Location: Insect Behavior and Biocontrol ResearchTitle: Behavioral response of gravid Culex quinquefasciatus, Aedes aegypti, and Anopheles quadrimaculatus (Diptera: Culicidae) to aquatic macrophyte volatiles Author
Submitted to: Journal of Vector Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2018
Publication Date: N/A
Interpretive Summary: Invasive aquatic weeds pose considerable problems to waterways in the US through obstructions of passageways and alternation of aquatic ecosystems. In particular in the Sacramento-San Joaquin River Delta, several weed species including the water hyacinth, water lettuce and parrot feather are particularly invasive. In this study, conducted by scientist from USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, in conjunction with ARS scientists from Albany, CA, the interaction of several invasive weed species and mosquitoes were examined. Some weed species were found to attract mosquitoes and increase mosquito oviposition. These data provide better insight into the potential risk of increased mosquito populations relating to the presence of aquatic weeds and can guide potential mosquito management strategies.
Technical Abstract: Mosquitoes use a variety of cues to assess whether a habitat is conducive for the development of their offspring. In addition to factors such as temperature, time of day, microbial fauna and turbidity, the presence of aquatic macrophytes can influence mosquito behavior. In the present study, the effect of odors of water hyacinth (Eicchornia crassipes), water lettuce (Pista stratioles), parrot feather (Myriophyllum aquaticum), and water pennywort (Hydrocotyle umbellata) on mosquito oviposition and attraction was investigated. In initial two-choice caged assays with gravid Culex quinquefasciatus significantly more egg-rafts were deposited in water that contained water hyacinth, water lettuce or Bermuda hay infusion (positive control) compared to water alone. In contrast, response to water containing water pennywort or parrot feather did not differ from the water control. Using a two-choice olfactometer, in-flight attraction responses of gravid Cx. quinquefasciatus, Aedes aegypti and Anopheles quadrimaculatus to volatiles from plants were evaluated. Strongest attraction of gravid Cx. quinquefasciatus and Ae. aegypti occurred in the presence of water infusions of water hyacinth and water lettuce, which were equal in attraction to that of hay infusion. Attraction to water pennywort and parrot feather infusions were low and similar to the water control. In contrast, strongest attraction of gravid An. quadrimaculatus was to hay infusion, with attraction to the four aquatic weeds not differing from water controls. These results suggest that water hyacinth and water lettuce are associated with volatile chemicals that contribute to attraction and oviposition by gravid Cx. quinquefasciatus and Ae. aegypti mosquitoes, and that the level of attraction of aquatic plant volatiles varies between mosquito species in ways that may have relevance to bait-based detection and control methods.