Age-Stage Two-sex Life Table Study of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) on Three Brinjal Varieties in Pakistan

Brinjal whitefly is one of the most serious insect pests of fruits and vegetables in Asia including Pakistan. To control this pest, various control measures including chemical control have been practiced but remain unsuccessful. Therefore, this work was designed to study the age stage two sex-life table parameters of the brinjal whitefly, Bemisia tabaci on three brinjal varieties including Black Nagina, Shamli and Twinkle star. This research was conducted using potted plants of each brinjal variety in cages under controlled experimental conditions of 24 ± 2ºC temperature, 55 ± 3% relative humidity and a 16:8 (L: D) hour photoperiod. The data revealed shorter egg incubation periods of B. tabaci (5.38 and 5.69 days) respectively and significantly reduced nymphal durations of 12.19 and 13.3 days on Twinkle Star and Shamli, respectively. In contrast, a significantly longer nymphal developmental period of B. tabaci (14.29 days) was recorded when the whiteflies were reared on the Black Nagina brinjal variety. Notably, the study highlighted significant variations in the net reproductive rate (R0) of whiteflies across different brinjal varieties. A significantly lower mean net reproductive rate of B. tabaci (55.90 offspring) were recorded on brinjal variety Twinkle Star as compared to brinjal varieties Shamli and Black Nagina. The data further showed no significant differences among the brinjal varieties in terms of the mean finite rates of increase (λ), intrinsic rate of increase (r) and gross reproductive rate (GRR) i.e., P ≥ 0.005. However, the mean generation time (T) of whitefly reared on different brinjal varieties varied significantly. The highest mean generation time of brinjal whitefly was recorded for the population reared on brinjal variety Black Nagina (27.20 days), followed by whitefly population reared on Shamli variety (25.75 days), while significantly lower mean generation time of whitefly population was recorded on brinjal variety Twinkle Star (24.17 days). The study concluded that whitefly has shown a greater host preference for brinjal variety Black Nagina as compared to Shamli and Twinkle Star with a short life span and comparative lower mortality rate. Hence, integrated pest management strategies should focus on closely monitoring Black Nagina variety, incorporating biological control agents, and using resistant brinjal varieties like Twinkle Star to reduce whitefly populations effectively and sustainably.