Tachinid Fly Parasitism and Phenology of the Neotropical Red-Shouldered Stink Bug, Thyanta perditor(F.) (Heteroptera: Pentatomidae), on the Wild Host Plant, Bidens pilosaL. (Asteraceae)

Field and laboratory studies were conducted with the Neotropical red-shouldered stink bug Thyanta perditor(F.) (Heteroptera: Pentatomidae) aiming to evaluate parasitism incidence on adults by tachinid flies (Diptera: Tachinidae), which were raised in the laboratory for identification. Egg deposition by flies on adult body surface was mapped. In addition, nymph and adult incidence on the wild host plant black jack, Bidens pilosaL. (Asteraceae), during the vegetative and the reproductive periods of plant development was studied. Seven species of tachinid flies were obtained: Euthera barbielliniBezzi (73% of the total) and Trichopodacf. pictipennisBigot (16.7%) were the most abundant; the remaining five species, Gymnoclytiasp.; Phasiasp.; Strongygastersp.; Cylindromyiacf. dorsalis(Wiedemann); and Ectophasiopsis ypirangaDios & Nihei added 10.3% of the total. Tachinid flies parasitism on T. perditoradults was significantly greater on the dorsal compared to the ventral body surface. On the dorsal surface, the pronotum was significantly preferred and the wings the least preferred site. No differences were observed on the number of tachinid fly eggs deposited on wings, considering the “under” and “above” sites. Results indicated a significantly greater number of nymphs on mature compared to immature seeds. Adults significantly preferred immature compared to mature seeds; both were less abundant on leaves/stems and inflorescences.