Spatiotemporal Distribution of Two Euschistus spp. Stink Bugs (Hemiptera: Pentatomidae) in Southeastern Farmscapes.

Stink bugs (Hemiptera: Pentatomidae) are ubiquitous, cryptic, phytophagous pests that are found in many crops. In agroecosystems, individuals disperse from adjacent noncrop hosts and tend to aggregate or cluster within fields. In this study, we characterized the distribution of Euschistus servus (Say) and Euschistus tristigmus (Say) (Hemiptera: Pentatomidae) over 2 yr at three southeastern United States farmscapes. Stink bugs were captured in pheromone-baited traps, and Spatial Analysis by Distance Indices (SADIE) used to identify the location of significant aggregations by habitat type and season. Euschistus servus adults were more likely to be captured in pecan orchards, cotton, other crops, or unmanaged habitats than in woodland habitats. Significant aggregations of E. servus were detected in a variety of habitats including pecan, corn, cotton, peanut, and tobacco, as well as fallow and hay fields, pastures, and hedgerows. Fewer adult E. tristigmus were captured than E. servus adults, and E. tristigmus adults were typically trapped and aggregated in woodland habitats. The resulting data provide an important understanding regarding the seasonal movement and relative abundance levels of stink bug populations, which are critical to the development of integrated pest management strategies.

CT screening for lung cancer: value of expert review of initial baseline screenings.

OBJECTIVE. Appropriate radiologic interpretation of screening CT can minimize unnecessary workup and intervention. This is particularly challenging in the baseline round. We report on the quality assurance process we developed for the International Early Lung Cancer Action Program. MATERIALS AND METHODS. After initial training at the coordinating center, radiologists at 10 participating institutions and at the center independently interpreted the first 100 baseline screenings. The radiologist at the institutions had access to the center interpretations before issuing the final reports. After the first 100 screenings, the interpretations were jointly discussed. This report summarizes the results of the initial 100 dual interpretations at the 10 institutions. RESULTS. The final institution interpretations agreed with the center in 895 of the 1000 interpretations. Compared with the center, the frequency of positive results was higher at eight of the 10 institutions. The most frequent reason of discrepant interpretations was not following the protocol (n = 55) and the least frequent was not identifying a nodule (n = 3). CONCLUSION. The quality assurance process helped focus educational programs and provided an excellent vehicle for review of the protocol with participating physicians. It also suggests that the rate of positive results can be reduced by such measures.

Rise and fall of cotton aphid (Hemiptera: Aphididae) populations in southeastern cotton production systems.

The impact of natural enemies on cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), populations in cotton, Gossypium hirsutum L., production systems in the southeastern United States was evaluated over 3 yr in irrigated commercial cotton fields. Fungal epizootics caused by the entomopathogen Neozygites fresenii (Nowakowski) Batko reduced aphid numbers to subthreshold levels in 1999, 2000, and 2001 and occurred consistently in early to mid-July in all 3 yr. Scymnus spp. were the most abundant aphidophagous predators, although other coccinellid species and generalist predators such as spiders, fire ants, heteropterans, and neuropterans also were present. Studies using arthropod exclusion cages demonstrated little impact of predators or parasitoids on aphid populations before fungal epizootics. Arthropod natural enemies were most abundant after epizootics and may have suppressed aphid populations late in the season. Seed cotton yield, and lint quality were not affected by aphicide applications in any year of the study. Implications of these findings for aphid management in the southeastern United States are discussed.