Friday, December 21, 2012

Don't eat that!

     One of the big pushes that has come up in popular science is to use insects as a food source for humans because of their high protein, low fat, and relatively low ecological impact. In fact, I wrote a blog post about it a few months ago. However, insects have been eaten by other animals for millions of years, and may provide the majority of the nutrition in their diets. Which brings me to two topics we're going to write about today: insect chemical defense against getting eaten, and chemical warfare.
       The first part is because my dog-owning friends have sent me images of potentially toxic beetles that they found their dogs munching on, or about to munch on. Even though domestic dogs primarily are carnivores, its well known that many dogs will eat other stuff if they can get their paws on them. Garbage, scraps...etc. It should be no surprise then that many dogs, if given the opportunity, will eat bugs. Especially if it peaks their hunting instinct, and they get to chase them around. There is a whole blog article musing about why dogs eat bugs, but for the most part its not really that dangerous. But, what if the beetle they do decide to go after IS actually a problem? Well, the two beetles that my friends sent me images of actually CAN cause a problem, and here is why.
Black Blister Beetle. Image of Epicauta pennsylvanica by Bruce Marlin. From wikipedia.com
       There is a group of beetles that we have here in Oklahoma and the United States called the Blister Beetles (Meloidae), and they get their name because in their blood they have a caustic chemical called cantharidin. This chemical, when secreted by the beetle in self defense, can actually burn your skin or even cause blisters (hence their name). Blister beetles can be anywhere from 2cm to as large as 6-8cm (the size of a quarter or so). The largest group of these beetles we usually run into here in Oklahoma is in the genus Meloe, called the Oil Beetles. These big, black beetles with a very large, bulbous abdomen ("butt" area), and are usually found wandering along the ground since they cannot fly. There are other beetles in the group that aren't as big and tend to be more rectangular in shape (see here for more info about the various kinds in North America), but all blister beetles tend to have big, round heads that are wider than the area behind the head, giving them an upside down, exclamation point appearance (!).
        My friend that caught her dog actually munching on the beetle before spitting it out unfortunately had her dog dealing with some of the symptoms of the cantharidin: upset stomach, hurting mouth, and other irritation. My other friend caught the beetle before her puppy could find it. Its unlikely that the dogs would die from eating one beetle, but if enough are eaten they can get fatal cantharidin poisoning, which is a major problem in horses.
        Not all animals have problems with poisonous insects, however. Poison dart frogs, for example, actually use the poison in the bugs they eat to make the poison on their skin to protect themselves. In fact, the poison in some dart frogs are some of the strongest poisons known on earth! How the frogs get the poison from their diet to their skin without dying from it is still an active area of research. However, its known that captive-bred dart frogs are not nearly as poisonous as their native colleagues because they don't have access to poisonous insects from their native habitat.
Briefly holding a wild Dendrobates auratus I found in Costa Rica, outside of our hotel in Manuel Antonio. The owner of the hotel, who knew of the population, had tried to hold one of the frogs to keep it away from some plumbing being re-done near a wall against the forest, trying to protect it. Apparently he held it so long the toxins leached into his skin just holding it. The story goes that one of his workers found him passed out on the floor, with the frog happily hopping all over him on its way back to the forest after. He was fine, and the frog was too.
Captive poison dart-frog, which doesn't have the toxins.
   In the tropics there are many cases of chemical warfare between insects and their predators, with poison dart frogs being the masters by beating the system. Those of us who live in the temperate regions of the world also have toxic insects, but few animals that can beat their system and not be affected by the poison or use it in another way. There are examples of animals here in North America that can, which I'll write more about later, but dogs are not one of them.
     If you have a dog here in Oklahoma, 99% of the bugs and beetles your dog may eat are not going to be a problem for them. You are more likely going to have problems with your dog eating garbage, poop, coffee, or chocolate than you are with a small beetle. However, if you do find a beetle that looks like the Blister Beetle above and your dog is showing some symptoms of an upset stomach, you may want to have your dog checked out due to the exposure to cantharidin. More than likely it will be nothing, but better safe than sorry.
       Have a Happy Holiday!

Friday, December 14, 2012

Its the season for Mistletoe...

