Trophic Behavior and Species Diversity of the Anopheles barbirostris Complex (Diptera: Culicidae) in Thailand

Abstract

Species of the Anopheles barbirostris complex (Myzorhynchus Series of the subgenus Anopheles) are potential vectors of malaria and filariasis parasites. Owing to the lack of reliable identification methods, the biting activity and host preference of the species within this complex have not been previous described. In this study, the trophic behavior and host preferences of the species in the complex were determined in Thailand, and a map of their geographical distributions constructed. Adult female mosquitoes in Chanthaburi and Prachuap Khiri Khan provinces were collected using human landings (indoor and outdoor) and cow-bait. Morphological characters were used to initially identify the mosquitoes, and then, species were further separated by multiplex PCR. Four species were identified in the An. barbirostris complex: An. wejchoochotei Taai & Harbach (Diptera: Culicidae), An. saeungae Taai & Harbach (Diptera: Culicidae), An. dissidens Taai & Harbach (Diptera: Culicidae), and An. campestris Reid (Diptera: Culicidae). The species showed exophagic and zoophilic behavior, except An. wejchoochotei in Chanthaburi, which displayed slight endophilic behavior. Indoor and outdoor blood feeding behavior of An. wejchoochotei and An. saeungae peaked at 2000 h. An updated distribution map of the An. barbirostris complex in Thailand is presented. With a better understanding of the sibling vector species and their spatial distributions, more specific and effective control strategies for vectors of malaria and filariasis in Thailand can be achieved.

Scientific achievements and reflections after 20 years of vector biology and control research at the Pu Teuy mosquito field research station, Thailand

“…AS-PCR used species-specific differences within the sequences of the internal transcribed spacer 2 (ITS2), a ribosomal DNA gene (rDNA) widely used to differentiate cryptic species of Asian Anopheles complexes [ 44 ] and reliably identified five species in the Barbirostris Complex in Thailand [ 73 ]. Another recent study by Udom et al [ 74 ] on the same group included PCR-identified Pu Teuy specimens and provided a national map of Anopheles species complex distribution. From these genetic studies in Pu Teuy, correct species identification is essential and mandatory for basic and applied mosquito studies and for the evaluation of vector control strategies [ 34 ].…”

Prevalence of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency among Malaria Patients in Southern Thailand: 8 Years Retrospective Study

“…Prescribing PQ without G6PD testing has been reported to cause hemolysis in P. vivax infected patients, particularly at risk for the individuals with low G6PD enzyme activity. Even with the correct dose, intravascular hemolysis in male with G6PD Mahidol variant can occur [50]. It has been demonstrated that the G6PD Viangchan and Mahidol, the most common variants observed in southern Thailand, cause low enzymatic activity in RBCs and risk for acute hemolysis induced by PQ [51,52].…”