Biocontrol agent Lilioceris egena (Coleoptera: Chrysomelidae) can also survive on the commercial yam Dioscoreacf. cayenensis subsp. rotundata (Dioscoreales)

Lilioceris egena (Weise, 1922), an Asian leaf beetle specialising on Dioscorea bulbifera L., is used as a biological control agent to manage this invasive plant in Florida, USA. This study investigated whether a commonly sold Dioscorea species, cf. cayenensis subsp. rotundata (Poir.) J. Miège, marketed as ‘ñame’ in Walmart stores, could serve as an alternative host for L. egena. Through food preference experiments involving both choice and no-choice tests, adult beetles were offered bulbils of D. bulbifera and tubers of D. cf. cayenensis subsp. rotundata. Each experiment included three treatments with six replications, repeated three times, using four adult pairs per replication. Results showed that L. egena can successfully complete its life cycle on D. cf. cayenensis subsp. rotundata tubers under lab conditions. In choice tests, the beetles significantly preferred feeding on D. bulbifera, though oviposition rates did not differ significantly between the two plants. No-choice tests revealed no significant feeding preference, but oviposition was significantly higher on D. bulbifera. Neonate larvae reared on D. cf. cayenensis subsp. rotundata had an approximate survival rate of 61%, and the adults that emerged from them continued to prefer D. bulbifera. This finding expands our understanding of the potential adaptability of L. egena to alternative hosts.