Quantum Units Education®

1. In the first decade of the 21st century, the non-native brown widow became established in Southern California, and although it isn’t nearly as dangerous as the black widow, it causes alarm because of its potentially deadly relative.

2. The clutter of humans repels the western black widow, these spiders shun homes, barns, outbuildings, and rock walls but prefer open spaces.

3. When baby black widow spiderlings emerge from their egg sac, they look like small versions of the mother except for the males. The male spiderlings have tan legs and tan cephalothorax, the body part to which the legs attach, while the abdomen is mostly white with a few black spots.

4. A black widow's web is shaped in a classical symetrical shape. The web is very strong and produces a crackling sound when swiped with a hand.

5. The black widow bite itself is painless or may feel like a little pinprick. Almost all medically important black widow bites are from the adult female, which is much larger than the male; the female also has stronger biting muscles and a larger venom reserve.

6. Bite victims might suffer from some but not all of the following symptoms: rigid stomach muscles, sweating, pain that can be local, radiating, or regional; urine retention; and—less commonly—numbness, agitation, fever, and patchy paralysis.

7. The brown widow is a lot smaller than the western black widow, but due to it's dark brown hue, is easily mistaken for the common black widow.

8. Although the brown widow's venom is as potent as black widow venom, drop for drop, the brown widow probably doesn’t inject very much venom during a bite, making it much less dangerous than the native black widow spider.

9. One of the easiest ways to minimize encounters with widow spiders is to reduce clutter around your home, which deprives them of places to make retreats.

10. One aspect that makes controlling widow spiders easier is that they, unlike many spiders, do not exhibit a behavior called ballooning.

11. The brown recluse, however, is an enigma: there are no populations of the brown recluse, Loxosceles reclusa, in the state and fewer than 20 verified specimens have been collected over several decades in California.

12. Most spiders have six eyes that typically are arranged in two rows of three, but recluse spiders have nine equal-sized eyes arranged in three pairs, called dyads.

13. Many publications refer to the violin marking on the dorsal (top) surface of the abdomen (rear region) as the most important diagnostic feature of the brown recluse.

14. To be properly identified as a recluse spider, the spider must have all five of these characteristics; six eyes in dyads (pairs), uniformly colored abdomen with fine hairs, no spines on the legs, uniformly colored legs, & a body not more than 3/8” in length.

15. Although the brown recluse does not live in California, we do have four species of native recluse spiders. The most common Californian recluse spider is the desert recluse, Loxosceles deserta.

16. Recluse spiders are relatively short lived spiders. Among the various species, they mature after about 2 months and average an 8 month to 1 year life span with some living more than 18 months under laboratory conditions.

17. One consistent life history characteristic of recluse spiders is that in the right environment their populations are usually dense. If you find recluses, you do not find one, you find many.

18. A medical condition that is frequently misdiagnosed as a spider bite or brown recluse bite is methicillin-resistant Staphylococcus aureus (MRSA) bacterial infection.

19. Other pest that may cause necrotictype wounds include mites, fleas, bed bugs, soft ticks, hard ticks, conenose bugs, and kissing bugs. These wounds can be confused with the recluse spider's bite.

20. Spiders typically bite only once as a last ditch defensive effort before they are crushed between flesh and some object, except for the recluse spider, which is known to bite multiple times to increase the amount of venom injected into it's victim.

21. Spiders resemble insects and sometimes are confused with them, but they are arachnids, not insects. Spiders have six legs and two body parts—a head region (cephalothorax) and an abdomen.

22. Unlike mosquitoes, spiders do not seek out people in order to bite them, except for the black widow, brown recluse, and wolf spider, which are hyper aggressive and use their venom with great effect.

23. Other species of arthropods whose bites or stings may be mistaken for that of a spider include ticks, fleas, bees, wasps, bedbugs, mosquitoes, the conenose (kissing) bug (Triatoma protracta), deer flies, horse flies, and water bugs (Lethocerus spp.).

24. The common, house-dwelling agrarian sac or yellow sac spider, Cheiracanthium inclusum, is a small spider that spins a silken sac web in the corners of ceilings and walls, and behind shelves and pictures; it is also commonly found outdoors in shrubbery. This spider is poisonous to humans, but lacks the fang size to inject their venom into humans.

25. The best approach to controlling spiders in and around the home is to remove hiding spots for secretive spiders such as black widows and regularly clean webs off the house with brushes and vacuums.

26. To prevent spiders from coming indoors, seal cracks in the foundation and other parts of the structure and gaps around windows and doors. Good screening not only will keep out many spiders but also will discourage them by keeping out insects that they must have for food.

27. Typically pesticide control of spiders is easy. Spiders must crawl up a structure and are susceptible to perimeter treatments.

28. Chemical spray residual have a long-lasting effect on spiders. This means a spider can walk over a sprayed surface a few weeks (and in many cases, a few months) after treatment and be affected.

29. Sorptive dusts containing amorphous silica gel (silica aerogel) and pyrethrins, which can be applied by professional pest control applicators only, may be useful in certain indoor situations.

30. Sorptive dusts are most advantageously used in cracks and crevices and in attics, wall voids, and other enclosed or unused places.

31. Scorpions are predatory insects that feed on a variety of insects, spiders, centipedes, and other scorpions. Large scorpions occasionally feed on vertebrates, such as small lizards, snakes, and mice.

32. Of the 70 or so species found in North America, only one, the bark scorpion, Centruroides exilicauda (formerly called C. sculpturatus), is considered dangerous to people.

33. Scorpions are easily distinguished by their crablike appearance, with a pair of pincers, four pairs of legs, and a long, segmented tail ending with an enlarged segment bearing a stinger.

34. Scorpions are arthropods in the class Arachnida and order Scorpionida. Notable species of scorpions in the southwestern United States include the bark scorpion, which has venom that is dangerous to people; the Arizona hairy scorpion, the largest of the North American scorpions; and the striped tail scorpion, one of the most common species.

35. Bark scorpions reach a length of 9 inches and have a very thick tail up to 2 inchs wide; the body is yellow with stripes in patterns. The bark scorpion is the only common climbing scorpion and does not normally burrow, but usually lives above ground under tree bark and in palm trees and crevices of rocky cliffs.

36. Indoors scorpions may be found in cracks and crevices of woodwork, behind baseboards, in closets and attics, and inside walls. Scorpions gain entry into buildings through poorly sealed doors and windows, cracks in foundations, attic vents that are not properly screened, and through plumbing and other openings.

37. Scorpions grow slowly. Depending on the species, they may take 1 to 6 years to reach maturity. On average scorpions may live 3 to 5 years, but some species can live as long as 10 to 15 years.

38. The sting of all North American scorpions, can be serious, producing severe pain and swelling at the site of the sting, numbness, frothing at the mouth, difficulty breathing, respiratory paralysis, muscle twitching, and convulsions.

39. In California, the bark scorpion occurs only in the extreme southeastern part of the state, along the Arizona border. Anyone stung by a bark scorpion or experiencing an allergic reaction to a sting should seek medical attention.

40. The first strategy for control is to modify the area surrounding a house because scorpions are difficult to control with insecticides. Adult scorpions are more difficult to kill with pesticides because of their larger body size and thicker cuticle.