Spiders

Let us kill what bugs you

Spiders

Spiders can be found nearly everywhere, indoors and out. Despite their creepy reputation, spiders are largely beneficial and help keep pests like flies and plant-feeding insects under control. With few exceptions, spiders rarely bite and are not generally dangerous to people. Spiders are arachnids and are more closely related to mites and scorpions than to insects.

Recluse spiders


(Left) Photo Credit:  Bart Drees, TAMU – (Right) Photo credit:  John Jackman, TAMU

Brown recluse spiders are potentially very dangerous.  They are usually light to dark brown, have no spines on their legs and are very un-interesting looking.  Adults usually have a dark, violin-shaped mark on the back. It’s one of the only ways a typical person can identify one.   Recluse spiders are most active at night but can occasionally be seen during the day. They actively hunt insects and other arthropods and do not use a web to trap their prey. As their name implies, recluse spiders are generally shy. They hide in cracks and crevices, which they line with silk. Their web is used mostly as a retreat where they place and protect eggs.  Outdoors, recluse spiders are found in stacked firewood, under stones, in rock ledges, under wood stored on the ground and under the bark on dead trees. Indoors they live in attics, crawl spaces, closets and living areas of the home. They prefer to hide in dry, narrow crevices, under insulation, and in wall voids. Females lay one to two egg masses per year in dark, sheltered areas. Brown recluse egg cases are about ⅝ inch in diameter, flat on the bottom, and convex on top. These spiders bite when they are trapped or pressed against the skin. They may bite if you accidentally roll over one in a bed or put on clothing that has a spider inside. Bites also occur when people clean garages and barns.  

Recluse spider venom breaks down skin and muscle tissue at the bite location. The initial bite may be painless and become mild to severely painful 2 to 8 hours later. The bite site may also itch, swell, and become tender. A blister usually forms about 24 hours after the bite and a slow-healing lesion form within 1 week. Reactions to recluse bites depend on a person’s age, health, and body chemistry and the amount of venom injected. In severe cases, surgery may be needed to clean the wound and minimize scarring. Diagnosis of a recluse spider bite can be difficult because Staphylococcus and other bacteria can cause similar lesions. If you think a brown recluse or other spider has bitten you, kill the spider and take it to the doctor for identification. If it is a recluse spider, the doctor can provide the required treatment.

Widow spiders

Photo Courtesy of The National Pest Management Association / Tom Myers

The southern black widow, and its relatives live throughout the United States. Other widow species found in Texas include the western black widow, the northern black widow and the brown widow. Coloration varies considerably among species. Adult female widow spiders are typically black. Males and juveniles may have orange, red and white markings on the back and sides. The abdomen is rounded, and the ventral region often has two reddish triangles that form an hourglass shape. Some of these spiders have irregular or spot like markings; others have no markings at all. Female adults average 1½ inches long; adult males are much smaller.  These spiders are usually found in protected areas outdoors or in structures that are open to the outdoors. They may live in wood piles, garages, cellars, shrubbery, crawl spaces, rain spouts, termite bait stations, gas and electric meters, and other rarely disturbed places. Black widow spiders build strong, sticky, irregular webs. They typically hang upside down in the web, revealing the hourglass markings. The egg sacs are rounded, about one-half inch long, and hang from the web. Females may make more than one egg sac. Newly hatched spiderlings usually stay near the egg sac for a few days before they disperse by ballooning. Widow spiders most often bite when they are threatened or pressed against the skin. People may be bitten when they accidentally disturb a spider or its web.

Widow spider toxin affects the nervous system. Initially, there may be a pinprick sensation that becomes red and swollen. The bite site usually turns pale in the center and it is surrounded by a tender redness. Within 1 to 3 hours, the person may experience moderate to intense pain throughout the body that could last from 2 to 3 days. Other symptoms include tremors, nausea, vomiting, leg cramps, abdominal pain, profuse perspiration, loss of muscle tone, and increased blood pressure.  Bites can be more dangerous for children, the elderly, and people with health problems. Few cases have been fatal. Seek medical care for a black widow bite; the patient should be taken to a hospital emergency room to receive the appropriate antivenom.
span style=”font-weight: 400;”>Female spiders are usually larger than the males. Most spiders have eight simple eyes, though some species have six, four, two or no eyes at all. The pattern and number of eyes is useful in identifying spiders.

