Writer: Edith A. Chenault, 979-845-2886, e-chenault1@tamu.edu
Contact: Dr. John Jackman, (979) 845-7027, j-jackman@tamu.edu
COLLEGE STATION — Ask most people and they’ll tell you spiders don’t make their top 10 list of favorite things. But according to one entomologist with the Texas Agricultural Extension Service, most Texas spiders are harmless and actually are helpful to homeowners.
“A lot of folks are afraid of spiders and they really shouldn’t be,” said Dr. John Jackman of College Station. “By and large, spiders are beneficial and they really don’t cause much problem at all. If anything, they do a lot of good in controlling insects.”
There are about 900 species of spiders in Texas and there is only a handful that are really dangerous to humans. Most of these are the widow and recluse spiders, Jackman said.
“A few people can react to any kind of bite, but most spiders aren’t going to be a problem at all,” he added.
To identify the good from the bad spiders, Jackman authored a book, A Field Guide to Spiders and Scorpions of Texas (Gulf Publishing Co.). The book is geared mainly toward the biology and identification of spiders and scorpions.
The Field Guide may help readers recognize species and learn more about how they live and their role in nature. The book covers 41 families of spiders, focusing on the spiders most often encountered, those with potentially hazardous venom, unusual spiders and those that are large and conspicuous.
It includes eight families of other arachnids, such as harvestmen, ticks, scorpions, whipscorpions, windscorpions and pseudoscorpions. Each family description includes what are called “quick recognition characters” to simplify identification.
There are 18 species of scorpions in Texas. There is only one species of spiders in East Texas — the striped scorpion — with the rest making their homes in western regions of the state.
“Texas has a good collection of scorpion species,” Jackman said.
The sting of Texas scorpions will hurt, but generally is not life- threatening. “If you go into Arizona, for example, there’s a couple there that are a little more dangerous. Down into Durango, Mexico, there’s quite a few deaths attributed to scorpions,” he said.
If someone is bitten by a spider, the book may be used to identify it and to get general information about the bite; however, it is not a medical guide. “If you have a bite that needs medical attention, you really need to get to a doctor, don’t look in the book for that,” he said.
Generally, spiders in the home are just part of the environment, he said, and benefits include their control of other insects and arthropods.
“The only ones you worry about are the recluse spiders and the widow spiders,” he said.
The widow spiders are slow-moving and are usually found hanging upside down in an irregular cobweb, usually underneath a table, eaves of a house or another sheltered area.
The recluse spiders are nocturnal hunting spiders and during the day like to hide in old rock and board piles, firewood, boxes stored in the garage, or even shoes that aren’t worn a lot. He suggested that everyone shake their shoes out before putting them on.
“They move around at night, so it’s a good idea to turn the lights on at night when you walk around and don’t walk around with bare feet,” he said.
Control recommendations for spiders include treating the outside of the home with an insecticide, paying particular attention to possible entry areas. Windows and doors should be sealed as well as possible with caulking and weather stripping. The inside of the home can be treated with aerosol insecticides found at the grocery store.
“When you spray with an insecticide, use it around the cracks and crevices and behind the furniture and places like that. It doesn’t do much good just to spray it up in the air and let the insecticide go everywhere. So try to aim it at the areas where the spiders might be hiding,” he said.
For serious scorpion problems, he recommended using a pest control operator.
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