Hi Carolyn,

You're talking about the "multi-colored Asian lady beetle," that is indeed related to our native lady beetles. We can't always explain why insects behave the way they do, but much of their behavior is related to weather.

To give you some background, these Asian lady beetles arrived to Minnesota some 10 years ago or more, and found the climate to their liking. Lady beetles are predators that feed on aphids, plant juice-sucking insects that can be very harmful to plants, including crop plants like soybeans. Some years back, the soybean aphid was also accidentally introduced to Minnesota from Asia, and has been causing severe damage to soybeans. As "luck" would have it, the Asian lady beetles discovered the soybean aphids, and have been helpful in lowering their numbers during the summer months.

When fall comes around, lady beetles, even our native ones, begin to search for places to shelter for the winter. The habit of the Asian lady beetle is to congregate in large numbers and look for rocky crevasses to crawl into. Finding no rocky crevasses in Minnesota, they use the next best thing - the cracks and crevasses around our homes.

Now, as to why we see fluxuations in Asian lady beetle populations, there could be several explanantions. A simple one is that the weather conditions haven't been optimal for their survival. It could be that as soybean aphid populations go down, the lady beetle populations follow it down as well, a typical pattern in predator/prey relationships. If this is the case, then be prepared for a year when numbers of aphids are high, and the lady beetles are on the increase again.

Forensically speaking, insects like lady beetles that may be knocked off of plants and collected into a body-bag with a corpse are not forensically important. When they show up in the insect evidence, we call them "accidental" species.

My background is in livestock entomology, so working with flies, maggots and muck never bothered me much. Almost twenty years ago while I was working in the University of Minnesota's Entomology Department livestock insects lab, I sat in on a forensic entomology symposium at a national conference and the light bulb came on. I knew of no one in Minnesota working in this field, so I approached the Hennepin and Ramsey County medical examiners to see if they would allow me to collect insect evidence to assist in estimating how long someone had been dead. They enthusiastically agreed.

At that time, there were no forensic entomology courses being offered anywhere, but there were a few people around the country conducting forensic entomology research in their own academic settings. Through hand's-on experience at crime scenes and in the morgue, reading forensic entomology literature and lots of long phone conversations with the practitioners, I developed a forensic entomology consulting business. Now I'm one of 15 board-certified forensic entomologists in the US and Canada.

That's my story and I'm stickin' to it.

Bryan,

Silence of the Lambs has got to be the earliest film reference to forensic entomology. I must say I resented the way entomologists were portrayed in that film, as two freaks playing chess with live beetles in a museum collection. Really, now. Who has time to play chess?

I don't watch CSI or other popular crime shows. I won't argue that they have vastly increased an interest in the forensic sciences; it's just that they are so far from what my experience has been in working with medical examiners and crime labs, and I can't seem to suspend disbelief.

FYI, I have a death's head moth in my collection...

Hi Emma,

Is that a trick question? Because only adult flies lay eggs, not "baby" flies, or maggots.

Blow flies (those in the family Calliphoridae) and certain other insects are attracted to decomposing animals (and sometimes humans), because that's where they meet mates and lay eggs. The eggs hatch into maggots, and maggots feed on the decaying flesh. We might think that their eating habits are disgusting, but flies are performing a very important function - recycling decomposing carrion (dead meat). Imagine what it would be like if flies weren't there to help decompose all the dead animals from road kills, natural deaths or predator kills. Not a pretty picture. Think of our friends the blow flies as natural recyclers in the circle of life.

Now get back to your homework, honey, and I'll see you after school.

Mom

Ah, but some wasps do eat meat! The wasps you've seen on carcasses are probably of the yellow jacket or paper wasp variety, who feed caterpillars (yes, a form of meat) to their larvae. The same wasps have been known to grab adult flies out of the air. In the fall especially, when the queen yellow jackets are storing up carbohydrates and protein for the winter, I have seen them take bites of hamburger or meat sandwich from people eating outside on a warm day.

Other insects may get moisture from a decomposing corpse. I've never seen moths around dead bodies, but butterflies are sometimes attracted to rotting fuit or animal feces. There's just no accounting for taste.

Well, Vicki, that is a really good question. Flies are very opportunistic and determined little creatures, and when they "smell" food (in this case, rotting hamburger), they do whatever it takes to get to it. I'm going to guess that there are openings, vents of some kind, in the back of the freezer, and the flies got in that way.

Once the eggs were laid on the hamburger, it would have taken very little effort for the larvae (maggots) to get into the package. Even if they were just on top of the package, there was probably enough moisture and juice leaking from the dissolving meat to keep them alive and growing.

I promise not to bring any crawly appetizers if you promise not to thaw the turkey outside.

Anon:

Like the cartoon icon Pogo said, "We have met the enemy, and he is us." By that I mean, what brought Asian lady beetles and lots and lots of other invasive species into the U.S. was world trade.

It's extremely easy - and common - for insects and other exotic pests to get to the U.S. on cargo ships in crating, packing, soil, food, etc. There will likely never be enough inspectors at all our international ports to make sure that everything that enters the U.S. (or leaves the exporting country) is clean and free of pests.

On the bright side, Asian lady beetles are terrific predators, and spend the summer feeding on aphids in soybean crops. It's just that they become pests when they try to find a protected spot to overwinter. The other bright side is that next year they may find someone else's house to be pests in.

Dan,

In a nutshell, it depends on several things, including temperature (hot or cold), location (humid or dry), exposure (indoors or outdoors, sun or shade), covering ( wrapped, clothed or naked), wounds on the body (more or less blood to attract flies) and insects present.

If the body is in a hot, humid, outdoor, sunny place, is nude, has multiple bleeding wounds, and insects have access to it, decomposition will happen much more quickly than if otherwise. In a nutshell.

Hi Kaitlyn,

When I was your age, I was really interested in insects, too, but I never dreamed I would become an entomologist! You are lucky to know what you want to do.

I did know that I wanted to do something where I could study plants or trees and took all the math classes that were offered in junior high and high school, and whatever was required for math in college. I ended up majoring in horticulture, the study of plants, and that lead me to entomology. Depending on which university or college you decide to attend, there will be certain science classes that are required, but as soon as you see an entomology class offered, take it! Once you have taken a course or two, you will know if that's the path for you.

Above all, pursue what you enjoy or have a passion for. You will be good at it!

There is no easy answer to your question, but it probably has to do with loss of habitat. More and more fields turn into housing developments, malls and other buildings, taking habitat away from many species of animals and birds, not just insects.

In recent years, though, I have seen more fireflies that I used to! That may be due to weather conditions that are more favorable to fireflies. I have also traveled to more rural areas lately, where there is still lots of firefly habitat left.