Many plant-feeding insects use a fairly well-defined set of hosts, but are occasionally observed on an atypical host. The seed beetle Callosobruchus maculatus infests several grain legumes, especially Vigna spp. It has rarely been reported to attack lentil, a distant relative of its typical hosts (Credland, 1987). In three previous mass-selection experiments, we showed that larval survival in lentil increased rapidly after a bottleneck, from 70% in only 5-7 generations. Host shifts by insects may also require modification of egg-laying behavior. Initial assays confirmed that most C. maculatus females fail to recognize lentil as a potential host. We used both quasi-natural and artificial-selection experiments to estimate the potential rate of change of host acceptance.
Available at: http://works.bepress.com/frank_messina/92/