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Stinging events involving honey bees and wasps are rare; most deaths or clinically important incidents involve very few stings (<10) and anaphylactic shock. However, mass stinging events can prove life-threatening via the toxic action of the venom when injected in large amounts. With the advent of the Africanized honey bee in the southwestern United States and its potential for further spread, mass envenomation incidents will increase. Here we review the literature on mass stinging events involving honey bees and wasps (ie, yellowjackets, wasps, and hornets). Despite different venom composition in the two insect groups, both may cause systemic damage and involve hemolysis, rhabdomyolysis, and acute renal failure. Victim death may occur due to renal failure or cardiac complications. With supportive care, however, most victims should be able to survive attacks from hundreds of wasps or approximately 1000 honey bees [ABSTRACT FROM AUTHOR]

Recent outbreaks of mysterious skin lesions on multiple personnel at several military facilities were initially blamed on spiders. Requests were made for pest inspection and control to remedy the situation. Greater scrutiny of the situation led to a hypothesis that instead of spiders, an infectious outbreak of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) should be investigated as the etiology. Subsequent culturing of the lesions on personnel at one facility confirmed this bacterial etiology. Barracks, as well as other close quarter military living conditions, are ripe environments for the establishment, persistence, and spread of CA-MRSA. Military medical personnel should consider CA-MRSA as a more likely etiologic agent than spider bites for cutaneous eruptions in which there are multiple lesions on one person or multiple patients with similar lesions. [ABSTRACT FROM AUTHOR]

Background: Conventional advice on immediate treatment of honey-bee stings has emphasised that the sting should be scraped off, never pinched. The morphology of the sting suggested little basis for this advice, which is likely to slow down removal of the sting.Methods: The response to honey-bee stings was assayed with a measurement of the size of the resulting weal. Injection of known quantities of venom showed that this measurement is a good indicator of envenomisation.Findings: Weal size, and thus envenomisation, increased as the time from stinging to removal of the sting increased, even within a few seconds. There was no difference in response between stings scraped or pinched off after 2 s.Interpretation: These data suggest that advice to patients on the immediate treatment of bee stings should emphasise quick removal, without concern for the method of removal. [ABSTRACT FROM AUTHOR]

From southern North America, five verified bites by crevice weaver spiders, Kukulcania spp. (Filistatidae), are presented here, three of which are pediatric cases. Although the envenomation manifestations were of minimal expression, the salient aspect of this report is that Kukulcania spiders are frequently misidentified as brown recluse spiders (genus Loxosceles ) which are infamous for causing serious dermonecrosis and rarely, life-threatening systemic effects. Misidentification of this relatively harmless spider as a medically important recluse when presented to a physician in an envenomation episode could lead to unwarranted and overzealous treatment such as contraindicated debridement of the affected area., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author.)

Spider venom is being researched for its potential use in applications such as insecticides, to better understand the dynamics of neuronal ion channel physiology and as potential remedies to counter antibiotic resistant bacteria. However, spider venom is more widely known for its ability to cause deleterious reactions after toxic envenomations in humans. In this short review, the "dark" side of spider venoms is presented to provide a counterbalance to the investigations of the positive potential that venoms can or might improve our world or its understanding. The goal was to present a short primer on species having clinical consequences in humans rather than be an exhaustive review of all spiders of medical importance., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Loxosceles rufescens is a circum-Mediterranean spider species, potentially harmful to humans. Its native area covers the Mediterranean Basin and Near East. Easily spread with transported goods, it is meanwhile an alien and invasive species to nearly all other continents and many islands. This species occurs in semi-arid steppe-like habitats, typically under stones and in cavities, which enables it to settle inside buildings when invading the synanthropic environment. This review analyses the literature of L. rufescens bites to humans (38 publications) of which only 11 publications refer to 12 verified spider bites (11% of the reported bites). Two published allegedly deadly spider bites (Thailand 2014 and Italy 2016) involve non-verified spider bites and are thus not reliable. The symptoms and therapy of these 11 verified bites are described: only five cases showed moderate systemic effects, nine cases developed necrosis, four cases needed surgical debridement, all cases healed without complications within a few weeks. In conclusion, L. rufescens is a spider species globally spread by human activity, it rarely bites humans and the bites are less harmful than often described. There is no known fatal issue., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Information on pesticide effects on spiders is less common than for insects; similar information for spider egg sacs is scarcer in the open literature. Spider egg sacs are typically covered with a protective silk layer. When pesticides are directly applied to egg sacs, the silk might prevent active ingredients from reaching the eggs, blocking their insecticidal effect. We investigated the impact of six water-based pesticide sprays and four oil-based aerosol products against egg sacs of brown widow spiders, Latrodectus geometricus C. L. Koch. All water-based spray products except one failed to provide significant mortality to egg sacs, resulting in successful spiderling emergence from treated egg sacs at a similar rate to untreated egg sacs. In contrast to water-based sprays, oil-based aerosols provided almost complete control, with 94-100% prevention of spiderling emergence. Penetration studies using colored pesticide products indicated that oil-based aerosols were significantly more effective in penetrating egg sac silk than were the water-based sprays, delivering the active ingredients on most (>99%) of the eggs inside the sac. The ability of pesticides to penetrate spider egg sac silk and deliver lethal doses of active ingredients to the eggs is discussed in relation to the chemical nature of egg sac silk proteins. Our study suggests that pest management procedures primarily relying on perimeter application of water-based sprays might not provide satisfactory control of brown widow spider eggs. Determination of the most effective active ingredients and carrier characteristics warrant further research to provide more effective control options for spider egg sacs., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

