Friday, March 30, 2012

Crane fly

Have you noticed these all over the place this spring?

Wondered what they are? Screeched when one flew near you because you thought it might bite you? Well, fear not. This leggy, mosquito-looking thing is not a mosquito, nor will it bite or sting you. This is a crane fly, which is a type of Dipteran, or two-winged fly.

If you look at this picture, you'll notice two little protrusions right below the wings. They look like sticks with little knobs on the ends. These are called halteres, which are what balancing organs. These help the crane fly balance in flight. As with many other insects, when you see a fly like this, it is nearing the end of its life. Most of a crane fly's life is spent in a larval stage, eating plants. When they become adults, they eat very little - nectar (not blood!), or nothing at all. Their main goal as adults is to mate before they die. The pointy part at the very end of the abdomen is the ovipositor, which is how females distribute their eggs.

Maybe it's just me, but it seems like there have been many more of these around than usual this year. I suspect that it is due to all of the rain we had a few weeks ago - perhaps that helped create an environment ideal for crane flies. All crane fly larvae live in water environments, and in fact have gills at their rear-ends. Here is a video of a crane fly larva:

So, if you notice the adults, don't be alarmed. They look a little creepy, I suppose, but they won't hurt you in the least. You could even catch one if you're feeling brave, and see if you can gently find the halteres, and whether or not it has an ovipositor.

Happy Friday, everyone!

Friday, March 23, 2012

Diversity and species

   The last couple of days here in my office I've devoted to identifying, then cataloging and accessioning (taking down the information about the specimen, and legally making the specimens ours, respectively) a donation by one of our former curators, Dr. Laurie Vitt.
Some of the specimens donated, including a lot of different orders and families of insects

Dr. Vitt and his wife Dr. Caldwell have done insect collecting (along with other animals) at their property in Le Flore Co., Oklahoma for several years, and have graciously donated the material here. They also did some collecting in Arizona, California, and Florida, so now we have those representatives too. When you look at just some of the beetles (Order: Coleoptera) donated, you can see some of the neat diversity that we now have in our museum.
   This isn't all of the beetles, just some of the ones I'm working on at the moment. Currently I'm trying to sort them to family (one of the higher categories of relationships), then if I can, I go as far as genus and species. The genus and species name make up the scientific name, which is part of our use of binomial nomenclature in science (e.g. Chrysina gloriosa...Chrysina is the genus name, gloriosa the species). If you notice, scientific names also are either italicized or underlined; this helps indicate they are scientific names and not common names (common names are the informal names, like "bumble bee" or "June bug").
Dung beetles; Canthon sp. and Deltochilum gibbosum
    Since I'm not really a beetle scientist (my expertise is on Heteroptera, or True bugs), a lot of the beetles are only identified to genus, and I'm leaving it to real experts on beetles to identify them to species. The sp. and the end of Canthon in the figure, for example, means the specimen is in the genus, but what species is left undetermined. To identify many insects to species you need to dissect them, and we have to make sure they are cataloged first.
Some of the easier to ID beetles; including the distinctive Rhinocerus beetle Dynastes (really big grayish-green beetle), Rainbow Scarab Phanaeus (second from the right, first row), and Jewel Scarab Chrysina (mint green beetle with silver stripes).
    Identifications to species is useful for several things. One, it helps understand what the real diversity is for an area. What may be recorded as just having one genus of a beetle may in fact, on further investigation, be 5-6 species: increasing the diversity by a factor of 5. Having the species names also helps understand the ecology of an area: if you know that one species lives in open water, the other in swamps, then you know that the area that they were collected included both environments. Having a total number of species and what species they are is also useful for ecology, and is the main goal for our Oklahoma Bioblitz and our Texas+ Oklahoma co-organized Entoblitz. The more we understand about what species live in a place can make the place even more unique!
    So to conclude, we have a lot of really neat beetles we're adding to our collection, including quite a few that even I, the Heteroptera person, will admit are pretty neat and kind of (kind of...) make me want to work on them a bit more myself. However, for now I'll stick to cataloging them and getting them into our collection, and later let the experts have all the fun. Happy Friday!

