Leaf Chemical Compositions of Different Eggplant Varieties Affect Performance of Bemisia tabaci (Hemiptera: Aleyrodidae) Nymphs and Adults.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) MEAM1 is a serious pest of many crops worldwide, and its control mostly depends on insecticides. One of the most preferred host plants of B. tabaci is eggplant, Solanum melongena, although preferences among different cultivars of the whiteflies vary. We hypothesized that certain nutritional and defensive chemicals of plant leaves, such as nitrogen, glucose, fructose, sucrose, amino acids, total phenolic components, and moisture content may affect whitefly's feeding and ovipositional preference, fecundity and longevity, nymph development, and survival among different eggplant varieties. To seek the most susceptible eggplant variety for use as an attractive trap crop for whitefly adults, we determined the variation of leaf chemical compositions among six eggplant varieties (H149, JSZ, JGL, TLB, DYZ, and QXN) and evaluated the effects of their leaf chemicals to the performance of nymphs and adults of B. tabaci. In choice feeding and oviposition tests, the varieties 'H149' and 'JSZ' had the most eggs. The whiteflies had significantly higher fecundity, longevity, lowest nymph development period, and higher survivals on JSZ than on other varieties. The least preferred TLB variety possessed the lowest adults and eggs, the lowest fecundity and longevity, and nymph development period. JGL, DYZ, and QXN were considered as a moderately preferred variety. Leaf chemistry revealed that highly susceptible variety possessed higher concentration of nitrogen, glucose, amino acids, and lower moisture content. The resistant variety possessed higher amount of total phenolic component. Both nutritional and defensive chemicals combined associated with nymph and adult performance of whitefly.