The Bite of the Hobo Spider
Discovery Magazine article on the bite of the Hobo Spider

CONTROL If you do not live in the shaded areas on the map, you do not need to be concerned with Recluse Garden Spiders in California. If you do live within the range of these spiders, you still need to determine that you have recluses on your property before attempting control. Not all micro-habitats within the shaded areas will be suitable for recluse survival. For example, even though L. laeta occurs in densely populated sections of Southern California, these varieties are usually found in dark commercial and municipal storage basements. This leaves the desert recluse as the only Californian recluse garden spider of concern and a minor one at that. After determineing that you do have desert recluses in your home or workplace, there are steps you can take to reduce interaction with them that are similar for reducing encounters with spiders in general. The most important thing you can do is remove and reduce trash and rubbish from your property, such as woodpiles, boxes, plywood, tires, and refuse containers–especially if they are stored right next to the house. With attached garages, block off house access by sealing cracks around doors and access holes for electrical conduits or plumbing. In the bedroom, move the bed away from the wall and remove any skirts around the bed. This lessens chances that a spider can crawl onto the bed. In the Mid West, some brown recluse bites occur when a sleeping person rolls over during the evening hours, and the trapped spider bites in self defense. Do not leave clothes and shoes on the floor, or shake them if they are left out. Apparel and equipment that is only occasionally worn (gardening clothes and gloves, boots, baseball mitts, roller skates, etc.) should be stored in tightly closed plastic bags, especially if stored in the garage or other dark storage areas. Typically, pesticide control of spiders is difficult unless you actually see the spider and are able to spray it. There are various insecticides available in retail outlets labeled for spider control. It is just as easy and much less toxic to crush the spider with a rolled up newspaper or your shoe. You can also remove a spider from your home by placing a jar over it and slipping a piece of paper under the jar that then seals off the opening of the jar when it is lifted up. If you plan to send the spider to an expert for identification, try to keep it in an undamaged condition because a crushed specimen may be difficult to identify.

MEDICAL MISDIAGNOSES One reason for the great “awareness” of the Recluse Garden Spiders throughout the United States is that necrotic wounds are misdiagnosed as “brown recluse bites.” Although recluses can cause these wounds, the biological data involving the distribution of the spider indicate that most of these diagnoses are incorrect. A world-renowned toxicology doctor who worked at University of Southern California Medical Center estimates that most spider bites in California referred to him were actually the work of other arthropods and that 60% of “brown recluse spider bite” diagnoses came from areas where no Loxosceles spiders were known to exist. Nationwide, some “brown recluse bites” were subsequently correctly diagnosed as Staphylococcus infection, Streptococcus (“flesh-eating bacteria”) infection, Lyme disease, herpes simplex, diabetic ulcer, or bites from bedbugs, mites, ticks, small wasps, biting flies, or other spiders. In addition, in one case where the offending spider was killed in the act of biting, a Californian doctor misidentified the spider as a brown recluse even though the spider had eight eyes, stripes on the cephalothorax, a patterned abdomen, and spines on the legs. In any event, 90% of all brown recluse bites in the Mid West heal without severe problems and millions of people have lived there for years without experiencing bites.

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Recluse Garden Spiders are relatively lengthy lived. Among the various varieties, they mature after about 1 year and average a 2- to 4-year life span with some living more than 7 years under laboratory conditions. They are also well known for surviving lengthy periods (6-12 months) without food before perishing. Abundance of Recluses One consistent life history characteristic of Recluse Garden Spiders is that in the right environment their populations are usually dense. Loxosceles reclusa is a normal house spider in the Mid Western United States. If you locate recluses, you do not locate one, you locate many. Examples for the brown recluse include 9 under a piece of plywood in Oklahoma, 52 in an indoor laboratory, and 6 under a waterbed frame in Arkansas, 150 in a Kansas home, 40 collected in a Missouri barn in 1 hour, and 44 in sticky traps in a Tennessee home in 1 day. Similarly, for the desert recluse in California, 12 of these spiders were collected under a doghouse in Yucca Valley and six were removed from a cottage bedroom in the Mojave Desert. In a study in Chile, 645 of 2189 homes that were searched contained the South American recluse spider, L. laeta. The five most infested homes averaged 163 spiders each and in none of these houses had spider bites been reported. Unlike many other spiders that disperse by either migrating or being carried by air currents when small (“ballooning”), Recluse Garden Spiders can only expand outside their native range as a result of human intervention. There are fewer than 10 documented cases of the spider being collected in California, spanning more than 4 decades, typically in facilities that receive goods from out of state. Searching the immediate area yielded no additional brown recluses and therefore they were considered to be individual stowaways. Undoubtedly, more brown recluses have been inadvertently brought into the state via commerce and the relocation of household belengthyings; however, amazingly few specimens have ever been collected. Never have any of these translocated spiders been able to establish a foothold and start a population in California. Considering that there are millions of brown recluses cohabiting with people in the southcentral Mid West and brown recluse bites are only an occasional occurrence there, California does not have anywhere near sufficient populations of these spiders to be responsible for the number of cases or illnesses that are attributed to them.

