- Restricted. Not recorded from Africa, South America (uncertain). Fiji (not officially authenticated).
- Serious orchid pest, particularly dendrobiums (and bitter gourd). Brown scaring on flower stems and brown spots, streaks and distortions on flower buds. Infestations cause premature loss of flowers and/or blemished unmarketable sprays.
- Eggs laid into open end of flowers, larvae mature in 5-7 days, and pupate in the soil. Adults emerge 14-21 days later. Similar to miniature mosquitoes, 1.5mm long. Midges favour high humidity.
- Spread: larvae disperse with spring-like action to the soil. Long distance with international trade in cut-flowers and nursery stock.
- Biosecurity: risk of imported flowers infested with larvae; cuttings have infested flower buds, and that coir chips used for propagation contain pupae.
- Biocontrol: none.
- Cultural control: site orchid nurseries away from alternative hosts. Monitor regularly, checking for spots, streaks and deformities of buds. Hygiene: collect fallen buds and place in alcohol to see maggots.
- Chemical control: several products used previously are no long recommended e.g., diazinon, acephate and neomicotinoids (imidacloprid and thiametozxam). Abamectin may be a suitable alternative. Discuss options with agricultural authorities.