In a survey of containers infested with Aedes aegypti (L.) conducted during September and October 1979 in a substandard residential area of New Orleans, LA, infestation indices were as follows: House--35, Breteau (foci)--85, Receptacle--69, Block--100, and Larval Density--169. A mean of 48.5 water-holding containers were found per block. More than 50% of these receptacles were narrow-mouthed containers, e.g., drink bottles, that held an average of less than 0.03 mosquito immatures each. After exclusion of data on the unproductive narrow-mouthed type, the average container held 7.8 liters of water, 105 1st and 2nd instars, 69 3rd an 4th instars, and 12 pupae. With assumed constant adult survival rates of 0.85-0.90 per day, the number of females per block on any particular day was estimated from pupal production data at 362-558, and the standing crop of females 12 days and older and therefore old enough to transmit dengue fever if they are vector competent was estimated at 51-158 per block.

Aedes↗

PubMed1980

Effects of adult sex ratio and stocking rate on viable egg production of Anopheles albimanus (Diptera: Culicidae).

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Animals↗

PubMed1980

Mass rearing the genetically altered MACHO strain of Anopheles albimanus Wiedemann.

Technology was developed for mass rearing males of the genetically altered MACHO strain of Anopheles albimanus Wiedemann, which allowed for elimination of females by treating the eggs with propoxur (o-isopropoxyphenyl methylcarbamate). This made it possible to eliminate virtually all the females (potential malaria vectors) being released in the field, and also reduced the space previously devoted to larval rearing by 50%, since the females were eliminated in the egg stage. Also, the difficulties involved in separating the sexes with previous techniques were eliminated. Because there is some genetic recombination, about 0.2% of the MACHO males become susceptible and an equal number of females become resistant each generation. Thus after 6-12 months, the strain is purged to remove these contaminants. With this system an average of more than 1 million pupae per day was produced during 3 weeks of a 5-week period, and an average of 968.2 thousand per day during the entire period. The pupae produced were 99.9% males with an average adult emergence of 90%.

Animals↗

PubMed1980

Efficiency of techniques for the mass release of sterile male Anopheles albimanus Wiedemann in El Salvador.

During a 3-year program that required daily releases of large numbers of sterile male Anopheles albimanus Wiedemann mosquitoes in a coastal area of El Salvador, we were able to compare methods of transport and release of adults and pupae. The disadvantages of the laboratory handling and packaging of adults were largely overcome when improved methods were devised for release of pupae. Such releases saved time and laboratory space and overcame several logistical problems arising from evening releases of the adults. We finally achieved 91.3% emergence with the pupal release methods.

Animals↗

PubMed1979

Sterlizing and packaging males of Anopheles Albimanus Wiedemann for field release.

Technology was developed for sterilizing and packaging as many as 1 million male Anopheles albimanus Wiedemann per day for field release. The average sterility produced in the males during a 1.5-year period was 98.9%. Mortality due to transport of the males in specially developed cages averaged 4.5% for 72-hour-old adults and 2.5% for 24-hour-old adults. The average mortality due to transport and field exposure of pupae was 1.2 to 9.8%, depending on the technique used.

Animals↗

PubMed1975