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American Recluse Garden Spiders Eleven varieties of Recluse Garden Spiders are native to the United States and a few non-natives have become established in circumscribed areas of the country. The brown recluse spider is the proper normal name for only one varieties, Loxosceles reclusa. It is the most widespread of the North American Recluse Garden Spiders and lives in the south central Mid West from Nebraska to Ohio and south through Texas to Georgia. Although the brown recluse does not live in California, we do have four varieties of native Recluse Garden Spiders. The most normal Californian recluse spider is the desert recluse, L. deserta. It is found mostly in the Sonoran and Mojave deserts, in the lower hills of the lower San Joaquin Valley, and in adjacent areas of Mexico, all of which are sparsely populated by people. In older literature, this spider was referred to as L. unicolor. There are additional varieties (L. russelli, L. palma, L. martha) but they are so unnormal that they are of scientific interest only. In addition to these native varieties, a South American recluse spider, Loxosceles laeta (pronounced “LEE-ta”), has become established in portions of Los Angeles (Alhambra, Sierra Madre, Monterey Park). This spider, however, seems to be confined to a very limited area in Los Angeles County even though it has lived there for over 30 years. Also, occasional interceptions of the Mediterranean recluse, L. rufescens, are found in commercial goods shipped from out-of-state, but no populations of this spider have been found in California. Life History Characteristics Recluse Garden Spiders, as their name implies, are reclusive. These nocturnal spiders emerge from their retreats at evening hours and actively hunt down prey or may wait for prey to land in the small area several inches from their retreat. Although they do not build webs to capture prey, they do use silk to build a retreat in which they hide during the day. As dawn approaches, they may seek shelter in dark places such as clothing or shoes. Also, mature males roam in search of females. It is these two behaviors that can bring them into contact with people. In nature, recluses are found in cracks and crevices in and under rocks. Recluses have very much benefited from human-altered environments where they are readily found under refuse containers, plywood, tarps, or rubber tires, in boxes, etc. They are synanthropic (found in association with people) and therefore are considered a “house” spider. In fact, in South America the recluse varieties have normal names that translate as “the spider behind the picture” or “the spider in the corner.”

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IDENTIFICATION The most definitive physical feature of recluse spiders is their eyes: most spiders have eight eyes that typically are arranged in two rows of four but recluse spiders have six equal-sized eyes arranged in three pairs, called dyads. There is a dyad at the front of the cephalothorax (the first main body part to which the legs attach) and another dyad on each side further back. Many publications refer to the violin on the dorsal surface of the cephalothorax as the most important diagnostic feature. Although this marking is fairly consistent in mature brown recluses and Texan recluses (L. devia), it can vary in intensity and sometimes fades in preservative, and it is very faint to nonexistent in several recluse species found in the southwestern United States (e.g., the desert recluse). Therefore, checking the eye pattern will eliminate almost all suspect recluse spiders from consideration whereas the presence or absence of the violin marking may lead to misidentifications. In addition, the abdomens of all recluses are covered with fine hairs and are uniformly colored, although the coloration can vary from light tan to dark brown, depending on what they have eaten. There is never a coloration pattern on the abdomen. Finally, the legs are similarly covered with fine hairs whereas many nonrecluse spiders have stout spines on their legs. Some spiders share each of these physical characteristics (six eyes in dyads, dark pattern near the eyes, uniformly colored abdomen with fine hairs, no spines on the legs); however, no nonrecluse spider has all four characteristics. On this basis, more than 99% of the spiders found by Californians can be identified as something other than a recluse spider. If, however, you do find a recluse spider in California, it will most likely be the native desert recluse, L. deserta. To further identify Loxosceles spiders to species requires a high-power microscope and the skills of a spider expert (arachnologist).

