Flight activity, reproduction, and adult nutrition of the beet webworm, Spoladea recurvalis (Lepidoptera: Pyralidae)

Abstract

The adult longevity, reproductive period, age-specific flight activity, suitable temperature range for flight, and effect of adult feeding on the subsequent flight of Spoladea recurvalis Fabricius were studied in the laboratory. Flight activity was evaluated using a tethered flight-mill. Females had a pre-oviposition period of 3 d, and continued to lay eggs up to 20 d post-emergence. Females flew longest between 17 and 23 °C, and 10% of females were capable of continuous long-duration flight even at 12°C. Females flew more actively in their pre-oviposition period, but the females' reproduction period was not clearly separated from their active flight period. The mating status of females had no clear effect on their flight activity. Uptake of honey solution (nectar) was essential for adult survival, and the survival rate was reduced markedly when honey solution was withheld. When honey solution was supplied after 5 d of starvation, the overall longevity of the moths was the same as that of the moths continuously supplied with honey solution since emergence. When honey solution was removed even for 1 d, subsequent flight activity was significantly depressed. Thus, the prediction that the strong propensity for long flights by S. recurvalis may be derived from their dispersal flights to seek flower nectar was not supported from the present experiment.