Melaleuca tip galling midge (Lophodiplosis trifida)

Biocontrol Agent Factsheet

The melaleuca gall midge has been part of a highly successful biological control effort to control the invasive weed melaleuca. 

Common Names

Melaleuca tip galling midge

Relative effectiveness

This biological control agent is highly effective, well established and moves readily within the ecosystem. 

Where to use

In forests and wetlands where Melaleuca is found

About melaleuca tip galling midge

Lophodiplosis trifida is one of several galling species in the genus that specializes on Melaleuca from Australia. While the adults will lay eggs on other plants, the larvae only complete their life cycle on M. quinquenervia. The mosquito-like adults lay eggs under the hairs of the terminal buds of melaleuca, after which they hatch and larvae begin feeding. This feeding induces the plant to form large galls around the larvae and shift resources to the gall. The melaleuca gall midge has been part of a highly successful biological control effort to control melaleuca. Seedlings infested with L. trifida have reduced above and below ground biomass and are 60-80% shorter in height than unaffected plants.

  • Native/Non-native: Non-native
  • Preferred climate: humid, sub-tropical
  • Region: Far south peninsular Florida (Greater Everglades Ecosystem)
  • Established: Yes
  • Where established: Florida

Melaleuca tip galling midge appearance

Lophodiplosis trifida is a delicate small fly and looks similar to other midges, including mosquitoes. The female has a pink to reddish appearing abdomen.

The galled and mishapen tip of a plant shoot has been cut in half longitudinally

Cross-section of a gall caused by the melaleuca gall midge (Lophodiplosis trifida).

Redish-brown stem that is thickened with a few knobby galls on it

Galls formed by the melaleuca gall midge on the stem of a melaleuca plant.

Dead brown tip of a plant stem deformed with several galls

Sufficient damage from the melaleuca gall midge can cause growing tips of the melaleuca plant to die.

How to Use Melaleuca tip galling midge

Biocontrol category: Classical—released once and persists

Maximizing effectiveness: Lophodiplosis trifida is well established in the landscape and does not require additional releases.

Pest stage: terminal buds of the plant are infested by the galling midge

Mode of action: Weed-feeder—The melaleuca tip galling midge diverts resources from the growing tips to the newly formed gall, effectively shunting the resources from plant growth to plant defense. 

Compatibility: This insect is part of a suite of three insects that work together to reduce biomass, flower and fruiting of melaleuca. When combined with removal strategies, the biological control essentially takes out the pest plant’s ability to recolonize an area. 

Commercially available: No

About cajeput tree (Melaleuca quinquenervia)

Melaleuca is an invasive tree that impacts much of south Florida, especially areas within the Greater Everglades Ecosystem. It alters fire regimes, hydrology and shades out native plants in what should be a grass-dominated ecosystem.

Thousands of small seedlings blanket a burned forest understory. These seedlings are from Melaleuca quinquenervia, an invasive tree from Australia

A sea of melaleuca seedlings emerge post-fire in Big Cypress National Preserve.

A close-up of thousands of seedlings that blanket the pine forest floor after a fire burned.

A close-up of the melaleuca covered pine forest floor after a fire.

Red tipped foliage on the terminal bud of a melaleuca seedling. This is due to the galling of L. trifida that impacts the growing tips.

The bright red tips are the infected foliage from L. trifida larvae. Larvae feed on growing tips and emerge as adults from the galls.

Author

Dr. Melissa C. Smith
USDA-ARS Invasive Plant Research Laboratory, Fort Lauderdale, Florida USA

Date: November, 2021

  • Center, Ted D., Matthew F. Purcell, Paul D. Pratt, Min B. Rayamajhi, Philip W. Tipping, Susan A. Wright, and F. Allen Dray. “Biological Control of Melaleuca Quinquenervia: An Everglades Invader.” BioControl 57, no. 2 (April 1, 2012): 151–165. https://doi.org/10.1007/s10526-011-9390-6.
  • Pratt, P. D., M. B. Rayamajhi, P. W. Tipping, T. D. Center, S. A. Wright, and M. Purcell. “Establishment, Population Increase, Spread, and Ecological Host Range of Lophodiplosis Trifida (Diptera: Cecidomyiidae), a Biological Control Agent of the Invasive Tree Melaleuca Quinquenervia (Myrtales: Myrtaceae).” Environmental Entomology 42, no. 5 (October 1, 2013): 925–935. https://doi.org/10.1603/EN13058.
Portrait of Amara Dunn
Amara Dunn-Silver

Senior Extension Associate

NYS Integrated Pest Management

Amara Dunn-Silver