This paper presents two newly established species for French Polynesia: the invasive brown widow spider, Latrodectus geometricus C. L. Koch, and its potential biocontrol agent, the parasitoid wasp, Philolema latrodecti (Fullaway). The brown widow spider was recorded from the island of Moorea in 2006 and, since that discovery, the occurrence of this species has expanded to two of the five archipelagos of French Polynesia including the main island of Tahiti and four of the Cook Islands. Although the tropical climate contributes to the establishment of L. geometricus, a biotic factor, P. latrodecti, may restrain population from demographic explosion. This eurytomid wasp is present in French Polynesia and is a parasitoid that has been used in biological control of the southern black widow Latrodectus mactans (F.) in Hawaii. This wasp could become a significant limiting factor for L. geometricus distribution on these islands, as it was found in 31% of the Tahitian brown widow spider egg sacs that were dissected. However, thus far, the wasp was only found on Tahiti in association with the brown widow spider. Although the brown widow is generally considered to be less toxic than its black widow relatives, it remains of medical concern in French Polynesia because reactions to its bites can, at times, be severe. The spider remains of public concern because it is a novel species; it has the word widow in its name and dark morphs are mistaken as black widows., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Spiders found in international cargo brought into North America are sometimes submitted to arachnologists for identification. Often, these spiders are presumed to be of medical importance because of size or a submitter's familiarity with a toxic spider genus from the continent of origin. Starting in 2006, requests were made for spiders found in international cargo brought into North America, in addition to the specimens from similar cargo shipments already in our museum collections. This was an ad hoc study that allowed us to focus on spiders of concern to the discoverer. We identified 135 spiders found in international cargo. A key for the most common species is provided. The most frequently submitted spiders were the pantropical huntsman spider, Heteropoda venatoria (L.) (Sparassidae), and the redfaced banana spider, Cupiennius chiapanensis Medina Soriano (Ctenidae). Spiders of medical importance were rare. The most common cargo from which spiders were submitted was bananas with most specimens coming from Central America, Ecuador, or Colombia. Lack of experience with nonnative fauna caused several experienced American arachnologists to misidentify harmless ctenid spiders (C. chiapanensis, spotlegged banana spider, Cupiennius getazi Simon) as highly toxic Phoneutria spiders. These misidentifications could have led to costly, unwarranted prophylactic eradication measures, unnecessary employee health education, heightened employee anxiety and spoilage when perishable goods are left unloaded due to safety concerns., (© 2014 Entomological Society of America.)

The body of pesticide research on spiders is sparse with most studies using topical or residual applications to assess efficacy. Data on the effects of fumigation on spider survivorship are scarce in the scientific literature. In this study, we exposed adult male and female brown recluse spiders, Loxosceles reclusa Gertsch & Mulaik, and female brown widow spiders, Latrodectus geometricus C. L. Koch, to a commercial fumigation event using sulfuryl fluoride directed at termite control. General consensus from the pest control industry is that fumigation is not always effective for control of spiders for a variety of reasons, including insufficient fumigant dosage, particularly, for contents of egg sacs that require a higher fumigant dosage for control. We demonstrated that a sulfuryl fluoride fumigation with an accumulated dosage of 162 oz-h per 1,000 ft(3) at 21°C over 25 h (≈1.7 × the drywood termite dosage) directed at termites was sufficient to kill adult brown recluse and brown widow spiders. The effectiveness of commercial fumigation practices to control spiders, and particularly their egg sacs, warrants further study., (© 2014 Entomological Society of America.)

