous too!  I love Agua Caliente!

Man, now I’m itching to get out and do some oding!  Maybe I can cram in a quick trip to Madera this weekend…

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Unless otherwise stated, all text, images, and video are copyright TheDragonflyWoman.com

Damselfly Taxonomy Fail

People who know me in person learn one thing soon after they meet me (assuming they don’t know already): how to tell damselflies and antlions apart.  Even friends and relatives who have no interest whatsoever in insects still know how to tell these apart.  This is because the general inability of people to distinguish these two insects is one of my biggest pet peeves.  It really shouldn’t bother me – after all, the ratio of entomologists to non-entomologists in the world is probably tiny and I certainly don’t expect everyone to know more than a handful of basic facts about insects – but it bothers me nonetheless.  It bothers me so much, in fact, that people quickly learn the difference if they spend time with me.  It might have something to do with the fact that I loudly point out every instance of misidentified antlions masquerading as damselflies or dragonflies that I see.  This wouldn’t be such a big deal except that I see this mistake ALL THE TIME!  Drives me nuts, and the people who are with me when I rant about how antlions and damselflies aren’t the same thing tend to pick up on the differences really fast.  I think it’s a defensive mechanism.  If someone shopping with me preemptively points out an antlion misidentified as a damselfly, I am less likely to make a scene and embarrass them.  :)

I’m sure the vast majority of people in the world wouldn’t even notice how often antlions are mistaken for damselflies on products.  The only reason I notice is because I happen to really like damselflies and dragonflies and I actively seek products depicting them.  As an entomologist, people also give me insect gifts all the time.  Because I love odonates, I get more odonate gifts than anything else.  But not all of them actually depict dragonflies.  These are a small handful of things I’ve been given that had the word “dragonfly” somewhere on the label:

art

This was a wedding gift from one of my husband's friends.

plate

I got two of these glass plates from my mom for my birthday in 2009

 

tee

My sister gave me this shirt a few months ago. I'm thrilled that outdoor clothing maker Columbia is using insects in their designs, but...

 

towels

One of my best friends' moms gave my husband and me two of these hand towels for our wedding.

 

necklace

This was the first thing my husband gave me after we started dating. He didn't know better at the time.

Did you notice what all of these things have in common?  If you didn’t, here’s a close up of the offensive body part:

antennae

Gah!

Look at those antennae!  Big, long antennae!  Damselflies and dragonflies have short, bristly antennae.  They’re basically little hairs that stick off the front of their heads.  No adult odonates have long antennae, so as far as I’m concerned, none of the insects depicted in the items above are damselflies and are all antlions instead.  It might say “damselfly” on the label, but the people who named these products are wrong.  Wrong wrong wrong!

This pet peeve of mine is so stupid.  I don’t really care what insects are on the things people give me.  I will display nearly any insect in my home.  I am just as happy with things that have antlions on them, long, showy antennae and all, as I am with things with damselflies and dragonflies on them.  Antlions are fabulous insects worthy of being included on products for people to buy.  And I like every one of the gifts pictured in spite of the misidentification.  After all, someone I care about bought me something he or she thought I would like.  I’m darn well going to like it!

I also realize that antlions and damselflies look so similar that most people aren’t even aware that they’re two different animals.  Artists who make odonate images often don’t draw from life and assume that odonates have antennae like most other familiar insects.  It’s not a bad assumption.  Unless you’re an entomologist, there’s very little reason why you might be taught the difference between damseflies and antlions.  Still, it gets to me every time I see an antlion labeled as an odonate.  Ultimately, it all comes down to that label, the proof that the person designing the product doesn’t know what they’re putting on a t-shirt or assumes that the consumer won’t notice the difference.  And the really stupid part is that if there was no label identifying it as a dragonfly or damselfly, I wouldn’t even care! Like I said, the pet peeve is really stupid.  Wish I could get over it.  I welcome suggestions for how to do so!

Before I end my little odonates-don’t-have-long-antennae rant I just want to point out a few things.  Damselflies and antlions might look similar, but they are really nothing alike.  Odonate nymphs are aquatic while antlion larvae bury themselves in sand.  Odonates fly during the day while antlions fly at night.  Odonates can’t fold their wings flat over their backs while antlions can.  Antlions are holometabolous while damselflies are hemimetabolous, so they’re not even remotely closely related.    In fact, they are so distantly related that they have a taxonomy fail index value (as defined by Myrmecos) of 67.02.  That means that this misidentification is almost 3 times as bad as mistaking an opossum for a cat!

