Dermestid Beetles… The Good and The Bad

This Post is Courtesy of Our IPM Manager here at the museum: Roxie Hites!

The Family Dermestidae consists of a group of beetles that thrive off of eating organic material with high protein content, such as feathers, and the skin and flesh of dead animals.  When it comes to the museum world, this family holds some of the most utilized and most feared insects in the world.

Many museum professionals, including myself, have a love-hate relationship with this family of beetles. In one regard, I dread members of this family.  There is no greater terror than having a research collection destroyed, and that is exactly what some members of this family can do. The Carpet Beetle is a 3mm long, beautifully painted, museum pest. The beetle’s larva eats organic matter, preferring keratin and protein packed substances. This means collections with any kind of animal material become extremely vulnerable to infestations.  For the Sam Noble Museum, this includes all of our life science collections (Mammalogy, Ornithology, Herpetology, Ichthyology, Recent Invertebrates) and even some of our social science collections (Ethnology and Archaeology).

Dermestid Larva and Adult

An example of a worst-case scenario comes from recent article about the South Australian Museum in Adelaide, South Australia, describing how carpet beetles are devouring their collections.  Which collection do you ask?  In a horrible irony – their insect collection! These tiny insects made their way into the museum and went wild. Described as “cannibals” by the museum’s Director Dr. Suzanne Miller, the Australian government is now having to allocate $2.7 million for securing the collection of nearly 2 million insect specimens that have been collected over the past 150 years. Considered by Dr. Miller as “the best insect collection in Australia”, this collection was residing in storage cases nearly 100 years old.  

Damage left to the South Australian Insect Collection

Museums have to be cautious with collections.  Specimens are one-of-a-kind, and oftentimes irreplaceable.  It is my job to make sure the Sam Noble Museum never encounters a problem like this.  We go to great measures to be proactive and ensure Oklahoma’s treasured collections are protected from these little “cannibals”.  Through our integrated pest management program (IPM), we implement methods that are designed as a primary line of defense against infestations from insects as well as rodents and other biological infestations.  IPM includes the use of good housekeeping, the use of sticky traps to regularly monitor insect activity, building inspections, and the occasional chemical treatment.

These critters are not all bad. Dermestid beetles, in their natural environment, have a real purpose and play an important role in the natural world. They are part of a group of organisms that break down organic matter, creating rich fertilizer for the soil. This allows for healthy plant growth, as well as preventing the build up of waste. They are the movers in the circle of life.

The museum world has caught on to this and has utilized one species in particular to do one of its dirtiest jobs – cleaning skeletons. Dermestis maculates, commonly known as the Hide Beetle, is regularly used in osteological preparation by taxidermist and natural history museums. The beetle’s larvae eat the muscle tissue off the bone, leaving a beautiful clean specimen behind. Some museums use other processes for cleaning skeletal material, but using hide beetles is less harmful to the bones than any chemical or heating treatment.

Dermestids cleaning skulls and other bones

These dermestid hide beetles  have even made their television début on the Discovery Channel’s  popular show Dirty Jobs. 

For such a tiny insect, this group of beetles sure have a made a big impact in the museum community.  Whether good or bad, they have also made a big impact in my world too.

Roxie

What are you going to call it???

   This week's post is going to be a short one, but a good one because we are going to talk about wacky species names. This topic has come up recently in the news because of a fly species being described as Scaptia (Plinthina) beyonceae which was named after the famous singer Beyoncé Knowles.

It got the name based on the golden rump (technically the end of the abdomen) that reminded the author, Bryan Lessard, of the singer's famous behind. The insect belongs to the family Tabanidae, which includes Horseflies and Deerflies (you can see the needle-like mouthparts sticking out).
     Is this the only species of insect that is named after a famous person? In fact, no! Another insect to make the news recently (but to a much lesser extent) is the beetle species Hydroscapha redfordi, named after the actor Robert Redford. This little beetle was found in Idaho, and named after Redford because "the entomologists also wanted to honor Redford for his efforts on behalf of the environment." according to the article by Helenair.com.

The tiny beetles were found eating green algae through sheets of water flowing over the rocks. The water where most of the beetles were found was 122 degrees Fahrenheit, according to the article. Very few animals can survive in such high-temperature waters!
   Most entomologists usually name species based on Latin or Greek-words for different aspects of the insects (use of the Latin and Greek is due to tradition). Most names are comprised of descriptions of what color it is (castaneous for brown, fasciatus for having a stripe, etc.), size (grandis-big, dimutatus-small), or other characters (punctate- with holes).  This is helpful for scientists because when someone says a name like Aitkenia grandis, you know that the name goes with a big insect.
   However, since most entomologists do not have a shortage of new species to describe, coming up with unique names can actually be difficult. Especially since to name a species, you have to make sure the name isn't already being used by something else. So, creativity can abound to make sure the name is unique, and it allows us some fun in describing new species. Its unlikely, though, that beyonceae is going to be used frequently!
     For more information about describing new species, check out this podcast and article by Krulwich Wonders of NPR: http://www.npr.org/templates/story/story.php?storyId=94886658
    Also, here is a story of Stephen Colbert demanding a spider to be named after him. Here is a video of his request:

Lastly, here is a case of my own fun with naming: Ausejanus tiramisu Menard and Schuh

Ausejanus tiramisu Menard and Schuh, named after the famous Italian cake due to the patterning of the wings looking like the layers of lady-fingers in the cake

 The Italian cake

Next week: Guest post from the SNOMNH Integrative Pest Manager!

