2009 Volume 74 Issue 3 Pages 259-266
The uzifly, Exorista sorbillans (=E. bombycis) a tachinid endoparasitoid of silkworm, Bombyx mori L., known to cause considerable damage to the silk industry. Earlier studies on various aspects of the uzifly indicated for possible presence of a number of cryptic species. Though the fly entered into South India 25 years ago, the basis for the existence of cryptic species was not known. To ascertain whether the genome of this parasitoid is differentiating into discrete gene pools in contrasting eco and geo-climatic conditions, an attempt has been made in the present study the molecular profiling of 8 populations (Chitoor, Kuppam, Erode, Bangarapete, Sira, Mandya, Chitradurga, and Kanakapura) from south India with 16 RAPD primers and also to explore the possibility of its endosymbiont Wolbachia as a causative agent as it known to cause cytoplasmic incompatibility in its host uzifly. The hierarchical clustering done on the basis of RAPD data and the Euclidean distance matrix put Chitradurga populations at the maximum distance from other south Indian populations studied and reveals the occurrence of spectacular region-wise pairing with separate clusters. Further, when we have crossed within and between selected populations for the Wolbachia induced reproductive isolation, the results showed the lower level (28–32%) of reproductive isolation within and between populations. The RAPD and crossing data clearly indicates the micro-level divergence in the uzifly, E. sorbillans. The significance of this study with a tachinid fly pest is discussed in the context of understanding the diversification of uzifly and also establishing this pest as a relevant biological material for studying microevolution in nature.
