Getting atop climbing fern - Old World climbing fern is targeted as weed by US Agricultural Research Service in Florida and Australia

Agricultural Research, Jan, 2002 by Marcia Wood, Jesus Garcia

The moth's cold intolerance is important because it means the insect is unlikely to survive cold winters in the eastern and northeastern United States, where a native fern and climbing fern relative called L. palmatum occurs.

In addition to the moths, a microscopic mite is making its way through the barrage of tests at Indooroopilly. CSIRO entomologist Tony Wright, stationed at the Indooroopilly laboratory, found the mite on climbing fern during expeditions to Indonesia, Malaysia, and Thailand. It has also been collected throughout Australia, where the fern is native.

To learn more about the mite's biology, Wright and Goolsby are collaborating with mite experts David Walter of the University of Queensland in Brisbane and Sebahat Ozman, there from Trakya University, in Turkey.

The researchers have determined that the mite, a member of the genus Floracarus, has a short life cycle--about 12 days when kept indoors at 70 [degrees] F. Female mites feed on young fern leaves, causing them to curl and soften. Then they lay their eggs in the curl, where their young, called nymphs, feed and develop on the soft tissue. The nymphs' feeding causes the leaves to fall off, so the vine has fewer leaves to capture sunlight for the energy it needs.

Tests showed that mite-infested ferns had one-fourth the growth of plants sprayed with a miticide. Says Goolsby, "We're running the study for 2 years so we can examine the long-term effects of the mite on the fern."

A petite beetle, brown and only about one-quarter inch long, might also become an important member of the fern-fighting team. Wright found the insect, Endelus bakerianus, during an expedition to Thailand.

The beetle is a leafminer, meaning that while in its caterpillar or larval stage, it tunnels into the leaves to feed on them.

"We're just now starting host-specificity testing," says Goolsby. With luck, this little beetle might end up playing a big role in protecting the Everglades.

This research is part of Crop Protection and Quarantine, an ARS National Program (#304) described on the World Wide Web at http://www.nps.ars.usda. gov.

To reach the scientists mentioned in this story, contact Marcia Wood, USDAARS Information Staff, 5601 Sunnyside Ave., Beltsville, MD 20705; phone (301) 504-1662, fax (301) 504-1641, e-mail marciawood@ars.usda.gov.