Yellow Hairy Flower Wasp
S2, Female, Face, very worn
Ellura
Yellow Hairy Flower Wasp
S6, Female, Face
 
                      
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:     S5, Male, Face

Thank you Dr Graham Brown for identifying, Joseph (cobaljoseph) & Tony and Jenny Dominelli for confirming and Dr Chris Lambkin & Dr Paul Whitington 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
Females have short antennae, where as males have longer ones. Paul said CSIRO states most Apocrita females have 10 flagellomeres & males 11. Female flagellomeres are very short with scollids, and longer with males (making the whole antennae much longer). Antennae tips can get broken off, corrupting the count.
There is a large size variation with these: ~17mm 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 the 2 species (R. tasmaniensis & R. radula), he said "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."
Joseph said R. tasmaniensis is widespread around the country. R. radula is restricted to the North.
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The males also have posterior spines that can be withdrawn to some degree.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.
The female (S6) has 2 very large spines on her hind legs, pointing down; probably helps hold the scarab beetle while she deposits her eggs into it.
This species is often confused with Laevicampsomeris formosa (Qld only); which doesn't have black stripes on the abdomen.

Similar Species: Robust Scarab Wasp (Pseudotrielis flavidula)

Copyright © 2022-2024 Brett & Marie Smith. All Rights Reserved. Photographed 29-Jan-2022
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.