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Natural history, phylogenetic relationships, and pest potential of Colaspis Fabricius species (Coleoptera: Chrysomelidae) in Nebraska
A series of laboratory and field experiments were conducted to increase the fundamental understanding of the insect genus Colaspis Fabricius (Coleoptera: Chrysomelidae) in Nebraska with special emphasis on Colaspis crinicornis Schaeffer, including natural history and pest potential. Little is known about C. crinicornis natural history or pest potential even though this species has become common in corn, Zea mays L., and soybean, Glycine max (L.) Merrill, over the last decade in southeastern Nebraska. The specific focus of this research was on C. crinicornis developmental biology, influence of diet on adult fitness, diel activity patterns, general life cycle, and seasonality. Colaspis crinicornis is univoltine in Nebraska. Adults are generally present from June through August with peak emergence in July. Adults readily feed on corn and soybean leaves, and adult longevity and fecundity are similarly affected by the two diet types. Adults are most active at night in the field. Egg clusters are deposited in the soil, and larvae subsequently feed on roots the remainder of the summer and then overwinter in the soil. Overwintering larvae resume feeding in the spring, pupation occurs in the soil, and eclosion to adults occurs during the summer. Because injury to crops appears to be minor at current population densities observed in the field, C. crinicornis is unlikely to cause economic loss. Colaspis crinicornis may be an example of an insect species that has been able to exploit open nitches in crops that have been created by changes in agricultural practices. Variation in DNA sequence data obtained from the mitochondrial cytochrome oxidase I gene was also compared among selected Colaspis species. Mitochondrial DNA (mtDNA) sequence data clearly separated four Colaspis species commonly found in Nebraska. However, previously designated Colaspis species groups based on morphological characters were not supported by a phylogenetic analysis of the mtDNA data.
Miwa, Kentaro, "Natural history, phylogenetic relationships, and pest potential of Colaspis Fabricius species (Coleoptera: Chrysomelidae) in Nebraska" (2014). ETD collection for University of Nebraska - Lincoln. AAI3618599.