Relative susceptibility of paddy varieties to Sitotroga cerealella oliv. (lepidoptera: gelichiidae)

Abstract

The results pertaining to the field incidence of the Sitotrogacerealellaon the different grain varieties (ADT 43 and CR 1009) of paddy cultivated during the different seasons of 2011-2012 were observed. The order of incidence has been ADT 43 > CR 1009. The infestation has been maximum in ADT 43 (mean 86.8 moths) and minimum in CR 1009 (mean 25.0 moths) irrespective of sex. The emergence of moth has been highly significant in both varieties. The length and breadth ratio is one of the physical characteristics of the paddy grain that has an influence on the moth emergence. The L/B ratio of ADT 43 is 2.4 and of CR 1009 is 1.96. The susceptibility index of the different grain varieties have been worked out. The index varies in different varieties. It is 271.25 for ADT 43 and 104.166 for CR 1009. It is clear that the susceptibility is the order ADT 43 > CR 1009.