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Megacopta cribraria (Kudzu Bug) (Hemiptera: Plataspidae) is an invasive insect in the Southeast. In Baldwin County, GA, we found adult Kudzu Bugs at high abundances throughout the summer, while juveniles showed peaks in early July and September. We conducted a series of choice-preference tests and determined that the insects preferred Glycine max (Soybean) over Phaseolus lunatus (Lima Bean). Additionally, they preferred Pueraria montana var. lobata (Kudzu) over Soybeans, highlighting the role of Kudzu as a primary host plant. Additionally, Kudzu Bugs continued to feed on Soybeans, even in the presence of Kudzu.

Induced plant responses to leaf-chewing insects have been well studied, but considerably less is known about the effects of phloem-feedings insects on induction. In a set of laboratory experiments, we examined density-dependent induction by the milkweed-oleander aphid, Aphis nerii, of putative defenses in four milkweed species (Asclepias incarnata, Asclepias syriaca, Asclepias tuberosa, and Asclepias viridis). We hypothesized that high aphid density would lead to increased cardenolide expression in species with low constitutive levels of cardenolides (e.g., A. tuberosa), but that there would be no induction in high constitutive cardenolide species (e.g., A. viridis). Based on previous studies, we did not expect cardenolide induction in A. incarnata. Contrary to our predictions, we observed feeding-induced declines of cardenolide concentrations in A. viridis. Cardenolide concentrations did not respond to aphid feeding in the other three milkweed species. Aphids also caused reductions in biomass accumulation by two of four Asclepias species, A. viridis and A. incarnata. High aphid density led to a decrease in A. viridis foliar nitrogen concentration. However, aphids had no effect on the defensive chemistry, growth, or nutritional quality of either A. syriaca or A. tuberosa. Our results highlight that congeneric plant species may respond differently to the same levels of herbivore damage.