Citrus diaspidids in Viet Nam: New,and confirmation of previous,records based on morphological and molecular verification of taxa

Armoured scales (Hemiptera: Diaspididae) belong to the largest scale insect family and are among the most invasive insects in the world. Accurate identification of armoured scales is essential for systematic and phylogenetic studies; biogeography; trade and plant quarantine; and pest management, particularly biological control. Several species are serious pests of citrus. Records of past field surveys conducted in Viet Nam between 1967 and 2010 indicated the presence of 28 species on citrus there. Discrepancies in these records, and the retention of specimens of only five species in collections, led us to undertake surveys throughout the citrus-growing regions of the country in 2013 and 2014 to verify previous records and conserve voucher specimens. The presence of 21 diaspidid species was confirmed based on morphological and molecular data. The species observed were common but rarely abundant. Populations in commercial orchards may have been influenced by use of pesticides, but most species were recorded also in gardens and orchards where pesticide use was uncommon. Natural enemies were abundant, but were not thoroughly documented for all the diaspidids we observed. An identification key to the species collected is provided. Differences between our findings and previous records from Viet Nam, from Yunnan and Guangxi in China, and from Indochinese countries neighbouring Viet Nam, indicate the need for extensive surveys to fully document the diaspidid fauna on citrus in the region.