    'Tis the season...for mistletoe. Every office Christmas Party or other Holiday-themed event in December has a sprig of the plant hanging from a hook in the ceiling. Both maligned and loved by single people, the tradition goes that once you stand under the mysterious green plant you are obliged to give a fellow trespasser a kiss. Its a plant both ardent...and avoided at the same time, depending on the person.
    So what exactly IS mistletoe, and why are we talking about it in our Recent Invertebrates Blog? Well, to start with the former, mistletoe is in the Santalales order of plants. Many of these plants (but not all) are known for their parasitic lifestyles. Most of us know what animal parasites are - they feed on animal hosts, taking their nutrients. However, most people don't know what plant parasites do. Plant parasites also take nutrients from other plants (hosts), and depend on their hosts for sugars and minerals that they can't get themselves. Chlorophyll, which is the chemical in plants that generates sugars and energy from sunlight while giving plants their green color, is often absent in parasitic plants. Since they just take the nutrients from their hosts, they don't need to generate the sugars themselves. The mistletoe found around here in North America, Phoradendron sp., is still green however, which may be due to it being a hemi-parasitic plant (it doesn't get ALL of its nutrients from its host tree, just some). In Europe the mistletoe plant is from a different genus, Viscum.
Phoradenron juniperinum, image taken by Stan Shebs and posted on Wikipedia.com
    You can find mistletoe in a lot of trees throughout North America as dense green clumps high up in the branches. They are most obvious in winter since trees drop the rest of their leaves and the mistletoe is the only green things left, which is maybe why they were selected out as Christmas decorations. If you are able to look at the plants more closely, however, you might see a little green bug, Viscacoris. These bugs are only found on mistletoe, and were named after the family of plants that the American mistletoe was thought to belong to, the Viscaceae. In North America there are about four species, and they are a similar green color to the plant but turn yellowish as it fades.
Viscacoris species on the bottom half. Image by Christiane Weirauch.
     However, mistletoe is not the only parasitic plant out there, and Viscacoris is not the only bug to feed on them. Many parasitic plants belong to the family Santalaceae, which include the very weird but oddly pretty plants and are often found in Australia. Another hemi-parasitic plant from Australia is Exocarpos sp., which requires another tree to survive by feeding from the tree's roots.
Exocarpos cupressiformis, from Wikipedia.com
   Found only on this tree are bugs of the genus Exocarpocoris. These bugs are from Australia, and have really unique structures found on bugs from nowhere else in the world.
Exocarpocoris praegracilis, from Discover Life.org
   Another parasitic mistletoe plant with weird plant bugs on it is Amyema miquelii. This plant is also found in Australia and has unique reddish flowers. Found on this plant are another group of bugs from the genus Hypseloecus sp. These bugs are also reddish like the flowers of the plant to blend in. They also are only found on these plants.
Hypseloecus neoamyemi, from Discover Life.org
     Why are these bugs only found on mistletoe? We are still investigating that. Many insects co-evolved with certain plants over time and maintain close ties. Its believed that insect pollination, for example, was one of the leading drivers for flowering plant evolution. Maybe these bugs stayed with these plants because of the nutrients they had, and became so closely tied to them that they are now reliant on them.
      So, next time you are under the mistletoe and you're not really that interested in kissing the person you're with under it, instead maybe point up to the plant and tell them that there are tiny bugs that are found only on mistletoe. While they are distracted by how cool that is and are looking for them, you can sneak away!
     Happy Holidays!

Friday, December 7, 2012

Living Jewelry

     As Christmas shopping continues here in the United States, fancy jewelry is on the minds as possible gifts. Most of the TV channels that I get have various commercials for Jared's Jewelry, Kay Jewelers, etc. all advertising their various diamonds, rubies, and other exotic and expensive wares as potential Christmas, New Years, and engagement gifts. Diamonds are forever, after all...not coffee makers or other gadgets that break, right? The message is to get something different, something that will really blow the receiver's socks off. Well, what if you could get bedazzled jewelry, but that its either from living insects or actually is a living insect?
Zoropheridae beetles used as living jewelery. Image by Shawn Hanrahan from TAMU and found on Wikipedia.com
 In some cultures, its possible to actually purchase what is considered "living jewelry", called The Mexican Maquech Beetle, in Mexico. These beetles, which are also called Ironclad beetles because their exoskeletons are so hard, were sometimes used as jewelry by gluing rhinestones to their backs along with a chain, and then then the chain was pinned to a blouse. The insect then crawled, tethered, all along your shirt as living jewelery. As adults they only eat rotting wood and occasionally need water, so they are pretty hardy beetles that could last crawling along your blouse for long periods of time fairly easily. For more information about these beetles and the culture surrounding them, check out this link and video:

http://www.odditycentral.com/news/maquech-beetles-mexicos-controversial-living-breathing-jewelry.html

 
So, next time you look at another jewelry commercial on TV and you think you want to buy something really special, you could get one of these uniquely decorated beetles as jewelry instead!

