Mosquito Repellents DEET N N Diethyl m toluamide has proven track record of effectiveness and safety Highest concentrations commercially available are not necessary however 15 30 DEET is sufficient Alternatives largely unproven citronella oil of lemon eucalyptus Avon Skin so soft and not recommended for small children Wearing long sleeves and long pants and avoiding being outside during crepuscular periods evening morning reduces exposure to mosquitoes Mosquito control approaches Targeting larvae Main advantage larvae found in specific locations And efforts may disrupt natural control Targeting adults widespread so cannot target control efforts But habitats can be difficult to find tree holes or environmentally sensitive wetlands pesticides need to be applied in areas with people birds bees Main advantage control applied after natural control has taken its toll no need to kill a mosquito that is already dead Mosquito control methods Source reduction eliminate breeding sites see cartoon below Chemical larvicides Adult spraying Environmentally benign materials Bti juvenile hormone mimics safe for other insects and Biological natural control mosquitoes have their own diseases mosquitofish predaceous insects FYI mosquitoes are too small for birds bats to bother with but mosquitoes will feed on animals them Emerging genetic control approaches Sterilizing insects non viable progeny produced Pathogen incompatiblities Wolfbachia bacterial insertion prevents dengue virus transmission A control measure pesticide biocontrol organism may kill many larvae but competition is then With control just as many or more mosquito adults may be produced and ones produced may be Problem public skepticism of GMOs Tree hole container breeding mosquitoes Intraspecific competition for food among larvae may be intense 95 natural mortality from starvation reduced fewer starve more robust and better vectors Control might make things worse Aedes albopictus Asian Tiger mosquito Introduced into USA in 1984 in a shipment of old tires from Japan eggs in tires spread through southeastern US up Mississippi valley now most abundant species in Athens Major virus vector in SE Asia e g Dengue so a concern here Aedes japonicus Most recent invader in Georgia Mosquito Arbo Virus Transmission Arbo virus transmission similar for all viral diseases Mosquito female picks up virus from reservoir humans birds while blood feeding Virus enters gut penetrates the gut wall into the hemocoel then migrates to the salivary glands where it multiples 7 10 days New host is infected when saliva it injected into bite site when a new blood meal is sought biological transmission because virus multiples