Friday, March 16, 2012

Insects to Dye for

    When people generally think of insects and what they do for society, the general consensus is usually that they aren't doing much and if they are doing something it must be bad. The usual examples are termites eating homes, mosquitoes making life uncomfortable, caterpillars eating our garden, or wasps invading our back yard barbeques. Occasionally someone reminds us that we do have some beneficial insects, such as honey bees producing honey and pollinating our flowers. But in general, insects aren't viewed in a very economically or socially beneficial way.
    However, there are other insects besides honey bees that have been really useful for society. One of these lesser known insects is the cochineal bug. This bug (part of the True Bugs, or Hemiptera) is a flat, pancake-shaped insect that pretty much lives its life flat on a cactus, feeding all day. Below is a picture of a colony of them feeding on a cactus pad.
   They are usually covered with a powdery coating of wax, which is thought to help protect them from predators and drying out (biting a block of wax isn't exactly enticing to a predator!). All of these insects are females; males usually only live long enough to mate and fertilize eggs before dying. Males don't even live long enough to eat, and don't have mouths!
   So why are these little, flat bugs such a good thing? Well, since the 15th Century Mayans and Aztec peoples of Central America have been harvesting these insects for dye, or carmine. If you take your finger and press on one of these insects to squish it, they produce a deep red colored fluid (carmic acid causes the color), which is used for dye.
    Central Americans would collect these insects off of the cactus plants, dry them, and then mix the ground material with salts to extract the dye. The dye was so invaluable, in fact, that it was only second to silver as an export during the early Colonial Period. Only until artificial dyes were developed in the late 19th Century did it wane in popularity.
Cochineal-dyed wool
    These days use of the dye is making a comeback, mostly due to people moving back to natural dyes and products. In fact, there is a resurgent industry in South America to produce the dye and farm the insects, and is once again becoming an important industry. If you search around here in Oklahoma and Texas, you can sometimes find these insects feeding on own native cactus pads.
A large colony of insects
Cochineal is often used in cosmetics, foods, and other red-items due to its ability to stay red even under bright light and because it can mix with water.  Its also now more widely available at natural food stores as an alternative to artificial food coloring. One item I see it listed a lot is in Jello snack-packs. Here is a video about how its used in many foods for the red coloring.
   If you want to learn more, check out the Wikipedia page about the insects, their history, and their dye...and next time you see a cactus, take a closer look for another beneficial insect!

Friday, March 9, 2012

Spring is for Springtails

   The Oklahoma weather is taking some rapid twists and turns in terms of temperatures lately, but there is one group of arthropods that are already starting to show up in fairly good numbers regardless: the Collembola, or Springtails. Springtails are very small, many less than a few millimeters long. They can be found in pretty much all environments, though most are linked to moist areas and water.  Here in North America you can most easily find them around moist soil and moss, like this video of Collembola in Ohio below.

Many can also be very colorful, being a dark purplish blue to yellow with red stripes. Anurida sp. is known for its bright blue color.
Anurida maritima, which lives in intertidal zones
    If you look closely at the surface of water near creeks and ditches lately, you'll see Collembola start to show up. Many are the size of a pin-head or smaller, but if you look closely they can come in a variety of forms. Some look like centipedes, like the picture above. Some even look like miniature bunny-rabbits, like the Sminthuridae :
   The reason Collembola are called Springtails are because they have a unique lock-and hinge system (retinaculum and furcula or "tail", respectively) that, when released, causes a spring-trap like flip into the air for escape. Here is a video about how some Sminthurid springtails keep themselves clean and jump:

    Springtails also have elaborate mating dances to get female spring-tails to accept the sperm of a male springtail. Here is another video of male springtails trying to convince a female to accept their sperm by pushing her with enough force on the head...if he's strong enough to move her, he can mate with her:
   We have specimens of Collembola in our collection, most of which are on slides and a few in alcohol. They are a very diverse and very neat group of arthropods, so next time you see something move outside, take a closer might be a springtail making its Spring appearance!
     Happy Spring Everyone!

Thursday, March 1, 2012


Last week we had an event at the museum, "Science in Action." It was a very busy
day for all of us, but it was great to see so many families interested in science, and encouraging their kids to learn more. We set out a beautiful display case of insects that were collected by a former curator. This display case got a LOT of attention - here, you can see it for yourself!

There are a lot of insects to examine here, but I noticed there was a particular kind that garnered a lot of intrigue. Let's look a little closer, and focus toward the bottom of the display:

Many people thought these looked positively ferocious, and everyone wanted to know what on earth these creatures are. These are a type of Megalopterans, in the family Corydalidae. These are commonly known as dobsonflies, and they tend to live near the water. These are males, and you can tell by their huge tusks on their head. While these tusks look like they could administer an unpleasant bite, they really can't do much harm to humans. The tusks are merely an attempt to show off for the female dobsonfly, and for holding her during mating once she's been suitably impressed.

When these Corydalidae are younger, they look like this:

If you fish, you might know these as hellgrammites, and you might also know that these can bite in their larval stage of life. You'll find these under rocks in cool, running water, and they're very common. They also throw quite a fit if, for instance, you try to collect them for your Aquatic Entomology class. I found one when we went on a collecting field trip, and this little insect would NOT let go of my net with its mouth. Once I finally managed to pull it off my net and drop it into my collection vial, it thrashed around and tore apart everything else in the vial. Several of us ended up with intact hellgrammites and a sad pile of other insect parts. These larvae definitely don't go down without a fight.

These larvae have gills, which you can see in the picture above - they look like tufts of fur. Most of Corydalidae's life is spent in the larval stage. When they become adults, however, they lose their gills and live on land. The adults also do not live long - only about a week or so. If you find a dobsonfly, it's near the end of its life, and is only interested in mating before it dies. As the weather warms up throughout this spring, see if you can find one!