This study compiled 33 verified spider bites from the state of Oregon (USA). The initial goal was to amass a series of bites by the hobo spider to assess whether it possesses toxic venom, a supposition which is currently in a contested state. None of the 33 bites from several spider species developed significant medical symptoms nor did dermonecrosis occur. The most common biters were the yellow sac spider, Cheiracanthium mildei (N = 10) and orb-weavers of the genus Araneus (N = 6). There were 10 bites from three genera of funnel web spiders of the family Agelenidae including one hobo spider bite and one from the congeneric giant house spider which is readily confused as a hobo spider. The hobo spider bite resulted in pain, redness, twitching in the calf muscle and resolved in 12 h. Also generated from this study were possibly the first records of bites from spiders of the genera Callobius (Amaurobiidae) and Antrodiaetus (Antrodiaetidae), both with minor manifestations., (Published by Elsevier Ltd.)

The medical importance of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik, is well known, but there is a need for more accurate information about the distribution of the spider in North America. We gathered information via an Internet offer to identify spiders in Illinois and Iowa that were thought to be brown recluses. We also mined brown recluse locality information from other agencies that kept such records. In Iowa, the brown recluse is unknown from its northern counties and rare in southern counties. In Illinois, brown recluse spiders are common in the southern portion of the state and dwindle to almost nonexistence in a transition to the northern counties. Although there were a few finds in the Chicago, IL area and its suburbs, these are surmised to be human-transported specimens and not part of naturally occurring populations. Considering the great human population density and paucity of brown recluses in the Chicago area, medical personnel therein should obtain patient geographic information and be conservative when diagnosing loxoscelism in comparison with southern Illinois, where the spiders are plentiful and bites are more likely.

In North America, spider envenomation is perceived to be a greater threat than in actuality; however, it still is a valid source of morbidity and, very rarely, mortality. Only 2 groups (widows, recluses) are medically important on this continent. Widow bites affect the neuromuscular junction, have minor dermatologic expression, and are treated with analgesics and antivenom. Recluse bites vary from mild, self-limiting rashes to extensive dermonecrosis. Recent awareness of methicillin-resistant Staphylococcus aureus as a ubiquitous cause of skin injury that is often mistaken as attributable to recluse bites has questioned the credence of spiders being the cause of idiopathic wounds., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Three verified bites from Hololena spiders (Family Agelenidae) are presented here. Two male victims, each over 100 kg weight (bitten by female spiders), experienced headaches and 4-h episodes of vomiting. A female bite victim (bitten by a male spider) experienced minor reaction. None sought medical attention; symptoms resolved in a few days. Although these incidents were not serious, reactions in the male victims were more dynamic than usual generic spider bites (minor edema, minor erythema)., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The brown widow spider, Latrodectus geometricus C. L. Koch, has become newly established in southern California during the first decade of the 21st century. Brown widows and egg sacs were collected within the urban Los Angeles Basin using timed searches. We also collected and compared the abundance and distribution of the native western black widow spider, Latrodectus hesperus Chamberlin & Ivie, to brown widows. Brown widows were very common around urban structures especially outside homes, in parks, under playground equipment, in plant nurseries and landscaping areas, greatly outnumbering native western black widows, and were very rare or nonexistent in garages, agricultural crops, and natural areas. Western black widows predominated in xeric habitats and were less prevalent around homes. Neither species was found in the living space of homes. In southern California, envenomation risk exists because brown widows are now common in urban areas and the spiders hide where people place their fingers and exert pressure to move objects (e.g., under the curled lip of potted plants, in the recessed handle of plastic trash bins). Nonetheless, brown widow spider bites are less toxic than those of native western black widow spiders and, hence, if they are displacing black widows, overall widow envenomation risk may actually be lower than before brown widow establishment.

