Yudthana Samung

Potential for Anopheles campestris (Diptera: Culicidae) to Transmit Malaria Parasites in Pa Rai Subdistrict (Aranyaprathet, Sa Kaeo Province), Thailand

Abstract Member(s) of the Anopheles barbirostris group Reid, particularly Anopheles barbirostris and Anopheles campestris Reid are the suspected vectors of Plasmodium vivax in Pa Rai (Aranyaprathet, Sa Kaeo province). To determine if An. barbirostris, An. campestris, or both, are present in Pa Rai and to determine their potential to transmit malaria, a field and laboratory study was conducted. Isofemale colonizations of wild caught mosquitoes captured by landing catches were made for species confirmation and to determine the mosquito life cycle. Pupal morphology indicated all mosquitoes were An. campestris. During the late rainy season (October and November), An. campestris populations comprised 78.6% of all females captured by human landing catches and 7.1% of mosquitoes in a cow-baited trap. The biting activity cycle peaked between 2000 and 0100 hours and was highest (17.6 bites per person per hour) at 2300 hours. More An. campestris bit people indoors (nine bites per person per hour) than outdoors (four bites per person per hour). Immature An. campestris were found in ponds, swamps, rice-fields, puddles, marshes, ground pools, and pits with open sunlight to partial shade. The time from egg hatch to adult was 18–47 d and 14–22 d under laboratory (25.0–27.0°C) and ambient (26–32°C) conditions, respectively. The fecundity of An. campestris ranged from 173 to 311 eggs. Based on experimental infections, An. campestris was able to support the sporogonic cycle of P. vivax with 76.2 and 23.8% oocyst and sporozoite formation rate, respectively. An. campestris shows high potential as a malaria vector in Pa Rai.

DNA barcoding and wing morphometrics to distinguish three Aedes vectors in Thailand

Aedes aegypti (Diptera: Culicidae) (L.), Ae. albopictus (Skuse), and Ae. scutellaris (Walker) are important mosquito vectors of dengue and chikungunya viruses. They are morphologically similar and sympatric in some parts of their distribution; therefore, there is a risk of incorrect morphological identification. Any confusion could have a negative impact on epidemiological studies or control strategies. Therefore, we explored two modern tools to supplement current morphological identification: DNA barcoding and geometric morphometric analyses. Field larvae were reared to adults and carefully classified based on morphological traits. The genetic analysis was based on the 658bp each of 30COI sequences. Some Culex spp., Mansonia bonneae, were included as outgroups, and inclusion of a few other Aedes spp. facilitated phylogenetic inference of the relationship between Ae. albopictus and Ae. scutellaris. The two species were separated by an average interspecific divergence of 0.123 (0.119-0.127). Morphometric examination included landmark- (392 specimens) and outline-based (317 specimens) techniques. The shape of the wing showed different discriminating power based on sex and digitizing technique. This is the first time that Ae. scutellaris and Ae. albopictus have been compared using these two techniques. We confirm that these morphologically close species are valid, and that geometric morphometrics can considerably increase the reliability of morphological identification.

Mosquito distribution and West Nile virus infection in zoos and in important sites of migratory and resident birds, Thailand

Objective To investigate the distribution of mosquito species in the zoos and in important sites of migratory and resident birds and evaluate West Nile virus (WNV) infection in mosquito species.

Corrigendum to “Wing geometry of Phlebotomus stantoni and Sergentomyia hodgsoni from different geographical locations in Thailand” [C. R. Biologies 340(1) (2017) 37–46]

Comptes Rendus Biologies - In Press.Proof corrected by the author Available online since jeudi 9 fevrier 2017