Evaluation of the AtrAedes™ Lure for Collection of Culex quinquefasciatus in Gravid Traps.

The typical attractant used in gravid trapping of Culex quinquefasciatus is an aged infusion of organic materials, which can change in attractiveness over time. A standardized chemical attractant dispenser derived from grass infusion, the AtrAedes™ lure, has been produced for the surveillance of the dengue vector Aedes aegypti. A study using this lure in combination with the Centers for Disease Control and Prevention gravid traps was conducted in Tanga, Tanzania. The addition of the lure to traps baited with either grass infusion or tap water did not result in significant increases in trap catch. Grass infusion-baited traps (with and without the AtrAedes lure) collected significantly more Cx. quinquefasciatus than traps baited with AtrAedes + tap water, tap water alone, or AtrAedes alone. The catches of the traps baited with AtrAedes + tap water, tap water alone, and AtrAedes alone were not significantly different from each other. Although the placement of the lure in the base of the trap may have decreased trap catches, it seems that the AtrAedes is not as effective as grass infusion for collecting Cx. quinquefasciatus in Tanzania.

Laboratory evaluation of avian odors for mosquito (Diptera: Culicidae) attraction.

Attraction of Culex quinquefasciatus Say, Culex tarsalis Coquillett, Culex nigripalpus Theobald, and Aedes aegypti (L.) to avian and other host odors was investigated in a dual-port olfactometer. Although attraction to a human arm was high for Ae. aegypti (>80%) and low for all Culex spp. (<25%), all species responded similarly to a chicken (55.3-73.6%). Responses of Ae. aegypti, Cx. quinquefasciatus, and Cx. nigripalpus to feathers were low (<20%) but greater than to controls. There was no difference in attraction of Cx. tarsalis to feathers or controls. Responses to CO2 (5 ml/min) were low for all species (<15%) except Cx. tarsalis, which were moderate (24.5%). When feathers were combined with CO2, the resulting attraction was additive or lower than responses to feather and CO2 alone for all species except for Cx. tarsalis, which had responses that were three-fold greater than expected if responses were additive. The CO2-feather treatments were less attractive than a chicken for all species. When olfactometer assays were extended from 3 to 20 min, responses by Ae. aegypti significantly increased to a chicken and CO2 and attraction of Cx. quinquefasciatus significantly greater to chickens, CO2, and feathers. None of the volatile compounds previously identified from feathers or uropygial glands tested were attractive. Both feather-rubbed cotton balls and hexane extracts of feathers were attractive and as attractive as feathers; however, ether extracts were not attractive. Feathers clearly contribute to the attraction of host-seeking Culex spp., and future studies will focus on identification of the attractant compounds.

Laboratory and field assessment of some kairomone blends for host-seeking Aedes aegypti.

Using laboratory Y-tube olfactometers, the attractiveness of lactic acid and 2 kairomone blends from the United States Department of Agriculture (USDA) and BioGents GmbH (BG) was assessed for attractiveness to Aedes aegypti. Four geographically disparate populations were assessed: North Queensland Australia (NQA), Florida USA, Minas Gerais Brazil (MGB), and Singapore. In descending order, populations were attracted to USDA, BG blends, and lactic acid. MGB was poorly attracted to lactic acid alone. The blends were less attractive than human odor. Proprietary blends were modified, and their attractiveness was assessed to find the optimum attractive mixture for NQA. Adding acetone to BG, and ammonia and caproic acid to USDA, improved attractiveness in the laboratory. Field attractiveness was assessed by coupling the blends with a newly developed BG-Sentinel Ae. aegypti trap. Trials were carried out using the BG blend, BG blend plus acetone, USDA blend, USDA blend plus ammonia and caproic acid, and a control trap with no kairomones. The traps were highly effective, with mean 24-h collections up to 11.15 Ae. aegypti per trap, and this species made up 91.7% of collections. However, the effectiveness of the unbaited control trap indicated that the BG-Sentinel has visual attractive properties for Ae. aegypti and that the kairomone lures added little to trap performance in NQA.

Regulatory oversight of biochemical pesticides by the U.S. Environmental Protection Agency: health effects considerations.

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) enables the Office of Pesticide Programs (OPP) of the U.S. Environmental Protection Agency to ensure that pesticide use in commerce will not result in unreasonable adverse effects to humans and the environment. Currently, two classes of pesticides are recognized: conventional chemical pesticides and biological pesticides. The latter group is divided into biochemical and microbial pesticides. The recent resurgence of biochemical pesticides as effective pest control agents has increased the number of applications for experimental use permits and for product registration. The fundamental information and data necessary to evaluate such products by the Health Effects Division (HED) of OPP are discussed, as well as the criteria for the classification of a pesticide as a biochemical versus a conventional chemical pesticide. In accordance with the Agency's effort to encourage the development of pesticides less toxic to humans and the environment, the scientific basis for providing future regulatory relief and reduced data requirements for biochemical pesticides is discussed.