Overwintering of the maize weevil, Sitophilus zeamais (Coleoptera: Dryophthoridae) in outdoor brown-rice warehouses in Ibaraki Prefecture, Japan

Abstract

We collected and counted overwintering maize weevils, Sitophilus zeamais, in outdoor brown-rice warehouses in Ibaraki Prefecture, Japan. The survey was conducted at 5 sites on 10 December 2015. We found S. zeamais adults under pieces of wood or concrete on the ground at 4 sites. There were 1, 4, 32, and 60 adults at these sites. We confirmed the ovipositional ability of the overwintering adults. The adults laid eggs in the brown rice. The resulting larvae developed into adults at 25°C, 70％ RH, and 16L: 8D.