Bj. Hicks et Dj. Larson, LIFE-HISTORY PATTERNS OF ILYBIUS ERICHSON FROM NEWFOUNDLAND (COLEOPTERA, DYTISCIDAE), The Coleopterists bulletin, 49(3), 1995, pp. 281-287
Adults and larvae of four species of Ilybius Erichson from Newfoundlan
d, Canada, were field collected and some were reared to determine thei
r life history. Female adults were dissected to determine their reprod
uctive status. Through temporal distribution of larvae and adults of v
arious reproductive stages, we determined that Ilybius species from Ne
wfoundland followed a mostly univoltine life history with larvae overw
intering and adults occurring during the summer. Fifteen percent had a
semivoltine life history where some adults overwinter during the seco
nd winter.