Chrysomelid Leaf Beetle

Chrysomelid, Paropsis and Chrysophtharta species and others

Family: Chrysomelidae

Order: Coleoptera

Description:

Adult

Colour - Usually bright. Red, pink, orange and browns.

Body - Variable. Most are less than 100 mm long.

Wings - 2 Pairs. Front wings modified to form hard protective cases (elytra) for rear wings. When at rest they meet in a straight line down the centre of the back. Rear wings membranous and folded both lengthwise and across so they fit under their protective cases. When in flight the elytra are held at an angle and the rear wings beat rapidly. Rear wings may be reduced or absent in some species. Wing-span up to 200 mm. Both pairs attached to the hind body.

Mouthparts - Chewing. Pointing forward.

Antennae - 7-11 segments.

Legs - Rear legs larger than front legs. Feet (Tarsi) have 3-5 segments with 1 or 2 claws on the end segment.

Head - Rigid. Large rounded compound eyes.

Thorax - Front segment associated with head to form distinct fore body. Front segment covered by a hard plate (pronotum). 2 rear segments fused and associated with the abdomen to form hind body.

Abdomen - 10 segments in male, 9 in female. Often only 8 can be counted by eye. Spiracles on segments 1-7 and often on 8 also.

Egg - Usually simple and ovoid and laid on leaves.

Habits - Can't fly when cold. Hibernate in winter.

Larva -

Colour - Usually yellow to cream with dark spots or patches.

Body - No legs. Up to 10 mm long.

Mouthparts - Chewing. Transverse action.

Antennae - 1 segment.

Legs - Has no legs or 6 legs. 5 segments.

Head - Usually a hard capsule. No ridges on forehead.

Thorax - No functional spiracle on middle segment.

Abdomen - 8-11 segments. No prolegs. Spiracles on segments 1 to 8.

Habits - Feed on leaves

Pupa - In soil

Biology:

Life Cycle:

Eggs usually laid on leaves in early summer. Larva hatch and feed voraciously for a few weeks causing damage very quickly. They drop to the soil to pupate. Beetles emerge in October and may be seen over summer until March.

Habitats:

Origin and History:

Distribution:

Significance:

These beetles and their larvae attack trees. The adults usually only chew the edges of leaves and are rarely of economic significance. The larva may defoliate the tree and can be serious pests of young tree plantations. In extreme cases young trees may be killed.

Management and Control:

Insecticides are effective but need to be applied promptly. Constant monitoring of young tree plantations is necessary to avoid damage.

Related Species:

Similar Species:

References:

CSIRO. The Insects of Australia. Melbourne University Press. (1991) p674.

Froggatt, W.W. Australian Insects. William Brooks & Co. p203-205(diagram).

WADA. Insects and Allied Pests of Extensive Farming. Department of Agriculture - Western Australia Bulletin No. 4185. p89.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.