I imagine that all of you will now start noticing antlions misidentified as odonates.  Welcome to my world!  You will find them everywhere.  And if you ever happen to hear a loud woman in the next aisle complaining about long antennae on a damselfly shirt that she would have bought except she can’t bring herself to do it thanks to the misidentification, come say hi.  It’s probably me.  :)

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

Mayflies, Damselflies, and Stoneflies: What’s the Difference?

I haven’t done an identification post for a while, so its high time that I write another one!  I find that a lot of people have a hard time distinguishing the aquatic insect nymphs with tails sticking off the back, the mayflies, the damselflies, and the stoneflies.  They’re easy to tell apart once you learn a few basics!  A lot of people have read my post on how to tell the damselflies and dragonflies apart as nymphs, so let’s start with them.

Behold, the mighty damselfly:

damselfly nymph

Damselfly nymph

There are several things to look for that will let you know this is a damselfly nymph and not a stonefly or mayfly.  However, the mouthpart is a dead giveaway!  If you don’t know about the awesome odonate mouthpart, allow me to enlighten you.  Odonates have highly adapted mouthparts that form a long, hinged structure that they can thrust out toward prey to capture it and draw it back to the chewing mouthparts to be eaten.  There are pictures of this structure available on the post linked above and you can see a little part of it sticking out past the head of the damselfly in the image above.  Odonates are the only insects that have this style of mouthpart, so if you have a nymph with tails sticking off the back-end and you can see a long, folded mouthpart under the head, you’re looking at a damselfly for sure.

But perhaps you’re looking at an insect in the water and you aren’t able (or willing) to pull it out to look at the mouthpart – what then?  Well, take a look at the location and structure of the gills:

Damselfly gills

Damselfly gills

The three damselfly “tails” are really gills that they use to help them breathe and swim!  They are always located at the back-end of the insect and they tend to be broad and leaf-shaped with varying levels of pointy-ness.  As you’ll see in a moment, the stoneflies and the mayflies have gills in other locations and do not have broad, leaf-like tails.  If you see gills that look like the image above, you’re looking at a damselfly nymph!

Let’s move along to the mayflies:

Mayfly

Mayfly

You should notice some differences between the mayfly and the damselfly right away.  First, look at the tails:

mayfly tails

Mayfly tails

Nothing broad and leaf-like about these tails!  Mayflies have long, filamentous tails, often longer than their bodies.  They also usually have three tails like the damselflies, but some groups only have 2.  Clearly, the flat-headed mayfly in the photo falls into the latter category.  This causes some confusion when distinguishing the mayflies from the stoneflies, as you’ll see in a moment.  However, if you see 3 filamentous tails, you’ve got a mayfly on your hands!

Now let’s take a look at the location of mayfly gills:

mayfly gills

Mayfly gills

The gills  are always attached along the sides or the bottom of the abdomen in the mayflies, never on the thorax or sticking off the back. If you see gills in another location, you’re not looking at a mayfly.  Mayfly gills tend to be broad and leaf-like as in the damselflies, though they may be fringed or sharply pointed in some groups.  They usually have a pair of gills on nearly every abdominal segment, though the exact placement on the abdomen varies by group.

Now we’re left with the stoneflies:

stonefly

Stonefly

Stoneflies and mayflies look a lot alike in most cases.  The mayfly in my photos above is a specialized species adapted for living in fast flowing water, but a lot of mayflies are shaped more like the stonefly depicted here.  How do you tell them apart when the body shapes are similar?  Let’s look at the tails first:

Stonefly "tails"

Stonefly "tails"

Stoneflies always have two tails.  Like the mayflies, they’re long and filamentous.  In some species, these tails are very long.  In others, they’re shorter than the length of the abdomen.  They’re never leaf-like.

Let’s check out the location of the gills too.

Stonefly armpit gills

Stonefly gill location

Unlike the damselflies and mayflies, stonefly gill placement is quite variable.  Many species don’t have gills.  Some species that do have gills don’t get them until they’ve matured to some specific point.  Some species have gills on the abdomen, but if they do they’re located only on the first few abdominal segments and never further down.  (This helps distinguish them from the mayflies, which almost always have gills on the 3rd-6th abdominal segments.)  But in most stoneflies with gills, you’ll find them in their armpits, as indicated in the photo.  Stonefly gills are very different from the broad, flattened gills of damselflies and mayflies.  They typically have a round main stalk with multiple branches.  These are called “finger-like” gills for some reason, but I think the structure is rather similar to the boojum tree, just on a smaller scale:

Boojum Tree

Boojum Tree. Photo by Bernard Gagnon, from http://commons.wikimedia.org/ wiki/File:Boojum_Tree.jpg.