Almost all spiders bite and use venom to paralyze their prey. After injecting the venom, the prey is often wrapped with silk to subdue it. Many spiders live solely on a liquid diet because the powerful digestive enzymes injected by the fangs dissolve their prey’s body tissues. Spider venoms are being studied for possible uses in medicine and pest control.

Only two types of spiders in Texas are considered medically significant: the brown recluse, Loxoceles spp., and widow spiders, Latrodectus spp.

Common spiders in Texas

Tarantulas:

Photo Credit:  Mike Merchant, TAMU.edu

Tarantulas are among the largest spiders in Texas. Despite their size and fearsome reputation, tarantulas are shy and are seldom seen. The common Texas brown tarantula (genus Aphonopelma) can have leg spans of more than 3 inches when fully grown. During the day tarantulas live in burrows or in natural cavities under rocks or logs. In the winter or the hottest months of summer, these burrows are plugged with soil. Tarantulas rarely go far from their burrow entrance; they wait for prey to come to them. Tarantulas can live 5 to 30 years. During mating season, male tarantulas leave the burrow in search for females and can be seen in yards or even by the hundreds along Texas highways. Females live in their burrows after maturity and do not participate in these seasonal migrations. Tarantula bites are not dangerous. When threatened, tarantulas rise up on their hind legs and wave their front legs to warn off predators. They also release abdominal hairs that can irritate skin, eyes or nasal passages of trespassers.

Jumping spiders:

Photo Credit:  spiderid.com

Jumping spiders, in the family Salticidae, are easy to distinguish from other spiders. Jumping spiders tend to be stocky and brightly colored. Some have conspicuous black and white bands on their bodies or legs. Common color patterns include browns, grays, black, brilliant red, yellow, and metallic or iridescent greens, blues, and coppers. Have you ever noticed that these little spiders always jump just when you are about to catch them?  That’s because jumping spiders have excellent vision – especially for hunting prey. They are territorial and hunt during the day. As their name implies, they are excellent jumpers. This behavior can startle observers, but like most spiders, jumping spiders are unlikely to bite unless cornered or handled.

Wolf Spiders:

 

 

 

 


Photo Credit – spiderid.com

Wolf spiders, in the family Lycosidae, are among the most common spiders in fields and backyards. They are hairy, and their drab color is mottled with brown, gray, black, yellow, or creamy white markings.  Wolf spiders often have two dark, longitudinal stripes on the cephalothorax. They range ½ to 3 inches long. Wolf spiders are most active after dark and have good night vision. Hundreds to thousands of wolf spiders may live in the average backyard lawn, where they feed on insects and small organisms. Although they may be a nuisance, they can control other pests. Wolf spiders commonly enter homes under gaps in doorways. Although some wolf spiders can be aggressive if handled improperly, they are generally not dangerous to people or pets.  Female wolf spiders sometimes carry around, silken egg case. They carry this case until the eggs hatch. The young climb onto their mother’s back and she carries the spiderlings with her until they are ready to hunt on their own. These spiders can get big and look scary – especially when it’s a mom with tiny babies all over her back.

