Itchy caterpillars

Family 

Limacodidae

Doratifera vulnerans (Lewin) identified by P. Mackey 28 June 1982.

Food plants

Collected from Eucalyptus tetrodonta (F. Muell.), (Darwin Stringybark) in Darwin 16 March 1982 by P. Whelan.

Also collected in Darwin, March 1982 by P. Whelan from:

• Eucalyptus miniata A. Cunn. ex Schauer (Woolybutt)
• Leptospermum longifolia (C.T. White & Fronin) S.T. Blake, (Weeping Ti Tree)
• Melaleuca species (Paper bark)
• Eucalyptus camaldulensis Dehnh., (River Red Gum).

Appearance

The larvae are bright colourful larvae with an overall light purple appearance with light green lateral edges with patches of yellow edged with black in the dorsal "saddle" with a characteristic hump at each end with four rosettes of stout black tipped stinging spines at each end. 

The four rosettes of stinging barbs at each end are partly retractile. There is a row of light green stinging protuberances along each side. The moth is small with light and dark brown patterns on the forewings with pale ends and rear edges.

Biology

The main food plant in the Darwin area is Eucalyptus camaldulensis and less commonly on Eucalyptus miniata and Eucalyptus tetrodonta. The larvae feed on the younger leaves and are primarily present during the Wet Season when the food trees are actively growing. 

Pupation occurs in a hard ovoid shaped cocoon which is attached sessile to the smaller branches of the food tree. After the moth emerges, the cocoon loses its top but remains firmly attached to the twigs as a small smooth grey cup resembling a small eucalypt fruit capsule.

Medical effects

Larvae were tested for reaction by touching lightly on the forearm with the point of contact being one of the apical groups of stinging spines.

There was an immediate very sharp painful sting. A sharp throbbing pain started after a few seconds and lasted for approximately five minutes. A white raised wheal of 1 square centimetre appeared within a few seconds with a surrounding reddened area 1 cm. wide. 

After 15 minutes the site was no longer painful. The whole area 9sqcm was raised and reddish after 45 minutes. After two hours there was no pain and while no longer red, there was a large 5cm x 5cm raised swelling on the forearm.

Remedy

Avoid food trees in urban or bush settings, particularly if there is evidence of fresh skeletonising or partly eaten leaves.

Remove trees in urban sites or destroy larvae at resting stage at the base of the food trees by residual application of insecticide to the trunk or leaves of the tree and by wrapping loose bagging impregnated with insecticide at the base of the tree. Burn the area around the base of tree during the day when the caterpillars are resting.

Do not have outside fluorescent or incandescent white lights on after sundown in problem areas or when moths are active.

Do not touch the small brown moths.

Do not sleep or sit under lights when the moths are attracted to the lights.

Wash affected clothes or skin well with soap and water.

Apply icepacks or soothing lotions such as Stingose, Calamine Lotion or papaya creme. Antihistamine medications may be required for severe or generalised reactions. Medical advice should be sought for severe reactions.

Reference

Southcott, R.V., 1978, ‘Lepidopterism in the Australian region’, Records of the Adelaide Children’s Hospital, vol. 2, pp. 87–173.