SEASONAL INFESTATIONS AND LIFE HISTORY TRAITS OF LITCHI FRUIT BORER CONOPOMORPHA SINENSIS BRADLEY (LEPIDOPTERA: GRACILLARIIDAE)

Abstract

The litchi fruit borer, Conopomorpha sinensis Bradley (Lepidoptera:Gracillariidae) is one of the most destructive cosmopolitan pests of litchi fruit. This experiment investigated the seasonal infestation and performance of litchi varieties on the life history parameters of C. sinensis. The fruit infestation was first detected on 18 April and 30% fruit infestation was recorded on April 25 while the fruits were (3.12 ± 0.04) cm in length, (1.33 ± 0.01) cm in diameter and (2.87 ± 0.12) g in weight and finally infestation increased up to 80% on May 30. Highest infestation was found in Bombai (44.29%) variety and lowest in China-3 (17.14%). Life history traits of C. sinensis was detected on two varieties of litchi viz. Madraji and Bombai. Female developmental times were shorter on Madraji (23.01 ± 0.42) than on Bombai (24.71 ± 0.52). The adult longevity periods were 11.75 and 11.83 days for female and male, when C. sinensis fed on Madraji and Bombai varieties respectively. On the contrary, it was shorter 11.57 and 10.60 days for both the sexes while reared on the two hosts. Lifetime fecundity was also the higher (31.28 ± 0.10) on Bombai and the lower (29.50 ± 0.53) on Madraji. The sex ratio (proportion of male) was the maximum (0.54) on Madraji variety and the minimum (0.47) on Bombai. Life table parameters were analyzed and found the lower generation time (T = 30.41) when C. sinensis fed on Madraji, but Ro (21.27) was the higher on Bombai. However, rm (0.10) and λ (1.10) were also the higher when fed Madraji and Bombai, respectively. Daily fecundity found higher (7.31 ± 0.45) in the variety of Madraji. Therefore both the variety had little effect on the biological performance of the litchi fruit borer