Taxonomy of Lutzia sp. (Diptera, Culicidae) Found on Doi Inthanon, Chiang Mai Province

Abstract

Three species of mosquitoes in the genus Lutzia Theobald, namely, Lt. fuscana (Wiedemann), Lt. halifaxii (Theobald) and Lt. vorax Edwards have been recorded in Thailand. The adults are distinct, but the larvae and pupae are difficult to separate due to overlapping characters. However, a recent collection of Lutzia larvae and pupae from Doi Inthanon, Thailand’s highest mountain revealed that they are distinct from Lutzia in the plains. The objective of this study was to compare the adult, larval and pupal morphology of the high altitude Lutzia sp. from Doi Inthanon with Lt. vorax, Lt. fuscana, and Lt. halifaxii in the plains of Chiang Mai Province, compared with the topotypic Lt. vorax from Tokyo, Japan. Larvae were collected and reared to adults preserved with associated larval and pupal exuviae. They were examined under stereo and bright field microscopes. Fine structure of larval integument was observed under a scanning electron microscope. The results revealed that although the adults of Lutzia from Doi Inthanon was identified as Lt. vorax, based on the abdominal banding pattern, the wing venation, mediocubital and radiomedial crossveins, was distinct from Lt. vorax in the plains. The larval setae 1-M, 8-II,III and average number of comb scales are different from the other three species in the plains. The integument of Lt. vorax from Doi Inthanon is covered with relatively short pointed spicules, whereas it is covered by denser, longer and more sharply pointed spicules in Lt. vorax and the other species in the plains. The pupal setae 1 and 5 of abdominal segments V and VI are different from the other three species. Surprisingly, the adults, larvae and pupae of Lt. vorax from Doi Inthanon are closely related to Lt. vorax from Japan. It is possible that Lt. vorax from Doi Inthanon may be conspecific with topotypic Lt. vorax from Tokyo and Lt. vorax in the plains may be an unknown species of Lutzia. Further study is required to determine the specific status of Lt. vorax in the plains and its distribution.