I find that people have the most trouble telling the mayflies and stoneflies apart.  If the mayfly has three tails, no problem!  It’s a mayfly for sure.  However, you have to remember those pesky two-tailed mayflies that throw a wrench in the whole system.  Plus, mayflies are notorious for losing their gills.  If you’re working with preserved specimens, sometimes it’s hard to figure out where the gills did or did not attach.  How then do you tell a two-tailed mayfly with no gills apart from a similarly shaped stonefly with no gills?  It’s easy!  Look at the claws on the legs.  Mayflies have one claw on every foot.  Stoneflies have two.  It couldn’t be simpler.

As with any identification, the more animals you see, the easier this gets.  For those of you who have little experience collecting and identifying insects, getting a specimen IDed to order can be a challenge at times!  Remembering the characteristics of tons of insects can be hard too.  I thus present this handy-dandy chart that summarizes the information I covered above:

Mayfly Damselfly Stonefly
Location of Gills abdomen end of abdomen when present, thorax, base of abdomen
Shape of Gills leaf-like, plate-like, or fringed leaf-like finger-like
Style of Mouthparts chewing chewing + hinged segment folded under head chewing
Number of Tails 2-3 3 2
Shape of Tails filamentous leaf-like filamentous
Number of Claws 1 2 2

If you forget the characteristics of the mayflies, damselflies, and stoneflies, use this chart as a quick reminder of what to look for!

Next up: another thrilling edition of Friday 5!  This week’s will feature 5 places I’ve found a particular type of tiny insect in my home.  Check it out to discover where these little beasts may be lurking!

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

Behavioral Responses of Damselflies to Storms

Fountain Creek Park

The pond where I did my research at Fountain Creek Regional Park, CO.

Last week I talked a bit about how weather affects odonate behavior, my favorite topic in biology. Today I’ll go over the study I did to look at these weather related behaviors more closely. Like the little study I did that focused on damselflies and weather in my first college ecology class, this study was done at the wetlands in Fountain Creek Regional Park outside Colorado Springs, CO.  This research was actually part of my undergrad senior thesis!

pond at Fountain Creek Park

My study site. It extended from the cattails on the left side out to the end of the log in the water and from the dock (not visible) to just beyond the log.

I had to work the summer I collected my data, but I went to the wetland most days after work and recorded observations from 4-5PM.  I plopped down on the dock with all of my weather measuring equipment and watched the damselflies in a 5.5 square meter area along the edge of the pond for an hour.  I divided the hour into 5-minute periods and recorded weather data (wind speed and direction, temperature, light intensity, barometric pressure, relative humidity, and whether it was raining or not) for the first minute of each period.  I then spent the remaining 4 minutes counting the number of damselflies that flew within my study area.  Part of that area was filled with cattails and the rest was over open water as you can see in the photo.

Having spent 14 years of my life in Colorado Springs, I can tell you one thing with certainty: in the summer it rains nearly every day between 4 and 5PM.  This meant that I was out watching damselflies during the exact time the storms were blasting over Pike’s Peak and ripping across the plains.  I would sit there watching these phenomenal storm clouds rolling straight toward me with fantastic speed.  Guess who got rained on A LOT that summer?  Me!  I also got hailed on, was sandblasted in high winds, and was once driven running the half mile back to my car when the lightning got a little too close.  However, the clouds moved so quickly (they have to build up a ton of momentum to make it over Pike’s Peak’s 14,115 feet!), the storms didn’t last long, usually 30 minutes at most.  During that time, the weather would transform from hot, sunny, and still to cold, windy, and rainy in the span of a few minutes.  It would usually rain, sometimes very hard, for 10 minutes or so.  Then the storm would suddenly be over and it would become sunny, warm, and still again.  This whole series of events would take place during my hour at the pond.

Now most sane people go inside during storms.  Rain in Colorado is incredibly cold and the storms can be quite powerful with a lot of lightning.  Call me crazy, but I loved curling my whole body into my enormous rain jacket and getting rained on.  I was rewarded for my insanity too because I got to see some things that very few odonate people get to see.

