Abstract:
Typhlodromus (Anthoseius) xini Wu is reported for the first time in Sri Lanka. Its original
description is not very detailed, being based on simple drawings and an absence of
diagnostic characters that include chelicera dentition and leg chaetotaxy. Therefore, a
complementary description and new illustrations of this species are provided, based on
specimens from both sexes collected from Cocos nucifera L. (Arecaceae) infested by
spiralling whiteflies in Puttalam District, North Western Province, Sri Lanka. In addition,
this is the first discovery and the first description of the unknown male. We also provide
a brief comparison between T. (A.) xini and some other species of the subgenus such as
T. (A.) diumbokus Schicha & Corpuz-Raros, T. (A.) foraminosus, T. (A.) hartlandrowei
Evans, T. (A.) neohartlandrowei Zannou, Moraes & Oliveira, and T. (A.) transvaalensis
(Nesbitt). All of these species are similar to each other based on the nature of their dorsal
and ventral aspects, chelicera dentition, and spermatheca morphology. Most importantly,
ventral seta JV3 is absent in all of these species. In our opinion, it is apparent that all of
the aforementioned species share a common ancestor. Therefore, additional molecular
analysis, in combination with the use of morphological characters, would help to confirm
the taxonomic relationship and evolutionary history of these species. Finally, we also
proposed T. (A.) gosabaensis Kar & Karmakar as a new junior synonymy of T. (A.) xini
based on the examination of its holotype.
