Category Archives: Coleoptera
Dermestid beetles (family Dermestidae) can either be a useful ally or a nuisance, depending on your point of view. There are several hundred species worldwide, and many have found ways to either enrich or aggravate our lives.
If you are interested in taxidermy or specimen preparation, these industrious beetles are one of the best ways to de-flesh and clean skeletons. Entire colonies are kept by hobbyists, universities and museum collections and put to use, both adults and larvae feasting on an array of carcasses. They especially enjoy hair, skin, and feathers.
Due to their knack for feeding on dead or decaying materials, they are essential outdoor decomposers. Some species prefer plants, some prefer animals, and some get rather esoteric in their choices (like specializing on praying mantis egg cases). Our knowledge of these ecosystem services also allows us to use them in forensic investigations.
But most people don’t think of these applications. They are more concerned with the “larder beetles” in their pantry, pouring out along with the cheerios into their cereal bowl. Or “carpet beetles” munching on wool coats, or silk scarves, and other natural fibers in their closet. Any open window is an invitation for a visit.
And if you’re an entomologist, the phrase “dermestid beetle” should strike fear into your heart. All the qualities that make these beetles desirable for cleaning vertebrate skeletons makes them especially destructive if let loose in an insect specimen collection. These beetles don’t just like the taste of skin and fur, they have quite a fondness for insect chitin and dried innards.
Every entomologist I know has horror stories of dermestid beetles infesting their collection. The main specimen collections here at UConn are chemical-free, meaning they have strict quarantine procedures in order to thwart these beetles and other pests. Specimen boxes must be frozen twice, if they’re allowed inside at all.
I was cleaning out a storage room for the entomology teaching lab, and came across a set of student specimen boxes. That had been overlooked since 1994. Needless to say, dermestid beetles had a feast. The boxes were absolutely filled with insect bits and old dermestid skins. Just about all of the specimens are ruined, and will be thrown away.
So, what should you do? In your home, make sure all food containers are tightly sealed and secured (anything that comes in a bag, I transfer to a jar). Store winter sweaters and other important clothes in sealed containers or plastic bags. Ensure all household screens are tightly fitting with no gaps.
For an insect collection, you can choose to use chemicals like mothballs, but they wear off after a while (I have personally observed collections with chemicals tacked into one corner… still filled with dermestid damage. See the first image above.) Your best bet is to keep the collection sealed in a tight wooden box or glass topped drawer. Cardboard boxes, such as we give students, should be temporary. When in doubt, if a collection will not be regularly used, keep the box(es) in a sealed plastic bag of some sort. Also keep workroom/lab windows closed, or ensure screens are tightly fitting. My advisor likes to say “dermestids smell insect specimens the way you smell Starbucks!” Which may or may not be true. Probably true.
Last week I went black-lighting with a few lab-partners-in-crime. I didn’t get many Acronicta (seems to be a theme this summer) but we had fun exploring the woods at night.
One thing we pondered… what’s with all the cockroaches in the trees? Here is a youngster.
This adult was calmly grooming her legs and antennae.
There seemed to be a cockroach on every stump (a lot of beaver damage in the forest) and one or two per tree trunk. I think they are beautiful little animals (as long as they are not in my kitchen), so it was quite fun! Just… unexpected.
Here are some other things we saw…
A cool caterpillar nibbling on lichen.
A geometrid caterpillar trying really hard to be a twig.
There were many beautiful leopard slugs in the trees as well. I would love to catch some mating one day! That scene from Life in the Undergrowth is one of my favorites of all time. Check it out HERE. Your life will never be the same.
Many of the june beetles were mating. I think they look sort of like little turtles.
Overall, we had a fun night! Though, while drinking from lab vials, I realized I am allergic to gin. Afterwards I learned that it runs in my family. Oops! My throat got really sore and started to close up, but I recovered.
There is a big field of milkweed plants near my new apartment.
I went for a walk to investigate the field, and saw that the milkweed beetles (Tetraopes tetrophthalmus) are in abundance. I saw many males mate guarding – holding onto females before or after copulation, I’m not sure which in their case. It can be tough for a female to find another mate when the first guy is still hanging on.
These beetles are interesting for a variety of reasons:
Their antennae bisect their eyes, making it look like they have two eyes on each side.
The beetles will stridulate (made a squeaky scraping sound) when they are handled.
Since they eat milkweed plants, they become distasteful to predators. Their red and black aposematic coloration serves as a warning.
I learned today that milkweed plants are also a popular spot for night pollinating moths, including sphingids (the hawk moths). It has been recommended that I spend some time outside by the milkweed at night to observe moths as they are pollinating. I will probably grab a lawn chair, a glass of wine, and a headlamp and do that the next night it’s not raining.
Had my first night of black-lighting with the mercury vapor light – pretty decent turn out. I got six species of Acronictines, but they were all males. I’m really hoping for some females in order to get eggs!
My friend and I also encountered some other interesting creatures. That is bound to happen when you set up a light and sheet at night.
Here is the set up: The base is a projector screen (looks to be about 1970s, cost $5 at a garage sale), covered by a sheet. We hung the mercury vapor light from a branch to hold it away from the sheet (my advisor has many sheets with holes burned into them).
Some of the earliest visitors were the luna moths (Actias luna). These were both males – I could tell based on the antennae, and small size of their abdomens.
This giant water bug (Lethocerus americanus) sounded like a small helicopter coming toward the sheet – and then it hit me on the back of the head! It was a feisty one.
The water bug made a friend at the sheet – an equally as large hydrophilid, a water beetle. Luckily hydrophilids are scavengers, so they do not have the same terrifying beak as the water bug. They are so smooth you can hardly pick them up.