Many medically important animals exhibit fluctuating seasonal abundance such that risk from envenomation or disease is not constant throughout the year. As indicated by homeowner submissions, brown recluse spiders, Loxosceles reclusa, show seasonal peaks of activity during summer and paucity in winter. This information should be incorporated as part of the diagnostic algorithm for physicians when considering the probability of loxoscelism in endemic Loxosceles areas especially if a skin lesion occurs when spiders are scarce., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Experiments reported in Sandidge (2003; Nature 426: 30) indicated that the brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, preferred to scavenge dead prey over live prey and that the spiders were not detrimentally affected when fed insecticide-killed crickets. Extrapolations made in subsequent media coverage disseminating the results of this research made counter-intuitive statements that pesticide treatment in houses would increase brown recluse populations in homes. This information was presented as if the scavenging behavior was specialized in the brown recluse; however, it was more likely that this behavior has not been well studied in other species. To provide a comparison, the current laboratory study examined the likelihood of non-Loxosceles spiders to scavenge dead prey. Of 100 non-Loxosceles spiders that were tested (from 11 families, 24 genera, and at least 29 species from a variety of spider hunting guilds), 99 scavenged dead crickets when offered in petri dishes. Some of the spiders were webspinners in which real-world scavenging of dead prey is virtually impossible, yet they scavenge when given the opportunity. Therefore, scavenging is a flexible opportunistic predatory behavior that is spread across a variety of taxa and is not a unique behavior in brown recluses. These findings are discussed in relation to pest management practices.

The spider Holocnemus pluchei (Scopoli) (Araneae: Pholcidae) is a nonnative species commonly found in the southwestern United States. In urban areas around homes and other structures, it is often the dominant spider species on outside surfaces; requests for control of spiders and their cobwebs are common for the commercial pest management industry. We tested two physical (brushing and vacuuming) and two low-impact chemical (permethrin and botanical insecticide) spray control methods for H. pluchei on outbuildings on the University of California-Riverside campus. Forty sites containing at least two H. pluchei spiders along a 5-m section of eave or overhang were chosen for treatment. Treatment was applied within 2 d of a pretreatment census. The number of spiders per section was counted at 2, 4, 8, 12, 16, and 52 wk posttreatment. Untreated sections showed an increase in spiders through summer and a decrease in autumn. Sites treated with permethrin significantly reduced spiders >95% and had strong residual effect throughout the remainder of the sampling period. Compared with untreated controls, the three other treatments did not significantly reduce spiders; these three were similar throughout the season and were intermediate between untreated and permethrin-treated sites. In comparison with the before and 2-wk posttreatments, spiders at the untreated sites showed no difference in body sizes, whereas those in the nonpermethrin treatments showed a decrease, indicating that larger spiders were eliminated. We also tested H. pluchei spiders in the laboratory against the two insecticides used in the field studies to determine the minimum lethal concentrations for controlling H. pluchei.

Most spiders use venom to paralyze their prey and are commonly feared for their potential to cause injury to humans. In North America, one species in particular, Loxosceles reclusa (brown recluse spider, Sicariidae), causes the majority of necrotic wounds induced by the Araneae. However, its distributional limitations are poorly understood and, as a result, medical professionals routinely misdiagnose brown recluse bites outside endemic areas, confusing putative spider bites for other serious conditions. To address the issue of brown recluse distribution, we employ ecological niche modeling to investigate the present and future distributional potential of this species. We delineate range boundaries and demonstrate that under future climate change scenarios, the spider's distribution may expand northward, invading previously unaffected regions of the USA. At present, the spider's range is centered in the USA, from Kansas east to Kentucky and from southern Iowa south to Louisiana. Newly influenced areas may include parts of Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania. These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification/treatment, potentially reducing bite misdiagnoses.

A novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), at White Beach, Camp Pendleton, in Oceanside, CA. White Beach is a nesting habitat for an endangered seabird, the California least tern (Sterna antillarum browni Mearns). The beach is heavily infested with Argentine ants, one of the threats for the California least tern chicks. Conventional pest control strategies are prohibited because of the existence of the protected bird species and the site's proximity to the ocean. The bait station consisted of a polyvinyl chloride pipe that was treated on the inside with fipronil insecticide at low concentrations to obtain delayed toxicity against ants. The pipe was provisioned with an inverted bottle of 25% sucrose solution, then capped, and buried in the sand. Foraging ants crossed the treated surface to consume the sucrose solution. The delayed toxicity of fipronil deposits allowed the ants to continue foraging on the sucrose solution and to interact with their nestmates, killing them within 3-5 d after exposure. Further modification of the bait station design minimized the accumulation of dead ants in the sucrose solution, significantly improving the longevity and efficacy of the bait station. The virtual bait station exploits the foraging behavior of the ants and provides a low impact approach to control ants in environmentally sensitive habitats. It excluded all insects except ants, required only milligram quantities of toxicant, and eliminated the problem of formulating toxicants into aqueous sugar baits.

In a previous experimental study, recluse spiders Loxosceles reclusa Gertsch and Mulaik and Loxosceles laeta (Nicolet) (Araneae: Sicariidae) preferred small cardboard refugia covered with conspecific silk compared with never-occupied refugia. Herein, we investigated some factors that might be responsible for this preference using similar cardboard refugia. When the two Loxosceles species were given choices between refugia previously occupied by their own and by the congeneric species, neither showed a species-specific preference; however, each chose refugia coated with conspecific silk rather than those previously inhabited by a distantly related cribellate spider, Metaltella simoni (Keyserling). When L. laeta spiders were offered refugia that were freshly removed from silk donors compared with heated, aged refugia from the same silk donor, older refugia were preferred. Solvent extracts of L. laeta silk were chosen approximately as often as control refugia when a range of solvents (methylene chloride:methanol, water, and hexane) were used. However, when acetone was used on similar silk, there was a statistical preference for the control, indicating that there might be a mildly repellent aspect to acetone-washed silk. Considering the inability to show attraction to chemical aspects of fresh silk, it seems that physical attributes may be more important for selection and that there might be repellency to silk of a recently vacated spider. These findings are discussed in regard to pest management strategies to control recluse spiders.

Misidentification of harmless or nearly benign arachnids as Loxosceles spiders by medical personnel and other authorities proliferates misinformation in regard to alleged loxoscelism and leads to decreased health care. This is especially true in areas of North America where Loxosceles spiders are rare or non-existent. A diverse assemblage of such misidentified arachnids is presented here. It is hoped that authorities will honestly assess their arachnological limitations and, instead, seek qualified arachnologists for spider identifications.

Objective: To provide a comprehensive review of relevant literature regarding the brown recluse spider (BRS) and to define those criteria that must be satisfied before making a diagnosis of brown recluse envenomation., Etiology: The complex venom of the BRS contains sphingomyelinase D, which is capable of producing all the clinical signs in the human and some animal models., Diagnosis: There is no current commercially available test. In humans there are many proposed guidelines to achieve a definitive diagnosis; however, there are no established guidelines for veterinary patients., Therapy: Currently, no consensus exists for treatment of BRS envenomation other than supportive care, which includes rest, thorough cleaning of the site, ice, compression, and elevation., Prognosis: Prognosis varies based on severity of clinical signs and response to supportive care., (© Veterinary Emergency and Critical Care Society 2009.)

Experiments tested the ability of newly emerged spiderlings of a black widow spider, Latrodectus hesperus Chamberlin & Ivie (Araneae: Theridiidae), to crawl through brass screen of various mesh size. The purpose was to determine whether immatures of these medically important spiders could be excluded from buildings. In horizontal orientation, black widow spiderlings were able to easily pass through mesh with openings of 0.83 mm and were prevented from passing in four of five tests with mesh of 0.59-mm openings. Spiderlings also readily pass through 0.83-mm mesh in vertical orientation. Our laboratory studies indicate that the mesh size sufficient for exclusion is too small for practical use in most cases, although there are some specialized situations where such small mesh might be useful. The results are discussed in regard to actual conditions found in typical commercial building situations.

