Figure 3. Mean ecdysteroid titers of filter chamber/gut complexes of silverleaf whiteflies reared on greenbean (GB), cotton, collard and sweet potato (SP) plants. Whiteflies were staged and collected, extracts prepared and ecdysteroid concentrations determined by EIA as described in Materials and Methods. Each sample contained 10 complexes. Each value represents the mean ± S. E. of at least three separate determinations and is expressed in femtograms 20-hydroxyecdysone equivalents/filter chamber gut complex.