INFLUENCE OF STARVATION ON DEVELOPMENT AND REPRODUCTION IN APTEROUS-VIRGINOPARAE OF THE PEA APHID, ACYRTHOSIPHON-PISUM (HARRIS) (HOMOPTERA, APHIDIDAE)

The influence of nutrient stress on growth, development, and reproduction in apterous virginoparae of the pea aphid, Acythosiphon pisum (Harris), was investigated in the laboratory. We tested the hypothesis that species with a high reproductive investment have low resistance to starvation. Aphids in two groups were starved daily from birth for 4 h and 6 h, respectively, and compared with feeding counterparts reared on leaves of broad beans, Vicia faba L. Aphid wet weight increased as an exponential function of age in all groups. Starved aphids had lower adult weight and required longer from birth to parturition than feeding aphids. These effects increased with the length of daily starvation. The number of offspring produced was correlated with adult dry weight. Aphids were unable to compensate, or to compensate completely, for water and nutrient loss resulting from starvation. It is suggested that pea aphids allocate resources first to maintenance and then to reproduction when deprived of food.