Read: more details in Agricultural Research.

Dynamic Duo Found to Control Melaleuca

Agricultural Research Service scientists and colleagues have identified a team of two organisms--the Fergusonina fly and the nematode Fergusobia--that might help limit the spread of the invasive weed Melaleuca quinquenervia. Melaleuca infestation causes about $168 million in environmental losses every year.

Ted Center of ARS’ Invasive Plant Research Laboratory in Ft. Lauderdale, Fla., and University of Florida nematologist Robin M. Giblin-Davis collaborated with researchers from the University of Adelaide and the Commonwealth Scientific and Industrial Research Organization, and the ARS Australian Biological Control Laboratory.

Like the melaleuca snout beetle Oxyops vitiosa, the Fergusonina fly and the tiny Fergusobia worm effectively attack melaleuca flowers and leaf buds, but in an entirely different way.

According to Giblin-Davis, the female Fergusonina fly carries the nematodes in her ovaries and deposits them--along with her eggs--into young melaleuca buds. The female Fergusobia nematodes and the fly larvae that hatch then feed on enlarged plant cells created by the microscopic nematodes. Eventually, galls form on infested buds, preventing flowers and seeds from developing.

To avoid introducing biological control agents that might impact non-target organisms, host-specificity studies were conducted in Australia. Giblin-Davis traveled more than 8,000 miles and collected different fly/nematode partnerships from a variety of melaleuca and related species, such as eucalyptus. Preliminary indications are that this fly/nematode pairing is so host-specific that each pair affects only a single species of melaleuca, eucalyptus, or closely related species.

If the duo performs well in host-specificity tests in Florida, it might soon be released at melaleuca-infested locations.

An article describing this research appears in the April issue of Agricultural Research, ARS’ monthly magazine.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.

Scientific contact: Ted D. Center, ARS U.S. Aquatic Plant Research Unit, Ft. Lauderdale, Fla., phone (954) 475-0541, fax (954) 476-9169, tcenter@eemail.com.