First record of Liriomyza huidobrensis (Diptera: Agromyzidae) and a survey of its parasitoids in Tibet, China.
Aim: Liriomyza huidobrensis is an important invasive pest in China. It was firstly found in Tibet in July, 2017. This study aims to confirm the occurrence status of L. huidobrensis and its parasitoids in Tibet. Methods: The occurrence and damage of L. huidobrensis and its parasitoids were investigated in four regions, Lhasa, Nyingchi, Lhoka and Shigatse, in Tibet from early June to mid-September in 2017 and 2018. Results: The results revealed that L. huidobrensis has already colonized and caused damage in all the four regions surveyed in Tibet from early June to mid-September in 2017 and 2018. The population occurred from early June to mid-September in green house and the peak of occurrence in the field was from late July to early August. Twenty-one species of host plants were reported to be damaged by L. huidobrensis and they belong to nine families, mainly Fabaceae, Solanaceae and Umbelliferae. L. huidobrensis caused the most serious damage to such economic crops as Vigna unguiculata, Lablab purpureus, Lactuca sativa var. angustana and Brassica rapa ssp. pekinensis. Sixteen species of parasitoids including Diglyphus bimaculatus, Diglyphus isaea, Diglyphus minoeus, Diglyphus wani, Diglyphus sp., Cirrospilus vittatus, Hemiptarsenus sp., Neochrysocharis formosa, Chrysocharis pentheus, Chrysocharis pubicornis, Chrysocharis sp., Pediobius metallicus, Pnigalio sp., Dacnusa sibirica, Dacnusa sp., and Gronotoma sp. were recorded, and they belong to nine genera of three families (Eulophidae, Braconidae and Cynipidae). Da. sibirica, Di. bimaculatus and Di. isaea were identified as the dominant species and their individuals accounted for 48.7%, 22.1% and 12.9% of the total individuals collected, respectively. Conclusion: The parasitoid species of L. huidobrensis are quite rich in Tibet, and these parasitoid species show strong natural control effect. It is suggested that the study of biology, control potential and utilization of dominant parasitoids should be strengthened in the future for the prevention and control of the invasive L. huidobrensis.