Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Dendrobium midge (518)

Click/tap on images to enlarge
  • 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.
Common Name

Dendrobium midge. It is also known as blossom midge, orchid maggot, orchid blossom midge.

Scientific Name

Contarinia maculipennis. It is a member of the Cecidomyiidae. Here it is known as Contarinia species as it has not been formally identified.

AUTHORS Mani Mua & Grahame Jackson
Information from Osborne LS et al. (Undated) A serious new pest is causing significant problems for dendrobium and hibiscus growers. University of Florida. (; and Jones S (2021) Orchid blossom midges. (; and Thompson B (2014) Blossom midge on dendrobium orchids.Pest management decision guide: green and yellow list. CABI, Barbados; and Pest risk analysis Contarinia maculipennis. (; and from Hara AH, Niino-DuPonte RY (2002) Blossom midge in Hawaii - a pest on ornamentals and vegetables. Cooperative Extension Service, College of Tropical Agriculture and Human Resources. University of Hawai'i at Manoa. Photo 1 Elizabeth Willhite, USDA Forest Sservice, Contarina gall midge spp. (Contarina sp.) Photos 1&2,4 Wilco Liebregts, Eco-Consult Pacific, Suva, Fiji.

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland, in association with the Pacific Community.

Copyright © 2022. All rights reserved.