Bites from the recluse or brown spiders (genus Loxosceles) can cause necrotic lesions and systemic effects in humans throughout the world. In the state of Paraná, Brazil, loxoscelism is considered a serious public health problem, and Loxosceles intermedia Mello-Leitão (Araneae: Sicariidae) is associated with the majority of reported accidents. In the present research we evaluated the susceptibility of L. intermedia to pyrethroid insecticides currently used for the control of spiders in both field and laboratory conditions. In laboratory tests, the most active pesticides in descending order were microencapsulated lambda-cyhalothrin (LC50 = 0.023 mg/kg), nonmicroencapsulated lambda-cyhalothrin (LC50 = 0.047 mg/kg), deltamethrin (LC50 = 0.26 mg/kg), and cypermethrin (LC50 = 1.38 mg/kg). Cockroaches, Phoetalia circumvagans (Burmeister) (n = 30), killed with microencapsulated lambdacyalothrin, were offered to the spiders. L. intermedia fed on 63.3% of the dead cockroaches during the first 6 h of experiment; none of the spiders died during the subsequent 15 d. Microencapsulated lambdacyalothrin was chosen for application in two contiguous houses. The mean volume applied was 22.8 mg (AI)/m2. Dead spiders were found during all the inspections up to 60 d after the initial application. In total, 297 dead spiders were collected; 65.7% in the attic shared by the two homes, 10.8% inside the house that had most cracks and crevices sealed and 23.6% in the control house. The use of lambda-cyhalothrin-based products for L. intermedia control is discussed.

One fundamental question in prey luring systems is to understand how visual signals are interpreted by the receiver. Predators lure prey by falsely imitating the signal of a model, or may exploit sensory preferences of the receivers, which search for rewarding signals. Crab spiders reflect ultraviolet (UV) light, ambush pollinators on flowers, and manipulate flower UV signals altering the behavior and response of prey. Whereas crab spiders typically depend on flowers to forage, adult Epicadus heterogaster departs from this standard behavior by preying on pollinators upon green leaves, even in the absence of flowers nearby. This species has a conspicuous abdomen resembling the shape of a flower, which may reflect UV signals similar to that of flowers, and thus attract pollinators. Nevertheless, no empirical evidence is available that E. heterogaster foraging on leaves mimics flowers, nor how this crab spider interacts with its prey. Field and laboratory experiments demonstrated that UV reflection of adult E. heterogaster is the main signal responsible for the attraction of pollinators. This is the first study to demonstrate that a crab spider attracts pollinators regardless of flower UV signal, which may represent an evolutionary pathway beyond the dependence of flowers.

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Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use) in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis) were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60), male (n=60), young (n=60) and just-hatched (n=60) L. intermedia, and all egg sacs (n=5) were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10) survived for 10 days; however, significant mortality was observed among male (n=10) and young individuals (n=10). Addition of cornstarch to the vacuum bag did not affect the spiders (n=20). Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments

Brown spiders (Loxosceles spp.) are venomous arachnids, successfully adapted to urban habitats in Brazil. Loxoscelism became a serious public health problem in Paraná State, especially at the capital Curitiba, where the most abundant species is Loxosceles intermedia. Hemidactylus mabouia (Gekkonidae) lizards are synanthropic predators of arthropods. In this paper, we describe the predatory behavior of the Tropical House Gecko H. mabouia on L. intermedia under laboratory conditions. Twelve geckos were observed, and all of them fed on brown spiders (n=123 observations). The attack consisted of a fast run followed by one bite on the spider’s abdomen or legs. The geckos did not attack L. intermedia anterior body parts, probably due to the fangs present in this region. Two Hemidactylus individuals were killed by L. intermedia bites: during a predatory encounter, and by an induced bite on a restrained lizard. The observations summarized in this paper show that H. mabouia could be used in the biological control of Loxosceles populations in human dwellings. However, additional field studies are necessary to quantify the impact of H. mabouia predation on urban populations of L. intermedia and other species of the same genus

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The fact that scorpions are strongly fluorescent when illuminated with long ultraviolet light (320-400 nm) has been known for decades (LAWRENCE 1954). Scorpions (and their exuviae) that do not fluoresce under UV have are yet to be found, although first instar nymphs are not generally visibly fluorescent. The fluorescence exhibited by scorpions and the intensity range of the light emitted by them may vary among species, and is affected by the time elapsed since the last molt (STAHNKE 1972). The UV light generally does not noticeably affect the behavior of scorpions (WILLIAMS 1968;STAHNKE 1972). Molecules associated with the cuticular fluorescence of scorpions have been identified as the beta-carboline (STACHEL et al. 1999) and 4-methyl, 7-hydroxycoumarin (FROST et al. 2001). However, the biological function of fluorescence has not been definitively demonstrated (KLOOCK et al. 2010). Some specialists have hypothesized that fluorescence has no function. For them, fluorescence, is either a relict trait (Frost et al. 2001) or is correlated with some other aspect of the functional molecules responsible for it (STACHEL et al. 1999). In experiments, scorpions continuously exposed to UV light for several weeks showed significant reduction in cuticular fluorescence (KLOOCK 2009). UV light can be also used to study the external morphology of a scorpion's epicuticle (VOLSCHENK 2005).Distinct invertebrate taxa, such as spiders (ANDREWS et al. 2007), harvestmen (ACOSTA 1983) In the field of pest control, the use of UV lamps is widely recommended to collect scorpions and also for locating rodent urine. In the past, mobile fluorescent lamps were used to collect scorpions (WILLIAMS 1968, STAHNKE 1972 and, more recently, low power LEDs (LOWE et al. 2003) have been used. Those, however, in order to be efficiently employed in the field, require a configuration with many LEDs -168 in the device described by LOWE et al. (2003). Our goal in this paper is to present a new device based on high power UV and white light LEDs, which can be interchanged. This new, versatile, and low cost device has long battery life. Even though it is optimized to detect and collect scorpions in low light situations, it can also be used with other groups of organisms.The device (Figs 1 and 2) employs, as illumination sources, two 3 W UV LEDs (model EDEV-SLC1-R, light emission 395 nm-410 nm ± 0.5 nm at 25°C), and two 3 W "white light" LEDs (model EDEW-3LS5-FR, light emission 455-470 nm ± 0.5 nm at 25°C), manufactured by Opto Edison ® . We used collimator lenses with an aperture angle of 25°, model LL1ED-CV25-L-M1, manufactured by Led Link ® . We chose not to apply a current exceeding 500 mA on the LEDs (below the nominal current of 750 mA), in order to prolong the lifespan of both the LEDs and the battery. As a further measure to increase the lifetime of the LEDs, the voltage on them is increased from 0 V to 7 V (3.5 V to each LED) by applying a tension ramp through pulse width modula-

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