Abstract
The bionomics of Dacne pieta, a major beetle pest of the shiitake mushroom was studied by means of mushroom-bait trapping and outdoor rearing. D. picta hibernates as adults and larvae. Most larvae die during hibernation. The adults reach mushrooms by walking and lay their eggs in May. The first adults emerge in mid-July, and fly to the mushrooms in August. They lay eggs, eat, and then die. The second adults emerge in mid-September and lay eggs until mid-October but rarely fly. They go into hibernation with their progeny larvae. Thus D. picta are supposed to be predominately bivoltine. Discussions were held on the factors which make D. picta a pest of shiitake mushrooms, comparing them with the bionomics of D. japonica as reported previously.
