The lily leaf beetle is not the only bright red Lilioceris beetle in North America. The beetle pictured here is Lilioceris cheni, the air potato leaf beetle. Like the lily beetle, the air potato beetle is an exotic insect introduced to North America, but unlike the lily beetle, this introduction was intentional. The air potato beetle is a biological control agent that was introduced in 2012 from China to combat air potato in Florida. It’s one of the good guys.
Air potato is a fast growing vine in the yam family (Dioscoreaceae) that has been spreading throughout Florida since the early 1900’s when it was introduced from Asia as an ornamental. The picture below, taken in March before the vines start to sprout, shows a potato or “bulbil” (red arrow) hanging from last year’s withered vine up in an oak tree. The bulbils drop to the ground and sprout, resulting in dense monocultures that smother native vegetation.
Air potato is a fast growing vine in the yam family (Dioscoreaceae) that has been spreading throughout Florida since the early 1900’s when it was introduced from Asia as an ornamental. The picture below, taken in March before the vines start to sprout, shows a potato or “bulbil” (red arrow) hanging from last year’s withered vine up in an oak tree. The bulbils drop to the ground and sprout, resulting in dense monocultures that smother native vegetation.
Like all biological control agents, the air potato beetle was subjected to rigorous testing to ensure that it would not eat native plants or crops once released. A second Lilioceris species, which eats the bulbils rather than the leaves of air potato, is also being considered for release (photo below). It is currently in quarantine at the USDA/ARS Invasive Plant Research Laboratory in Fort Lauderdale, where it is being tested on a wide variety of plants to make sure that it is safe to release.
For the time being, the lily leaf beetle and the air potato beetle are separated geographically by at least 1000 km*. However, as the lily beetle extends its range southward and as air potato moves northward, the distributions of the beetles might someday overlap. When this happens, will our biological control agents, the wasps Tetrastichus setifer and Lemophagus errabundus, attack the beneficial air potato beetle?
* but we could be wrong--help us update the lily beetle's geographic distribution by reporting an infestation!
* but we could be wrong--help us update the lily beetle's geographic distribution by reporting an infestation!