Fauna of whiteflies (Hemiptera: Aleyrodidae) in citrus orchards.
Whiteflies (Hemiptera: Aleyrodidae) are economically important pests of citrus. In Europe and in the Mediterranean Region the whiteflies' fauna consists of 57 native and naturalized species in 26 genera, mostly living on woody perennials. Six species are major pests of citrus in the Mediterranean Region, whereas three others occasionally feed on citrus. They cause direct and indirect damages on their host plants. Direct damage arises by adults and larvae sucking on plant sap from the leaves, which affects quantity and quality of yield. Indirect damage is a consequence of transmitting of plant viruses and excreting honeydew on which the sooty moulds subsequently develop. Faunistic investigations of whiteflies, conducted in citrus plantations from 2015 to 2019 in four coastal counties in Croatia, resulted in recording of five species. Whiteflies collected in leaf samples of citrus were identified to the species level on the basis of morphological characters of puparium and/or pupal case, using the classical identification method according to the relevant morphological keys. Species Dialeurodes citri Ashmead, 1885 is still the most widespread and harmful whitefly species in citrus plantations. Identification key based on brief descriptions of puparia of recorded species and their photographs are presented to aid detection on citrus in the field. However, formal identification requires microscopic examination of slide-mounted puparia, for which identification key and photographs are also presented.