Viability of prepupae of the leafcutting bee Megachile rotundata (Fab.) during extended storage

Abstract

In the management of the leafcutting bee Megachile rotundata, diapausing prepupae are overwintered at 3–5 °C for approximately 260 days before use for a current season's pollination. In this study, viability of diapausing prepupae was investigated at 28-day intervals between days 260 and 641 of storage. Substantial numbers of bees emerged from prepupae stored for up to 501 days. However, 50% of the sampled prepupae became nonviable after 417 days. About 95% of the emerging bees survived for at least 24 h. Survival of emerged adults did not appear to depend on storage time or sex.