Banugopan Kesavaraju

The Asian tiger mosquito, Aedes albopictus, was first detected in North America twenty five years ago. It utilizes water-holding container habitats as immature development sites, and has rapidly spread throughout the eastern United States. Aedes albopictus has occasionally been detected in the western United States, but until recently no established populations of A. albopictus were reported. The western tree-hole mosquito, Aedes sierrensis, is the most common tree-hole mosquito throughout the western United States, and is expected to more frequently encounter A. albopictus. In this study, competition between A. albopictus from the eastern United States and A. sierrensis from the western United States was tested in order to better understand the potential for either competitive displacement of A. sierrensis by A. albopictus or competitive resistance of A. sierrensis to A. albopictus. Varying densities of each species were reared with limited resources in a response surface design. Consistent with a prior study, we found that A. albopictus was clearly a superior larval competitor than A. sierrensis. Aedes sierrensis λ′ (finite rate of increase) decreased with increasing A. albopictus density, but in contrast, A. albopictus λ′ actually increased with increasing A. sierrensis density; a result that was not reflected by individual fitness parameters. These results indicate that A. sierrensis will not be an effective barrier to A. albopictus invasion into tree-holes in the western United States.

Malathion is an organophosphate insecticide that is used for the control of adult mosquitoes and agricultural pests. Recent studies have shown that m

The rapid analyte measurement platform (RAMP) system is an immunoassay test for West Nile virus (WNV) detection. Although reverse transcriptase-polymerase chain reaction (RT-PCR) methodology has been regarded as the gold standard for confirming WNV presence, usage of RAMP testing kits has increased in the past years. We collected RAMP test result data that were subsequently confirmed with RT-PCR methodology from mosquito control agencies to evaluate the efficacy of the RAMP testing. Results indicate that there are a high number of false positives (RAMP positive, RT-PCR negative) with RAMP testing. Correlation between RAMP unit values and RT-PCR cycle threshold values were varied depending on the primer/probe being compared. Comparison of RT-PCR results (on the same samples) between laboratories also indicates variation among the procedures and their potential to influence the RAMP testing efficacies. We discuss the potential issues and solutions that could prevent the high rate of false positives.

Aquatic prey show behavioral modifications in the presence of predation-risk cues that alleviate their risk from predation. Aedes albopictus (Skuse),

Aedes albopictus (Skuse) and Aedes atropalpus (Coquillett) (Diptera: Culicidae) are container-dwelling mosquito species that are well established in

In aquatic systems, prey animals associate predation risk with cues that originate either from the predator or from injured conspecifics. Sources and benefits of these cues have received considerable attention in river, lake, and pond ecosystems but are less well understood in small container ecosystems that can hold less than a liter of water. Mosquitoes Aedes triseriatus (Say) and Aedes albopictus (Skuse) encounter predatory Corethrella appendiculata (Grabham) and Toxorhynchites rutilus (Coquillett) in small containers and show antipredatory behavioral responses. We investigated the sources of the predation cues to which these prey larvae respond. We tested whether Ae. albopictus larvae show behavioral responses to cues emanating from the predator or from damage to prey caused by the act of predation. We also tested whether Ae. triseriatus respond to cues present in fluid or solid residues from predator activity. Ae. albopictus showed behavioral modifications only in response to waterborne cues from a feeding predator and not to cues from a starving predator, indicating that Ae. albopictus respond to cues created by the act of predation, which could include substances derived from damaged prey or substances in predator feces. Ae. triseriatus showed behavioral responses to solid residues from predation but not to fluid without those solids, indicating that the cues to which they respond originate in predator feces or uneaten prey body parts. Our results suggest that cues in this system may be primarily chemicals that are detected upon contact with solid residues that are products of the feeding processes of these predators.

Competitive interactions may facilitate or repel invaders into new communities, and these interactions may depend on other environmental conditions s