Friday, November 30, 2012

Burying Beetles

    Earlier this fall we got a donation of American Burying Beetles (Nicrophorus americanus) to safeguard in our collection, the specimens of which were part of a survey project done by one of our museum's curators, Dr. Gary Schnell. He, along with students, did surveys of the endangered beetles in Arkansas and Oklahoma to study what habitats they prefer, and to learn more about their biology. Dr. Schnell had been working on the project from 1992 to about 2005 surveying the two sites (Fort Chaffee and Fort Gruber, respectively) during several summers in that time frame. The beetles that were found dead in the survey were kept as voucher specimens, and are now part of our collection thanks to the work of our volunteer Sally, who has diligently been pinning and processing them from alcohol.
American Burying Beetles Sally has processed.
   Why are American Burying Beetles so important? Well, the reason is that they are one of the few insects on the Endangered Species list. Its believed that these beetles used to have ranges across the entire Eastern United States, but are now just limited to a few counties in Oklahoma, Arkansas, Kansas and Nebraska.
   These beetles feed on a very specialized diet: carrion (dead animals), which is one of the reasons that its thought they have had such a reduction in their distribution. Dead animals, especially in the right size that the beetles can use, is fairly hard to find. These beetles need animals the size of a dove or chipmunk that they can easily manipulate into a burrow to bury with their eggs. The eggs then feed on the nutrients of the carrion to develop. As land use changes and the availability of small animals decreases, so have the beetles. According to information on Wikipedia.com from the US Forest Service, their life cycle is as follows:

   "During the winter months when temperatures are below 15 °C (60 °F) N. americanus adults bury themselves in the soil to overwinter. When temperatures are above 15 °C (60 °F) they emerge from the soil and begin the mating and reproduction process. Burying beetles are unusual in that both the male and female take part in raising the young. Male burying beetles often locate carcasses first and then attract a mate. Beetles often fight over the carcass, with usually the largest male and female individuals winning. The victors bury the carcass, the pair mates, and the female lays her eggs in an adjacent tunnel. Within a few days, the larvae develop and both parents feed and tend their young, an unusual activity among insects, but a characteristic shared with the. Brood size ranges from one to 30 young, but 12 to 15 is the average size." 

Its this complex behavior, among other things, that makes them so interesting as well as atypical for beetles. Most beetles do not have this type of maternal care (parents taking care of the young); usually beetles lay their eggs and then leave them to fend on their own!
American Burying Beetles are recognized by their orange antennae segments, the orange area on the head and pronotum (shield like structure behind the head), and the orange stripes on the wings.
     Having these beetle specimens in our museum helps keep the record of their existence for future generations. Hopefully the beetles will have a bright future ahead of them with their protected status and captive breeding, but if not we can safeguard their record of being here none the less.

Thursday, November 15, 2012

Mantids!


This is the first inaugural post from Mantidae, our Collection Manager. Thank you Mantidae for posting!

Hello!  This is my first contribution to the Recent Invertebrates blog!  I’m a member of the department but actually a trained Ornithologist (a biologist who studies birds).  Hopefully, I can provide some non-Entomologist perspective to this blog.

My favorite group of insects has always been the praying mantis. The name “Praying Mantis” comes from their typical "prayer-like" posture with folded forelimbs.

European Mantis (Mantis religiosa)
http://en.wikipedia.org/wiki/Mantis_religiosa
  According a Muslim myth, the praying mantis always prays facing Mecca. Mantis is a Greek word for “prophet” and has the reputation of having supernatural power in some cultures.  For example, many Europeans believe that the mantis points lost children home, and in some African cultures, it is thought to raise the dead. 


 
Praying mantises are the most voracious predators in the insect world and will devour any creature they can overwhelm, including small scorpions, lizards, frogs, fish, and even birds and rodents!  In the 17th century, Chinese fighters created a style of Kung Fu (Chinese martial arts) inspired by the praying mantis that can defeat much larger opponents with the split second timing and precision.

 
 
Praying mantises have forelimbs with the jackknife like apparatus, and once they grab their prey, there is no chance of escape for the victim.  Their compound eyes are widely spaced and laterally situated, creating a wide binocular field of vision and, at close range, precise stereoscopic vision.  They can judge the speed and distance of preys by swaying their head side by side, computing perfect timing of attack.

There are over 2,400 species of mantids in the world.  I was a little bit disappointed when I learned that they are the most closely related to termites and cockroaches (Eew!). Who could imagine such beautiful creatures could be related to cockroaches?  You may have only seen brown or green ordinary-looking praying mantises in the backyard or roadside of Oklahoma, but it includes species that are incredibly diverse in size, shape, and color.  Some of them are so well camouflaged in the background, and you may never be able to find them.  Here are some of the good examples:

Giant Dead Leaf Mantis (Deroplatys desiccate)
Orchid Mantis (Hymenopus coronatus)
http://en.wikipedia.org/wiki/Hymenopus_coronatus
Spiny Flower Mantis (Pseudocreobotra wahlbergi)
http://en.wikipedia.org/wiki/Pseudocreobotra_wahlbergi
Ghost Mantis (Phyllocrania paradoxa) http://en.wikipedia.org/wiki/Phyllocrania_paradoxa
 
If you are lucky enough, you may find egg cases of the praying mantis in your backyard in late fall or winter (or you can also buy their egg cases online).  When I was in the first or second grade, I decided to keep a little brown foam-like egg case in the plastic insect case all the winter.  One day in the following spring, I discovered hundreds of small praying mantises started to come out of the egg case.  You can imagine how excited I was!  Although I wanted to stay with the baby mantises, I had to go to school that day. When I came back home in the afternoon, I discovered that the tiny mantises all escaped from the small slits of the insect case, and I couldn’t find even a single one of them anywhere in the house.  So be careful if you decide to experience the wonderful birth of baby mantises!  The following video shows the life cycle (from egg to adult) of preying mantis: 

Aren’t they just fascinating? 