First, I learned that there was a rather distinct pattern of behaviors that was associated with the weather patterns I observed.  The damselflies were most active in sunny, warm, still conditions, the typical weather central Colorado experiences during the summer.  They flew readily into and out of my study area, hunting, looking for mates, mating, and laying eggs.  As soon as a storm approached, you’d see some pretty interesting things.  As the clouds moved in and it became darker and cooler, the number of flights the damselflies made decreased so that fewer individuals flew during a counting period.  As the wind picked up, the activity decreased even further.  Flight activity ceased altogether if it started to rain.  Of all the many hours I spent at the pond, I saw only a single damselfly flying while it was raining, and it was during a very light rain when the sun was still shining.  Most interestingly to me, the damselflies would start to leave the pond when the weather deteriorated sufficiently.  They were displaying pond abandonment behavior.  However, as soon as the storm was over and the sun came back out, the damselflies would return to the pond and resume their normal activity as if nothing had happened at all.  It was fascinating and I am so happy I got to see this behavior!

pond at Fountain Creek Park

My pond at Fountain Creek Park during a light storm.

The flight activity of the damselflies at Fountain Creek Regional Park was clearly affected by the weather, but I was interested in knowing which of the seven weather parameters I measured were contributing to the flight activity I observed.  I used a statistical procedure (multiple regression for those interested) to determine that light intensity, temperature, wind speed (but not direction), and whether it was raining or not were the weather parameters most closely associated with the flight activity that I recorded.  Of these, light intensity showed the greatest association, followed closely by temperature.  Essentially, the brighter and warmer it was, the more damselfly flights you see.

(Brief aside: Remember how I said last time that I didn’t agree with that Russian scientist who thought that barometric pressure was a major player in shaping odonate behavior?  My results didn’t indicate that barometric pressure had any effect.  This coupled with the fact that the Russian didn’t even measure barometric pressure in his study makes me skeptical of his results.)

So four weather parameters were important.  The statistical test confirmed what I’d observed visually, that damselflies flew more readily in good weather than in poor weather.  “Good” conditions were warm and sunny with little or no wind while “bad” conditions were cold, rainy, windy, and dark.  I definitely observed pond abandonment behavior.

The most important question is this: what does all this mean?  I think my data suggest two things:

pond at Fountain Creek Park

My pond at Fountain Creek Park, right after a storm.

1) The damselflies might be able to pick up on cues in the changing weather that alert them that a storm is approaching.  Think about a damselfly, those big wings on a scrawny little body.  If you’re a damselfly, it could be physically dangerous for you to be out in a storm.  Being blown into the vegetation or the water could be deadly, heavy raindrops could impart a significant blow, and evaporative cooling could cause your body to cool down so fast that you can’t escape if the weather gets worse.  Better to leave the pond before a storm than risk getting caught exposed in one.  I think storms are dangerous to odonates, so the pond abandonment behavior that has been so often reported might be a means of protecting them from harm during bad weather.

2) Pond abandonment behavior might be related to roosting behaviors.  Consider these ideas: Damselflies roost in sheltered areas away from the water at night.  Storms usually result in a drop in the light level and temperature, which are the same things that happen as it gets dark at night.  Damselflies disappear from the water before it starts to rain.  It is therefore quite possible that pond abandonment behavior and simple roosting behaviors might be the same thing: odonates returning to their overnight roosts when it gets dark and cools down.  It is likely also advantageous for damselflies to seek shelter during storms, but this could be a secondary benefit, something they gain by completing a behavior that has nothing to do with protecting them from storms.

Are odonates using weather cues to abandon ponds before storms?  Or are they simply returning to their roosts because it’s getting dark?  Are storms dangerous to odonates?  These are some of the endless new questions I had after I finished this project and would like to answer.  I had intended to study this behavior in more depth in grad school, but then I decided to attend grad school in Arizona.  Colorado’s clockwork storms are perfect for studying these behaviors.  Arizona’s wildly unpredictable storms are not.  So, I changed my focus to the water bugs and have studied them ever since.  I will go back to my beloved odonates someday though!  I also decided a while back that my damselfly study was actually pretty unique and could make a real contribution to the scientific literature on odonates.  Ten years after I wrote my undergraduate senior thesis, my data was published.  If you’d like to read more about my study, look at some pretty graphs and whatnot, the citation is listed below.

I am dealing with some heavy things in my personal life at the moment, so I have no idea what I’ll do for the next few posts.  I’m going to let myself be driven by whims for a week or two.  I hope you’ll all check back to see where my whims take me!

