Ab. Idris et Ej. Grafius, EVIDENCE OF PREIMAGINAL OVERWINTERING OF DIAMONDBACK MOTH, PLUTELLA-XYLOSTELLA (LEPIDOPTERA, PLUTELLIDAE) IN MICHIGAN, Great Lakes entomologist, 29(1), 1996, pp. 25-30
We investigated the possibility of overwintering of the diamondback mo
th, Plutella xylostella L., in central Michigan. In the spring of 1993
, counts of immature stages on brassicaceous weeds in a field previous
ly planted to broccoli revealed a small but significant number of late
instars that could not be attributed to oviposition of immigrant moth
s from the southern United States. We suggest that crop debris and sno
w cover played an important role in sheltering the larvae, which are k
nown to tolerate sub-freezing temperatures. There was no indication of
adult survival.