Hiatus

Hi, this is Katrina. This past Friday both myself (Miridae) and Laura (Tardigrade) were at the Entomological Collections Network Meeting and the Entomological Society of America Annual meeting, so we unfortunately could not post a blog article for that day. But, stay tuned for the one this week by our Collection Manager Tamaki about Mantidae, and we will get back on schedule next week!

Friday, November 2, 2012

Hairs!

      As someone who studies bugs for a living, one of the most difficult parts of my job is trying to convince people that the little guys should get as much attention as the big, furry, and feathery guys. There is something innately attractive to humans because fur reminds us of our own mammal ties: one of the unifying characters of being a mammal is having hairs or fur, among other things. So when we see fur, fluff, or hairs we feel a slight sense of kinship.  
Awwww!....fluffy, sleepy kitty and fellow mammal
       Well, bugs don't really have "hair" or "fur", which sets them in a slight disadvantage in that respect. Words that come to mind with bugs are "slimy", "squishy", and "gross". However, many insects have setae, which are like hairs, but since insects come from a different ancestor than mammals its actually something different. The function of the setae is also different.
Awwww?!?...fluffy-legged Clearwing moth...not mammal
        For insects, setae are often used to sense their environment around them. If a setae is bent a certain direction by a puff of air, it triggers nerves in the exoskeleton to let it know there is wind. Because insects have a hard exoskeleton rather than skin, its less sensitive to mechanical (physical) stimulation unless there is something like setae to interact with the environment. Even the hardest-shelled beetles with tough, smooth exoskeletons have setae around the joints between segments to "sense" where the other segments are and how they are moving. 
Rhinoceros beetle. If you look at the bottom of its top "horn" you'll see an example of setae for sensing when it touches something with the structure, as well as a band of golden setae below it, over its head.
        Another interesting use of setae with insects is for self defense. Caterpillars are the stars of using setae to either a.) make themselves completely unpalatable by becoming one giant cotton ball of hair, like the photo below:
Caterpillar covered in setae; its old, shed exoskeleton is to the right
         Or b.) a caterpillar can use what are called urticating hairs, which actually can cause itching and other irritation. These break off when you touch the hairs, and again help make the caterpillar as unpalatable as possible. The Douglas Fir Tussock Moth below can actually cause a significant allergic reaction if touched, or if the hairs are inhaled.
Tussock Moth. Image from http://www.fs.usda.gov/detail/r6/forest-grasslandhealth/insects-diseases/?cid=stelprdb5377760
     So...the moral of this story is that there are insects that are furry and fluffy, and may in some cases draw the same "aww, this is cute!" response as our mammalian furry friends. However, the "hairs" in insects are there for different reasons than in mammals, such as for sensing their environment or self defense against predators. Yay fluff!

Friday, October 26, 2012

Scary specimens!

I don't know about you, but I still get a big kick out of Halloween. I like all of the pumpkins and candy and decorations, and the crisp feeling in the air - especially today after that cold front! Anyway, over the years I've noticed that one little invertebrate seems to be featured around this time of year in various decorations - the black widow spider.

Most people are very familiar with the black widow spider (genus Lactrodectus). They're easy to spot, and it's hard to mistake them for something else - most of the time. More than likely, if you live in the United States, you're quite familiar with this gal here: 
http://en.wikipedia.org/wiki/File:Black_Widow_11-06.jpg
Beautiful, isn't she? Black widows are certainly very striking spiders. Here is a great close-up picture of her hourglass marking. It serves as a warning, saying "Danger! Do not mess with me."

http://en.wikipedia.org/wiki/File:Blackwidow_macro.jpg

Female black widows are the ones that are particularly dangerous to humans, as her bite contains much more neurotoxin than that of a male black widow. Black widow bites can cause severe pain and cramps in humans. In rare cases it can be fatal, but more than likely the bite just leads to a very unpleasant experience.  

Male black widows look much different than females. They are usually more of a brown color, but also have some white and orange coloration as well. They're smaller than females, and sometimes have the unfortunate fate of being snacked on by the female after mating. They are not dangerous to humans. Below is a picture of a brown widow - unfortunately I could not find a usable male black widow photo. I think that they look similar in to this brown widow, both in coloration and body structure, except for the hourglass - males don't seem to have those.
http://en.wikipedia.org/wiki/File:Brown_widow_spider_Latrodectus_geometricus_underside.jpg
Black widows tend to have very tough and sticky webs, and they look chaotic and somewhat half-hazard. When we think of spider webs, we usually think of round, intricate webs that have a pattern. Not so with black widow webs. If you see a web like this outside, stay away. Black widows will leave you alone if you leave them alone. 

