Leaf Morphological Characters And Volatiles Of Differenteggplant Varieties Affect The Behavior Of The Sweetpotato Whitefly, Bemisia Tabaci(Hemiptera: Aleyrodidae)

The sweetpotato whitefly, Bemisia tabici(Gennadius) MEAM1(Hemiptera: Aleyrodidae) is one of the serious agricultural pest that have more than six hundred host species worldwide. Prior to the study, a little has been known about the host selection behavior of whitefly among different varieties of a plant species; therefore, the mechanisms of susceptibility in different varieties of a plant species are not well understood and have not been carefully studied. In this study, we evaluated the response of whitefly to different eggplant varieties for adult feeding & oviposition, immature development & survival and fecundity & adult longevity. Subsequently, we observed the leaf morphological characteristics, leaf chemical composition and plant volatiles in relation with the response of whitefly. Our result demonstrated that eggplant variety JinSheng Zilongchangqie(JSZ) and H149 were observed as highly preferred for whitefly feeding and oviposition whereas variety Tuo Lu Bamu(TLB) was found as resistant to whitefly. The varieties Jinguangbo luqie(JGL), JinGuangbo Ziquanqie(JGZ), QinXing Ziguanqie(QXZ), DaYang Ziguanqie(DYZ), and QinXing Niuxinqie(QXN) were moderately preferred by B. tabaci. Significantly higher fecundity, longevity, lowest nymph development period and higher survivals of B. tabaciwere found in variety ‘JSZ’. Leaf trichome density, its length and leaf lamina thickness were significantly and positively correlated with whitefly adults and eggs. B. tabaci preferred the leaves of moderately bright green(medium G value) whereas it was less attracted with the leaves that reflect long and middle wavelength light(higher R and G values). The degree of hue had a positive effect, and per cent brightness and saturation had a negative effect on whitefly attraction. Analysis of Leaf chemistry revealed that highly susceptible variety possessed higher concentration of nitrogen, amino acids, glucose 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. The volatile compounds released from different varieties were qualitatively & quantitively different. Susceptible variety releases 3-Hexen-1-ol, acetate; α- linalool; Cyclohexane, 2-ethenyl-1,1-dimethyl-3-methylene- etc that’s may be attracted whitefly. On the other hand, resistant variety emits α-pinene; Naphthalene, 2-methyl-;(Z,E)-α- Farnesene; α-Humulene;(-)-Thujopsene, Azulene, α-Copaene and α-chamigrene etc that’s may be repelled whitefly. The results will provide important information about different plant factors that controlled the susceptibility as well as resistance of plant against B. tabaci.