During 1989 and 1990, field studies were conducted to determine effects of cypermethrin
and sulprofos, which are used for control of Heliothis virescens and Helicoverpa zea in
cotton, on outbreaks of cotton aphid, Aphis gossypii Glover. During 1989, cotton aphid
outbreaks occurred in both insecticide-treated and untreated plots. However, aphid densities
were greatest in the sulprofos-treated plots and lowest in the cypermethrin-treated plots,
even though insecticide-induced aphid mortality could not be detected in either treatment. In …