Charles L. Graham

The effect of age on the flight performance of female Aedes aegypti mosquitoes

Abstract The paucity of information concerning mosquito flight ability resulted in experiments designed to estimate some aspects of mosquito flight potential under laboratory conditions. Each day for 6 weeks, eight female Aedes aegypti mosquitoes were flown on flight mills, and the distance flown, duration of flights, flight speed, and weight lost during exhaustive flights were recorded. Comparisons of the performances of mosquitoes of different ages indicated that no statistical differences existed in flight ability as measured between consecutive days. Differences did occur between weekly age groups. Flight performance was maximal during the first 14 days of adlut life. Flight performance (distance flown) decreased by 42 per cent at the beginning of the third week (day 15) and again, sharply, in the fourth week. Exhausted mosquitoes were analysed for glycogen content (the primary source of flight energy) and comparisons were made with glycogen levels of non-flown controls of identical physiological age. Mosquitoes aged from 1 to 12 days utilized almost all available glycogen in exhaustive flights. During the third and fourth weeks, glycogen in exhausted mosquitoes increased concomitantly with a reduction in flight ability.

The effect of temperature and relative humidity on the flight performance of female Aedes aegypti.

Abstract The influence of temperature and r.h. on the flight performance of tethered virgin female Aedes aegypti was investigated. Mosquitoes of similar age were flown to exhaustion on flight mills at various temperatures and relative humidities. Parameters measured were distance flown, duration of flight, speed of flight, initial weight of mosquitoes, and live weight lost during exhaustive flight. The temperature range at which sustained tethered flight occurred was 15 to 32°C. Temperature extremes at which flight was possible were 10 and 35°C; however, performance was minimal in both duration and distance at these temperatures. The optimal temperature for flight was 21°C. Mosquitoes flew farther at 15°C than at the commonly reported optimal temperature of 27°C. In general, flight performance was greater below 27°C. Relative humidity within 30 to 90 per cent had no demonstrable influence on flight performance at any temperature studied except at 32°C, where 30 per cent had a marked limiting effect on mosquito flight.