Submitted to: Meeting Abstract
Publication Type: Other
Publication Acceptance Date: October 25, 1999
Publication Date: N/A
Technical Abstract: The carabid Lebia grandis is an indigenous natural enemy of the Colorado potato beetle, Leptinotarsa decemlineata. Adults are predators of egg, larval, and pupal stages of L. decemlineata, whereas 1st instar larvae are external parasitoids of L. decemlineata mature larvae or pupae. Adults forage on plant foliage and the ground for prey during the day or night, depending on the conditions of humidity and temperature. Female L. grandi have very high reproductive potential. A single female can produce as many as 1300 eggs in its lifetime. Adults can live through two consecutive field seasons. Often two generations are produced in the same season. The parasitic habit of the L. grandis larvae is very unique and is the exception for the family. Larvae probably have difficulty successfully parasitizing their host; this accounts for the inordinate number of eggs that are produced per female adult. L. grandis 1st instars must locate L. decemlineata mature larvae in their soil chambers before they seal the chamber around them. Apparently, the pupation chambers are impenetrable by L. grandis 1st instars once they are closed. L. grandis will have considerable potential as a part of an IPM program in fields of nontransgenic potato in which pesticides are used judiciously. This enemy has considerable potential for mass rearing and then releasing into fields of potato to augment their existing populatins.