Triatomine insects are a problem for human health in southwestern United States because of the moderate-to-severe allergic reactions their bites can cause and because they are potential vectors of Chagas Disease. Although both infected insects and wild mammalian reservoirs are plentiful in southern U.S., only seven cases of autochthonous transmission (plus 16 new presumed cases) of this disease have been reported to date. Therefore, the purpose of this study was to investigate triatomine distribution and abundance in a metropolitan area in southern Arizona. Species, life-stage, locality, and date of collection were recorded for 1,878 triatomine insects collected during 4 yr inside and around houses. For both sexes of the most abundant species, Triatoma rubida (Uhler) (>95% of triatomines collected), dispersal followed a typical year-to-year pattern: dispersal started at the beginning of May and peaked during the first-second week of June. T. rubida was found widely distributed in suburban areas. Triatomines of the two less abundant species, T. recurva (Stal) and T. protracta (Uhler), were collected in all suburban areas throughout the 4-yr survey. All of these population characteristics were observed both at a large (i.e., all collection sites pooled) and a small (i.e., single collection sites) scale. In total, approximately 55-60% of the triatomines were collected inside houses, and 30-35% of those were found in or near beds; thus, it is likely that they fed on humans. To our knowledge, this study is the first comprehensive multi-year analysis of triatomine distribution and abundance in the U.S., providing data that allow inferences about risks to human health.

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A two-generation laboratory study was conducted on a captive population of American kestrels (Falco sparverius) to investigate the possible reproductive and teratogenic effects of the pesticide dicofol. Paired females were exposed to three levels of dicofol: 0, 5, and 20 mg/kg. Integrity of the reproductive tract of the resulting embryos was examined. Viable eggs were hatched, and these birds were permitted to breed the following year. Breeding performance for these birds was measured based on their ability to form pair bonds and exhibit normal behavior in the presence of a mate. Clutch completion, fertility, hatchability, and number of hatchlings reared to the fledging were used as reproductive parameters. Females dosed with 20 mg/kg of dicofol laid eggs with shells that were significantly (p < 0.05) thinner than those of the control birds. Residue levels of dicofol in the form of dichlorobenzophenone were detected in the first and second clutch eggs of the 20-mg/kg dose group only. Male embryos from females dosed with 5 and 20 mg/kg of dicofol had gonads that were significantly different (p < 0.05) from the control chicks. Feminization of male embryos was confirmed by the presence of primordial germ cells in the male gonad. Second-generation adult 5-mg/kg females showed a significantly (p < 0.05) greater number of eggs and hatched chicks lost when compared to second-generation control females. Similar results were found in second-generation 5-mg/kg males paired with normal females and had a significant (p < 0.05) number of chicks die posthatching. Results of second-generation breeding parameters indicate a negative effect on reproductive behavior.

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