The alfalfa leafcutting bee,Megachile rotundata (Fabricius), is used to pollinate alfalfa, Medicago sativaL., for seedproduction in theUnited States andCanada. It is difÞcult to reliably sustain commercialM. rotundata populations in theUnited States because of problemswith disease, parasites, predators, and unexplained mortality. One possible explanation for early immature mortality is that, re...
