Mass rearing protocol and density trials of Lilioceris egena (Coleoptera: Chrysomelidae), a biological control agent of air potato

Abstract

Lilioceris egena (Weise) (Coleoptera: Chrysomelidae) is an approved classical biological control agent that feeds on the aerial reproductive structures (i.e., bulbils) of the invasive air potato vine in Florida. The Florida Department of Agriculture and Consumer Services, Division of Plant Industry, has mass-produced and released over 100,000 beetles since 2021. Mass rearing can be challenging for highly specialized herbivores like L. egena. Therefore, we present a detailed protocol to mass rear L. egena under laboratory settings. This protocol ensures consistent production of approximately 675 beetles per month/colony for research and field applications while maintaining efficiency and affordability. Additionally, we determined how the number of mating pairs and the condition of air potato bulbils (whole or bisected) used in the mass rearing system influenced the number of adults produced. Results showed that 17 mating pairs per bulbil (of approximately 150 g) was an optimal beetle density to maximize beetle production and maintain a healthy colony. The condition of bulbils utilized did not influence the number of adults produced. This protocol can be adopted by integrated pest management (IPM) and master gardener programs, universities, and regulatory agencies in other southeastern states currently facing air potato infestations.