Orbweaver Spiders:

These come in many shapes, colors, and sizes. Most orbweavers make a vertically hanging orb web with concentric rings of silk—a “typical” spider web.  Orb webs are marvels of architecture. The spider uses seven different types of silk to build the web; the rings eventually trap the flying prey. Many spiders tear down and rebuild their webs daily. Spiders that are active during the day do this work each morning. Some spiders eat the webs and recycle up to 90 percent of the material every day. Some of the larger orbweavers, known as Argiope spiders, weave a zipperlike seam of heavy silk into the web called a stabilimenta. The precise function of the stabilimenta is not known. One idea is that it serves as a warning to birds to avoid the web, reducing the need to rebuild as often. Stabilimenta also reflect UV light, which may make the web more attractive to flying insects. Unlike jumping and wolf spiders, orbweavers do not see well. Instead, they use the web to get information from the environment and to locate insects that are caught in the web. Prey is usually quickly subdued by wrapping it in silk so the web is not destroyed. Though orbweavers are harmless to people, their large webs can be a nuisance.

Photo Credit:  TAMU.edu

The black and yellow garden spider ( AKA – Banana Spider),  belongs to the orbweaver family and is common in Texas. The female’s body is more than 1 inch long and its legs are even longer.

Spinybacked orbweavers are distinctive spiders that are common in wooded areas.  These spiders have a flattened, spiny shape that makes them resemble crabs. Their abdomen colors include white, yellow, orange, or red.

Crab spiders:
Crab spiders, in the family Thomisidae, are common on leaves and flowers, and some species are found on the ground. These spiders are easily recognized by the crablike way they hold their two front pairs of legs and the way they scuttle sideways and backwards. These spiders do not spin a web, instead they ambush their insect prey. Some crab spider species can change color to match the flower on which they are perched.

Daddy Longlegs / Harvestmen

These are not spiders – though closely related.  Like spiders, harvestmen have eight legs that often are very long, though some have short legs. Many are brown to gray, but some have brighter coloration. Harvestmen do not have venom and cannot spin silk. They have a pair of glands that release a scent when they are disturbed. Some harvestmen are scavengers; others feed on small insects, fungi, or plant material. Harvestmen may congregate in groups of dozens to hundreds. When they do, it is not uncommon to see the harvestmen bob up and down when disturbed. This behavior may help to ward off predators.

Control:

The best way to control spiders is to prevent and eliminate them.  Because spiders often live on webs above treated surfaces, it is difficult to treat them with insecticides as you would crawling insects. Spiders also appear to tolerate conventional pesticides better than do common indoor insects. Therefore, sanitation and physical removal are the best way to manage most spiders.

Keep spiders outside by installing or repairing weather stripping around doors and windows. Seal and caulk around lighted doors and windows where insects and the spiders that feed on them gather.  

The best way to eliminate spiders is a good hand vacuum. Vacuums can remove the spiders, their webs, and their egg cases. Webs and spiders can also be removed with a broom, cotton dust mop or extendable web dusters. After sweeping up webs, take the mop or broom outdoors and wash or rub it in grass to remove and crush any live spiders or egg cases. A water hose or high-pressure sprayer can remove webbing from under roof eaves. Do not handle a spider unless you know that it is harmless.  Because spiders can be difficult to control, it is best to hire a professional. They have access to products and know how to effectively manage spiders.

First Aid for spider bites:

Treat spider bites by applying an ice pack to relieve local swelling and pain. If the reaction is severe, consult a doctor immediately and, if possible, take along the spider for positive identification. Specific antivenom is sometimes available to treat widow spider bites.

Fun Facts:

  • Spiders are found on every continent of the world except Antarctica.
  • Giant Huntsman spiders have leg-spans of around 12 inches.
  • Textiles can be made with their golden silk, including a shawl woven in 2004 and a cape in 2012.
  • Fishermen in the Indopacific Ocean make balls with spiders’ silk. After being tossed into the ocean, the balls unravel and form a net to catch fish.
  • The banana spider species is the oldest surviving spider genius.  Fossil remnants are 165 million years old.

How do we get rid of this bug?

The best way to avoid a spider infestation is to use our quarterly service plan as it includes the removal of all external spider webs and spray of a chemical the spiders dislike.  If you have a true infestation, we will need to pull out the big guns, which will involve some strong chemicals applied over a schedule. These bugs are difficult to kill so let’s avoid them!