Scarab beetle
Large swarms of scarab beetles can cause defoliation in eucalyptus canopies
© Queensland Government
Swarming scarab beetles (Automolus spp.) feeding on a eucalypt seedling
© Queensland Government
Swarming scarab beetles (Coleoptera: Scarabaeidae) can be important pests in young eucalypt plantations. Several species are pests in Queensland, including Automolus species, Liparetrus species and Epholcis bilobiceps.
Because beetles feed in swarms, they can cause severe defoliation and/or dieback of the growing tips of young trees. They are also known as spring beetles because most damage occurs in spring to early summer when the adults emerge in south-eastern Queensland.
Scientific name
Automolus spp., Liparetrus spp., Epholcis bilobiceps
Other names
- Spring beetles
Description
- Typical head shape has 2 strongly projecting lobes at the front.
- Automolus species are:
- reddish brown
- 4–5mm long with elytra (wing covers) covering the abdomen
- short body hairs
- active during daylight.
- Liparetus species are:
- light brown
- 5–7mm long with short elytra (wing covers)
- long body hairs on the end of the abdomen
- active at night.
Distribution
- South-eastern Queensland.
Hosts
- Spotted gum (Corymbia citriodora subsp. variegatae)
- Rose gum and hybrids (Eucalyptus grandis)
- Dunn's white gum (E. dunnii)
- Western white gum (E. argophloia)
- Gympie messmate (E. cloeziana).
Damage
- Jagged leaf edges caused by adult beetles feeding on young eucalypt foliage and shoots.
- Dieback and defoliation caused by swarms of feeding beetles.
- Reduced early season growth and delayed forming of dominate central stem.
- Larvae feed on the roots of improved pasture grasses, turf and decaying organic matter.
Resources and research
- Carnegie, A, Lawson, SA, Smith, T, Pegg, GS, Stone, C, and McDonald, J 2008, Healthy hardwoods: a field guide to pests, diseases and nutritional disorders in subtropical hardwoods, Forest and Wood Products Australia, Victoria.
- Australian Pesticides and Veterinary Medicines Authority (APVMA)
- Last reviewed: 12 Dec 2018
- Last updated: 12 Dec 2018