Egg Extraction Methods for Bagrada hilaris (Heteroptera: Pentatomidae) with Notes on Ovipositional Preferences

Abstract

The ovipositional preference of Bagrada hilaris (Burmeister) was evaluated, and egg extraction methods from soil were compared. In a choice test between soil, plant material, and exposed plastic surfaces, females laid eggs only in the soil. Significantly more eggs were deposited in dry soil than in most soil. A significant preference for ovipositional depth within the soil was found, with the greatest proportion of eggs laid in the upper one-third (i.e., 0–0.4 cm) of the soil. Two egg extraction methods (i.e., wash and flotation) were compared for effectiveness, sampling time, and cost of setup. The wash method consisted of two types (wash methods 1 and 2, with or without a paint strainer, respectively), whereas the flotation method consisted of several solutions. The wash method (both types combined) was more effective in egg extraction than the flotation method from both small and large volume samples, but the two types differed from each other; method 1 had a higher recovery rate than method 2 for small soil volumes but a lower recovery rate than method 2 for large volumes. Total sampling time was shorter for the wash method than the flotation method and less expensive.