Friday, May 25, 2012

Hummingbirds and Moths


   Recently our collection has been wrapping up some accessioning of different insect specimens donated by our former Herpetology curators Dr. Vitt and Dr. Caldwell. The insects are from their properties in Oklahoma and a few sites in Arizona, California, Florida and Louisiana. We've been cataloging and accessioning them for a while now, and we're finally about to wrap up the moth and butterfly specimens.
Some of the butterfly and moth diversity we received
    If you look at the center of the picture and slightly to the top, you'll see two unit trays (white boxes with foam on the bottom) with moths that have narrow wings with pointed tips. These moths are part of a group of moths called the Sphinx moths or Hawk moths. The name Sphinx comes from the ability of their caterpillars to rear-up with the front part of their body into an "S" form, which apparently gives the appearance of a Sphinx.  The Hawk part of the name comes from the fact that many of these moths are very stealthy fliers, and their overall body gives the appearance of a hawk in flight. I'm not so sure about how accurate that is, but they are pretty elegant moths.
     If you look at the center of the first picture, you'll see a unit tray with four, clear-winged moths. The slightly bigger ones of these are called Hummingbird Clearwing moths, the smaller ones are Snowberry Clearwing moths. The reason I'm focusing on these guys is that they are often confused with Hummingbirds when people see them fly. They fly with the same rapid-beating wings, and can actually hover when they fly. Check out this video of some other Sphinx moths feeding on nectar in a similar manner to the birds.
    The Clearwing moths even look a little bit like hummingbirds. In the pictures below of the Hummingbird and Snowberry moths, you can see how at the end of the abdomen there are patches of setae (hair) that even look like tail-feathers of birds. I'm not sure whether they're for camouflage to look more like birds or if it actually helps them fly like birds, but its unique for this group of moths.
Snowberry Clearwing. See the patch of setae at the base of the abdomen ("butt") that looks like tail feathers?
     One other neat thing about Sphinx moths is that they have really long proboscises ("tongues") that they can be curled-up state at rest (think of a garden hose roller) and extend to feed on the nectar of flowers. You can see the proboscis in the video above as the long tube sticking out at the front of the head. In the picture below, you can see it rolled up.
Hummingbird Clearwing. The dark, half-circle thing at the front of the head is the bottom of the curled-up proboscis.
      Because Hummingbirds and Hummingbird moths share similar flight abilities, feeding habits, and size, there has been a lot of research comparing the two groups to see how they can fly so rapidly, hover, and survive with such high energy needs despite coming from very different evolutionary lineages. Both groups seem to share the same body size (which is on the larger size for moths) at least, and both expend tremendous amounts of energy to fly by hovering. However, when it comes to which came first in exploiting this method of getting flower nectar, the Hummingbird or the Hummingbird moth, its likely the moth. Insects evolved much earlier than most vertebrates (birds, mammals, etc.) and diversified rapidly along with flowering plants (angiosperms) millions of years before Hummingbirds graced the land.
     So, as usual, when it comes to something as cool as hovered flight, insects always are the first to set the trend!

Monday, May 21, 2012

Rad Reduviids

Hi Everyone,
    Last week I went to California to do some collecting of Miridae (plant bugs), and when I got back I was busy trying to catch up. But we're back! And today, we're going to talk about Reduviidae, or Assassin Bugs. They are a very diverse group of primarily predators, and come in many different body forms. Here is a nice page of all of the different forms in one group of Reduviidae.
One of the stockier assassin bugs. Image from Wikipedia.com
    Assassin bugs belong to the group Heteroptera, or True Bugs, and have the distinctive piercing mouth parts (the "tube" at the end of their head). They feed by piercing their prey with that tube, injecting digestive chemicals like a needle, and then sucking the juice back out. Yes it sounds brutal, but having a straw-like mouth means they have to live on a liquid diet. Kind of like living off protein shakes your whole life, but only having chemicals to do the job instead of a blender!
Image from http://www.insectsexplained.com/06Hemiptera.htm.
     One of my favorite things about Assassin bugs is that they have different ways of catching prey, with very novel adaptations for whatever they are going after. For example, there are Assassin bugs with thick, strong front-arms for holding down Millipedes, which is the prey of choice for Assassin bugs in the family Ectrichodiinae.
Image taken and copyrighted by Ted C. McRae, whose really great blog is found here
      Other Assassin bugs, like this species here in the video (Acanthaspis petax), cover themselves with the left-over exoskeletons ("skins") of the ants they've already eaten so that they can wander undetected on the nest. Ants primarily use chemo sensory information ("scent") to determine what is friend versus foe, so by covering themselves with the bodies of ants they can then "smell" like ants, and hide among their prey.
     One of the ways that Assassin bugs can stick the ants on their body is by using resin. This is either produced by resin glands on their body, or its spread on from other sources. One group of Assassin bugs, the Bee Assassins, use resin from other sources that they coat their legs with to catch bees flying by. Here is a video of a female one spreading some resin on her legs to get them nice and sticky (many Assassin bugs have very hairy front legs for that reason: more surface area for the resin to attach, and the more sticky they become!).
      Assassin bugs that don't use resin or other sticky traps to catch their prey have other neat ways to catch prey. The group Emesinae, or Thread-legged Bugs, capture prey by stealing it off of spider webs before the spiders can get to it. Their extra thin bodies that look like tiny threads (hence the name!) are light enough that they can step on the webs without getting caught or breaking it. Here is a photo of a larger one from my trip to Costa Rica. You can see how delicate they are compared to the other thick, stout Assassin bugs.
    One of the most commonly found Assassin Bugs and the most striking is the Wheel Bug. Nobody knows for sure why it has the wheel-shaped structure on its thorax (middle part of the body), but it gives a unique form that looks like half of a wheel. The website where I got this really neat image has some videos of these bugs capturing prey and feeding, so I encourage you to check it out here.
Image by and copyrighted for Jim McCormac, from website http://jimmccormac.blogspot.com/2009/08/wheel-bug-attacks-kills.html
        I could go on and on about all the neat habits and body forms of Assassin bugs, but I wanted to wrap up on one of the most famous members, the Kissing Bug. This Assassin bug, which is part of a group that evolved to feed on mammal blood, can transmit the dangerous disease, Chagas, to humans. These sometimes brightly colored and rather large Assassin bugs have taken advantage of stealth maneuvers. During the day they live in cracks and other spaces in houses, waiting. At night, however, they quietly sneak out and look for mammals, including humans and their pets, and quietly sneak up to feed on blood without you noticing. You don't run into these bugs very often in the United States (so don't worry too much!), but they do occasionally occur in some Southern States. There are several research groups working on this special group of Assassin bugs partly because they have this disease-transmitting ability, so they may not be a problem for us much longer.
Triatoma infestans. Image from http://www.servidorpublico.net/noticias/2006/06/09/brasil-elimina-transmissao-da-doenca-de-chagas-pelo-triatoma-infestans.
    So as you can see, Assassin bugs are really neat insects. Next time you head out and investigate your natural environment, look for these unique little predators and take a closer look at the Lions of the bug world.
    Have a great week!

