NATURAL PERSPECTIVES:Learning about creepy, crawly critters

Last week, Vic invited Larry Shaw, the director of operations at Orange County Vector Control, to guest lecture in his natural history class at Irvine Valley College. Larry is into bugs in a big way. It’s not only his job to study mosquitoes and ants, but studying insects is his lifelong hobby as well.

Larry moved from collecting insects to photographing them many years ago. We got to look at lovely slides instead of icky dried bugs. I sat in on Vic’s class so that I could share Shaw’s wisdom with you.

The phylum Arthropoda includes crustaceans (like lobsters and crabs), arachnids (like scorpions, mites, ticks and spiders), and insects. Arthropods are invertebrates that have paired jointed legs and exoskeletons made of chiton. Their bodies are segmented, generally into a head, thorax and abdomen.

I don’t know about the others in the class, but this lecture gave me the willies. I was shocked to learn that there were 2-foot-long prehistoric scorpions and that there are three species of scorpions living today in Orange County. We have ticks ihere, too. Right now, they’re questing for some nice, warm-blooded animal to latch onto. They hang on to grass stems with their front legs, waving their back legs in search of a hiker, deer or dog. At the slightest touch, they grab on and then search for a tender spot to bite. Tick bites can transmit diseases such as Lyme disease, which is now established in Orange County.

Larry launched into spiders and my mind wandered onto something I had heard recently. Out of the top-10 fears, arachnophobia, or fear of spiders, is No. 1. About 50% of women and 10% of men have it. It beats out fear of being evaluated negatively in social situations such as public speaking (social phobia), fear of flying (aerophobia), fear of being unable to escape (agoraphobia), fear of confined spaces (claustrophobia) and fear of heights (acrophobia), which are the next five fears in the top 10.

We have many species of spiders in Orange County. Although most spiders are harmless to humans, some aren’t. There are probably black widow spiders in every yard in Huntington Beach. Orange County also has brown widow spiders. Although the brown recluse hasn’t been documented in the county, Larry said that it is probably here.

Larry talked mainly about insects, the most numerous group of arthropods. Indeed, there are more species of insects than there are of all species of plants and animals combined. That blew me away.

Scientists have identified only a fraction of the insect species that exist on earth. In an effort to determine insect species diversity in tropical rain forests, a team of researchers tented an area of jungle in South America, fogged the interior with insecticide and studied what fell to the ground. They found an amazing 3,000 species of insects during their study, with an average of more than 600 species per tree.

I became so fascinated with this aspect of the lecture that I later searched the Internet for more information. I found that the total number of insect species in the world has been estimated at 5 to 15 million by some groups of scientists, and at 30 to 50 million by other scientists. That means that there are still an incredible number of species that are still undiscovered. And at the rate at which species are going extinct with global climate change and rapid destruction of habitat, many species will undoubtedly go extinct before they have been discovered and described.

I’ve often bemoaned the lack of in-depth historical biological studies in the U.S. I wonder what was there before the invasion of European settlers and mass conversion of the hardwood forests of the Midwest and the tall grass prairies of the Great Plains to farmland during the 1800s.

The Palos Verde blue butterfly was thought to be extinct before a few individuals were discovered in Los Angeles County recently, but what about other insects that might have lived in the greater Los Angeles area before 13 million people spread over the land like locusts? And how many species remain, say in Orange County? No one knows, because in even as well-studied a place as Orange County, the total number of insect species hasn’t been determined. Amazing, isn’t it?

We learned interesting things about Orange County’s dragonflies, damselflies, grasshoppers, walking sticks (there are several species locally, but they’re small and inconspicuous), plant hoppers, kissing bugs (they carry chagas disease), bee flies, hover flies, robber flies, bot flies, ants, wasps, bees, and beetles. Larry impressed upon us the importance of controlling dangerous insects such as mosquitoes.

Larry closed his lecture with photos of a few of Orange County’s 78 species of beautiful butterflies. After all those poisonous and disease-carrying creepy-crawlies, it was a nice change of pace.