Middle East DVEP - Armed Forces Pest Management Board

crevices, leaf litter, or moist tree holes. Eggs hatch and larvae develop in warm, moistmicrohabitats that provide abundant organic matter for food. In military fortifications,larvae may live in the cracks between stacked sandbags. The four larval instars require 4to 8 weeks to reach the pupal stage. Fourth instar larvae may diapause for weeks ormonths if the environment is excessively cold or dry. Alternatively, if environmentalconditions improve, diapause may be quickly broken. Pupation occurs in the larvalhabitat. There is no cocoon; rather, the pupa is loosely attached to the substrate by thecast skin of the 4th larval instar.Phlebotomus papatasi feeds most intensely at dusk and dawn, with some feedingcontinuing sporadically through the rest of the night. Phlebotomus papatasi and P.sergenti are both endophilic and follow odor plumes to their hosts. Only females takeblood, but both sexes feed on plant sugars and nectar. Female sand flies feed on theblood of humans as well as that of a variety of birds and mammals, commonly dogs,gerbils, and hedgehogs. On humans, they feed on exposed skin around the head, neck,legs, and arms. Female sand flies will crawl under the edge of clothing to bite skin whererepellent hasn't been applied. Sand flies feed outdoors or indoors, and readily penetrateordinary household screening. After engorgement, P. papatasi and other sand flies restbriefly on objects near their host, then move to gerbil burrows or other cool, moistenvironments to lay eggs. They also rest in caves and other areas that are relatively cooland shaded during the daytime.Sand flies are weak fliers and do not travel in wind that exceeds a few kilometers perhour. Phlebotomus papatasi may be active at low relative humidities of 45 to 60%, butother vector species require 75 to 80% relative humidity in order to fly and feed. Sandflies fly in short hops, which usually limit their feeding radius to about 100 to 200 m frompupation sites. However, unengorged females may occasionally disperse as far as 1.5km. Mating dances occur on the ground, often at dusk, with males landing first, followedby females.Vector surveillance and suppression. Because of their small size and retiringbehavior, sand flies must be collected with specilized methods. The simplest is activesearching of daytime resting sites with an aspirator and flashlight. Human-landingcollections are an important method of determining which species are anthropophilic.Sticky traps (paper coated with a sticky substance or impregnated with castor oil) areused to randomly capture sand flies moving to or from resting places. Traps are placed atthe entrances of animal burrows, caves, or crevices. A variety of light traps have beenused to collect phlebotomines, but their effectiveness varies according to the speciesbeing studied and the habitat. Light traps are inefficient in open desert. Traps usinganimals as bait have also been devised. Collection of larvae is extremely labor intensiveand is often unsuccessful because specific breeding sites are unknown or hard to find.Emergence traps are useful for locating breeding sites.Because of their flight and resting behavior, sand flies that feed indoors are verysusceptible to control by residual insecticides. When sand flies are exophilic or bite awayfrom human habitations, control with insecticides is impractical. Some success in75