At Riacho dos Padres, Chácara Evíssima, a small agribusiness venture featuring fish, poultry and cattle farming; a recreation outdoor facility and Event Hall, ubicated in Curitiba's Metropolitan Area, simuliid populations boast high proliferation rates, delivering serious impact to local people with their noxious bites, to such an extent as to impair the daily meetings of people. From January to August 2002, 24,021 pupae were collected from which the following species and respective frequencies were identified: Simulium inaequale (55.24%), Simulium perflavum (16.81%), Simulium pertinax (13.93%), Simulium orbitale (8.03%), Simulium subnigrum (4.92%), Simulium distinctum (1.03%) and Simulium incrustatum (0.04%). Local pest control measures were carried out from the February 28 to August 8, 2002. Main integrated pest control measures taken consisted in the application of biopesticide Bacillus thuringiensis israelensis (Bti) and mechanical handling, not only by removing the immatures (eggs, larvae and pupae) by means of drain brushing, but also by removing natural and artificial substrates from the bed. Larval mean density, monitored at artificial polythene strips substrates (area 13,500 cm²), averaged 6.7 and 11.5 larvae/cm² before the application of Bti at the creek bed extension 75 m and on the dam spillway, respectively. Larval mass reduction at creek bed and at the spillway with application of Bti from 1.77 to 2.09 mg/litre of active ingredient for one minute exposure time and means of mechanical handlings monitored at polythene strips substrates (area 20,250 cm²) varied, respectively from 72.61% to 99.97% and from 74.91% to 99.45 with outflows from 0.39 to 0.45 and from 0.38 to 0.43 m³/minute. At the one of the dam spillways with area of 5,110 cm², average larval density in the first mechanic handling was 10.27 larvae/cm². However, at this spillway, larval reduction by means of mechanical handlings was from 53.81% to 99.59%. Integrated pest control did down sized the number of bytes to the level wished, thus obtaining the positive effect aimed.
Control Bti; mechanical handling; creek; pisciculture spillway dam; Simuliidae