We do have some black widows in our collection. Something that I've noticed is that when they are kept in ethanol, their red hourglass turns white or sometimes even a chartreuse color. 


This spider is in a large jar of spiders in the black widow family, Theridiidae. You can just barely see the hourglass that has turned white from the ethanol preservation. The spider is upside down, with the abdomen facing up towards the top left of the vial. 



Happy Halloween, everyone!

Friday, October 19, 2012

Mini Urban Zoo

      Over the last one hundred or so years of human civilization there has been a dramatic shift from people living primarily in rural areas, where agriculture and other primary resource generating activities occur, to living in urban areas such as cities. It was estimated that in 2007 the majority of the world's people would be living in urban centers (McKinney, 2002). What this means is that more people that ever are living in altered urban environments and farther away from native wildlife and plants, so getting out and finding nature can be a bit more difficult. However, compared to other animal groups, insects are a bit easier to find for even a little dose of nature.
     When I moved to Oklahoma to start my job here at the Sam Noble Museum, I rented a tiny apartment not far from the museum. There is a field behind the museum that was left to return to a prairie environment, but the area around my apartment complex proper was far from natural. It was mowed, sprayed, chopped, and otherwise a very neat landscaping job. When I poked around the little yard I had behind my apartment, I wasn't expecting to find much in the way of bugs or plants.
      However, come later that summer, I saw a plant start to crop up in the back area of my yard. Looking closely at the flowers, I noticed it was a monocot (one of the two major groups of plants) and that there was stuff feeding on it. Excitedly I started looking more closely at it, trying to figure out what plant it was, hoping it was a native plant.
Commelina communis, image from wikipedia.com
    I took a plant sample (traditionally botanists take as much of the plant as they can, including the flowers and roots if possible, to identify it), and sat down with my botany book to figure out what it was. It is Commelina communis, or the Asiatic dayflower. And...found out its an invasive, non-native plant from China. Sigh. Its still pretty.
    My second thought was "well, even if the plant isn't native to Oklahoma, maybe the bugs that are feeding on it are!". Many native species of insects have successfully "switched over" to feeding on plants not originally from North America. This includes feeding on things like apple, corn, and other crops produced for food as well as landscaping plants (bushes, ornamental trees). Maybe what was munching on the plant switched too. So, sitting next to the plant one afternoon in the sun with a container to put the bugs in, I caught two things that were feeding on the plant.
     First, I found this beetle.
Criocoris sp. Sorry for the fuzzy image, still figuring out my new camera!
     The beetle is part of the Chrysomelidae family, or the Leaf Beetles. These beetles primarily feed on plants, and usually on one or two types of plants only for each species. This particular beetle, a member of the Criocoris genus, feeds mostly on asparagus (hence its common name, asparagus beetle). They are native to Europe and Asia, where asparagus is also from, and were likely brought over when we brought the plant to farm and eat here in North America. And what is interesting is that not only was little guy not feeding on the non-native asparagus, but instead switched to the non-native dayflower. Both plants are part of the monocot group, so it was a relatively similar group of plants to switch to.
     The second thing I found was this bug:
Sixeonotus sp.
   These bugs, which are members of the Miridae family (or, Plant bugs). They are part of a subfamily of bugs called the Bryocorinae, which primarily feed on ferns and monocots. Because Commelina is a monocot, these guys also seemed to switch over to feeding on that plant versus our native Oklahoma monocot plants. However, unlike Criocoris, with Sixeonotus I finally found a native Oklahoman bug, since these bugs are found in North America. I was really happy to find a native Oklahoma bug, even in my highly maintained apartment complex back yard!
     So, in short, even in modified urban habitats where you have a lot of non-native plants and insects, if you look close enough you still can find a little native Oklahoma sneaking in and persisting. Next time you are in your back yard, even in one as small as one like mine, take a closer look at what is there. You may have your own little patch of nature ready to be explored!

