Explaining the Green-Bellied Stink Bugs Diceraeus spp. Booming in the Neotropics: Changing from a Secondary to a Key...

The green-bellied stink bugs Diceraeus furcatus (F.) and Diceraeus melacanthus (Dallas) (Hemiptera: Heteroptera: Pentatomidae) were traditionally known as secondary pests of crops in the Neotropics. This situation has changed dramatically, and nowadays, they turned to be key pests of major commodities, such as soybean and maize. They are polyphagous, showing preference for Fabaceae (Leguminosae) and Poaceae (Gramineae). Despite being predominantly seed feeders (soybean bearing pods and cereals bearing seedheads), they also feed on vegetative (seedlings of maize, wheat, and other cultivated spring cereals) plant stages. Feeding activity includes ingestion from xylem vessels, parenchyma cells, and endosperm tissues. Feeding strategies consist on salivary sheath strategy on xylem, laceration (mechanical action by stylets, mostly mandible indentations), and maceration (chemical action of enzymes) causing cells rupture on the parenchyma and seed endosperm. Resulting damage on seedlings of Poaceae includes emission of excess tillering, whitish spots on leaves, wrinkled leaf areas, and tissue necrosis. Feeding during booming causes discolored and deformed seedheads. Fabaceae damage on the seed endosperm shows whitish spots and seed deformation. The uncommon exploration of seedlings by these seed feeding stink bugs, which result in heavy damage, occurs in order to seek for water to get hydrated; acquisition of some nutrients; and achievement of nutrients balance by diluting the concentrated in nutrients sieve from the seed endosperm they usually feed on. Understanding those feeding behaviors allows to establish some important management recommendations such as reducing soybean seed losses and weeds presence at harvest. Seeds on the ground and presence of green weeds are crucial food sources for the green-bellied stink bugs, keeping them active from first to second crop season in the field, favoring their outbreaks.