Residual Activity of Pyriproxyfen Against Mosquitoes in Catch Basins in Northwestern Riverside County, Southern California.

A field study was carried out on the year-long residual activity of the insect growth regulator (IGR) pyriproxyfen (Nylar 0.5G) in comparison with methoprene (Altosid® XRP Pellets) against mosquito developmental stages in catch basins in northwestern Riverside County, southern California. Pyriproxyfen was applied at 75, 100, 125, 150, 175 g per catch basin and methoprene at 3.

Rickettsial Infections among Cats and Cat Fleas in Riverside County, California.

Presently, few studies have investigated the role of domestic cats () in the recrudescence of flea-borne rickettsioses in California and the southern United States. In this study, we aimed to investigate the presence of or in domestic cats () and the fleas (primarily , the cat flea) associated with these cats in Riverside County, California. Thirty cats and 64 pools of fleas collected from these cats were investigated for rickettsial infections.

Host-Feeding Patterns of Culex stigmatosoma (Diptera: Culicidae) in Southern California.

Knowledge of the blood-feeding patterns exhibited by arthropod vectors is essential for understanding the complex dynamics of vector-borne disease transmission. Some species of mosquitoes belonging to the genus Culex have been implicated as having major roles in the transmission of arboviruses such as West Nile virus, Saint Louis encephalitis virus, and Western equine encephalitis virus. Although the host-feeding patterns for many of these Culex species are well studied, the host-feeding patterns of Culex stigmatosoma Dyar are relatively poorly studied, even though this species is suspected to be an important maintenance vector for West Nile virus and other arboviruses.

Field Evaluation of Pyriproxyfen Against Mosquitoes in Catch Basins in Southern California.

In a field trial, pyriproxyfen (Sumilarv 0.5% G) applied at 10 g and 50 g per catch basin and S-methoprene (Altosid XR briquet 2.1%) at 1 briquet per catch basin at a local park provided 100% inhibition of adult emergence (IAE) of the test species, Culex quinquefasciatus , for the first 3 wk.

Population Dynamics of Blood-Fed Female Mosquitoes and Comparative Efficacy of Resting Boxes in Collecting them from the Northwestern Part of Riverside County, California.

Objectives: Testing of blood-fed mosquitoes plays an integral role in arbovirus surveillance and in understanding its interaction mechanisms between host, vector and reservoir. The present study was undertaken to evaluate the efficacy of two different traps (gravid and resting boxes) for collection of blood-fed mosquitoes in the northwestern part of Riverside County.

Materials And Methods: Three trapping sites were selected in the Northwest Mosquito and Vector Control District of Riverside County, California.

Antigenic distribution of west nile virus in various organs of wildly infected american crows (corvus brachyrhynchos).

Objective: Since its discovery in the western hemisphere in 1999, West Nile virus (WNv) has caused extensive bird mortality across North America, especially in American crows (Corvus brachyrhynchos) which are highly susceptible to WNv. In this study, antigenic distribution of WNv among different organs of American crows was studied, using the immunohistochemistry technique (IHC).

Materials And Methods: Dead crows reported by residents were collected, transported on ice, and were necropsied for heart, lung, brain, intestine, kidney, liver, spleen, pancreas, and gonad tissues.

Comparison of immunohistochemistry and polymerase chain reaction for detection of West Nile virus in naturally infected dead birds.

Introduction: Credible vector-borne disease surveillance programs, especially in developing countries with limited resources, must include diagnostic tests that are efficient, inexpensive and simple and safe to administer while maintaining high levels of sensitivity and specificity. Since immunohistochemistry (IHC) includes most of these features, its sensitivity, specificity, predictive positive value (PPV) and predictive negative value (PNV) for West Nile virus (WNv) screening were compared to those of the gold standard, RT-PCR testing of kidney tissue in dead birds.

Methodology: IHC and RT-PCR were performed for WNv antigen on 41 dead birds (belonging to five orders) collected from the northwest region of the Riverside County of California.

Effect of effluent-treated water on mosquito development in simulated ponds at the Prado Wetlands of southern California.

Studies were conducted to determine the effect of water quality on mosquito development at the Prado Wetlands in southern California during 2003-04. In field experimental ponds, mosquito abundance was significantly higher in the sewage effluent-treated water than in untreated control. As compared to untreated control, treated water had higher dissolved oxygen, total nitrogen, phosphorus, and turbidity, and it showed lower electrical conductivity, sulfate, carbonates, and bicarbonates.