Comparing larval performance traits on known host vs. novel host. Is dragon fruit a host for Cactoblastis cactorum?

Dragon fruit (DF) (Hylocereus undatus) is gaining popularity around the world as a healthy food for consumers and an economic promise for growers.  Cactoblastis cactorum (Cc) is famous as a successful biological control agent against non-native Opuntia spp. in Australia, South Africa, and Hawaii, but has recently been found attacking DF in Hawaii plantations.  Florida DF growers do not consider Cc a pest of their crops, having only one documented case of Cc infesting DF.  This paper reports on an evaluation to find out if Cc can utilize DF as a host plant.  Rearing trials were conducted with Cc on 4 Florida color varieties of DF (red, yellow, Pedro white, and Max white) and the Florida native Opuntia stricta.  Larval performance traits measured on each host plant type were development time, survival rate, pupal weight, and sex ratio.  Larval survival rates on the five hosts were red DF 39%, Max white DF 46%, yellow DF 53%, Pedro white DF 73%, and O. stricta 85%.  Other larval performance traits were similarly ranked, with O. stricta outperforming all DF varieties.  However, C. cactorum larvae did survive and successfully develop on DF and could potentially adapt to this new host.