2011 Annual Report - Sacramento-Yolo Mosquito & Vector Control ...

SurveillanceBEES AND WASPSThe District maintains honey bee swarm traps with swarm trap lures inlocations which may give an early indication of arrival of the Africanizedhoney bees to our counties. The program currently consists of threelocations in Yolo County and six in Sacramento County. In 2011, wehad two honey bee hives become established in our swarm traps. Uponinvestigation they were determined to not be overly aggressive and thusgenetic testing was not initiated. Local beekeepers removed the hives sothey did not have to be destroyed.The District’s yellowjacket monitoring and control program was establisheddue to nuisance and safety issues associated with high yellowjacketpopulations. The program consists of trapping at different times of theyear to target different populations of yellowjackets. In the spring, theDistrict initiates apple juice-baited trapping to capture queens beforenests can be established. The laboratory identifies and counts these trapsand keep historical data on all sites. In 2011 we placed 20 of these trapsin the Herald area, a known focal point for yellowjacket nests. 1,051yellowjacket queens were trapped and identified to species in these trapsin the spring and early summer of 2011. In addition to queen traps,worker traps are set throughout the year. These are baited with heptylbutyrate, an attractant. These traps are set in locations throughout 23 sitesin Sacramento and Yolo Counties. 1,982 total yellowjacket workers werecollected and identified to species in these traps in 2011.IDENTIFICATION OF ARTHROPODSOF PUBLIC HEALTH SIGNIFICANCEMosquitoes are vectors of various diseases, including West Nile virus,Western Equine Encephalomyelitis virus, St. Louis Encephalitis virus,canine heartworm, dengue, and malaria, while ticks serve as themain vectors of Lyme disease, Babesiosis and Ehrlichiosis, and fleasare potential vectors of the plague. Besides identifying mosquitoesand ticks collected through our surveillance program, our laboratoryreceives and identifies many other arthropods brought in by thepublic, such as ants, termites, springtails, mites, solitary and carpenterbees, long-horned beetles, honey bees, yellowjackets, spiders, storedproduct pest beetles, moths, midges and a variety of flies.PESTICIDE RESISTANCE MANAGEMENTPesticides play an important role in mosquito and vector controlintegrated vector management (IVM) programs. We have to remainwary of resistance to pesticides evolving and spreading, which wouldthreaten the efficacy of our current control programs and allow thepotential for new and reemerging vector-borne diseases. Therefore,our laboratory performs resistance testing on mosquito samplescollected from areas of concern throughout both counties. Ourlaboratory maintains mosquito colonies that have been tested and aresusceptible to the active ingredients in the products used by our District.These are susceptible reference colonies used as comparison whentesting mosquitoes collected from the field, following resistance testingprotocols from the Centers for Disease Control and Prevention (CDC).If the testing results of field populations indicate possible resistanceissues, the samples are submitted to the University of California or theCenters for Disease Control and Prevention for further molecular andbiochemical testing.RESEARCH AND SPECIAL PROJECTSThe laboratory is responsible for performing analyses of the effectiveness of ULV treatments in Sacramento and Yolo Counties.Bioassay cages with live adult mosquitoes and slide spinners that collect droplets for analysis are used to monitor the sprayingevents. In addition, our District is involved in many research projects that may directly affect some aspect of our operations, suchas ongoing evaluation of control methods and products, and alternative materials. The District also works closely with researchersfrom the University of California, Montana State University, and from the industry sector, on collaborative research projectsinvolving the ecology of West Nile virus in California, effectiveness of ULV treatments, pesticide deposition, and evaluation ofdifferent products and formulations for mosquito control.The District provides immature and adult mosquitoes from the colonies kept on its premises or wild-caught, upon request, toa variety of researchers from the National Institutes of Health (NIH), the California Department of Public Health (CDPH), theUniversity of California, California State University - Sacramento, Industry sector, and other Mosquito Control Districts throughoutthe country.2011 Annual Report15