![]() ![]() It has distinctive black spots on its forewings. The third, an unnamed species, belongs to the genus Acroclisoides sp.in the family Pteromalidae. When this wide host range was discovered in the 1960s, it was regarded as beneficial, because at that time protection of crops was regarded as more important than protecting native insects. It also parasitizes eggs of other shield bugs, including the Australian green shield bug, Glaucias amyoti, and the green potato bug, Cuspicona simplex. Another egg parasitoid, Trissolcus basalis (Wollaston 1858), was released into New Zealand in 1949 to control green vegetable bug, Nezara viridula (L.). Trissolcus oenone, a native species, parasitizes several native shield bugs. Two belong to the family Platygasteridae. Feeding of the green potato bug has not been studied, but it probably can use its saliva to digest the tissues of the plant.Įggs of the green potato bug may be parasitized by three species of tiny wasps. The stylets form two tubes, one through which saliva is injects into the plant and a second through which plants juices are sucked up into the insect. The stylets are then gradually pushed into the plant. When it feeds the bug moves the tip of the rostrum to a berry or other suitable part of the plant. The long stylets, special shaped rods, are held in the rostrum. Like other Hemiptera, the green potato bug has piercing and sucking mouth parts. Part of the forewing is coloured green, while the rest is membranous. The adults have two pairs of wings, the front pair is modified as it covers the hind wings. The nymphs and adults have three pairs of legs. The time in days for each life stage were: eggs 5 (5-6), first instar 3.6 (3-4), second instar 3.4 (3-5), third instar 3.8 (2-7), fourth instar 7.1 (4-10), fifth instar 7.3 (4-12). McDonald and Grigg in New South Wales, Australia, found that at a constant temperature of 21☌, the time from egg to adult was 28.8 days (range, 28-30 days). The length of the lifecycle (time from egg to adult) varies with temperature. Depending on climate there may be 1-3 generations per year. ![]() In early summer, new eggs may be laid, but egg laying ceases in late summer. They are larger and more obvious on fifth instar nymphs. Small wing buds can be seen on fourth instar nymphs. ![]() The body of the 3rd, 4th and 5th instars is green with fine black speckles, the legs are pale brown. The brown antennae of the 3rd, 4th and 5th instars have a black terminal segment black with the basal quarter is white. The terminal segment of the antennae is dark, with the basal quarter white, and the third segment from the end is white or brown. The feet of the first two pairs of legs are black, while on the last pair the base of the femur (the long segment before the feet) and the feet are white. The thorax is pale with many black speckles and the abdomen is covered in brown and black speckles. The second instar also has a black head, but it protrudes forward between the bases of the antennae. The antennae are brown with the terminal segment darker than the previous two. The legs are black but the feet (tarsi) are pale. It has a black head and thorax, and the abdomen has black scent glands and red-brown speckles. ![]() The first instar is almost circular in outline. As the insects progress through the nymphal stages their body and antennae change colour. During moulting, the “skin” on the dorsal side splits and the next stage pulls itself out. Nymphs go from one stage to the next by moulting, changing their skin. There are five nymphal stages, each is called an instar. First instar nymphs are like small, black and grey, wingless adults. It appears as a dark rod between the eyespots of the nymph. It is a dark T-shaped chiton structure that assists with pushing the lid of the egg. Just before eggs hatch the ‘egg burster’ can be seen. The eggs are white when first laid and then turn pale green. Egg laying continues until late summer.Įggs are laid in a cluster of up to 14, one for each ovariole. Each female lays several batches of eggs over several weeks. The overwintering adult females start laying eggs late spring. Breeding may occur preferentially on plants with berries. They are probably attracted to each other by an aggregation pheromone (volatile chemical). Adults appear to gather in suitable overwintering sites and on plants for breeding. ![]()
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