INFLUENCE OF TEMPERATURE AND PLANT-GROWTH STAGE ON DEVELOPMENT, REPRODUCTION, LIFE-SPAN, AND INTRINSIC RATE OF INCREASE OF THE RUSSIAN WHEAT APHID (HOMOPTERA, APHIDIDAE)

Plant growth stage and temperature exhibited a significant interaction (P < 0.05) in their effects on reproductive life span, total life span, and production of nymphs per female of Russian wheat aphid, Diuraphis noxia (Mordvilko). Immature development and daily fecundity were not significantly affected by temperature and growth stage interactions. Minimum threshold temperature for immature development was estimated to be -1.57°C, and the number of degree-days to complete preimaginal development was 225.57. The intrinsic rate of increase (rm) was highest (0.255 ± 0.005) at 18-21°C during the jointing stage of wheat. At all other growth stages except tillering, rm also was highest at 18-21°C. Wheat growth stages from jointing to heading and a temperature regime of 18-21°C seem to be most suitable for rearing Russian wheat aphids in the laboratory, considering aphid fecundity and plant tolerance to insect and temperature stress. © 1990 Entomological Society of America.