Another group of phorids with strange females are the Termitoxeniinae. In these flies, the females are found in the nests of fungus-gardening Old World termites. The males and females of at least one African species fly at the same time as their host termites’ swarming, mating and often returning to the same nest.
The females then strip off most of their wings, and incredibly, start to grow (few adult holometabolous insects have post-imaginal growth). The head and legs lengthen, and the abdomen becomes grossly swollen, eventually mimicking a termite nymph. The abdomen also has glands that produce secretions that termite lick off. Apparently, they act as appeasement compounds that help integrate the fly into the termite society.
These flies are found in Africa to Southeast Asia. My colleague in England, Dr. Henry Disney, has done most of the modern taxonomy of Termitoxeniinae, including recognizing that the males of the phorid subfamily Alamirinae were the previously “missing” males of the termitoxeniines. These males have little in the way of mouthparts, probably do not feed, and are likely short lived.