This page provides an overview of bug pests in vegetable crops. The related tools listed at the end of the page provide detailed information about their identification, damage and management. It is important to be able to identify insect pests such as bugs, and to have unknown species expertly identified so that they can be appropriately managed.
Bugs are sap-sucking pests, and damage to susceptible plants is similar to that caused by aphids. Both immatures (nymphs) and adult bugs can cause damage to a wide range of vegetable crops through using their needle-like mouthparts to pierce the plant and suck up the cell contents. Bugs can move into crops from nearby weeds and may be found on all plant parts.
Host vegetable crops
|Rutherglen bug (Nysius vinitor)||Adult bugs are about 5 mm long, with narrow grey-brown-black bodies. Their wings form a cross-like pattern on their back.||Found in a range of crops, mainly lettuce.||Cause plants to wilt when present in large numbers and contamination problems.|
|Green vegetable bug (Nezara viridula)||Adults have a bright green chisel-shaped body.||Beans; sweet corn; tomato; potato; cucurbits||Feeding through piercing and sucking sap causes water soaked lesions to develop and some malformation in growth around the affected area. Reduced vigour, premature flower drop, seed damage, and distorted development may be observed. In beans, pods may abort.|
|Mirid bugs – Green mirid (Creontiades dilutus)||Adults have slender, green bodies with light brown markings on translucent wings. Very active.||Cucurbits||Suck sap and release enzymes that destroy surrounding plant cells, causing parts of the plant to wilt and die.|
|Mealybugs||Wingless insects, usually less than 6 mm long, with an oval body like a slater and covered with white waxy powder or threads.||Prefer plants with high nitrogen content. Greenhouse crops.||Cause extensive damage to roots, stems, and leaves.|
- Cultural control: Control weeds in and around the crop.
- Chemical control: Insecticides may be required if numbers of Rutherglen bug become too high. Refer to the APVMA website or a commercial chemical database for pesticide options.
- Biological control: Green vegetable bug numbers are often kept under control by small wasp parasitoids. Green vegetable bug eggs are frequently controlled by a tiny introduced wasp Trissolcus basalis – green vegetable bug egg parasite. Other natural predators of this pest include ants, spiders, and predatory bugs.
- The most effective is biological control – important predators of mealybugs include lacewing larvae and ladybirds. Both scales and mealybugs are parasitised by tiny wasps that lay eggs in the body of the host insect.
- Chemical controls include oil sprays that control scale insects and mealybugs by smothering them. Eggs that are under the adult scale insects will not be killed. Various contact and systemic chemicals are available to kill mealybugs that are feeding. Once the pest has stopped feeding, it is too late to control it.
- Scale Insects and Mealybugs on Ornamentals
- Green vegetable bug
- Mega Pests – Managing Sucking Pests
- Cucurbit Ute Guide -
- Green beans: insect pests, beneficials and diseases
- Brassica integrated pest & disease management
- Brassica Best Practice - Integrated Pest Management Guide
- Field guide to pests, diseases and disorders of vegetable brassicas
- Insect pests of cucurbit vegetables
- Pests, Beneficials, Diseases and Disorders in Cucurbits
- Insect pest guide: a guide to identifying vegetable insect pests and their natural enemies in the dry tropics
- The Good Bug Book (2nd Edition) and CD
- Diseases of Cucurbit Vegetables
- Pests, beneficials, diseases, and disorders in lettuce: field identification guide
- Integrated pest management in lettuce: information guide
- Best practice – Sclerotinia in lettuce
- Lettuce Best Practice - Integrated Pest Management Guide
- Pest and Disease Management (Vegetables WA)
- National IPM newsletter
- Australian Vegetable Growing Handbook