Evaluation of preference of brown marmorated stink bug, Halyomorpha halys (Stål) for different colour bell peppers and the role of plant protein

The brown marmorated stink bug (BMSB), Halyomorpha halys, (Stål) (Hemiptera: Pentatomidae) a highly polyphagous invasive pest from Asia, has become a major agricultural pest in the United States. Laboratory experiments were conducted to determine nymph and adult BMSB preference for bell peppers of different colours (red, yellow, green, and orange). Peppers were presented to BMSB using a Dual Choice Arena Test (DCAT) with and without a standard (cowpea pod). The experiments were video recorded using the Noldus ObserverXT video system. A 4-arm olfactometer was used to determine plant volatile involvement in observed preferences. The Pierce Bicinchoninic Acid Protein assay was used to measure total protein concentration of the peppers. Results on preference measured by a Preference Index (PI, range 0–2), showed that nymphs and adults preferred peppers (PI ≥ 1.1) over cowpea pod. In a pairwise DCAT with all possible combinations, orange-coloured pepper was preferred over all the other peppers. Olfactometer test indicated that H. halys were more attracted to red and yellow peppers. Orange peppers showed the highest protein concentration whilst green peppers showed the least protein concentration.