Yellow flower (or Scoliid) wasp
Radumeris tasmaniensis
Yellow flower (or scoliid) wasp
Photo courtesy of: Landcare Research 
This species is established in parts of New Zealand.
Description
Female yellow flower wasps Radumeris tasmaniensis are about 3 cm long with a 4 cm wingspan and have a large robust body with a broad abdomen. Males are about 2 cm long with a 2.5 cm wingspan and have a more slender body with a narrow abdomen. Females have a dark brown thorax, a narrow waist and a broad orange abdomen with narrow black stripes. Their underside has wide black stripes with narrow white stripes. Males have alternating black and yellow stripes on both the upper and lower surfaces. The female has short antennae about the same length as the width of the head; the male has longer antennae, about half the length of the forewings. Both male and female have orange to brownish wings, with very fine veins towards the wing tips.
Yellow flower wasps have a distinctive flying pattern; they fly on a horizontal plane only a few inches above the ground in a regular circular "figure 8" course.
Impact
Yellow flower wasps are ectoparasitic (it lives on the outside of its host) and are solitary in nature. Instead of forming a nest, the female tunnels into soil and locates a scarab beetle larva, which they sting and paralyse before laying an egg nearby. The larva then becomes a source of food for the young wasp as it grows.
In New Zealand there is a concern that native beetles could be affected by the presence of the yellow flower wasp.
Scoliid wasps are not considered a significant public health hazard, as their venom is of lesser toxic effect than other wasps and they have less aggressive stinging behaviour. If you are stung by a wasp, relieve the pain by applying a cold compress (e.g. ice in a cloth, plastic bag or plastic wrap) on the site for 15 - 20 minutes. Paracetamol may be taken. Talk to your pharmacist about an over-the-counter antihistamine to spread on the bite or to take by mouth to reduce the itching and swelling. If you experience shortness of breath, a widespread rash or pronounced swelling seek immediate medical attention. If you are stung on the mouth, face or neck or if pain and swelling persist for a few days, seek medical advice.
Distribution
The yellow flower wasp is a native species of Australia and Papua New Guinea. In Australia the wasp is present throughout eastern and southern parts with a few records from inland and north-western Australia. The yellow flower wasp is established in three isolated coastal localities in Northland. It has also been found further south in coastal habitats in the Bay of Plenty.
Management
Little is currently known about it or its effects in New Zealand. The Department of Conservation is undertaking an investigation to determine its distribution and hosts.
Resources
- Landcare Research
- Department of Conservation - Observations of yellow flower wasp activity at Butlers Creek, Ninety Mile Beach
Page last updated: 22 October 2008