Wasp (Golden spider wasp) Cryptocheilus australis
Species: C. australis
Binomial name: Cryptocheilus australis
Common names: Golden spider wasp, Australian golden spider wasp
Cryptocheilus australis is a spider hunting wasp accidentally introduced into New Zealand around 1960. It is native to Tasmania and south-eastern Australia, In New Zealand they are now found from the North Cape to Auckland. It habitats are urban areas, forests, wetlands and open shrub land.
The adults wasps are orange and black with yellow-orange wings with black tips. They have long thin legs. Females are >22 mm in length while males are >18.5 mm. Their diet is nectar usually from Leptospermum species (manuka) and Apiaceae species (wild celery, carrot or parsley). They are not aggressive but their sting is very painful.
Cryptocheilus australis are active mostly during January and March. They first constructed a complete cell and cell-passage nest before running around searching for spiders. Their multi-celled, compound nests are constructed in pre-existing cavities under stones, beside stumps and posts, in cracks in exposed compacted clay or in unmodified clay. One daughter may occupy her mother's nest and construct further cells extending from the main burrow the following season, while her adult male siblings may continue to occupy the nest.
When hunting the females mainly use their vision but antennal chemoreception (chemical sampling by the sensory hairs on that antenna) plays some role.
The prey in New Zealand is usually a spider from the Pisauridae family (Nursery web spiders). Once a spider is found it is pursued until it stops and cowers, and then the wasp rushes in and stings it twice. After being stung the spiders looses the movement of their legs. It is then dragged backwards with its back uppermost. The wasp mostly uses her pedipalps to hold the prey by the chelicerae (mouth parts). She can drag a prey many meters to her burrow.
The wasp then positions its prey in a nest cell with the underside facing upwards. The egg ventral, and the posterior of the abdomen of the spider facing the burrow and the cell entrance. That is because the prey is taken into the cell by the pedipalps. A single egg is laid on the abdomen of the still living paralysed spider and the nest cell is then closed with compacted earth. The main burrow of the nest and its external entrance are kept open for the duration the nesting cycle.
When the wasp larva hatches, it begins to feed on the still-living spider. After consuming the edible parts of the spider, the larva spins a silk cocoon and pupates, usually emerging as an adult the next summer. The young males wasps emerge first, 3-8 days before the females and gather around the nests, often entering them and sometimes assisting the females to hatch before mating with the docile, newly emerged females. After around two days the females commence hunting.
Photographed at Ngnguru, Northland, New Zealand