Trissolcus basalis
Trissolcus basalis, or the green vegetable bug egg parasitoid, is a parasitoid wasp in the family Platygastridae known primarily for parasitising the horticultural pest "Nezara viridula", the green vegetable bug. Description. Like other species of "Trissolcus", "T. basalis" is small (around 2mm long), mostly black in colour, and females have clubbed antennae. "Trissolcus basalis" can be separated from other nearctic "Trissolcus" species by the presence of coriaceous microsculpture on the mesoscutellum, pustulate setal bases, shallowly impressed episternal foveae on the mesopleuron, and an incomplete netrion sulcus. Life cycle. "Trissolcus basalis" is a solitary endoparasitoid, completing development within  the eggs of pentatomid bugs. Females use their clubbed-shape antennae to palpate eggs laid by their primary host, "Nezara viridula". When ready to oviposit, the female faces away from the egg and backs into it, inserting her ovipositor through the wall of the egg. Once finished ovipositing, the female withdraws her ovipositor and wipes the tip across the egg surface to mark the egg. After adults have completed development, males emerge first followed by females a couple of days later. Males mate with females as they emerge from the egg. Ecology. In New Zealand, "T. basalis" has been recorded  from non-target hosts including "Cermatulus nasalis" (Woodward, 1837), "Cuspicona simplex" Walker, 1867, Green potato bug, "Dictyotus caenosus" (Westwood, 1837), "Glaucias amyoti" (Dallas, 1851), "Monteithiella humeralis" (Walker, 1868), and "Oechalia schellenbergii" (Guerin, 1831). It has no known natural enemies in New Zealand, although "Acroclisoides", a genus containing a species known to hyperparasitise "T. basalis" in Australia, is known to be present in New Zealand. Distribution. "Trissolcus basalis" is considered to be an effective biocontrol agent in New Zealand, Australia, and the United States, all places where it was deliberately introduced. In 1949 "T. basalis" was released in New Zealand in  an effort to control damage caused to crops including sweet corn and green beans by "Nezara viridula". Over 48,000 parasitoids were reared from a shipment of between 200 and 300, and these were released at Awanui, Kaitaia, Paihia, Kawakawa, Whangarei, New Plymouth and Te Kaha (Bay of Plenty).