Differenziamento genetico del complesso Lymantria dispar (Lepidotera: Lymantriidae)

lsozyme variation and genetic relationships among populations of the Lymantria dispar complex, having different geographic origin, were electrophoretically analyzed on the basis of 32 loci. Samples from Japan were found to be genetically more variable (average He=0.13) than those from Europe (He=0.09) and north America (He=0.04). The low values of Nearctic populations reflect founder effects involved in their origin. Populations from Europe and north America (L. dispar dispar) were genetically homogeneous: Nei's D=0.016. The Japanese samples from Hokkaido (L. dispar hokkaidoensis) and northern Honshu Island (L. dispar subsp.) were more differentiaded, showing a D from L. dispar dispar of 0.093 and 0.104, respectively. A higher genetic distance (D=0.252) was estimated between L. japonica (from central Honshu) and all the L. dispar samples tested. Lab crosses between these two taxa showed that their reproductive isolation is only partial; therefore L. dispar and L. japonica should be considered as semispecies.