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Aedes albopictus is a serious nuisance species and a potential vector of domestic arboviruses in the U.S. Public health and mosquito control agencies have taken numerous actions to address the problems posed by this species. Federally mandated programs of disinsection and inspection of tire casings imported into the U.S. are aimed at preventing additional introductions of this and other exotic mosquito species. Control programs, including the use of traditional chemical larvicides and adulticides, as well as the introduction of predatory copepods into larval habitats, have been developed and tested for population management. A few of the established populations in the northern areas of Ae. albopictus distribution in the continental U.S. have been successfully eradicated through source reduction and insecticide application.

The ability of time-release formulations of larvicides and insect growth regulators (IGRs) to provide long-term control of Aedes albopictus was investigated in the field. Larvicides used in the study were Bactimos pellets (Bacillus thuringiensis var. israelensis, active ingredient) and Abate pellets (temephos, active ingredient). The IGR Altosid (methoprene, active ingredient) was used in pellet and sand formulations. Application rates were higher than label recommendations. In a preliminary test, clay flower bowls were treated with 2 g of material. Bactimos pellets failed to provide control after 60 days. Abate pellets and the Altosid formulations provided essentially 100% control for 150 days. After 360 days in the field, the Abate pellets produced 100% larval mortality, and significant levels of control were provided by the Altosid formulations and the Bactimos pellets. In a small-scale operational trial of this technique, 1 g of Altosid pellets was applied to every container that could be located in 2 urban residential neighborhoods in Lake Charles, LA. Aedes albopictus biting populations were monitored weekly in the treated areas and in an untreated control area. Biting population densities declined significantly in treated areas compared with the control area. Results suggested that long-term control of Ae. albopictus populations can be achieved economically with one application of Altosid pellets or Abate pellets in containers.

The results of a field test conducted in cooperation with the Jefferson Davis Parish Mosquito Abatement District (JDPMAD) during 1988 in southwestern Louisiana suggested that the biweekly treatment of cattle with permethrin reduced the number of adult Psorophora columbiae in nearby areas. Routine mosquito control operations by JDPMAD were similar from 1987 to 1988 in the cattle-treated area but increased an average of 41% in control areas. In spite of this, during the year of cattle treatment, captures in New Jersey light traps averaged 86 and 26% of the previous 4-year average in control and treated areas, respectively. Similarly, the proportion of trap nights in 1988 when Ps. columbiae captures exceeded 500 averaged 73 and 30% of the previous 4-year average in control and treated areas, respectively. Simulation model projections that took into account differences in JDPMAD operations, weather, cattle density, agricultural practices and the presence of treated cattle were accurate within an average of 9% of observed values for the treated and control areas. The simulation studies indicated that the treatment of cattle with permethrin reduced Ps. columbiae populations by 83%. These results suggest that host management may be a viable method for suppressing populations of Ps. columbiae and that some form of host management be considered for inclusion in integrated control programs in this environment. Further evaluation of this concept is warranted.

The percentage of resting mosquitoes that had fed on blood or were gravid-parous was determined in two pastures associated with the riceland agroecosystem in southwestern Louisiana. In one pasture, all of the cattle were treated with permethrin every 14 d over a 22-wk period, whereas cattle in the other pasture were untreated. The percentage of blood-engorged Psorophora columbiae (Dyar & Knab) was significantly lower in the vicinity of the treated herd. The effectiveness of the permethrin treatment in reducing blood feeding decreased over the interval between applications and as a result of increased rainfall. The proportion of Ps. columbiae that was gravid or parous was not significantly affected by the treatment. Anopheles quadrimaculatus Say engorgement rates also were significantly reduced by the treatment; however, Anopheles crucians Wiedemann and Culex salinarius Coquillett engorgement rates did not differ between the two areas. The results indicate that host management by permethrin treatment has potential for controlling Ps. columbia and An. quadrimaculatus populations in the Louisiana riceland-pasture agroecosystem.

The effects of exposure to sublethal concentrations of Bacillus thuringiensis var. israelensis (Serotype H-14) on second instar Aedes aegypti larvae were investigated. A test system was developed in which adverse effects would be detected as increased duration of larval development and decreased adult body size. No evidence of negative effects on survivors could be detected when sufficient B.t.i. dosages were applied to kill approximately half of the larvae in the treatment groups. However, when larval density was not controlled, and competition for food decreased as a result of larval mortality in the B.t.i.-treated groups, adult wing length was greater in the B.t.i. survivors than in the untreated controls. In addition, a residual mortality was noted in larvae that had been exposed to B.t.i. for 24 hr and then removed to habitats without B.t.i.

The article provides an overview of West Nile Virus (WNV). Although first identified in 1937 in Africa, the article states, the first detection of WNV in the western hemisphere occurred in New York City in 1999. Topics of discussion include seasonal epidemics in the U.S. of febrile illness and neurologic disease, cases of WNV neuroinvasive disease (WNND), and mosquito control. Also discussed are personal protection from mosquito bites, research into prevention strategies, and WNV surveillance data for 2007.

This article presents information from studies conducted by the U.S. Centers for Disease Control and Prevention (CDC). This study examines West Nile Virus (WNV) Activity in the U.S. during 2006. During 2006, WNV transmission to humans or animals expanded into 52 counties that had not previously reported cases and recurred in 1,350 counties where it had been reported before. Nearly 1,500 cases of WNV neuroinvasive disease (WNND) were reported for a 14 percent increase over 2005. In humans, a total of 4,261 cases were reported and the number is almost the same in birds. Horses and squirrels also showed significant infection. Community level mosquito control is the most effective way of reducing the disease.