Yellow Hairy Flower Wasp
S5, Male: profile
Yellow Hairy Flower Wasp
S2, Female: Wing Venation
Yellow Hairy Flower Wasp (Radumeris tasmaniensis)Class: Animals (Animalia) - Jointed Legs (Arthropoda) - Insects (Insecta)
Order: Ant Bee Wasps (Hymenoptera)
Family: Hairy Flower Wasp (Wasp: Scoliidae)     iNaturalist Observation
Species: Yellow Hairy Flower Wasp (Radumeris tasmaniensis)
This Photo:     🔍S6, Female: profile🔎

Thank you Dr Graham Brown for identifying and Dr Chris Lambkin for helping with the id of this species for us

General Species Information:
Found on Ellura (in the Murray Mallee, SA), the Adelaide Hills and elsewhere
Like other Scoliid wasps, the females have short antennae, where as males have much longer ones.
We were surprised at the size variations of these. ~18mm to ~25mm long.
Graham said "These wasps are scarab larval parasites and the size varies depending on the size of the host larva." In refering to separating out the 2 species (R. tasmaniensis & R. radula), as listed on Atlas, he said "tasmaniensis in the south and radula in the north. The easiest way to distinguish them is in the colour of the setae on the top of the thorax of the female - it is mostly uniformly reddish brown in the latter where as it is yellowish in tasmaniensis. These hairs are often partially abraided in older specimens."
The common name refers to the male which has very yellow stripes with different "tick" marks on the side.
An image of a mating pair, showing the different antennae lengths & colours can be seen here.
The males also have posterior spines that can be withdrawn to some degree. They are a protection measure to stab their predators in defence and called "Trident Pseudostingers". They don't carry any poison, and aren't tubes. Stingers in female wasps & bees are modified ovi-positors (which males don't have). Already consisting of a tube for eggs, injecting poison wasn't such a large evolutionary step.
Notice the female (S6) here has 2 very large spines on her hind legs, pointing down; probably helps hold the scarab beetle while she deposits her eggs into it.
We photographed 6 specimens in Jan, Mar, Apr, Nov & Dec.

Similar Species: Scarab Wasp (Campsomerinae sp)

Copyright © 2022 Brett & Marie Smith. All Rights Reserved. Photographed 28-Mar-2022
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.