Parasitism and Predation on Sentinel Egg Masses of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) in Three Vegetable Crops: Importance of Dissections for Evaluating the Impact of Native Parasitoids on an Exotic Pest.

Abstract

We conducted a survey to examine parasitism, predation, and the species composition of native parasitoids attacking sentinel egg masses of the invasive pest, the brown marmorated stink bug, Halyomorpha halys (Stål), in bell pepper, squash, and tomato. A 2-yr survey was conducted for each crop. The species composition of parasitoids was determined for parasitoids that successfully emerged from eggs, parasitoids that were identified from dissections, and parasitoids that were found attending egg masses at the time of collection. The overall rate of brown marmorated stink bug nymphal emergence was 82.7% from laboratory-reared control egg masses compared with only 23.4% from sentinel egg masses due to a combination of predation, parasitism, and unknown mortality causes. Overall, 12.4% of sentinel eggs were parasitized. Parasitoids emerged successfully from only 2.3% of eggs, but they were dissected from an additional 10.1% of eggs. Telenomus podisi Ashmead was the predominant species identified from emerged parasitoids (57.4%), dissected parasitoids (90.2%), and parasitoids attending egg masses (77%). This study provides further evidence that the impact of native parasitoids on brown marmorated stink bug egg mortality may be greatly underestimated based solely on parasitoid emergence rates alone.