Heat Tolerance of the Brown Recluse Spider (Araneae: Sicariidae): Potential for Pest Control.

The brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, is a well-known venomous spider common in the south-central United States where infestations can reach thousands of individuals in a single structure. Bites from this spider pose a risk of dermonecrotic lesions (loxoscelism) or, rarely, more serious systemic effects. The heat tolerance of this spider is understudied but may offer an alternative pest control solution to pesticides or fumigation, both of which have their disadvantages. We subjected brown recluse spiders to increasing temperatures to establish the upper lethal temperature (LT). Using probit analysis to generate probability of mortality at increasing temperatures, we then exposed adult spiders to the observed LT50 to simulate whole-room heat treatment. Laboratory results predict exposure to 48°C for 130 min will achieve 100% mortality of adult spiders. Field tests need to be conducted to determine the efficacy of heat treatment in a variety of real-world situations.

Distribution of the brown recluse spider (Araneae: Sicariidae) in Illinois and Iowa.

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.

The elusive nature of self-measurement: the self-construal scale versus the twenty statements test.

In the present study, the authors compared 2 frequently used measures to operationalize the construct of the self, namely, the Self-Construal Scale (SCS; T. M. Singelis, 1994) and the Twenty Statements Test (TST; M. Kuhn & T. S. McPartland, 1954), in a sample of 324 male and female undergraduate psychology students of diverse ethnocultural backgrounds. Results demonstrated low intercorrelations between the 2 measures, suggesting that the qualitative and quantitative measures did not evaluate the same construct. A factor analysis of the SCS scale revealed 3 constructs-an independent construct, an interdependent construct, and a power distance or hierarchy construct. Implications for future research included the need for ongoing work in identifying and measuring the constructs of the self.