PEST

NAME
Green Vegetable Bug
Nezara viridula

ORDER
Hemiptera

FAMILY
Pentatomidae

Description of the Pest
The green adult may become purplish-brown during winter and is identified by the triangle on its back that has a black spot in each corner with three small yellow spots between them. It grows to 20mm long and the adults commonly shelter under plant litter or under bark during winter.
Eggs are laid in groups up to 80 in a hexagonal pattern and the nymphs are brightly coloured red, green or blackish. As the nymph develops to the 4 [th] or 5 [th] stage there is two distinct forms, green and black and both nymphs and adults have piercing and suckingmouthparts.

     

Appearance and Distribution of the Pest
This is an introduced pest and is found widespread throughout New South Wales in Australia preferring sub tropical to temperate conditions. They appear from late winter to late autumn and can be seen on the new growth and fruit.

Life Cycle
This insect has a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.
There are five nymphal stages with the eggs laid during late winter and up to 4 generations each season. The insect over winters as an adult.

Period of Activity
This pest is active throughout spring and summer, with large numbers occurring in autumn.

Damage Caused
The nymphs feed on the new shoots and mature bugs feed on fruit or seeds. This causes bean pods to become shrivelled and distorted, or tomatoes form mottled areas.

Susceptible Plants
Legumes such as beans or lucerne or pumpkin, spinach, passionfruit and many ornamental species.

Cultural Control
Small infestations may be removed by hand or infested plants may be removed after cropping. Weed control around the plants will also reduce possible infestation.

BiologicalControl
Parasitic wasp eggs may be introduced to help keep numbers down.

Chemical Control
Spraying with insecticides is effective, such as fenthion or dimethoate.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.