Biology of Thyanta perditor (Hemiptera: Pentatomidae)

The biology of T. perditor (E.) was studied on Bidens pilosa L., wheat, and soybeans in Brazil. Females collected in the field from B. pilosa produced significantly larger numbers of eggs and egg masses on B. pilosa than on wheat; on soybeans, only one pair copulated, n o eggs were deposited, and longevity of adults was severely reduced. The incubation period of T. perditor eggs in the laboratory was 6 .0 days. The durations of the first through fifth nymphal stadia on B. pilosaaveraged 4.3, 6.3, 4.3, 4.7, and 8.9 days, respectively. Cumulative mortality reached 58%, the greatest mortality occurring i n the fifth instar. Of 150 nymphs reared on soybean, none reached the fourth instar. The sex ratios of cohorts of adults collected in the field and reared in the laoratory were 1female:1male and 1.2female:1male, respectively. The tachinid fly, Eutrichopodopsis nitens (Blanchard), parasitized 50.5% of the field-collected adults and the egg parasite Trissolcus (Microphanurus ) scuticarinatus (Lima) parasitized 53 % of the egg masses collected from cages in the field.