Paper citation:

Goforth, C. L.  2010.  Behavioural responses of Enallagma to changes in weather (Zygoptera: Coenagrionidae).  Odonatologica 39: 225-234.

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

Studying Invertebrate Behavior on YouTube

image from class

An experimental setup in my recent insect behavior class. The students were studying how water temperature impacted respiratory rate in the giant water bug Abedus herberti.

As a lab instructor for an insect behavior class, I use a lot of live insects in my class.  The students enjoy working with them and are generally happy they don’t have to watch videos the entire semester.  Trust me – watching hours and hours and hours of insect behavior video can get really dull really fast.  Live insects are definitely the way to go for a class where most of the students do not have the level of patience that I do.

Unfortunately, the class is held in the spring, so there’s just not many insects out until the end of the semester.  This means that my students work mostly with my favorite insects, the aquatic insects, which is good.  However, it also means that they have a fairly limited variety of things to work with, i.e. things that overwinter as nymphs or adults.  I am able to collect a decent variety of aquatic insects during the winter in Arizona.  Still, there is one lab that would be SO much better if we had a bigger variety of insects to work with: the predator lab.

I developed the predator lab four years ago when my students at the time were constantly begging to put two hungry predators together and watch what happened in the ensuing death match.  (Did I mention that my students are college seniors and grad students and NOT 5 year olds?)  In the interest of turning this morbid curiosity into a teachable experience, the predator lab was born.  In it, I have the students feed several different predators and compare and contrast their feeding behaviors.  They have to watch how the insects capture and devour their prey and describe how they do it in detail.  They also have to tell me whether the insect is a sit and wait predator (they stay in one place and wait for food to swim, walk, or fly by), an active predator (they purposefully hunt down and attack their prey), or something else.  This way, the students get to watch several predators capture prey and eat it, fulfilling their need to promote death and destruction, but they are doing it in some meaningful context.

The predator lab is my favorite.  It requires a lot of work on my part to collect the insects and prepare the containers and prey items for the bugs, but the students get so into the activity that I can’t help but love it.  Even my quietest class, the class I just finished last month, got into it and actually made some noise in class for once!  And things get even better toward the end of the class period when they have finished their work for the day and I let them feed the things that don’t survive well in the lab to my water bugs or to each other.  This is the treat at the end of the semester, their reward for making it through what I consider a very work-intensive course: the death match they’ve been eagerly hoping to set up all semester.  This year there was also a water bug eating a fish to watch (click on the link to see the video!).  That really got the students excited.

Unfortunately, this year was a terrible year for aquatic insects in my part of Arizona.  We got a ton of rain during the winter and there was extensive flooding in the mountain streams that washed out the insects.  The populations didn’t rebound very quickly and there was hardly anything in the streams even several months after the floods.  I was hard pressed to get enough insects for my class this year and we ended up with a measly three types of insects for the predator lab this year: some small predaceous diving beetles, some dragonfly nymphs, and some of the smaller giant water bugs.  It doesn’t take very long to feed a hungry insect, so I brainstormed ideas for activities to fill up half of the class period.  I eventually settled on something I knew the students would love: showing some of the spectacular videos of predatory insects on YouTube.

YouTube is a rather amazing repository of insect behavior data.  A lot of the video is collected by amateurs and many of them know very little about the insects they’ve filmed.  That doesn’t matter – there is some great stuff on there if you know where to look!  For my class, I chose some of the most showy videos I could find.  My students had spent the semester watching live insects.  A video has to be amazing to hold my students’ interest at the end of the semester and the 8 videos I settled on fit the bill well.  And because they are too good not to share, I am posting them here so that everyone who reads my blog can see them too!

Army ants:

Damselfly eating another damselfly – check out the mouthparts moving!:

Preying mantis vs. mouse – and the mantid wins!:

Centipede vs. mouse – and the centipede wins!:

Spider captures and kills a bat:

Antlions (are awesome!):

Orchid mantid captures fly:

I can safely say that this was an excellent way to kill some time in class.  The students loved the videos (there were several collective cries of “Whoa!” during lab that day!) and actually learned something in the process.  A few of them even referenced the videos in their lab write-ups!  It was so successful that I think I will do this again the next time I have an opportunity to teach a behavior class, even if I do have a lot of animals to use in class.  It was great for the students to get to see some things we couldn’t possibly duplicate in class and let them see some more insects in action after their regular lab activities.  It was a great way to finish the last lab of the semester.

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