Lilioceris egena (Weise): An additional biological control agent of air potato

Dioscorea bulbifera (air potato) is an invasive vine that displaces native vegetation. In 2012, the leaf-feeding beetle, Lilioceris cheni, was introduced in Florida to control air potato. Although L. cheni reduced the dominance of air potato in natural ecosystems, its impact in South Florida was limited. To enhance the control efforts, the USDA approved the release of another biocontrol agent, Lilioceris egena. This beetle is highly specific towards air potato bulbils and is expected to work synergistically with L. cheni to further suppress the air potato population. However, there is limited information available on the biology of L. egena and how the Florida climate would affect its performance. For this, we investigated L. egena’s development and oviposition at different temperatures (15, 20, 25, and 30 °C) and its longevity on different food sources. We found that life cycle completion only occurs at 25-30 °C. Lilioceris egena held at 15 °C exhibited a significant decrease in egg-laying compared to those held at warmer temperatures. Interestingly, the longevity of L. egena feeding exclusively on air potato leaves was higher than those feeding solely on bulbils. These findings suggest that warmer temperatures may positively impact L. egena’s oviposition in South Florida. Additionally, L. egena can survive for extended periods even in the absence of its primary food source (bulbils). Understanding a biocontrol agent’s biology is crucial for the success of a biocontrol program. This study provides a foundation for future research aimed at comprehending the impact and establishment of L. egena in Florida.