Green-glowing cats and jellyfish

    If you have been following some of the popular science articles in the news over the last few months, you may have passed several articles talking about a new breed of cats that glow green in the dark. These cats have been genetically modified to resist a very insidious disease in cats: Feline Immunodeficiency Virus [FIV]. Genetically modified means that genes were not originally part of the cat's original genetic makeup (genome) were added to the cat's DNA.

Glow in the Dark cats. Image from http://news.sciencemag.org/sciencenow/2011/09/glowing-kittens-fight-feline-aid.html

So why make the cats glow in the dark? What does that have to do with fighting FIV disease? And where does the jellyfish Aequorea victoria fit in?
    First, lets start with the jellyfish (logical start, right?). In the 1960s and 1970's a Japanese organic chemist named Osamu Shimomura was investigating what made certain invertebrates glow under different wavelengths of light, or different chemicals. There are several groups of invertebrates that naturally glow in addition to jellyfish, like corals (below).

Example of glowing coral. Images of other corals from the same site can be found here

Dr. Shimomura decided to investigate how the jellyfish species Aequorea victoria would spontaneously produce its green glow. He took over 1 million individuals from his field site in Washington State to do so! Through his research of the jellyfish he discovered that there were two proteins involved, one called aequorin that produced a blue glow, and another called Green Fluorescent Protien (GFP), which would glow green when it was mixed with calcium.

Aequorea victoria

It wasn't until the early 1990's that the jellyfish was investigated at the level of its DNA to see how exactly it produced the protein. It was in 1992 that the gene wtGFP (which transcribes the protein) was discovered by a collaboration of Dr. Martin Chalfie and Dr. Roger Tsien. Initially the importance of this discovery was not realized (so a jellyfish glows? so what?). Yet in 2008, the latter two scientists and Dr. Shimomura were awarded Nobel Prizes for their discovery. So, why was it so important that we discovered this glowing protein from jellyfish and have its DNA sequence?
   This is where the virus part comes in, and genetic modification. As science has progressed to understand how our DNA produces different results in our bodies (brown hair versus blond hair, type A blood versus type B blood, etc.), we also have found ways to alter DNA to hopefully either get rid of things we don't like (cancer), fix things that aren't working (cystic fibrosis, which is due to mutation in DNA and some proteins not working correctly), or enhance things we want (insect resistance in corn, etc.). In the case of the cats, DNA was added to try to stop the virus of Feline Aids from replicating in their cells.
     Adding outside (or foreign) DNA to cells is a very tricky and tedious process. Most of the time it doesn't work for various reasons. Or, if it works, then only on parts of an organism and not the whole body. This is where they glowing protein plays a part. The gene wtGFP is also added to the DNA being inserted, and when the body starts to use the foreign DNA, the GFP protein is also made. The activation of both pieces of DNA cause those cells to glow, and indicate the reaction worked and where. This is why the Green Florescent Protein is often called a "marker" protein, because it "marks" where the transfer occurred successfully.

 Video summary of article on glowing cats (weird music, but still interesting)

 

Example of cats that glow red from another protein

    So that is why the cats in the article glow green. Because the genes that help prevent the Feline Immunodeficiency Virus were successfully transferred to the cells of the cat, the wtGFP gene linked to those genes also started to produce the glowing jellyfish protein too.
     It was the ability to be used as a marker that led to a Nobel Prize the jellyfish protein's discovery. The big question now is, what else can we discover from invertebrates that help shape our world in such new and exciting ways?

Water scorpions!

Welcome back from the holidays, and Happy New Year! As we get further on into winter (well, assuming these unusual 60-70 degree highs that central Oklahoma has been having don’t last!), it’s only natural that our thoughts turn to summer activities such as swimming, or, say, collecting aquatic insects.

My first experience with collecting aquatic insects was during a summer class at a central Oklahoma university. I enrolled in an Aquatic Entomology class, taught by my favorite professor, and proceeded to go on several collection field trips. During one of these trips, I caught a curious-looking creature in my net that at first glance appeared to be a blade of dead grass. In fact, I very nearly plucked it out of my net and flung it back in the water. But upon more careful examination, I saw that it was actually an insect that looked like this:

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

When we returned to the lab after our trip, I was excited to figure out the classification of the insect. It turned out that it was a water scorpion, in the genus Ranatra, from the family Nepidae, and in the order Hemiptera. Despite the name, this insect won’t hurt you – it only resembles a scorpion and does not have a stinger. The water scorpion has front legs that are raptorial, or folded in a praying-mantis sort of way. It also has two tubes that form a siphon on the end of the abdomen. When the water scorpion is in the water, the tubes curl up towards the water surface, taking in air to breathe. It’s as though the insect “snorkels” from its abdomen.

http://en.wikipedia.org/wiki/Nepidae

The water scorpion that I found was barely an inch long, so it can only hold tiny invertebrates in its front legs to eat. Sometimes the larger ones will eat tadpoles and very small fish as well, but they’re not terribly intimidating to us. However, if you were around the shores of the U.K. about 330 million years ago, you would probably beg to differ. According to an article in the National Geographic News, the tracks of a 5-foot giant water scorpion were found in the Scotland area in 2005.

If you’d like to read more about this enormous water scorpion, here is a link to the article:

http://news.nationalgeographic.com/news/2005/11/1130_051130_giant_scorpion.html