A two-variable approach used to distinguish between aphids (Hemiptera: Aphididae) that were reared on different varieties of cotton

Abstract

Identifying the plants aphids have fed on can increase our understanding of their roles in food webs, and help in improving management and implementation control strategies in agricultural systems. Field sampling and laboratory experiments were carried out to determine the stable isotope ratios of carbon (δ13C) and nitrogen (δ15 N) in three different varieties of cotton and the aphids (Aphis gossypii) that fed on these varieties. The results were used to test the hypothesis that stable isotope signatures of aphids that have fed on different varieties of cotton differ. Two-dimensional plots of stable isotope signatures for aphids and the cotton varieties they fed on displayed a non-overlapping pattern, indicating that stable isotope signatures of the three cotton varieties and the aphids that fed on them differed. The results indicate that stable isotope analysis can potentially be used to identify aphids that have fed on different varieties of cotton. When the stable isotope signatures of diets clearly differ then it is highly likely the consumers will be distinguishable.