Location: Invasive Plant Research LaboratoryTitle: Fundamental host range of Lophodiplosis indentata (Diptera: Cecidomyiidae), the last proposed biological control agent for Melaleuca quinquenervia (Myrtaceae) in Florida
|WRIGHT, SUSAN - Retired ARS Employee|
|PURCELL, MATTHEW - Commonwealth Scientific And Industrial Research Organisation (CSIRO)|
|BROWN, BRADLEY - Commonwealth Scientific And Industrial Research Organisation (CSIRO)|
Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2020
Publication Date: 7/12/2020
Citation: Smith, M., Wright, S., Clark, P.T., Pratt, P.D., Purcell, M., Brown, B. 2020. Fundamental host range of Lophodiplosis indentata (Diptera: Cecidomyiidae), the last proposed biological control agent for Melaleuca quinquenervia (Myrtaceae) in Florida. Biocontrol Science and Technology. 30(10):1073-1082. https://doi.org/10.1080/09583157.2020.1787345.
Interpretive Summary: Controlling invasive Melaleuca quinquenervia in South Florida has been a largely successful endeavor. The area that melaleuca infests has shrunk by 400,000 hectares, a combined effort in an integrated management approach. Despite the overall success of the melaleuca biological program, areas that do not have conducive conditions for the melaleuca weevil (Oxyops vitiosa) continue to experience persistent and spreading infestations. The pea-galling midge (Lophodiplosis indentata) was pursued as a final insect to address these areas specifically. Like its congener, L. trifida that has a significant impact throughout the range, L. indentata shows that it has extreme host specificity. We tested 48 species of related and non-related species and found that L. indentata can only complete its life cycle on melaleuca. Based on these results, we contend that L. indentata will be a safe and potentially quite effective insect for melaleuca in areas where O. vitiosa fails to thrive.
Technical Abstract: Melaleuca quinquenervia (hereafter melaleuca) was very recently one of the worst ecological invaders in Florida. Brought in for horticulture and levee stabilization during the early 20th century, melaleuca spread to cover vast areas of the largest freshwater wetlands ecosystem in North America, The Everglades. From 1998 until 2012, four insects were approved and released for control on melaleuca, three of which established. Biological control is frequently a slow and incremental process, but with the integration of complimentary control methods (e.g. chemical and mechanical removal), melaleuca infestations have now contracted to only a fraction of their former range. These few persistent infestations are facilitated by conditions that are unsuitable for the full suite of current biological control herbivores, which prompted the testing and release of a final insect, Lophodiplosis indentata (Diptera: Cecidomyiidae). The melaleuca pea-galling midge feeds on leaves and initiates pea-sized galls throughout the canopy. No-choice host range tests suggest that L. indentata will occasionally oviposit on unsuitable host plants, but gall induction and formation is only accomplished on M. quiquenervia. A petition for release was submitted in September 2019.