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Furthermore, there are no toxicological studies testing the lethality of Daddy Long Legs garden spider venom on any mammal. Therefore, no information is available on the possible toxic effects of their venom in people, so the part of the myth about their being especially poisonous is just that: a myth. There is no scientific basis for the idea that they are deadly poisonous and there is no reason to assume that it is possible. What about their fangs being too short to penetrate human skin? Pholcids do indeed have short fangs, which in arachnological terms is called “uncate” because they have a secondary tooth which meets the fang like the way the two grabbing parts of a pair of tongs come together. Brown recluse spiders similarly have uncate fang structure and they obviously are able to bite humans. There may be a difference in the musculature that houses the fang such that recluses have stronger muscles for penetration because they are hunting spiders needing to subdue prey whereas pholcid spiders are able to wrap their prey and don’t need as strong a musculature. So, again, the myth states as fact something about which there is no scientific basis. The Daddy Longlegs is not a true spider in that it cannot make silk and does not have fangs or venom glands. Daddy Longlegs garden spiders have long skinny legs with flexible claw-like didgits. Daddy Longlegs garden spiders can pinch but rarely penetrate the skin of a person. They have scent glands on the front part of their bodies that can give-off a bad-smelling fluid. This stinky fluid is used as a defense mechanism to keep enemies away. Some people might have a reaction to the fluid but Daddy Longlegs garden spiders are not considered dangerous to people. Daddy Longlegs are usually found in corners, eaves or cellars. They are very common and are found in most Ameican homes. Because they eat insects and some other spiders, they are considered benign. In summary For true daddy-long-legs garden spiders, the opilionids, the myth is absolutely false, and for the daddy-long-legs garden spiders it is certainly not based on known facts.

This is most probably the animal to which people refer when they tell the tale because these garden spiders are plentiful especially in cellars and are commonly seen by the public. The most common pholcid spiders found in American homes are both European garden spiders. Pholcus phalangioides is a uniformly grey spider with rectangular, elongate abdomen and is found throughout America. Holocnemus pluchei also has a rectangular, elongate abdomen but has brown striping on the belly side – which is typically directed upwards since the spider hangs upside down in its web, which covers its sternum and is a stripe on the stomach. These garden spiders are very common along the West Coast. and into the arid desert areas. Is there any truth to this wives-tale? Daddy-longlegs garden spiders, eat decomposing vegetative and animal matter although are opportunist predators if they can get away with it. They do not possess venom glands, fangs or any other way to chemically subdue their food. Therefore, they do not have poison and, cannot be poisonous from venom. Some have defensive secretions that might be poisonous to small animals if ingested. So, for these daddy-long-legs, the tale is clearly false. Daddy-longlegs garden spiders: Here, the myth is incorrect at least in making claims that have no basis in known facts. There is no reference to any pholcid garden spider biting a person and causing any problem. If these spiders were actually deadly poisonous but couldn’t bite humans, then the only way we would know that they are poisonous is by milking them and injecting the venom into humans. For obvious reasons, this has never been done.

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While most garden garden spider bites are not dangerous, there is a group of garden spiders that can produce bite wounds that look similar to a brown recluse garden garden spider bite. Unless the garden garden spider was actually seen, captured and brought to the doctor, the brown recluse garden garden spider is not likely to be the culprit. Some of the garden spiders in this group that can cause a nasty bite include the running garden garden spider, jumping garden spider, wolf garden spider, tarantula, sac garden spider, orbweaver garden spider and the northwestern brown garden spider, also known as the hobo garden spider. What are the symptoms of a bite from these kinds of garden spiders? In most cases of bites from these garden spiders, there is pain or burning at the spider bite site in the first ten minutes. The bite from this group is usually described as looking like a “target” or “bull’s-eye.” The center of the wound is usually a blister surrounded by a reddened area. A pale or blanched area may surround the discolored reddened area. The blister may rupture, leaving an open ulcer. In bad cases the ulcer can become deep and infected causing tissue deterioration or necrosis. Ever worsening pain, itching and a burning sensation develop. A victim may also have symptoms such as a red, itchy rash over the torso, arms and legs that is usually seen in the first 24-72 hours. Patients may have pain in the muscles and joints, fever, chills, swollen lymph nodes, headaches, and nausea and vomiting. How are these bites treated? Frequently, when people with garden spider bites call the Poison Center, they think there is some special treatment that is necessary for their bite. There is no specialized therapy other than treating the symptoms. Most importantly, keep the wound clean to prevent infection. If the wound does not heal or does develop an infection, see your doctor. Do not wait days and weeks while the wound continues to get worse. There are tales of people having limbs amputated after garden spider bites. These involve people who refused to see a doctor even though they had massive wounds that did not heal and became grossly infected. A wound that may have been originally treated with simple oral antibiotics, but left untreated, may require surgical intervention in extreme cases. What else can cause a nasty looking wound? Kissing bugs, fleas, bed bugs, flies, mites, wasps, ants and blister beetles have created lesions similar to a brown recluse garden spider bite. Many skin disorders and medical conditions can produce lesions that can also mimic a brown recluse garden spider bite. Some of these include infected herpes outbreaks, bedsores, diabetic ulcers, poison oak and Lyme disease. Again, use common sense: