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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #246447
Title: Reproductive Traits of Northern Corn Rootworm (Coleoptera: Chrysomelidae) in Relation to Female and Male Body Size

Author
item French, Bryan
item HAMMACK, LESLIE - Retired ARS Employee

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2010
Publication Date: 7/1/2010
Citation: French, B.W., Hammack, L. 2010. Reproductive Traits of Northern Corn Rootworm (Coleoptera: Chrysomelidae) in Relation to Female and Male Body Size. Annals of the Entomological Society of America. 103(4):688-694. DOI 10.1603/AN09174.

Interpretive Summary: Corn rootworms are serious pests of corn and have evolved resistance to cultural and chemical management practices. Transgenic corn producing a rootworm-toxic protein derived from the bacterium, Bacillus thuringiensis, provides a new approach to corn rootworm management. Wide spread resistance to this toxic protein is a concern and a refuge of non-transgenic maize must be planted within or adjacent to the transgenic maize. Resistance evolution may be associated with fitness related traits such as longevity, fecundity, and body size. We examined the mating behavior and reproductive biology of the northern corn rootworm in relation to male and female body size. Large and small males were reciprocally paired to large and small females to compare against average sized males and females. The proportion of pairs that copulated successfully did not vary with size category, and there was no significant difference among crosses in pre-copulation duration however; large males crossed with small females copulated for the shortest duration while small males crossed with large females copulated for the longest duration. Large females lived the longest regardless of mating partner. Small females mated to small males produced the fewest eggs and viable eggs. Most egg production occurred during the first four weeks and then steadily declined. If selecting for resistance to transgenic maize decreases male size then non resistant males may have a mating advantage over the resistant males and thereby prolonging the efficacy of the transgenic maize.

Technical Abstract: Diabrotica spp. are serious pests of maize (Zea mays L.) and have evolved resistance to cultural and chemical management practices. Transgenic maize producing a rootworm-toxic protein derived from the bacterium, Bacillus thuringiensis, provides a new approach to Diabrotica spp. management. Wide spread resistance to this toxic protein is a concern and a refuge of non-transgenic maize must be planted within or adjacent to the transgenic maize. Resistance evolution may be associated with fitness related traits such as longevity, fecundity, and body size. We examined the mating behavior and reproductive biology of Diabrotica barberi in relation to male and female body size. Large and small males were reciprocally paired to large and small females to compare against average sized males and females. The proportion of pairs that copulated successfully did not vary with size category, and there was no significant difference among crosses in pre-copulation duration however; large males crossed with small females copulated for the shortest duration while small males crossed with large females copulated for the longest duration. Large females lived the longest regardless of mating partner. Small females mated to small males produced the fewest eggs and viable eggs. Most egg production occurred during the first four weeks and then steadily declined. If selecting for resistance to transgenic maize decreases male size then non resistant males may have a mating advantage over the resistant males and thereby prolonging the efficacy of the transgenic maize.