LIFE-HISTORY PATTERNS OF ILYBIUS ERICHSON FROM NEWFOUNDLAND (COLEOPTERA, DYTISCIDAE)

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.