Dr. Stafford Tick Management Handbook - Newtown, CT

StaffordThe Connecticut Agricultural Experimentation Stationare registered for use in the state. Depending upon the state the agency may be associated with thestate Department of Agriculture, Consumer Protection, or Environmental Protection.Biological Control of TicksTicks have relatively few natural enemies, but the use of predators, parasites, and pathogenshas been examined for tick control. Tick predation is dif. cult to document and observations aresporadic. Most arthropod predators are non-speci. c, opportunisticfeeders and probably have little impact on ticks. Anecdotal reportssuggested that guinea-fowl or chickens may consume ticks andimpact local tick abundance. However, there is no good evidenceto support this, and turkey foraging was not found to reduce thelocal density of adult ticks. A minute parasitic wasp, Ixodiphagushookeri, parasitizes blacklegged ticks in a few geographicallyisolated tracts in New England with superabundant deer and tickpopulations. However, my studies indicate that the usefulnessof this wasp to control I. scapularis is very limited. The waspdisappears at deer and tick densities typical of most mainland areas.Insect parasitic nematodes have been studied as possible biologicalcontrol agents. Engorged female I. scapularis are susceptible tocertain types of nematodes, but these nematodes are too sensitive tothe colder autumn temperatures when the ticks are present.The application of insect pathogenic fungi, however, is apromising approach for controlling ticks. Several fungi, suchas Beauveria bassiana and Metarhizium anisopliae have beenshown to be pathogenic to I. scapularis in the laboratory and. eld. A perimeter treatment of existing commercial formulationsof the fungus Beauveria bassiana and Metarhizium anisopliaeat residential sites has been shown to control I. scapularis insmall experimental trials. Metarhizium is a naturally occurringsoil fungus that is considered nonpathogenic to mammals. Thefungus infects host insects (and ticks) when conidia (spores) attachto the host cuticle, germinate, penetrate the cuticle and hyphae(. laments) grow. Metarhizium also produces insect toxic secondarymetabolites. The green muscardine fungus M. anisopliae Strain 52is being developed as a tick control biopesticide by NovozymesBiologicals Inc., Salem, VA. Additional residential trials with thisfungus in Connecticut and New Jersey in 2007 provided goodcontrol of nymphal I. scapularis and a limited launch under theTick-Ex label is anticipated in 2008. A granular product is alsounder development. This fungus posses minimal risk to non-targetorganisms and does not harm many bene. cial insects such ashoney bees, green lacewings, lady beetles, parasitic Hymenopteraor earthworms at rates used. The Metarhizium spores, appliedlike a traditional pesticide, may become an option in future tickmanagement programs and could readily meet organic standards.Illustrations top to bottom: Adult of H. hookeri, engorged nymph of I.scapularis showing parasitoid emergence hole, female I. scapularisshowing infestation by M. anisopliae (two pictures).11011111211370Bulletin No. 1010