False wireworms







Darkling beetle - adult


True wireworms are the larvae of click beetles belonging to the family Elateridae and feed on roots bulbs and tubers. There are several species which are native to Australia. False wireworms are the larvae of the Tenebrionidae family of beetles. The fast moving larvae, commonly referred to as grubs, have slender, segmented hard bodies which are a cylindrical shape. Their colouring can vary from cream to golden brown to blackish-brown to grey with a darker, round head. They have 3 pairs of legs just behind the head and either pointed tails that turn upwards or have a pair of spines on the last body segment. The most common ones are: *Grey or small false wireworm- 9 mm These have a shiny, grey/green body. From the last (tail) segment there are two protrusions. The adult beetles are slender, 8mm long and are dark brown in colour. *Large or eastern false wireworm- 50 mm This is the largest, most commonly found group. Their colouring is light cream to tan with tan or brown rings around each body segment giving a banded appearance. They have no protrusions from the tail segment. The adult is a large, oval-shaped, black and shiny beetle. *Southern false wireworm- 20 mm These are similar to the large false wireworm but a little smaller. The adult beetles are oval-shaped, usually dark brown/grey; sometimes called “pie-dish” beetles because the edges of their bodies have a flanged appearance. Sometimes they have a coating of soil over them.

Adult size: 9 mm- 50 mm

Out and about

These larvae of beetles are at their worst in the spring and autumn and when the soil has been freshly turned. Their natural habitat is grasslands and pastures where they do very little damage. There are more than 20,000 species world-wide with around 1,500 widespread throughout Australia especially in the south-east.

Reproduction and Life cycle

The adults emerge mid- spring through to summer, laying their eggs one month later on the soil surface or just below, or within the plant roots. Each female can lay up to 1000 eggs or more in a season. The onset of cooler weather stops the female from laying eggs. The eggs will hatch in 3 to 10 days. The larvae develop through autumn, winter and spring, sometimes taking 2-6 years to mature. In the tropics and subtropics larvae pupate during early to mid-spring, brought about by rain. All the instars look the same. There is usually only one generation each year.

To deter

To control

-Plant tubers when the soil is warmer as wireworms prefer cool soil. They go deeper into the soil if the ground temperature rises. -crop rotation can help keep numbers in check - trap by burying raw potato or carrot pieces 5cm deep in the soil (place a marker so they are easy to find). Dig them up after a day or two with larvae- feed to chooks. -disturbing the soil can destroy the larvae when they are most active near the surface.

Plants to repel

Plants to attract


Parasitic nematodes/ birds
Why they are a Pest
They will feed on most vegetables and grains with potatoes, corn, onions, beans, peas, sugar beets and carrots amongst the most affected. Generally all winter sown crops can be affected in cooler areas with common crops such as potatoes, sweet potato, chilli, sweetcorn and tomatoes in warmer regions. They will feed on seeds and seedlings as well as the tubers and corms of plants. Adults do not cause as much damage as the larvae, tending to feed on leaves and flowers. Damage on potatoes and sweet potatoes is small round holes. They chew holes in tubers and chew on roots and stems of other vegetables. Most species prefer to feed on decaying organic matter. They like to feed at night when the soil surface is cool and damp. Seedling damage is on the stem, near the soil surface. They effectively ‘ring-bark’ the seedling. Once the plants have grown they are less susceptible to wireworm damage.