Shield bug (Southern Green Stink Bug) Nezara viridula
Species: N. viridula
Binomial: name Nezara viridula
Common name: Green vegetable bug, Southern green stink bug,
Nezara viridula is native to South Africa and is a pest of vegetables with a wide host range. These plant-feeding buga are believed to have originated in Ethiopia, It was first recorded attacking bean crops at New Plymouth in 1944 and is maily confined to warmer areas of the North and South Islands.
These are green, shield-shaped flattened bugs, 12mm - 15mm long with 3 small spots in a line between the wing insertions. These spots distinguish them from the native green bug (Glaucius amyoti), which lacks the spots.
The Pentatomidae are often called stink bugs because when handled they emit a strong smell. The nymphs have prominent glands on the upper (dorsal) side of their abdomen, while adults have glands between the base of their legs. The chemicals may deter predators and cause other bugs to drop to the ground, but some of the chemicals produced may also act as aggregation pheromones.
Their eggs are cylindrical, about 1mm long, and usually laid in clusters. They are creamy-white in colour when freshly laid but turn reddish close to hatching. The nymphs are orange initially, these later change to black marked with spots of yellow, green and red. The green colour becomes dominant in the last instars, and in the overwintering adults becomes much darker, often with a purplish tinge. Green vegetable bug overwinters as the adult in long grass or other suitable plant cover. Eggs are laid in the spring and hatch after about ten days. The entire life span occupies about eight weeks and there are two to three generations a year. Adults may live for three - six months.
Adult photographed early September
Showing its wings.
An adult Nezara viridula in cold weather
Another during winter.
A second stage instar, 2mm body length.
Mid stage instar.
Mid stage instar
Mid stage instar underside
The next four photos are of final instars of Nezara viridula.(8 mm long)
This the empty moulting shell of the above last instar.