Scorpions are close relatives of spiders having broad, flat bodies with eight legs. Adults are 2 to 4 inches long and readily identified by their two pincer-like pedipalps at the front of their bodies and the five-segmented stinger-tipped tail at the back. Depending on the species, scorpions range in color from the mustard yellow of the deadly sculptured scorpion to the black of the black scorpion; typically they are mottled to a striped brown tan in color.
A female scorpion does not lay eggs, but produces an average of 35 live nymphs per brood which she carries on her back for from seven to 30 days. The nymphs undergo an average of six molts over a period of several months to four years before reaching maturity. Adults live for one to six years. Scorpions are predators, feeding primarily on insects and spiders, and are able to survive up to six months without feeding.
Though scorpions are most commonly found in the South, especially in desert areas of the Southwest; however their northern occurrence extends along the line from Baltimore to St. Louis to San Francisco. Scorpions are poisonous; the poison glands are in the bulbous last segment of the tail. Most species are not dangerous but inflict a sting comparable to that of a wasp. However, the deadly sculptured scorpion common in Arizona, has been responsible for many deaths.
Scorpions are active at night, feeding on spiders and insects. During the day they hide under stones and tree bark, in rock and woodpiles, and in masonry cracks. They enter structures seeking water and shelter and are frequently found in bathrooms, crawlspaces, attics, dry stone walls, foundations, and in clothes and shoes left on the floor.
The body of the female black widow spider is about Â½-inch long, glossy black with a globe-like abdomen. The abdomen has two triangular red spots on its underside arranged in such a way that the spots look like an hourglass. Males are much smaller than the females, Â¼-inch long with a larger, narrower abdomen and somewhat longer legs. Spiderlings are mostly orange and white but become increasingly blacker as they mature.
Black widow spiders lay their eggs in silken sacs, which they protect in their nests. A female produces from six to 21 sacs during her lifetime, each containing 185 to 464 eggs. The young spiderlings remain in the case until the second molt. They live in the vicinity of the nest for two to three weeks before producing long threads of silk that help them float away, much as kites float. Female spiderlings undergo from four to nine molts before maturing; this process requires from 54 to 107 days. Development time (i.e., from egg to adult) is approximately one year. Females live up to three years and males approximately 180 days.
Black widows are shy, preferring to build their webs in dry, protected locations where their prey is likely to travel. Outdoors they can be found among rocks and woodpiles, under decks, in hollow stumps, rodent burrows, beneath benches, etc. They prefer basements, crawl spaces, and garages in structures as well as other protected areas such as barns, sheds, meter boxes, brick veneer, pump houses, etc. The webs, which are irregular in shape and approximately one foot in diameter, are used to trap their insect prey, which is then paralyzed by their venom. Females often eat the males after mating, thus, giving them their rather morbid name. Females produce a neurotoxin and bite if disturbed or handled roughly. Each year several deaths are attributed to the bite of the black widow spiders as a result of anaphylactic reactions, however in most cases, the bite is no worse than a wasp sting.
Brown Recluse Spider
Adult brown recluse spiders are soft-bodied, yellowish-tan to dark brown, about 1/4 to 1/2 inch long and have long, delicate grayish to dark brown legs covered with short, dark hairs. The leg span is about the size of a half dollar. Distinguishing characteristics are the presence of three pairs of eyes arranged in a semicircle on the forepart of the head and a violin-shaped, dark marking immediately behind the semicircle of eyes with the neck of the violin pointing towards the bulbous abdomen.
The severity of a person’s reaction to the bite depends on the amount of venom injected and individual sensitivity to it. Bite effects may be nothing at all, immediate or delayed. Some may not be aware of the bite for 2 to 8 hours, whereas others feel a stinging sensation usually followed by intense pain if there is a severe reaction. A small white blister usually rises at the bite site surrounded by a large congested and swollen area. Within 24 to 36 hours, a systemic reaction may occur with the victim characterized by restlessness, fever, chills, nausea, weakness and joint pain. The affected area enlarges, becomes inflamed and the tissue is hard to the touch. The spider’s venom contains an enzyme that destroys cell membranes in the wound area with affected tissue gradually sloughing away, exposing underlying tissues. Within 24 hours, the bite site can erupt into a “volcano lesion” (a hole in the flesh due to damaged, gangrenous tissue).
The open wound may range from the size of an adult’s thumbnail to the span of a hand. The sunken, ulcerating sore may heal slowly up to 6 to 8 weeks. Full recovery may take several months and scarring may remain. Plastic surgery and skin grafts are sometimes required.
The brown recluse spider is not aggressive and normally bites only when crushed, handled or disturbed. It is aptly named since it is a reclusive creature seeking and preferring seclusion.
Late summer is the time of year when populations of yellowjackets (commonly called “bees”) and other social wasps become large and noticeable. Yellowjackets build paper nests similar to hornets, but either in the ground, a log or landscape timber or building wall or attic. If a nest is located where it is out of the way and not likely to be disturbed, it is best left alone. If, however, a nest is located in a “high traffic” area such as along walks or near doorways, control is justified to reduce the threat of being stung.
Bumble bees are big, fuzzy insects recognized by almost everyone by their robust shape and black and yellow coloration. The common species are 3/4 inch in length or more. Bumble bees usually nest in the ground in a deserted mouse nest or bird nest. Occasionally they nest in cavities within a wall or even in the clothes drier vent. If the vicinity of a bumble bee nest can be avoided, then leaving them alone and waiting for them to die in the fall would be the preferred “management” option. However, bumble bee nests are often found in yards, flowers beds, wood piles, or walls in high traffic places where the threat of being stung is great.
Trapping bumble bees is not practical and exclusion techniques may not solve the problem. When controlling bumble bees is necessary, using insecticides to poison bee colonies is the control method of choice.
Have a pest problem that we haven’t covered here? Just give a call at 1-817-558-PEST (7378) and talk to a Double D representative, or
- You can send us a e-mail.