Green Vegetable Bug

Nezara viridula

Family:

Order: Hemiptera

Description:

Adult

Colour - Adult is uniform green. Young nymphs are variously patterned in red, green, yellow, orange, black and brown. Older nymphs tend to be green and brown with pale spots and pinkish around the edges.

Body - Up to 15 mm long and 10 mm wide. Broad. Flat. Shield shape.

Wings - 2 Pairs, both used in flight. Held flat and overlapping position when at rest. Coupled. Wing-span 25 mm.

Mouthparts - Stylet. Sucking. Near rear of head.

Antennae - 5 segments in adults, 4 in nymphs.

Eyes - 2. Compound. 2 simple.

Legs -Feet (Tarsi) have 4 segments.

Head -Wedge shaped

Thorax - 3 segments. Large triangular plate (scutellum) in the middle of the back. Plate behind head (pronotum) is dimpled.

Abdomen - Eight pairs of spiracles on underside.

Egg - Barrel shaped. Pale yellow changing to red brown before hatching.

Habits - Can't fly when cold. Give of an obnoxious odour threatened. Tend to congregate.

Nymphs

Similar to adults. Usually 5 stages (instars).

Biology:

Life Cycle:

Adults change colour to brown and over-winter in sheltered crevices. In spring and early summer large numbers of eggs are laid in 'honey comb' clusters or rows on leaves. These hatch to produce nymphs that grow quickly and moult 5 times. They look and behave similarly to the adult. In 5 weeks they have reached full size. Often develop into large numbers in hot dry summers. There may be several generations each year. Tend to fly in hot weather.

Habitats:

Origin and History:

Distribution:

Significance:

A species introduced about 1911. It is a pest of lucerne, beans, tomatoes, potatoes, peas, pumpkins, melons. oranges, passion fruit and other vegetables. It attacks young shoots reducing growth. On tomatoes it causes mottling and brown corky areas at feeding punctures. A biological control agent has reduced the pest significance green vegetable bug.

It is similar looking to the native Glaucias amyoti (New Zealand vegetable bug) that is a minor pest of vegetables in Queensland.

Management and Control:

Spaying is not usually required as a biological control agent (Trissolcus basalis from the Scelionidae family) was introduced in the 1930's.

Related Species:

Aphids, Lerps, various bugs, leafhoppers and scales.

Similar Species:

References:

CSIRO. The Insects of Australia. Melbourne University Press. (1991) p232, 233, 430f30.1head, 431f30.3thorax, 433f30.5wing, 434f30.5ovipositor, 438f30.11egg, 442, 508, 509.

Goode, J. Insects of Australia. Angus and Robertson. p69.

Victorian Department of Agriculture. Insect Bulletins. p52.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.