Biology Of Trialeurodes Vaporariorum, Bemisia Tabaci And Trialeurodes Ricini (Hemiptera, Aleyrodidae) On Four Host Plant Species

In recent years, banker plant system has become a common type of biological control toTrialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius).I determined thegeneral biology of the three whitefly species, T. vaporariorum, B. tabaci and T. ricini (Misra)on four species of host plants, cotton, eggplant, greenbean and castor. The main findings wereshown as follows:(1) Development time and survival rate of T. vaporariorum, B. tabaci and T. ricini oncastor. The results showed that there were significant differences in development time amongthe three whitefly species on castor, and the development time of B. tabaci (31.9d) waslonger than the greenhouse whitefly (24.3d) and the castor whitefly (28.3d), There weresignificant differences in survivorship, and the lowest was74.4%on cotton; there were nosignificant differences between T. ricini (92.5%) and T. vaporariorum (96.6%). Thedifference was mainly in hatch rate and the survival rate of the first instar nymphs.(2) Development time and survival rate of T. ricini on the four host plant species. Theresult showed that the development time of T. ricini on cotton was the longest (33.3d) ascompared with that on castor plant (28.3d), eggplant (28.5d) and green bean (25.4d). Thedifferences were primarily in egg stage and the fourth instar nymphs. The survival rate waslowest (42.6%) on cotton. The differences were mainly in the third and the fourth instarnymphs.(3) Sex ratio, as shown with female ratio (♀%), and body size on the four host plantspecies. The result showed that the highest female ratio was on cotton (71.6%), the lowestwas on eggplant (42.8%), and intermediate on castor and green bean (~50%). There weresignificant differences in the size of nymphs of T. ricini on the four host plant species. Thenymphs were remarkably smaller on green bean than the other plants.(4) Life table parameters of T. ricini. The life table parameters of T. ricini on castor werecalculated: the net reproductive rate (R0) was57.656offspring/individual, generation time (T)was35.9d, the intrinsic rate of natural increase (rm) was0.1128d, the infinit rate of increase (λ) was1.1194d, the gross reproductive rate (GRR) was108.04offspring/individual, anddoubling time (DT) was6.1149d.(5) The preference of feeding and oviposition among the four host plants. In bothno-choice and choice tests, T. ricini adults remarkably preferred castor to other host plants forfeeding and oviposition, and did not lay eggs on the other three plant species. The preferenceof T. ricini can be ranked as follows: castor> eggplant> cotton> green bean, although therewere no significant differences among the last three host plants. The results indicate that:castor plant were the most preferred host plants for T. ricini, and could be evaluated as abanker plant in the plant-T. ricini-parasitoid system.