Arachnids: The Recluse Spiders

Insects are everywhere. I try not to dwell on the idea that insects are crawling on everything all the time, but entomologists seem to love the fact that there are of multitudes of insects everywhere we go. That's probably why I'm not a entomologist. Still, insects are a vital part of life, and I am interested in learning more about them.

Mediterranean recluse. Photo by Antonio Serrano

This past week I attended The New York Entomological Society’s meeting on arachnids. Biologist James Beck came up from Louisiana to The American Museum of Natural History in NYC to talk about a specific genus of arachnids the Loxosceles, commonly known as recluse spiders. James Beck studies the ranges of two species of recluse, the native brown recluse (Loxosceles reclusa) and the invasive Mediterranean recluse (Loxosceles rufescens).

Recluses aren’t rare, but the public knows very little about these spiders except the fact that they are venomous. At the lecture I learned that people, even doctors treating spider bites, tend to think every spider that isn’t a widow is a recluse. James Beck told us that misidentification of recluses went so far in a nationwide survey conducted in 2005 that people asked to send in specimens of brown recluse didn’t send in a single one. The public did send many other spider species, and even a scorpion, but no brown recluses.

I’ll admit that I would probably not be able to tell the difference between a brown recluse and a Mediterranean recluse if I saw either one. I don’t think I would mistake a scorpion for a spider like someone in the study did, but identifying Loxosceles is not an easy feat, as James Beck explained. Brown recluse and Mediterranean recluse can be distinguished by their tibial segments (a part of the leg) and mouthparts, both of which require magnification to see. Different recluse species don’t like to live side by side, so if a Mediterranean recluse is identified, there shouldn’t be any brown recluse around.

Knowing the difference between the two types of recluse might be tricky, but identifying the general genus Loxosceles isn’t as hard. Loxosceles are terrestrial spiders that like to live in places like crowded sheds and basements.

Brown Recluse Photo by Rosa Pineda

Don’t worry about finding a recluse if you don’t want to. They are named “recluse” for a reason, and Loxosceles are timid spiders. They rarely bite unless provoked and aren’t at all interested in harming humans. Spiders get a bad rap for being venomous and aggressive, but in reality they are helpful creatures that kill pests like cockroaches. To avoid being bitten, if you see a spider on you, don’t smack it, gently put it down. Try to bring out that bug loving entomologist we all have within us and both you and the spider will come out happier.

 photo of a live brown recluse from the lecture

Enthusiasm is Catching, Entomology Edition

This past week I went to a meeting of the New York Entomological Society at the American Museum of Natural History.

Before the lecture I was actually reading a book about entomology, which I posted about a few weeks ago, and I just read that beetles and caterpillars will drop out of the trees if they sense a predator approaching. Right after reading that, I stepped out of my apartment on the way to the entomology lecture, and I saw a caterpillar on the city sidewalk, vigorously crawling back to it's tree home. The caterpillar was probably using the escape method I just real about. What timing! It's not every day that I read about a concept, go outside and see it demonstrated for me. Since the caterpillar was in danger of being stepped on, I rescued it and put it back on the tree.

Rescuing the caterpillar.

The entomology event was fun, and the talk was easy to follow for a lay-person like me. Louis Sorkin, who I've also mentioned before in another post, started off the evening by talking about insects as food. He is very enthusiastic about people eating bugs, despite the fact that he himself is allergic to mealworms.

The caterpillar happily crawling up the tree.

Next on the evening's agenda, Richard Falco, Ph.D. talked to us about tick and mosquito activity in the NY area for this summer. He told us not to believe any of his predictions, but there should be medium-high tick activity and medium-low mosquito activity this year. Now we'll have to see if his predictions come true!

Multitude of Insects

Butterfly Room at AMNH

Insects are everywhere. Over 900,000 currently known species live with and around us, and most of the time we barely even notice them. Tiny mites cover our skin, house pests inhabit our homes, and millions of insects make the great outdoors their home. Yet, most of us still don't even acknowledge these bugs. It's like they are part of a whole alternate universe.

I'm not a huge fan of insects, but they don't petrify me either. I simply just don't think about them much. After meeting Louis Sorkin in my Tree of Life class at the American Museum of Natural History, and reading How Not to Be Eaten: The Insects Fight Back by Gilbert Waldbauer, I became more interested in creepy-crawlies. Here's some cool stuff I recently learned about them.

• Insects are the most widely available source of animal food on the planet and most animals, other insects, and even some humans will readily eat them. Insects have developed countless ways to evade predators and predators have developed countless ways to catch and eat bug
• Flying insects are another great food source for birds and bats. Swallows and swifts fly at different heights in the air divided by species to avoid competing for food. Kingfishers aren't into cooperation, they viciously fight off any possible competition in their territory.
• Have you ever wondered how cockroaches manage to scurry away so quickly? Well, cockroaches and other insects like them have light and touch sensors on their tail end so they are aware of approaching predators or angry humans at all angles. They know we're there before we know they're there.
• Burrowing owls place dung around the entrances to their burrows to attract their favorite snack, dung beetles. Some researchers once removed the dung, and the owls became agitated and began to bob up and down in distress.

Not only are insects fascinating, the people who study them get to do some interesting stuff at their jobs like help the police investigate homicides. Louis Sorkin told my class that entomologists can look at the insects found in a corpse and tell how long the body has been expired, based on how developed the insects are, and whether or not the body was moved, based on what type of insects are in the corpse and what area they are native to. Aren't bugs amazing?

Butterfly Room at AMNH

As I continue to read How Not to Be Eaten: The Insects Fight Back I'm excited to learn more about insects. I have to say bugs are a little less creepy when you learn about them, but I'll still jump and shudder every time I find a cockroach in the kitchen.