Host plant or geographic barrier? Reproductive compatibility among Diatraea saccharalis populations from different host plant species and locations in Argentina

Abstract

The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), is one of the main lepidopteran pests of sugarcane and maize. The association of insects with different environments and/or host plants may occur by adaptation and this can generate host races. Adaptation may produce phenotypic or genotypic variation, which results in the differences in bioecological characteristics such as reproductive compatibility that reduces gene flow among populations. The objective of this study was to determine the reproductive compatibility of three population combinations collected in various geographic locations and from different host plants, thereby determining the influence of geographic distance and/or insect plant association. Interpopulation crosses of D. saccharalis populations from Tucumán (maize and sugarcane) and Jujuy (sugarcane) provided evidence of pre-zygotic and post-zygotic incompatibility. The results indicate that gene flow barriers are influenced by the host plant. However, populations from various locations revealed that geographical location is the main factor influencing gene flow among populations of D. saccharalis.