Antibiosis resistance to cereal leaf beetle, Oulema melanopus (L.) (Coleoptera: Chrysomelidae), in Central Asian wheat germplasm

The cereal leaf beetle, Oulema melanopus (Coleoptera: Chrysomelidae), is a new invasive pest of cereals in western Canada. Host plant resistance is a potential option in the integrated management of this insect. Wheat (Triticum aestivum L.) genotypes are known to possess antixenosis against O.melanopus; however, mechanisms involving antibiosis are relatively less explored. We present results of an investigation exploring antibiotic resistance in wheat germplasm of Central Asian origin with putative resistance to O.melanopus. Our laboratory assessment of development and survivorship of O.melanopus on test genotypes indicated antibiotic properties in four of the six genotypes evaluated. Antibiosis effects were reflected through lower survivorship, extended developmental periods and low adult fitness. However, two genotypes were excellent hosts, and beetles had higher survivorship and fitness on them. The performance of O.melanopus on these two genotypes was comparable to that on the susceptible genotype CDC GO included as a check. The genotypes with antibiotic resistance identified by this research can now serve as sources of genetic resistance for breeding cultivars adapted to western Canadian conditions.