Friday, October 12, 2012

To fly or not to fly

   One of the first, and maybe the biggest advantages invertebrates have over vertebrates, is their ability to fly. Primitive insects were the first animals on earth to fly: before dinosaurs, before birds, before bats. There are many different hypotheses about how flight evolved in insects and it remains a contentious subject. However, once insects did evolve the ability to fly, they were able to take over an environment no other animal had laid claim on. And they soon dominated it.
Some Pepsis wasps, showing off their large orange-colored wings
 Once insects were able to fly, they were able to move across large areas very quickly in search of food, new habitats, and mates. If the water dried up in a pond, they could fly to another one. If the plant they were feeding on lost most of its nutrition, they could fly off to find a new plant. Until dinosaurs, birds and bats evolved, the only other predators insects had to worry about were other insects. Many insects got very large earlier in Earth's history, with some species related to dragonflies getting as large as 6 feet in diameter, wing-tip to wing tip (Meganeura)!
    So, with all of the benefits of flying and having wings, why would a grasshopper, like the ones in the family Romaleidae (Lubber grasshoppers) have evolved to have small, nearly non-functional wings?
Brachystola sp. Lubber grasshopper found at Black Mesa, Oklahoma
   Well, its because having wings can be "expensive" for the body. Being able to fly requires large amounts of muscle tissue to be able to bend, twist, and move the wings. Especially for insects, which have a hard exoskeleton they have to pull and push like plates. This requires a lot of protein, energy to fuel the muscles, and weight.
    In many cases where the cost to the insect's body to maintain the muscles and wings is higher than the cost without them for finding food, a mate, or escaping predators, some insects have evolved to put those resources and energy to other structures as part of a "trade off". For insects such as grasshoppers, which spend most of their time munching on plants as herbivores to extract the nutrients from the grasses and other plants (think of them as the cows of the insect world of sorts), it may be better to not have wings if you aren't going to use them. Especially since grasshoppers have another formidable way to get away and disperse...they can jump really well! If investing more in their legs to jump is better than the wings, then evolution will likely push the grasshoppers to bigger legs and smaller wings. Check out how big the hind legs are on the grasshopper above!
     So, while most insects still fly and fly very well, there are a few insects that took the route less traveled and are now sticking to the ground again. If you are looking for insects, don't forget to look down as well as up!

Friday, October 5, 2012

Creating a stink about Stink Bugs

This weekend I will be attending the annual Oklahoma Bioblitz, which is held every fall at a different location in the state to count as many species as possible in a 24hr period. This year's meeting is in Foss State Park in Oklahoma, which is in the Western-Central area of the state. My duties at this year's meeting will be the Invertebrate Team leader (which means I keep track of how many species we find), and the resident expert on Heteroptera (true bugs).
   One of the most common bugs I usually run into on Bioblitzes here in Oklahoma are stink bugs. Stink bugs are members of the family Pentatomidae, and have a very distinctive, shield-like shape and are intermediate to small in size. They also get the name "stink bug" because they have tiny little glands on the underside of their body that look like little slits that, when threatened, will secrete a peppery smelled chemical that some people think stinks.
Some pinned stink bugs from West Virginia showing their body shape.
Scent glands in stink bugs on the bottom of their body. Drawing from Jason M. Squitier, University of Florida and found at http://entnemdept.ufl.edu
Most stink bugs feed on the soft parts of plants, especially the fruits and seeds. In the wild you can usually find them near trees or other plants in small numbers. However, in agricultural settings you can get them in large numbers when they find a crop of plants they like to feed on. This is a serious problem for many farmers, especially for crops such as cotton and rice. The needle-like mouth of the bug causes tiny holes in the plants, which can scar them to the point they can't be used or sold.
     One particular stink bug has received a lot of attention: the brown marmorated stink bug. This stink bug was accidentally brought over from Asia, and has caused significant damage to trees and other crops on the East Coast. It also has the annoying habit of clustering together inside houses because in their native habitat they group together on cliffs and caves to stay warm and protected during the cold months. Unfortunately houses are perfect artificial "cliffs" here in the United States.

However, there are some that are actually useful for keeping pest insect levels down in some crops or other agriculture because they feed on other insects. These bugs are part of the group Asopinae, which are also unique because they are able to bend their needle-like mouth parts forward to stab their prey. They are especially effective against caterpillars or other insects that can damage plants.
  The reason I like to collect them, though, is because many stink bugs are really pretty. Many come in reds, blues, yellows, and a lot are various shades of greens and browns to match their plants. So, I hope to collect a few beautiful Oklahoma ones this weekend too and add them to our species list!
         Have a great weekend everyone!

Friday, September 28, 2012

Tarantulas!

