Aphid body size measurement
The body size and body color of A. gossypii varied greatly on suitable and unsuitable host plant, and nymphs of A. gossypiideveloped into adults in about 6 d, and then did not increase in body size (Watt and Hales 1996). So, we measured aphid body length and wide of the HI lineage in the life table experiments at age of 10 d under binocular microscope (Nikon, Japan). Each treatment replicated 30 measurements.