The southern and eastern margins of the range of the brown recluse spider run through the southeastern quadrant of the United States. Populations vary from abundant in states such as Arkansas and west and central Kentucky and Tennessee to absent in the Atlantic seaboard states. The diagnosis of loxoscelism should be restricted to areas of the southeastern United States where brown recluse spiders are both common and widespread. Better knowledge of the local presence of recluse spiders in one's area, along with the list of differential diagnoses for dermonecrosis, will allow medical personnel in the south to better assess the probability of spider involvement in a necrotic skin lesion. In North America, there are two groups of spiders proven to be medically important: the widow spiders (genus Latrodectus) and the recluse spiders (genus Loxosceles). The widow spiders are a known entity, because their distinctive coloration makes them readily identifiable by nonarachnologists. Also, the physiological mechanism of the venom, the antivenom to counter it, and the symptoms are known, causing misdiagnosis to rarely occur. In contrast, recluse spiders are almost at the other end of the spectrum. They are readily misidentified or confused with harmless spiders, and the physiological mechanism of the venom is still being elucidated. Furthermore, no antivenom is commercially available, and the brown recluse's infamy causes many skin lesions of nonarachnid origin to be misdiagnosed as brown recluse spider bites.

Georgia is on the southeastern margin of the native range of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik. The brown recluse is not a common Georgia spider and has limited distribution in the state. Using recent submissions, previously published records, and examination of museum specimens, we document the spider's presence in 31 (19.5%) of Georgia's 159 counties, with almost all being found in the northern portion. The spider was collected almost exclusively north of the Fall Line (a transition zone separating the Piedmont and the Coastal Plain geological provinces). Only two locations in the southern Coastal Plain province produced L. reclusa specimens; these southern finds are considered spiders that were transported outside their range. There were six finds of the non-native world tramp species, L. rufescens (Dufour), three south of the Fall Line. In conspicuous contrast, over a 5-yr period, a Georgia poison center database recorded 963 reports of brown recluse spider bites from 103 counties. These figures greatly outnumber the historic verifications of brown recluses in the state for both specimen quantity and county occurrence, indicating improbable spider involvement and the overdiagnosis of bites. In the southern half of the state, medical diagnoses of brown recluse spider bites have virtually zero probability of being correct. Bite diagnoses should be made with caution in north Georgia given the spider's spotty distribution with low frequency of occurrence.

Spiders have been incriminated as causes of human suffering for centuries, but few species worldwide cause medically significant envenomation. Widow spiders (Latrodectus spp.) occur worldwide and cause latrodectism, which is characterized by pain (local and generalized) associated with nonspecific systemic effects, diaphoresis, and less commonly other autonomic and neurological effects. Recluse spiders (Loxosceles spp.) are distributed mostly through the tropical and subtropical Western Hemisphere and can cause severe skin lesions and rarely systemic effects; most bites are unremarkable. Highly dangerous spiders in South America (armed spiders) and Australia (funnel-web spiders) cause rare but severe envenomation requiring medical intervention and sometimes antivenom. Most other spiders involved in verified bites cause minor, transient effects. Many spiders blamed for causing medical mischief have been elevated to medical significance via circumstantial evidence, poor reporting, and repetitive citation in the literature; several species have been shown to be harmless with more stringent scientific evidence involving verified bites in humans.

A variety of refugia were offered to different instars of brown recluse spiders, Loxosceles reclusa Gertsch and Mulaik, and a South American recluse spider, L. laeta (Nicolet), to determine whether they preferred certain types of refugia spaces. Variables included (1) crevice widths ranging from 3.2 to 21 mm, (2) horizontal and vertical orientations, and (3) new refugia or refugia that had silk deposited by a previous conspecific resident. An additional 30-d assay with similar-sized refugia studied each species' propensity for site fidelity or movement among refugia. L. reclusa preferred crevice widths > or = 9 mm with no correlation of body size to crevice width, whereas L. laeta preferred crevice sizes > or = 6.4 mm with a marginally significant correlation between crevice width and body size. Both species preferred (1) vertical instead of horizontal-oriented refugia and (2) refugia with conspecific silk compared with previously uninhabited refugia. There was no significant difference between the species in their propensity to move among refugia in the 30-d trial; however, both species had individuals that were always found in the same refugium for the entire assay and individuals changing refugia every 2-3 d. The propensity to switch refugia was not affected by the degree of starvation for the period tested as was initially hypothesized. The possible implications of this research toward developing novel control measures for Loxosceles spiders are discussed.