Friday, May 11, 2012

Oh, what pests!

Have you ever wondered how museums are able to keep their artifacts and animals in such good shape? Pay attention on your next visit - the museum is full of textiles, animal skins, paper, and pinned insects - all things that make up a dream buffet for some insect pests. How do we keep them away from our treasures?

You may have also wondered why we seem to have such strict rules in regards to food and what is allowed into the museum. What harm would it do to take your cookie into the gallery and enjoy it there while you look around? It's not like you're going to smear it all over the artifacts, after all. Well, more harm than you think, unfortunately. Recently, we had a visit from an expert in the area of Integrated Pest Management (IPM). When the museum was built, he outlined a program for us to follow in the hopes of keeping pests to a minimum, and to prevent damage. This week he returned for a visit and to see how we were doing with the program. Our own IPM expert has done a great job educating all of us about the types of pests to look for, and what kind of damage they can do - in fact, you might remember her blog post!

So, why are we so strict about food? Why can't you eat your snacks in the galleries in peace? Any time food is taken outside of the Redbud Cafe, there is the probability of dropping crumbs on the floor - no matter how careful you are. These crumbs can attract and feed any pest that has found its way into the building. More food available leads to more pests, which rapidly becomes a large problem for us if these get out of control. You also have to be careful of things like cut flowers and cardboard, as insects can hitch a ride onto these items and can be carried into the museum that way.

We received a good "grade" from the visiting IPM specialist, and he provided us with other helpful tips to keep pests at a minimum. The next time you come and visit the museum, you'll know the explanation behind these rules. You can help us to keep pests under control, and our animals, insect collections, and artifacts safe.



Friday, May 4, 2012

Entoblitz 2012

   This past weekend the Sam Noble Oklahoma Museum of Natural History at the University of Oklahoma joined up with the Entomology Graduate Student Organization [EGSO] of Texas A&M University to organize a joint Oklahoma+Texas Entoblitz. Entoblitz is a yearly effort by Texas A&M to bring in scientists and experts in the field of insects to collect, study, and identify taxa in different areas of Texas. This was the first time that we had a joint-one with another state, and held it at the University of Oklahoma's Biostation next to Lake Texoma which is right on the border of Texas (so it was NEARLY Texas!). The Biostation is a fantastic facility, and we here at OU are so thankful to have it!
Beautiful weather for Entoblitz at the Station! The only quirk was the high winds near the lake.
    Over 40 people attended the Entoblitz, which is a really high number for us. The group included several experts of different groups (Beetles, Moths and Butterflies, etc.) as well as several soon-to-be experts in the future. Our goal was to have scientists of both states meet and greet, since many of the insects we study share distributions in both states.
The Red Admiral Butterfly, which is found in both states and were in large numbers at Entoblitz.
     Some of the neat insects that were found at the Entoblitz were photographed by Mike Quinn, who established a page of photographs. His primary expertise is beetles, and he does a lot with Bugguide.net, which is a really good resource for North American insects. My personal favorite insect he found at the Station was the mirid Plagiognathus.
    Other neat finds include a large series of dung beetles called Phanaeus sp., which was found under dead catfish near Lake Texoma (I guess stinky fish are as bad smelling and therefore attractive as dung!), and several different butterflies not usually found this early in Oklahoma, like the Queen butterfly. Many other insects were found that are new records for that species in Oklahoma or are possibly new species themselves, but we'll be finding out more in the future as the collectors and experts start pinning and processing their catches from the trip.
Entoblitz attendee Brittany with an NTO (non-target organism, meaning not a bug!)
   Overall the best part of the Entoblitz is to have an excuse for us Entomologists to get together, learn from each other, and share our knowledge. For example, beetle and butterfly experts Ed Riley and Tom Riley, respectively, even taught lessons on how to point-pin and spread insects from 1-2am on the last night Saturday so our graduate students could see how "the best" do it. How often do people have that opportunity to learn that from the experts and have that hand's on experience? :)
    Next year the Texas A&M EGSO is probably going to pick another location in Texas, and we here in Oklahoma are planning on what we want to do next (maybe a joint one with Arkansas?). No matter what though, we will do what it takes to keep the Entoblitz tradition going to learn more about the neat diversity of the South!