Flower Wasp
Large Yellow Flower Wasp
Male, S1: profile
Large Yellow Flower Wasp (Elidothynnus melleus)Class: Animals (Animalia) - Jointed Legs (Arthropoda) - Insects (Insecta)     iNaturalist Observation
Order: Ant Bee Wasps (Hymenoptera)
Family: Flower Wasp (Wasp: Thynnidae: Thynninae)
Species: Large Yellow Flower Wasp (Elidothynnus melleus)
This Photo:     Male, S1: dorsal, ~25mm

Thank you Dr Graham Brown for identifying this species for us

General Species Information:
Found on Ellura (in the Murray Mallee, SA) and elsewhere
As with other Thynnid flower wasps, the female is much smaller & wingless. She may also be blind, or at least have poor vision. This is our 1st Thynnidae found on Ellura and luckily we not only saw & photographed them mating (proves male/female relationship), but also caught them to get sizes and detailed photographs.
We released her were we found her, where she'll find a beetle to parasitise with her now fertile eggs.
Even with his large size, he had a lot of trouble flying with her and allowed us to capture them.
While similar in appearance, with the naked eye, to the European Wasp, this species is much larger and has a cigar shaped abdomen. On closer inspection, and with photographs, the differences are much clearer.
A more technical term for reduced wingless insects is "Apterous". Originally thought this was a Catocheilus sp.
Graham also said "this is almost certainly a complex of species that occur around the country. The male fits in my key but the female doesn't."
We since found another 3 pairs of these mating in one Sugarwood tree at the same time, in November.
The males were ~19-22mm, while the females ~10-12mm. It doesn't sound a lot, but the size variation appeared more substantial. Notice there are some differences:
1. The neck/collar has different black markings. It's not at all obvious and you need to get photo's at the right angle to see it.
2.They all had a strong orange tint to their abdomens.
3. The legs, up near the body, look thinner; not as robust.
Graham said "Colour patterns can vary a little and the abdomen can be stretched a bit because the segments can move."

Copyright © 2017- Brett & Marie Smith. All Rights Reserved. Photographed 27-Apr-2017
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.