Nymphal and Adult Performance of Neomegalotomus parvus (Hemiptera: Alydidae) on Wild and Cultivated Legumes

Performance of nymphs and adults of the Neotropical alydid Neomegalotomus parvus (Westwood) depended on their legume diet. No nymphs reached adulthood on pods (mature or immature) of the indigo species Indigofera truxillensis H.B.K., I. suffruticosa Millsp., or I. hirsuta L. On soybean, Glycine max (L.) Merrill, pods (mature or immature) mortality was ≈77% and dropped to ≈12% on mature seeds; similar mortalities were observed on mature seeds of pigeon pea, Cajanus cajan (L.) Millsp., and lablab, Dolichos lablab L. On pods of these last 2 foods, nymphal mortality ranged from ≈17 to ≈26%. Nymphs tended to complete development faster on pigeon pea (≈19 d) than soybean (≈22 d) or lablab (≈20 d). There were no differences in nymphal developmental times between sexes; the 5th stadium was the longest and the 3rd the shortest. Fresh body weight at adult emergence was greater for nymphs reared on mature seeds of pigeon pea (≈34 mg) and lablab (≈32 mg) than on mature seeds of soybean (≈27 mg); on pods (mature or immature) of pigeon pea and soybean it varied from ≈26 to ≈31 mg. Survivorship and total longevity of adult N. parvus were greater on mature seeds of pigeon pea and soybean (mean longevity of females and males >40 d), less on mature pods of pigeon pea (=40 d), on mature seeds of lablab (≈33 d), and on mature pods of soybean (≈26 d), and even less on green pods of these legumes (≈17 d). Drastic reductions in survivorship and longevity were observed on pods (mature or immature) of indigo legumes, with mean longevities of females and males of <8 d. Reproductive performance was variable, mature seeds and pods of pigeon pea being the most suitable foods. Fresh body weight of females at the end of day 29 was greater on mature seeds and pods of pigeon pea, soybean, and lablab (≥40 mg) than on immature pods of pigeon pea (37 mg) and soybean (23 mg). Considering the performance of nymphs and adults across all foods, mature seeds of pigeon pea were the most suitable food for N. parvus.