Local News

Beetle army being harnessed to fight invasive vine

SEBRING - Highlands Hammock State Park is on the front lines of the ongoing "exotic wars" in Florida. It was the first state park to undergo a release of lilioceris cheni, a beetle native to Asia, commonly known as the "air potato leaf" beetle. Air potato, a twining vine with tropical Asia origins, was introduced to Florida in the early 1900s. A member of the yam family, it produces underground and aerial tubers and climbs rapidly into the tree canopy, engulfing native vegetation and disrupting the ecology of hardwood hammocks.
As with most exotic, invasive plants, there is very little help from indigenous insects, herbivores and other natural controls to prevent infestation. Listed as a noxious weed in 1999, the United States Department of Agriculture and the Florida Department of Agriculture and Consumer Services researched introducing lilioceris as a biological control. Both agencies are rearing large numbers of beetles to release in locations throughout the state where air potato is a problem. Ken Hibbard, a biological scientist from the FDACS Division of Plant Industry in Fort Pierce, released the first batch of beetles at Highlands Hammock in October 2012. His objective was to determine how well the beetle would stand winter in the heartland. As no beetles were seen from this release, he released a second group of 50 adult beetles at the end of April. By early June, it was evident the beetles had become established with both adults and larvae feeding on the vines. Adults chew round roles in the leaves and deposit eggs on the undersides of young leaves. Oviposition causes the leaves to curl around the edges, forming a protective cup. After four days, newly hatched larvae feed voraciously and literally skeletonize the leaves of the vine. In another seven to 10 days, they descend or drop to the ground and form a hardened foam-like cocoon in the pupa stage. Two weeks later, an adult generation emerges to mate and deposit another batch of eggs. Beetles have also been released at Terra Ceia, St. Lucie River, St. Sebastian River and Kissimmee Prairie Preserve State Parks. Research on a beetle that will consume the potato tuber is now underway. As the beetles were present in June, Hibbard and his assistant, Beth Curry, released another group of beetles in proximity to the others. "It is our hope that the beetles will become a self-sustaining biological control for this weed and will save money and help the environment in the long run," said Hibbard. Highlands Hammock staff is cautiously optimistic and thrilled and excited that the beetles are munching away, states a news release. They are monitoring the release areas and looking forward to the next release.