Potential Use of Pyriproxyfen for Control of <I>Aedes aegypti</I> (Diptera: Culicidae) in Iquitos, Perú

Abstract

The effects of pyriproxyfen were tested against a local population of Aedes aegypti (L.) in Iquitos, Perú. Bioassays showed that, when applied to late instars, pyriproxyfen prevented adult emergence at extremely low concentrations (LC 50 0.012 ppb). There was no adult emergence from water sampled from storage tanks that had been seeded with the equivalent of 50 Ð 83 ppb (AI) pyriproxyfen. Five months after treatment, despite constant dilution of these tanks, water sampled from these sources continued to be lethal to larvae and pupae. Additional studies, carried out in the laboratory, showed that groups of Þve or 20 female blood-fed mosquitoes, exposed to residues of 0.003 g (AI) pyriproxyfen/m 2 , could transfer enough chemical to new oviposition sites to prevent 80% of adult emergence from larvae developing in that previously uncontaminated water. Moreover, although the fecundity of the adult females used as the transfer vehicles in these tests was unaffected, the subsequent eclosion of the eggs that these mosquitoes laid was decreased by 70 Ð90%. It also was shown that, at very high concentrations (30,000 ppb), pyriproxyfen-treated water sources were as likely to be used as oviposition sites as untreated sources. These data suggest that treated sites might act as sinks for mosquito reproduction and moreover that such sites might act as dissemination sources for the horizontal transfer of larvicides to new environments by mature females. We review the literature on the environmental and human health effects of this compound and discuss its potential for use as a mosquito control agent in the Þeld.

Identification of bacteria and bacteria-associated chemical cues that mediate oviposition site preferences byAedes aegypti

“…aegypti in disease-endemic regions (16). Second, increasing the residence time within containers would assure that females receive ample exposure to traps impregnated with lethal toxicants (17,18) or with biologically active materials, such as insect growth regulators, that can be horizontally transferred to adjacent water containers through skip-oviposition (19,20). In addition to their potential in mosquito management programs, the oviposition-inducing semiochemicals will facilitate investigations of contact-mediated chemoreception in a mosquito vector of substantial public health importance globally.…”

Field Efficacy of New Larvicide Products for Control of Multi-Resistant Aedes aegypti Populations in Martinique (French West Indies)

“…Sihuincha and others 41 demonstrated longer performance (i.e., mortality rate > 80% for 5 months) against Ae. aegypti in water tanks treated with the same dosages in Peru.…”

Bacillus thuringiensis var. israelensis (Bti) Provides Residual Control of Aedes aegypti in Small Containers

“…Several products offer residual control of Ae. aegypti including the insect growth regulators (IGRs) s-methoprene 5 and pyriproxyfen, 6 the chitin synthesis inhibitors triflumuron 7 and novaluron, 8 and the organophosphate temephos 9 and synthetic pyrethroid insecticides. 10 However, IGR efficacy is difficult to assess and requires collection of pupae to assess emergence inhibition.…”