Geographic Variation in Larval Feeding Acceptance and Performance of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Abstract

Larval feeding behavior and performance on three plant species ( Solanum tuberosum L., S. angustifolium Miller, and S. elaeagnifolium Cavanilles) were compared between populations of Leptinotarsa decemlineata (Say) obtained from Morelos (Mexico) and Rhode Island. Population differences in larval feeding, cumulative mortality, and growth rate depended upon host species. For the most part, no divergence in feeding behavior and larval performance was noted between the populations on the ancestral host, S. angustifolium . Compared to Rhode Island beetles, a smaller percentage of Morelos beetles fed on S. tuberosum (potato) and S. elaeagnifolium . For those Morelos larvae that accepted potato, mortality of early instars was higher, and growth rate of early instars was slower, on potato than on S. angustifolium . Percentage of siblings that accepted potato was positively correlated with larval growth rate and survival on potato but not pupal weight of the survivors. The Morelos population showed significant variation among females in offspring acceptance of potato and S. angustifolium ; all Morelos larvae rejected S. elaeagnifolium . Variation among individual females in offspring acceptance of the three hosts was not significant for the Rhode Island population. All Rhode Island beetles were consistently less likely to accept S. elaeagnifolium than potato or S. angustifolium . Estimated heritability of larval feeding acceptance of potato by Morelos beetles was 0.48 by full-sib analysis.