Spiders: the good, the bad and the ugly

Good bugs and bad bugs, good spiders and bad spiders. It all depends on your point of view.

Tomato plants probably don't like hookworms or aphids. Humans don't like spiders that bite, but should love the rest of the arachnids that eat insects, who probably don't like spiders.

It's gardening time, as anyone at a garden store can tell you because of the long lines at checkout counters. Even editors have been seen in line, baffled of course.

And since newspaper writers are know-it-alls, we are happy to share our cribbed knowledge. It helps if you have someone like state entomologist Jeff Knight of the Nevada Department of Agriculture to lean on.

So what are some good insects for Carson Country gardens?

"Well, first you have lady bird beetles," Knight says. "They're commonly called ladybugs -- you know, red with black spots. They gobble up bad bugs."

Good idea to hustle off and buy 500 or so from the local garden shop?

"Not unless you want to help some other gardener. They fly off to someplace else when you let them out of the jug."

But not to panic: Buy eggs, and they'll stay put.

"However, most gardens will naturally attract ladybugs." And other good bugs -- as well as some bad 'uns.

"Now the lacewing is OK, and some people like praying mantises, not that they are whole lot of good. And there are the parasitic wasps. They lay eggs in aphids."

That's good?

"You bet. Aphids are bad bugs. Get at roses and plants like hookworms that go after tomato plants. Big, long, green things. Pick 'em off and step on them. Hookworms, that is.

"And squash bugs, they get on squash plants and do damage. Again, pick them off and squash them.

"Then there's the cabbage looper, the larva of a moth. Goes after cold-crop vegetables. And the corn ear worm. You see them on the ends of ears of corn. No big deal, just cut the inch or so off and cook the ear."

More bad news?

"How about leaf miners? They feed on leaves of vegetable crops, naturally, on Swiss chard, spinach. Pick 'em off."

Pesticides got a bad name from Rachel Carson years ago. Now?

"I stay away from pesticides in my garden. A good mix of flowers and vegetables will help with bugs. I figure that if I'm going to have to use a pesticide for some vegetable, I just won't plant it. You start to spray pesticides, and you upset the whole balance of things. We're pretty lucky here in Nevada. We can have great gardens without pesticides."

Mosquitoes?

"Sure, we got them. You know what to do about them -- eliminate breeding places. West Nile virus hasn't hit Nevada yet, but it probably will down south this year. Dead birds are a clue that it's here."

If you have a mosquito problem, Knight suggests calling the mosquito district to spray before trying to do it yourself.

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If you're not an entomologist, you probably don't love spiders, but you should. Most of them chow down on insects all the time. But arachnids like black widows give all spiders a bad name, as the Internet advises.

Spiders have a look which is easily recognized by most people. They have eight legs, which immediately separates them from insects, which only have six legs. Spiders lack wings and antennae.

Young spiders or spiderlings resemble the adults except for size and sometimes coloration. All spiders have a pair of jaw-like fangs. Each fang has a small opening in the end in which venom is injected into its prey. Spinnerets at the end of the abdomen are silk-spinning glands used for web making.

Certain common U.S. household spiders spin webs over lamps, in corners and in basements.

Although all spiders use venom to kill prey, the black widow and the brown recluse spiders are the only spiders in North America that are consistently dangerous to humans.

The hobo spider is also dangerous and often mistaken for the brown recluse. Even though there is little danger of complications from most spider bites, victims should take the spider with them to the doctor.

Under most conditions outdoors, spiders are considered beneficial because they eat insects. However, they are undesirable when indoors, and their unsightly webs usually make us less likely to love them.

The black widow's web is an irregular mass of fibers with a small central area where the spider waits until its prey becomes trapped. Webs are usually found outside behind shrubs, along foundations, under boards, stones and especially where wood siding or brick extends close to the ground. Black widows usually do not enter homes.

The black widow's venom contains a neurotoxin that affects the nervous system. The severity of a person's reaction depends on the area where the bite occurs, the person's size and general sensitivity, the amount of venom injected, depth of bite, seasonal changes in venom potency and temperature.

The bite produces a sharp pain similar to a needle puncture which usually disappears rapidly. Local muscular cramps may be felt from 15 minutes to several hours after the bite, spreading and becoming more severe. Respiration becomes spastic. A feeble pulse, cold skin, labored breathing and speech, light stupor and delirium may be noted. Convulsions and death may occur. An antivenin for the black widow is available from most physicians.

The brown recluse is a soft-bodied and secretive spider. The adult is 1/3-inch to 1/2 -inch long with the arrangement of the legs producing an overall size of 1-inch in diameter or greater. The body is yellow to dark brown and has a distinctive, darker brown, violin-shaped mark on the top of its head.

The brown recluse can also inflict a very dangerous bite. The initial pain of a brown recluse's bite is not intense and generally less troublesome than a bee sting. Within eight to 12 hours, the pain becomes quite intense, and over a period of a few days, a large ulcerous sore forms. This sore heals very slowly and often leaves a large, disfiguring scar.

The brown recluse is usually found in bathrooms, bedrooms, closets, garages, basements, cellars and attic areas. They may also be found in outside buildings. Their web is best described as an off-white to gray, nondescript webbing. Gardeners should wear gloves and be especially alert when handling leaves or bark mulch.

The hobo spider is also known as the aggressive house spider. Both names are derived from characteristics and perceived personalities exhibited by the spider -- it seems to be more aggressive, and it travels a lot.

Awareness of the potential danger of these spiders has been widely unknown because people haven't heard of the hobo spider, and the brown recluse is falsely accused.

There have been numerous reports of bites in the Northwest, and the brown recluse was blamed, even though it chiefly lives in the mid-South to Southeast.

Typically, when hobo venom is injected, the victim will experience an immediate redness around the bite site that begins to disappear within a few hours. Very often, for the first 24 hours, the bite appears to be no worse than that of a mosquito; then it begins to blister in the center. Within 24 to 36 hours, the blister breaks open, leaving an open, oozing ulceration. This ulceration scabs over within three weeks, leaving a permanent scar. If the bite is delivered in fatty tissue, the lesion may not heal for two to three years.

Reactions include severe headaches, nausea, vomiting and flu-like symptoms. In extreme cases, skin graft, amputation and bone marrow failure may occur.

Hobo spiders make non-sticky webs shaped like a funnel. They have a series of V shapes on their backs, and their legs do not have rings at the joints. The middle of their underside is a gradient of brown to a light brown or tan.

The hobo spider lives primarily under rocks, wood, plants, and other objects in yards and gardens.

Dealing with spiders indoors with liquid sprays such as Demon WP or Flee. Spiders must be killed by spraying directly on contact. Residual sprays are ineffective since spiders do not absorb chemicals through their feet or legs.

Vacuum and remove webs and egg sacs helps. Remove clutter and take other sanitation steps to remove conditions favoring spiders and insects.

Keeping all of that mind, remember most spiders help keep insects under control. Meanwhile, I think I'll just hibernate until it's ski season again.