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ABSTRACTInformation on the mosquito species that transmit canine filariosis is scanty. Hence, an experimental study was conducted to identify the potential vectors responsible for the transmission of D. immitisLeidy and B. pahangiBuckley & Edeson. A total of 367 mosquitoes belonging to six species containing both laboratory and field strains (i.e. Aedes togoiTheobald, Aedes aegyptiLinnaeus, Aedes albopictusSkuse, Culex quinquefasciatusSay, Culex vishnuiTheobald and Anopheles dirusPeyton & Harrison) were used in this study. All mosquitoes were artificially fed on either D. immitisor B. pahangi microfilariae (mfs) infected blood by using the Hemotek™ membrane feeding system. Out of 367 mosquitoes, 228 (64.9%) were fully engorged. After feeding on D. immitis(20%) and B. pahangi(33%) mfs positive blood, the mortality rates for Cx. quinquefasciatuswere found to be slightly lower than that of other species of mosquitoes. On the other hand, majority of An. diruswere found to be incapable to withstand the infection of mfs as the mortality rates were relatively high (D. immitis = 71.4%; B. pahangi = 100.0%). Brugia pahangiwas detected in Ae. togoiand Cx. quinquefasciatuswith infection rates of 50% and 25%, respectively. Aedes togoiwas the only species infected with D. immitiswith an infection rate of 69%. Our results showed that Ae. togoiwas an excellent experimental vector for both D. immitisand B. pahangi. This study also documented the observation of B. pahangi, for the first time in the head region of Cx. quinquefasciatus under a laboratory setting.

Previous studies suggested the presence of species complex in the so-called Simulium asakoaeTakaoka & Davies (Diptera: Simuliidae) in Thailand due to its high morphological variability and genetic divergence. To investigate whether the true S. asakoaeis present in Thailand, we performed a detailed morphological identification of S. asakoaeand compared its DNA barcodes with the morphospecies S. asakoaefrom Myanmar and the typical S. asakoaefrom Malaysia. Phylogenetic analysis revealed the Thai materials analyzed in this study were indeed genetically similar with those from Myanmar and Malaysia, though genetic distances 0–2.27% were observed. We tentatively regard this divergence as intraspecific variation, and the automatic barcode gap discovery analysis further supports them as a single species.

Simulium(Gomphostilbia) yvonneaesp. nov. is described based on adults, pupae, and mature larvae from Vietnam. This new species belongs to the Simulium duolongumsubgroup in the S. batoensespecies-group of the subgenus GomphostilbiaEnderlein. It is distinguished by having a relatively larger number of male upper-eye facets in 16 vertical columns and 16 horizontal rows and a pupal gill with eight filaments arranged as 3+(1+2)+2 from dorsal to ventral, of which two filaments of the ventral pair are 1.8 times as long as the longest filament of the middle and dorsal triplets. Morphological comparisons are made to distinguish this new species from all 22 related species. The genetic distinctiveness of this new species in the S. duolongumsubgroup is also presented based on the DNA barcoding COI gene.