RAPID COMMUNICATION HERITABILITY FOR SIZE IN THE MEGACHILID BEE OSMIA LIGNARIA PROPINQUA CRESSON

Abstract

Heritability (narrow sense) for size in the blue orchard bee, O. lignaria, was estimated with a maximum likelihood method by weighing and releasing marked bees into a greenhouse provided with nesting material and excess bloom. Parentage of all offspring was recorded during frequent daily observations of nesting blocks throughout the nesting period. Progeny were weighed after reaching adulthood. Heritability was higher for male offspring (0.34) than for females (0.15) but there was no significant difference between them. Because of the low heritability for size among females, we conclude that a selective breeding program to increase size in this bee of potential commercial importance would be unprofitable.