Situation of Aulacaspis yasumatsui in Guadeloupe
In Guadeloupe, the recent introduction of Aulacaspis yasumatsui (Homoptera: Diaspididae – EPPO Alert List) is threatening Cycas revoluta and C. circinalis (see EPPO RS 2007/220). A. yasumatsui was discovered for the first time in 2003 in the Botanical Garden of Basse-Terre and it is now found in several communes of Guadeloupe where it causes considerable damage and plant mortality.
Possible control methods of A. yasumatsui have been studied in the USA. Several insecticides have been tested in Florida (e.g. dimethoate, methidathion, imidacloprid) but did not give satisfactory results. Biological control has also been studied in Florida, Hawaii and Guam with the following species of predators and parasitoids and appeared more promising: Coccobius fulvus (Hymenoptera: Aphelinidae, originating from South-East Asia), Cybocephalus nipponicus (Coleoptera: Cybocephalidae; previously misidentified as C. binotatus) and Rhyzobius lophanthae (Coleoptera: Coccinellidae, originating from Australia).
In Guadeloupe it is considered that control methods which are currently applied (i.e. pruning and burning of affected plant parts, insecticide treatments) are not sufficiently effective. It is stressed that studies on the potential establishment and efficacy of biological control agents should urgently be undertaken to eventually save Cycas populations from total destruction.
Etienne J (2007) Pour la sauvegarde des Cycas en Guadeloupe. L’Entomologiste 63(5), 271-275.