When most people think of spiders, the first thing that usually comes to mind is the tarantula. Its big, its fluffy...its fierce. Because of its large size, it is one of the most commonly used spiders in movies, TV, or commercials. If you ever seen the movie Indiana Jones, you'll remember the scene in the opening of the film where Indy and his assistant get covered in tarantulas going for the Golden Idol. Or, if you've seen Arachnophobia, where they fall from the trees during a scene canopy fogging and are used profusely in the movie trailer.
  Tarantulas are even so well known that they have their own movie, made in 1955 and bears their name as title. For more information about this movie, check out the IMDB site here.
    All of these movies take advantage of a human's innate fear of spiders, which has been actually found to be partially genetically based. A study at the anxiety disorder clinic at Sydney University in Australia found that some fears, like fears of snakes or heights, might be genetically inherited to prevent us from harm. Super big spiders, like tarantulas, are some of the strongest triggers for this fear if you have it, and that is why they are used so frequently. They super-size the shock!
    However, not everyone has an inherent fear of tarantulas, and they are really not as fearsome as people would like to believe.  For their large size they are really fast runners, especially when they are running away from something scaring them. Their bite will not kill humans (unless you are allergic to them), and for most of the time they hang out hiding in their webs on the ground. Tarantulas can be found in lots of places across the world, but mostly in desert areas and the tropics. Because they also can be fairly attractive spiders, ranging from pink haired ones to blue, they can also be popular pets. They mostly feed on insects, though some larger spiders in the Old-World tropics have been recorded catching birds and other vertebrates!
     Here in Oklahoma, though, the native tarantulas are mostly brown. This past weekend I was in Black Mesa with the Mammalogy department and found this male tarantula crawling around looking for a female spider. In the fall many male spiders go out in a massive "migration" to look for females.
Male tarantula from Black Mesa. You can tell its a male because of the "fat" pair of structures that look like legs in front of its head area, called the pedipalps.
 Many tarantulas in the tropics are also brown too. This spider I found near a 2000m site in Costa Rica where I was helping to sample frogs.
Smaller, female tarantula from Costa Rica. Note the darker coloration of the "head" (cephalothorax) area
     While I don't suggest you pick up a wild tarantula to put on your hand for a photo like I did, its important to note that these spiders are actually pretty mellow and nothing really to fear! If you don't threaten them, they don't threaten you, and they are doing their own thing. If you were born without a fear of spiders, I encourage you to check these guys out because they are a really neat group of spiders.
      If you'd like more information about tarantulas, check out this nice fact sheet! Have a good one everyone!

Friday, September 21, 2012

Let's see if you can solve a riddle.

What can be as small as the head of a pin, or as large as a desk, lives in the sea (but also sometimes in fresh water!), has no brain, but can kill a human? 

Do you have a guess?

That's right, it's a jellyfish! Despite the potential danger of these invertebrates, jellyfish have an almost hypnotizing, soothing quality about them when they swim in a tank, and can be very beautiful as well. 

Jellyfish (phylum Cnidaria) come in many different colors and sizes. Most everyone knows that they live in the oceans, but there are also some freshwater specimens as well - even in Oklahoma!

The squishy-looking "jelly" part of the jellyfish is called the bell, and it is mostly made up of water. There is a thin layer of skin on top of the bell, which is where the nervous system is located. But since jellyfish have no brain, they also don't have a central nervous system. Their nervous system is called a "nerve net." Jellyfish also do not have eyes, but some have ocelli, which can detect light. You might remember ocelli from other entries - many insects have ocelli instead of eyes as well. 

Not all jellyfish stings are harmful to humans - in fact, many are so slight that we would never even if a sting occurred. Jellyfish sting by a type of stinging cells that they have on their tentacles, called nematocysts. These are used to kill fish or other small animals that are unfortunate enough to get entangled. Jellyfish do not actively hunt their prey - they simply eat whatever swims through and is stung in their tentacles. They have a "mouth" under the bell, and a simple or "incomplete" digestive system in that they expell wastes through that same hole. Many other invertebrates have this same sort of digestive system. 

Large jellyfish populations can be a sign that the habitat they're living in is in trouble. Too many jellyfish can be a sign of overfishing. They can take over the ecosystem they're in, essentially choking out other marine life. 

Jellyfish washed ashore in CT
Isn't that one beautiful? It almost looks like a flower. My sister spied this one and took its picture for me.

Happy Friday everyone!


Tuesday, September 11, 2012

COME TO THE LIGHT!!

