Citrus whiteflies in Spain
In Spain, several whitefly species are present in citrus. In 1932, Bemisia hancocki was reported as a damaging pest on lemon, but nowadays it is well controlled by an hymenopteran (Eretmocerus mundus) and is no longer considered as a real pest. In the 1940s, Aleurothrixus floccosus was found in the Canary Islands and contributed to the reduction of lemon crops. Since 1968, this pest has become a major citrus pest in Spain and is considered as the most damaging whitefly of citrus crops. In 1987, Dialeurodes citri was detected in the Province of Alicante. It is now limited to the Provinces of Alicante and Valencia, as in other regions it is effectively controlled by natural enemies. In 1991, Parabemisisa myricae (EPPO A2 quarantine pest) and Paraleyrodes minei were observed in Málaga. At first P. myricae caused serious problems in this region, and then spread to all citrus-growing areas in Spain. Natural enemies (Encarsia sp.) are able to reduce its population levels but, under certain conditions, P. myricae can still cause significant damage. P. minei is limited to Málaga. Finally, Aleurodicus dispersus was found in large numbers in 1992 on lemon, although it has been sporadically observed in the Canary islands since 1963. It is not considered as a serious citrus pest, although when abundant it may cause damage on other host plants such as banana and palm trees. Control methods against citrus whiteflies are reviewed in this paper.
Sources
Garrido, A. (1995) Moscas blancas en España en los cítricos: Importancia, interacción entre especies, problemática y estrategia de control.
Phytoma España, No. 72, 41-47.