Nymph and adult biology of Dichelops melacanthus (Dallas) (Heteroptera: Pentatomidae) feeding on cultivated and non-cultivated host plants.

The biology of the pentatomid Dichelops melacanthus (Dallas) feeding on cultivated and non-cultivated plants was studied in the laboratory. Nymph mortality varied from approximately 60 on corn (seed mature) to 77% on wheat (ear immature); no nymphs survived on seedlings of corn or wheat. Nymph developmental time on soybean, corn or wheat (seed, pod or ear) varied from 25.5 to 32.8 days. Body weight at adult emergence was similar and greater on most foods than on wheat ear. Nymphs fed preferentially on soybean (pod immature). On non-cultivated hosts, nymphs showed high mortality (73%) on crotalaria (pod immature); on tropical spiderwort (stem) all nymphs died. Nymphs took longer time to develop on crotalaria and/or on spiderwort than on soybean. Body weight at adult emergence did not differ on crotalaria or soybean. Survivorship decreased with time on most foods, with approximately 50% of adults alive at day 30. On corn and wheat seedlings approximately 80% of adults were dead on day 20. Adult longevity ranged 31-43 days, except on corn and wheat seedlings < 15 days. Females % ovipositing peaked ( approximately 76%) on soybean (pod or seed immature), and was minimum ( approximately 9%) on wheat ear (immature); no females reproduced on seedlings of corn or wheat. Preoviposition period was shorter ( approximately 12 days) on soybean (immature pod or seed) and longer ( approximately 37 days) on wheat (ear immature). Fecundity was similar and higher on all foods than on wheat (ear immature). Body weigh gain occurred on all foods, but on corn and wheat seedlings. Adults fed preferably on soybean (pod immature and seed mature); wheat (seedling) was the least preferred food.