A very pretty moth – the hog sphinx, (Darapsa myron).
I am excited for future black-lighting endeavors this summer.
Just for fun! Perhaps not frivolous, but I wanted some alliteration… well, frivolous in the fact that I’m a sucker for side projects that do not relate to my dissertation research.
I am collaborating with a very enthusiastic alumni of our department, who is still quite keen on collecting, observing, and learning about insects. His name is Stan and he has his own website where he uploads photos and commentary about wildlife found along the Airline Trail here in CT. I like mornings, but it takes a special sort of morning person to be out there photographing bugs and birds every day throughout the year. You can check out his website here! He also joins our weekly lab meetings and always has fun things for show-and-tell.
During his travels Stan has come across these awesome beetles, called forked fungus beetles (Bolitotherus cornutus). They are unusual, slow moving beetles which live and feed inside large mushrooms. They have some really interesting life history traits and behaviors, such as the fuzzy horns of the males, and their defensive secretions. You can learn much more about forked fungus beetles and see lots of photos on this page of Stan’s website.
Most interesting (isn’t sex always the most interesting?) are their courtship behaviors. The males appear to create a stridulatory sound by rubbing the tip of their abdomen against the top of the female’s prothorax. You can see this behavior in the following video (taken by researchers in Virginia).
So far, it appears that the actual mechanisms behind how this sound is generated, or even reasons why the males do this as part of their hours-long courtship rituals, are unknown. Since Stan had captured several fungus beetles, and I had some extra allotted SEM time for this semester, I thought it would be fun to get some beetles under the scope to see if we could get good images of the structures on the male’s abdomen and female’s prothorax – the contact points for the scraping sound.
And that is what we did! After cleaning (the beetles were covered in mites and dirt and fungus) drying, mounting, and sputtercoating we were ready to examine them. I don’t want to give anything away, but we came across some small structures that had gone unnoticed under a dissecting scope, which could potentially be involved in this strange behavior. Stan got to watch as I used the scope. As you can tell, this machine is a few years old. But it works!
And here are the fuzzy horns of the male, just because they are kind of nuts.
Our next goal is to set something up to capture our own video and sound recordings of fungus beetle courtship. No matter what it will be fun to continue working with these funny looking beetles.
My interests have always converged on the art-and-science combination (as opposed to the math-and-science relationship you always hear about). I have always enjoyed drawing nature, mostly with pencils and markers. Paint is fickle and difficult to tame (especially watercolor), colored pencils are too delicate… for someone who likes bright, bold, in-your-face colors, markers are the way to go. Besides, when you are illustrating insects, those fanciful colors tend to be more accurate (of course, this is all personal preference, other people with more skill are able to master those techniques!).
One of my marker drawings, a scarab beetle. For sale in my shop!
Over the years I have collected hundreds of sharpies, and got myself a nice set of prismacolor markers. I have sold my work at art shows and in my online shop, and have designed a few t-shirts. But aside from a plethora of high school art classes (and some private lessons when I was in 3rd and 4th grade), I have not had any training. All through undergrad I wished I could take a scientific illustration class, but none were available. McGill didn’t even have regular fine-arts, and I didn’t have time to commute to another university. UConn does not have any scientific illustration classes either, but we do have a full time biological illustrator here in my building. I finally got to meet her, and we clicked right away!
I am currently signed up for a few credits worth of scientific illustration independent study for next semester. I’m incredibly excited!!! Learning techniques from an expert, and working toward better images for my thesis.
Here are some practice sketches for a species I am helping describe. I can’t use these because I had touched the paper beforehand, meaning the markers didn’t adhere to where my oily fingers touched. Did not realize it had screwed it all up until I was done. Oh well… more practice!
It’s sort of like how human couples hold hands. Except tiger beetles hold on with their jaws.
Cicindela sedecimpunctata – Western Red-bellied Tiger Beetle.
This post doesn’t need much of an explanation (except that I’d check it out before deciding to let young wandering eyes over here – insect mating photos but no snarky commentary…)
Went on a collecting trip to Killingly, CT – set up blacklights and a mercury vapor light. We were aiming to collect moths (I got a handful of Acronicta species), but we attracted plenty of other visitors to the lights. Here are some of the insects that were… rather… busy…
Enjoy! (but not too much…) Read the rest of this entry
(this post describes events which happened on June 1st)
And now for some cool insects that aren’t caterpillars!
These are still lepidopterans, though… I mean hymenopterans… I mean… well… what do you think they look like?
Here are some reasons why these are moths (in the family Sesiidae), and not wasps (please pardon the fact that they are copulating). This is just my personal run-down, I’m sure there are more exact ways of defining the differences. But if you are in the field and just get to glance at a wasp-like insect, these are some things to look for.
Heck, it took me a few minutes to realize they were not wasps or sawflies. Luckily they were so busy (hehe!) they did not care that I was photographing them.
Now how about a big pretty beetle. Everyone likes beetles, right? Especially when they’re shiny. And adorable.
I think this guy is Strategus antaeus, please alert me if I am incorrect. They are big and LOUD. One of the undergrads thought he heard a toad rustling in some leaves on the ground… he pounced only to find this beetle! We ended up finding one more on the trip. Like most scarab beetles they are bulky, clumsy, and have sharp claws.
And here is a pretty little membracid I got my hands on. I am tentatively identifying it as Smilia camelus (I put up a photo on bugguide.net, it’s been moved to that species page but is awaiting confirmation by an expert). I don’t know much else about the species, can’t find very much online. If anyone has any insights about this beautiful creature, please share!