Resting and energy reserves of Aedes albopictus collected in common landscaping vegetation in St. Augustine, Florida.

The resting behavior of Aedes albopictus was evaluated by aspirating diurnal resting mosquitoes from common landscape vegetation in residential communities in St. Augustine, FL. Energy reserves of the resting mosquitoes were analyzed to determine if there was a correlation between mosquito resting habitat and energy accumulation. Six species of plants were selected and 9 collections of resting mosquitoes were aspirated from each plant using a modified John W. Hock backpack aspirator during June and July 2012. Eight mosquito species were collected, with Ae. albopictus representing 74% of the overall collection. The number of Ae. albopictus collected varied significantly with the species of vegetation. When comparing the vegetation and abundance of resting mosquitoes, the highest percentages of Ae. albopictus were collected resting on Ruellia brittoniana (Mexican petunia), Asplenium platyneuron (fern), Gibasis geniculate (Tahitian bridal veil), followed by Plumba goauriculata (plumbago), Setcreasea pallida (purple heart), and Hibiscus tiliaceus (hibiscus). There were significant differences in lipid and glycogen accumulation based on type of vegetation Ae. albopictus was found resting in. Resting mosquitoes' sugar reserves were not influenced by species of vegetation. However, there was an overall correlation between vegetation that serves as a resting habitat and energy reserve accumulation. The results of our study demonstrate the potential to target specific vegetation for control of diurnal resting mosquitoes.

Evaluation of a new formulation of permethrin applied by water-based thermal fogger against Aedes albopictus in residential communities in St. Augustine, Florida.

The efficacy of a new water-based formulation containing 30% permethrin and 30% piperonyl butoxide against laboratory and field populations of Aedes albopictus was evaluated in the laboratory, in semifield experiments, and in residential communities in St. Augustine, FL. In laboratory bottle bioassay, 3 doses (3.18 g/ml, 2.26 g/ml, and 1.59 g/ml) of the permethrin product resulted in 100% mortality of adult mosquitoes in 1 h. In semifield experiments, the insecticide sprayed by the water-based thermal fogger at 381.5 ml/min application rate caused 99% mortality of caged mosquitoes. At 24 h posttreatment in the residential communities, there was 79% and 83% reduction of the natural population (numbers) of adult Ae. albopictus and all adult mosquito species collected in BioGent (BG) sentinel traps baited with a BG lure in the 3 test sites, respectively. There was also a 79% reduction in the number of Ae. albopictus eggs collected in ovitrap used in the treated sites. The reductions were significant for adult Ae. albopictus and all mosquito species at 1 wk posttreatment, but no significant reduction was observed at 2-3 wk posttreatment. These findings demonstrate the effectiveness of the new water-based permethrin product against Ae. albopictus populations in residential communities.

Evaluation of boric acid sugar baits against Aedes albopictus (Diptera: Culicidae) in tropical environments.

Attractive toxic sugar bait (active ingredient, 1% boric acid) was evaluated against Aedes albopictus Skuse populations in the laboratory, semi-field trials, and field trials in residential communities in St. Augustine, Florida. Laboratory evaluations of boric acid sugar baits applied to the plant Pentas lanceolata (Rubiaceae) demonstrated 100 and 92% mortality of A. albopictus at day 7 and 14, respectively. A semi-field study evaluating the bait application to the upperside or topside of leaves resulted in no significant difference on mortality (P>0.05). Overall combined top and bottom boric acid sugar bait application mortality at day 7 was 95% based on leaf bioassays. Field application of the boric acid sugar baits significantly (P<0.05) decreased adult A. albopictus populations up to day 21 post-treatment compared to the pre-treatment population numbers. A significant reduction in oviposition was demonstrated both at day 7 and 14 post-application (P=0.001) as monitored by ovitraps. Attractive toxic sugar bait application in tropical environments demonstrated efficacy, persistence, and feasibility in controlling A. albopictus populations.