MELALEUCA (MELALEUCA QUINQUENERVIA)

Authors: Pratt, Paul; Center, Ted; Rayamajhi, Min; Van, Thai

Submitted to: Biological Control of Weeds in the United States
Publication Type: Book / Chapter
Publication Acceptance Date: 3/20/2003
Publication Date: 3/20/2004
Citation: Pratt, P.D., Center, T.D., Rayamajhi, M.B., Van, T.K. 2004. MELALEUCA (MELALEUCA QUINQUENERVIA). Biological Control of Weeds in the United States. 268-270. 2004.

Interpretive Summary: This book chapter is intended to provide an overview of the Australian tree Melaleuca quinquenervia, its general biology, invasive ecology in southern Florida and biological control. Specific reference is given to the invasion of melaleuca into freshwater herbaceous marsh communities in Florida, which results in a 60-80% loss in biodiversity. When considering economic impacts to the region, the South Florida Water Management District alone spent nearly $11 million to control melaleuca during 1991 to 1997 and estimates of losses to the local economy range as high as $168.6 million per year. The biological control agents Oxyops vitiosa and Boreioglycaspis melaleucae are also discussed in relation to their biology and impacts on the invasive tree. O. vitiosa larvae are specialized flush feeders, consuming the seasonal flush of newly developed, expanding leaves at branch apices. This damage may persist for months, ultimately resulting in leaf drop. Adults feed superficially on young leaves and fully expanded, tough leaves resulting in narrow scars along the leaf surface. Adult melaleuca psyllids are unadorned, small insects about 3mm long and pale yellow-orange to white in color. Females lay an average of 80 eggs during their lifetime. The melaleuca psyllid has 5 nymphal instars. Early instars crawl about the leaves but later stages are more sessile unless disturbed. Nymphs produce copious amounts of honeydew and also exude waxy filaments from glands located on their dorsum. These filaments form a dense flocculence that may partially cover later instars and facilitate locating colonies in the field.

Technical Abstract: This book chapter is intended to provide an overview of the Australian tree Melaleuca quinquenervia, its general biology, invasive ecology in southern Florida and biological control. Specific reference is given to the invasion of melaleuca into freshwater herbaceous marsh communities in Florida, which results in a 60-80% loss in biodiversity. When considering economic impacts to the region, the South Florida Water Management District alone spent nearly $11 million to control melaleuca during 1991 to 1997 and estimates of losses to the local economy range as high as $168.6 million per year. The biological control agents Oxyops vitiosa and Boreioglycaspis melaleucae are also discussed in relation to their biology and impacts on the invasive tree. O. vitiosa larvae are specialized flush feeders, consuming the seasonal flush of newly developed, expanding leaves at branch apices. This damage may persist for months, ultimately resulting in leaf drop. Adults feed superficially on young leaves and fully expanded, tough leaves resulting in narrow scars along the leaf surface. Adult melaleuca psyllids are unadorned, small insects about 3mm long and pale yellow-orange to white in color. Females lay an average of 80 eggs during their lifetime. The melaleuca psyllid has 5 nymphal instars. Early instars crawl about the leaves but later stages are more sessile unless disturbed. Nymphs produce copious amounts of honeydew and also exude waxy filaments from glands located on their dorsum. These filaments form a dense flocculence that may partially cover later instars and facilitate locating colonies in the field.