Odontoloxozus longicornis is a neriid cactus fly associated with decaying cacti in the Southwestern United States and arid parts of Mexico and Central America (Ryckman & Olsen 1963). Females oviposit into cracks and crevices of damaged columnar cacti, and the larvae develop in the rotting stem tissues. Adults feed on the exudate of decaying cacti and can also sometimes be found at compost piles.
Females are about 5-7 mm long, while males vary greatly in size ranging from 5 mm to over 1 cm long. Males stake out territories at feeding and oviposition sites, and repeated matings as well as postcopulatory guarding have been observed (Mangan 1979).