Purpose: To determine whether the number of brown recluse spider bites diagnosed by South Carolina physicians coincides with evidence of brown recluse spiders found in the state., Methods: Brown recluse spider bite diagnosis data were extracted from 1990 and 2004 surveys of South Carolina physicians. This was compared with the known historical evidence of brown recluse spiders collected in South Carolina and derived from various sources, including state agencies, arachnologists, and museum specimens., Results: South Carolina physicians diagnosed 478 brown recluse spider bites in 1990 and 738 in 2004. Dating to 1953, 44 brown recluse spider specimens have been verified from 6 locations in South Carolina., Discussion: The number of brown recluse bites reportedly diagnosed in South Carolina greatly outnumbers the verified brown recluse specimens that have been collected in the state. The pattern of bite diagnoses outnumbering verified brown recluse specimens has been reported in other areas outside of this spider's known endemic range.

Bites by the woodlouse spider, Dysdera crocata, are virtually innocuous. The main symptom is minor pain, typically lasting less than 1h, probably due mostly to mechanical puncture of the skin. However, because the spider has a strong proclivity to bite, has large fangs which it bares when threatened and is commonly mistaken for the medically important brown recluse spider in the United States, documentation of the mild effects of its bites may prevent excessive, unwarranted and possibly harmful treatment. We present information on eight verified bites reported to us as well as eight additional bites recorded in the literature.

Spiders of the genus Cheiracanthium are frequently reported in review articles and medical references to be a definitive cause of dermonecrosis or necrotic arachnidism in humans. We provide 20 cases of verified bites by Cheiracanthium spiders from the United States and Australia, none with necrosis. A review of the international literature on 39 verified Cheiracanthium bites found only one case of mild necrosis in the European species C. punctorium. The basis for the suggestion that this spider genus causes dermonecrosis seems to be mostly inference from venom experiments in rabbits and guinea pigs, circumstantial spider involvement in human skin lesions, and repetitive citation of non-definitive reports in the medical literature. We discuss factors that lead to the erroneous elevation of virtually innocuous spiders to that of significant medical concern, which is a recurring problem in the medical community.

Loxoscelism (bites by spiders of the genus Loxosceles) is the only proven arachnological cause of dermonecrosis. Although Loxosceles spiders can be found worldwide, their distribution is heavily concentrated in the Western Hemisphere, particularly the tropical urban regions of South America. Although Loxosceles bites are usually mild, they may ulcerate or cause more severe, systemic reactions. These injuries mostly are due to sphingomyelinase D in the spider venom. There is no proven effective therapy for Loxosceles bites, although many therapies are reported in the literature.

There is currently a debate about the role played by temporal patterns in neural activity in olfactory coding. An accurate analysis of this question, however, is only possible if the temporal properties of a stimulus itself are well defined. So far, no technique with sufficient temporal resolution has been available to accomplish this. Using a photoionization detector (PID), we show that the configuration of the odor delivery apparatus and the airflow settings greatly influence the integrity of a stimulus profile within an odor delivery apparatus. In a situation where pulsatile odor stimuli are applied to a stationary preparation, we tested the effect of 1) axial and off-center location within the airstream, 2) airflow of the odor delivery, 3) exit tube length, 4) exit tube diameter, 5) orientation of the odor delivery device in relation to the exhaust flow, and 6) exhaust tube air speed. This has important implications for the study of time in olfaction; significant planning must be incorporated into the design of the experiment to provide a well-defined odor delivery system.

An Internet offer was made to identify any spider in the United States perceived to be a brown recluse spider, Loxosceles reclusa Gertsch & Mulaik (Sicariidae). In total, 1,773 arachnids from 49 states represented three orders (Araneae, Solifugae, and Opiliones) and the identifiable spiders (Araneae) consisted of 38 families, 88 genera, and 158 recognizable species. Participants from states at least half within the known brown recluse distribution submitted Loxosceles spiders 32- 89% of the time, except Louisiana and Mississippi with no submissions. From 25 of 29 states completely or almost completely outside of the range of Loxosceles spiders, no recluse spiders were submitted. Only two discoveries of brown recluses and two of the worldwide tramp species Loxosceles rufescens (Dufour) were submitted from nonendemic Loxosceles areas. States on distribution margins of brown recluse or other native Loxosceles spiders were intermediate in their Loxosceles submissions. This study showed that 1) the general public perceives brown recluses to occur over wide-ranging areas of the United States; and 2) brown recluses are frequently submitted from endemic states and almost never from nonendemic states, and therefore are virtually limited to their known distributions. This study corroborates opinions that diagnosis of brown recluse spider bites is best restricted to areas historically supporting proven, widespread populations of Loxosceles spiders.