ABSTRACT
In an effort to develop a more effective measure for use in emergency control of the dengue vector Aedes aegypti. applications of a combination of a larvicide (Bacillus thuringiensis israelensis [B.t.i.]) and an adulticide (permethrin) were made using a truck-mounted forced-air generator (Scorpion 20) and evaluated in the Dominican Republic. This method has the potential to simultaneously control adults and larvae. In bioassay cages placed in household water containers at the time of application, larval mortalities were 95.1 and 100% for 2 application rates of permethrin mixed with B.t.i. Adult mortalities were not as impressive, probably because of resistance to permethrin. Higher adult mortality in caged specimens (78.5%) and a substantial reduction in the natural population (68.4%) of Ae. aegypti were obtained following a 2.1-g AI/ha application of deltamethrin alone.
Subject(s)
Aedes , Bacillus thuringiensis , Insecticides , Mosquito Control/methods , Pyrethrins , Animals , Dominican Republic , Emergencies , Entomology/methods , Evaluation Studies as Topic , Larva , Mosquito Control/instrumentation , Permethrin , Pest Control, Biological/methodsABSTRACT
Baseline field studies were conducted from April 1987 to July 1988 on Aedes aegypti in Santo Domingo, an endemic area for dengue fever. Premise, container and Breteau indices were measured in one treated area and 2 nearby control areas. These indices averaged 69.6, 46.3 and 142.1, respectively. The principal larval habitats of Ae. aegypti were 208-liter (55-gal) concrete-lined drums. The estimated daily adult production was approximately 60 per house. Adult mosquito populations were monitored using oviposition traps and by sweep net collections. There was no correlation between adult abundance and the larval indices. Monitoring the natural adult densities was more efficient for evaluating the impact of ULV malathion application than the use of standard bioassay procedures.
Subject(s)
Aedes , Animals , Culex , Dominican Republic , Ecology , Entomology/methods , Female , Larva , Male , Population Density , PupaABSTRACT
Efficacy of ground and aerial ultra-low volume (ULV) applications of 91% malathion at 438 ml/ha against Aedes aegypti in the Dominican Republic was evaluated using indoor collections, oviposition trapping and adult sentinel mortality rates. Ground compared to aerial ULV applications in this study were found to have a greater effect on Ae. aegypti when measured by the described sampling techniques. Neither application method provided the level of Ae. aegypti suppression believed necessary for control in the event of a dengue virus epidemic.