A Bugs Life is one of the most popular digitally animated movies about insects. It was made in a while ago, in 1998, but still remains a classic despite the digital film advances since then because of its witty humor and detailed observations about insect life. One classic joke is when Flick the ant, the main character, arrives at the insect "city" and encounters other types of insects. His arrival at the city opens with two insects being drawn to a bug-zapper light, with one warning the other "don't look at the light!!" as his partner slowly swirls closer to it, exclaiming "I can't help it!!" as he get zapped.
Don't look! Image from http://www.kwaree.com/blog/wp-content/uploads/2007/05/bug-zapper.jpg
    The reason everyone laughs at this joke is because almost everyone knows that many insects are drawn to artificial lights at night. This is why bug-zappers work, and why you'll find a pile of dead insects under your porch light [or in your porch light, if its not sealed correctly!]. Its so ubiquitous in our culture, there even is an iPad app for bug zapping. Even before electricity insects were noted for being drawn to candle light. If you search on Google for "Poem, moth, candle" you get over 1 million references for poems about moths being drawn in a death waltz with a candle flame. So, why are insects drawn to the light that it makes it an effective trap?
     Many insect groups are drawn to light because of a property called phototaxis, which is an organisms to or away from light [photo=light, taxis=movement]. Many insects are actually negatively stimulated by light, and run to darkness. Cockroaches are a good example of this...turn on a light in a room full of them, and they go hide. Most other insects, however, are attracted to light, especially at night. This is because many groups of insects, especially flying insects such as Lepidoptera (moths) and Diptera (flies, mosquitoes) use the moon for navigation at night. Before electric lights and other artificial lights came about by humans in the last couple of centuries, moon light was the strongest light source available at night. By using the light to orient themselves, they could migrate, and find new habitats.
What the insects adapted to use to navigate, until we hijacked their system. Flynn, Texas
    The way the phototaxis works is one sensor on the bugs (often the eyes) gets the information from the light as wavelengths, and the insect then turns in the direction of the source of the light so both sensors or eyes get the same amount of light. This turning towards the direct of the light causes an insect that passes the bug zapper to pick up the light information, turn towards it, then slowly keep getting in closer. It keeps getting closer and closer with tighter circles around the light, until its zapped by the light's electrical current. Using just light, and not the zapping part, many entomologists can draw in insects to observe their behavior and collect specific ones that they need to study (this is called spot lighting, UV lighting, or using light sheets), and leave the other insects they are not interested in alone.
Fellow entomologists being creative by using a white garage door as a "light sheet"
      While bug zappers are effective at killing insects, its often effective at killing both "good" AND "bad" insects. Most people purchase bug zappers to kill mosquitoes, which are annoying due to their bites and dangerous because they can transmit diseases. However, bug zappers are effective at killing insects like moths which are good pollinators in some cases, beetles that are good predators of garden pests, and various other insects that happen to use the moon to navigate in their otherwise harmless lives.
    So, the lesson here? Before humans brought artificial lights, many insects used the moon at night to navigate. However, when we brought in much brighter light sources that are actually within reach of the insects in flight, we were able to take advantage of it for trapping them and studying them. Next time you see bright light at night swarming with insects, come to the light yourself and see what other six-legged friends are drawn to it. Have a good week!

Friday, August 31, 2012

Edible Invertebrates

    If you ask a person whether they like eating invertebrates, you'll almost always get a resounding "NO!". However, if you ask them if they like eating seafood, ninty-nine percent of the time you'll get the completely opposite response. "Of course!", "I love shrimp...and lobster, and crabs..", "Calamari rocks my world"...etc. But...they are the same question! Almost all seafood that people eat and love are in the invertebrates, but most people don't like to think of them that way.
Looks yummy, huh? Image from http://en.wikipedia.org/wiki/File:Plateau_van_zeevruchten.jpg
       Most seafood, which includes things like lobsters, oysters, crabs, shrimp, snails and other groups, comes from the sea. But there are freshwater invertebrates (crawfish, mussels) that are also included in the group. Overall, though, what most Americans consider "food" in the invertebrates category comes from the aquatic world where we normally don't really "see" them or interact with them. Oysters come from a "murky bay", or lobster "from the bottom of the ocean". We really don't know what they are doing or why. Just that they are tasty when we fish them out.
       Terrestrial invertebrates, on the other hand, we interact with on a more regular basis. We stomp on them on the sidewalk, we swat them when they land on our wall, we curse them when they eat our plants. We see what they are doing, and we know what they are eating. Our terrestrial ecosystem is the same one shared with them, and therefore we know more about them. And people don't really like to eat things that they know more about, especially when its one of the largest terrestrial arthropod groups, the insects.
      Insects share many of the same characteristics as their larger kin, the Crustacea, which is again one of the favorite types of seafood for people. They have a hard, jointed exoskeleton, and a muscular thorax (or head-thorax in crustacea, called a cephalothorax) and abdomen ("tail" in shrimp). Both groups share the same muscles, or "meat", but the biggest difference in edibility is how much meat there is relative to how much exoskeleton (how much work you have to do to get past the hard shells to get to the meat). Insects have a relatively high amount of shell to meat ratio, but they taste very similar to seafood. Yes, over the years I've eaten lots of different insects, and they can taste great!
       Because insects are so numerous compared to seafood invertebrates (whose populations are declining due to habitat loss, over fishing, etc.), there has been a push to change the way people see insects. Other countries and cultures have been eating insects for centuries, but it hasn't really taken off in America or European countries. Denmark has been on the fore-front of this issue, though, and several other European countries have been pushing for insects to be used instead of meat for protein sources. Even here in the United States, we have started to see some offerings of insect fares in popular culture!
Some wares found at the Pop store in OKC. Yes, I've had the Crick-ettes!
     Will Americans catch the love for terrestrial invertebrates the way we have with seafood? I'm not so sure, but I think we're headed in the right direction. Hopefully when I ask the next person whether they like eating invertebrates, soon it will be a big "YES!!".