BIOLOGICAL EVIDENCES FOR THE ESTABLISHMENT OF ALIEN PECTINOPHORA GOSSYPIELLA SAUNDERS (LEPIDOPTERA: GELECHIIDAE) IN THE YANGTZE RIVER REGION OF CHINA

Biological behaviors of Pakistani and Chinese populations of Pink bollworm, Pectinophora gossypiella (Saunders), were studied at State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China during 2006 for seeking evidence of the hypothesis that this alien specie has been introduced indiscriminately into China from Pakistan and established successfully in the Yangtze River Region of China. The pink bollworm populations collected from the various cotton growing regions (Sindh and Punjab) of Pakistan (PP) and (Yangtze River) China (CC) were subjected to mating in no and free choice tests. The mating behaviors of the two different strains were compared and mating compatibility along with the age effect on mating between these strains was investigated. All the biological parameters between the two strains differed significantly except for the hatching period was found at par for the two populations. Results indicated successful mating compatibility between the strains with no adult’s sterility. Fecundity was significantly higher in the inter strains crosses PP×CC followed by CC×PP over intra strain PP×PP and CC×CC crosses. The sex ratio effected fecundity significantly and increased parallel with increasing sex number. The mating percentage of these strains was significantly reduced with increasing age. However, the fecundity of the young and old moth’s crosses up to age of 8 days was at par as compared with the same age crosses. The rituals, feeding and mating activities of these two different strains were studied by using harmless red dye on the wings for identity. Results on the mating behaviors showed no significant difference between the strains in all the tests including reciprocal crosses. In all the tests the male initiated fluttering and upwind movement for finding the female partner. The mating time was recorded from 01:30 to 7:00 after a series of visual and videocassette record (VCR) tests. The current studies highlighted the evolution, possible wide adoptability and invasive nature of this pest. Therefore, these findings can be helpful in redesigning the management strategy based on the random mating of the overlapping and migrating generations of the different invasive strains of pink bollworm in the cotton growing areas of the world.