Figure 1. Mean length, width and maximum depth dimensions of 4th instars reared on six host plants. Plants were infested with silverleaf whiteflies that had been maintained on a variety of plants as described in Materials and Methods. Length, width and depth were measured using an optical micrometer. For each stage, length and width dimensions of at least 20 individual whiteflies were determined. Each value represents the mean ± S. E of these stage means. Approximately equal numbers of all stages of 4th instars and pharate adults were included. The depth dimension is the maximum observed prior to the initiation of adult development. Means having the same upper case or lower case letters were not significantly different. GB = greenbean; Poins = poinsettia; SP = sweet potato. Greenbean, tomato and poinsettia plants have pubescent leaves; cotton, collard and sweet potato plants have glabrous leaves.