Adult flea beetles are very tiny, just 2-3mm (1/10 inch) long. They're black, brown, or bronze sometimes with stripes and with enlarged hind legs. They jump like fleas when they're disturbed. The larvae live in the soil and are thin, white, legless grubs with brown heads.
What to Look for:
When attacks are severe, foliage will be peppered with small holes and pits, and growth may be reduced. The tissue around damaged areas will become dry and discoloured.
Plants most often affected:
- Many plants from the Brassica family are attacked, as well as a small number of ornamentals.
About the Flea Beetle
- Adult beetles are up to 3mm long, usually shiny black in colour and may have light coloured stripes down their wing casing.
- Larvae are small white coloured grubs with brown heads and pairs of fleshy legs.
- Eggs are tiny opaque yellow elliptical forms, and are laid around plant roots.
- Adults usually have long, hinged hind legs that enable them to jump like fleas.
- Over-wintering takes place as adults, either beneath the soil surface or amongst plant debris around the base of the plant.
- Adults re-emerge in early spring to feed and mate.
- During dry periods in April/May, feeding can be severe and may result in plants dying. During this time adults can be seen jumping on and around infested plants.
- Eggs are laid towards the end of May/ early June, and will hatch a few days later.
- The larvae will begin to feed immediately after hatching. Mainly on plant roots, although some larvae feed on leaves.
- Pupation occurs in late summer, with second generation adults emerging during autumn.
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
- Fleeces can be used to protect new seedlings from infestation.
- Encourage insectivorous birds by hanging boxes and feeders.
- Use yellow sticky traps to catch adults.
- Flea beetles prefer dry conditions, so keep plants well watered.
- Remove all plant debris from the base of your plants, to reduce over-wintering sites.
- Try “trap planting” by growing more susceptible hosts between your primary plants.