Melittobia australica

Melittobia australica is a small wasp between 1.1 and 1.4 mm in length but has the typical wasp body plan of a head, thorax, abdomen body structure with the "wasp waist". It is sexually dimorphic with males is normally being larger than females, males are 1.2 to 1.4 mm in length while females are 1.1 to 1.3 mm. Males also have a with a wider head and smaller wings are smaller and their antennal scape is significantly broader. The colour difference is that the males are also a honey brown whereas the females are coloured dark brown. There are at least two morphs of females in M. australica which differ in the size of the abdomen, the size of the eyes and the extent of wing development. The "crawler" morph have a normal abdomen, small eyes and underdeveloped wings. The "flier" and possibly the "jumper" morphs have larger eyes and wings and a smaller abdomen. The "crawlers" remain within the host nest for the whole of their life cycle while the other morphs disperse as adults.

Melittobia australica was first described by the American entomologist Alexandre Arsène Girault in 1912 from Australia but it has since been recorded from North America, Central America, northern South America, the Caribbean, Africa, eastern Asia, Europe (Sicily) and New Zealand. Some authorities believe that it is indigenous to Australia but that human commercial activity has allowed it to spread and become cosmopolitan.