PERFORMANCE OF ULV FORMULATIONS (PESGUARD(TM)-102 VECTOBAC(TM) 12AS) AGAINST 3 MOSQUITO SPECIES

Adulticidal and larvicidal performances of a water-based pyrethroid mi croemulsion Pesguard(TM) PS 102 (AI d-allethrin and d-phenothrin, both at 5.0% w/w) and Vectobac(TM) 12AS, an aqua-suspension Bacillus thuri ngiensis israelensis (B.t.i.) formulation (Al 1,200 ITU/mg) were asses sed against mosquitoes Aedes aegypti, Aedes albopictus, and Culex quin quefasciatus using a Leco(TM) ULV Fog Generator Model 1600 and a Scorp ion(TM) 20 ULV AirBlast Sprayer. Laboratory-cultured mosquito adults a nd larvae were used for efficacy assessment. For trials using Leco, bo th pyrethroid and bacterial formulations were dispersed both singly an d in combination with Pesguard PS 102 at a dosage of 0.2 liters/ha and B.t.i. at a dosage of 1.0 liter/ha. Similar trials with the Scorpion were also conducted with Pesguard PS 102 at a dosage of 0.2 liters/ha and a higher dosage of B.t.i. (1.5 liters/ha). Experiments were conduc ted in a football held (200 x 100 m) where five check points at 10, 25 , 50, 75, and 100 m downwind from the spray nozzle were chosen for eff icacy assessments. Knockdown and mortality were scored at 1 and 24 h p ostspraying. Results from both trials showed that mortality values var ied with distance from spray nozzle. For trials with Leco, fogging wit h the combination of Pesguard PS 102 and B.t.i. provided larvicidal mo rtality of >80% for both Aedes species and of >60% for Cx. quinquefasc iatus larvae at several check points, depending on wind conditions. Co mplete mortality of adult Aedes mosquitoes at 24 h posttreatment was a lso achieved, while mortality values for Culex adults reached >90% und er strong wind conditions. As for trials with the Scorpion 20, high ad ult and larval mortalities were also achieved, with >90% mortality at some check points. The above study demonstrated the possibility of ach ieving both larvicidal and adulticidal effects when using a combinatio n of B.t.i. and Pesguard PS 102 in ULV space spray.