A new species of the Anopheles barbirostris complex (Diptera: Culicidae) from Bhutan.

Anopheles sarpangensis Somboon, Namgay & Harbach is described as a new species of the Barbirostris Complex of the subgenus Anopheles Meigen. The adults differ from other species of the complex in having wings with a prehumeral pale spot on the costa, foretarsomere 1 with an apical pale band more than half as long as foretarsomere 5, midtarsomeres 1 and 2, and occasionally 3 and 4, with incomplete apical pale bands, and abdominal sterna with many white scales as in An. campestris Reid, An. saeungae Taai & Harbach, and An. wejchoochotei Taai & Harbach. The pupa and larva are indistinguishable from the pupae and larvae of other species of the complex. Phylogenetic analysis revealed that COI sequences form a clade separate from clades consisting of the sequences of other species of the complex. The immature stages were commonly found in fishery ponds in foothills at low to moderately high altitudes in the Sarpang District of Bhutan.

Biodiversity and Spatiotemporal Variations of Mecoptera in Thailand: Influences of Elevation and Climatic Factors.

Ecological analyses of the small and lesser-known insect order Mecoptera in Thailand are presented. Specimens were collected monthly over a period of 12 consecutive months, using both Malaise and pan traps, from 29 sampling sites located in 18 national parks throughout Thailand. A total of 21 species in four genera were identified from 797 specimens, including Panorpa (1 species), Neopanorpa (18 species), Bittacus (1 species), and Terrobittacus (1 species), with the latter genus representing a new genus record to Thailand. Neopanorpa harmandi, N. siamensis, N. byersi, and N. malaisei were the most abundant species, representing 27.4%, 11.3%, 10.3% and 8.8% of the total specimens, respectively. The species with the highest frequency, as indicated by the high percentage of species occurrence (%SO), was N. siamensis (51%), followed by N. byersi (34%), N. harmandi (34%), N. spatulata (27%), and N. inchoata (27%). Eleven species (52%) exhibited specific regional occurrences. N. tuberosa and N. siamensis had the widest distribution, being found in almost all regions except for western and southern regions for the first and second species, respectively. The seasonal species richness of Mecoptera was high during the rainy season in the northern, northeastern, central, eastern, and western regions, with the highest richness observed in July (15 species), followed by the hot (10 species) and cold seasons (7 species), while there was no significant difference in species richness between seasons in the southern region. Multiple regression models revealed a negative association between species richness and abundance of Mecoptera with both elevation and temperature, and a positive association between rainfall and species evenness. It is predicted that climatic changes will have a detrimental effect on the mecopteran community. The results of this study enhance the understanding of the ecological aspects of Mecoptera, offering crucial insights into its biodiversity and distribution, which are vital for conservation and forest management.

Dirus complex species identification PCR (DiCSIP) improves the identification of Anopheles dirus complex from the Greater Mekong Subregion.

BACKGROUND: The Anopheles dirus complex plays a significant role as a malaria vector in the Greater Mekong Subregion (GMS), with varying degrees of vector competence among species. Accurate identification of sibling species in this complex is essential for understanding malaria transmission dynamics and deploying effective vector control measures. However, the original molecular identification assay, Dirus allele-specific polymerase chain reaction (AS-PCR), targeting the ITS2 region, has pronounced nonspecific amplifications leading to ambiguous results and misidentification of the sibling species. This study investigates the underlying causes of these inconsistencies and develops new primers to accurately identify species within the Anopheles dirus complex. METHODS: The AS-PCR reaction and thermal cycling conditions were modified to improve specificity for An. dirus member species identification. In silico analyses with Benchling and Primer-BLAST were conducted to identify problematic primers and design a new set for Dirus complex species identification PCR (DiCSIP). DiCSIP was then validated with laboratory and field samples of the An. dirus complex. RESULTS: Despite several optimizations by reducing primer concentration, decreasing thermal cycling time, and increasing annealing temperature, the Dirus AS-PCR continued to produce inaccurate identifications for Anopheles dirus, Anopheles scanloni, and Anopheles nemophilous. Subsequently, in silico analyses pinpointed problematic primers with high Guanine-Cytosine (GC) content and multiple off-target binding sites. Through a series of in silico analyses and laboratory validation, a new set of primers for Dirus complex species identification PCR (DiCSIP) has been developed. DiCSIP primers improve specificity, operational range, and sensitivity to identify five complex member species in the GMS accurately. Validation with laboratory and field An. dirus complex specimens demonstrated that DiCSIP could correctly identify all samples while the original Dirus AS-PCR misidentified An. dirus as other species when used with different thermocyclers. CONCLUSIONS: The DiCSIP assay offers a significant improvement in An. dirus complex identification, addressing challenges in specificity and efficiency of the previous ITS2-based assay. This new primer set provides a valuable tool for accurate entomological surveys, supporting effective vector control strategies to reduce transmission and prevent malaria re-introducing in the GMS.

Genetic compatibility between Anopheles lesteri from Korea and Anopheles paraliae from Thailand

To assess differentiation and relationships between Anopheles lesteri and Anopheles paraliae we established three and five iso-female lines of An. lesteri from Korea and An. paraliae from Thailand, respectively. These isolines were used to investigate the genetic relationships between the two taxa by crossing experiments and by comparing DNA sequences of ribosomal DNA second internal transcribed spacer (ITS2) and mitochondrial DNA cytochrome c oxidase subunit I (COI) and subunit II (COII). Results of reciprocal and F1-hybrid crosses between An. lesteri and An. paraliae indicated that they were compatible genetically producing viable progenies and complete synaptic salivary gland polytene chromosomes without inversion loops in all chromosome arms. The pairwise genetic distances of ITS2, COI and COII between these morphological species were 0.040, 0.007-0.017 and 0.008-0.011, respectively. The specific species status of An. paraliae in Thailand and/or other parts of the continent are discussed.

Susceptibility of Anopheles campestris-like and Anopheles barbirostris species complexes to Plasmodium falciparum and Plasmodium vivax in Thailand

Nine colonies of five sibling species members of Anopheles barbirostris complexes were experimentally infected with Plasmodium falciparum and Plasmodium vivax. They were then dissected eight and 14 days after feeding for oocyst and sporozoite rates, respectively, and compared with Anopheles cracens. The results revealed that Anopheles campestris-like Forms E (Chiang Mai) and F (Udon Thani) as well as An. barbirostris species A3 and A4 were non-potential vectors for P. falciparum because 0 percent oocyst rates were obtained, in comparison to the 86.67-100 percent oocyst rates recovered from An. cracens. Likewise, An. campestris-like Forms E (Sa Kaeo) and F (Ayuttaya), as well as An. barbirostris species A4, were non-potential vectors for P. vivax because 0 percent sporozoite rates were obtained, in comparison to the 85.71-92.31 percent sporozoite rates recovered from An. cracens. An. barbirostris species A1, A2 and A3 were low potential vectors for P. vivax because 9.09 percent, 6.67 percent and 11.76 percent sporozoite rates were obtained, respectively, in comparison to the 85.71-92.31 percent sporozoite rates recovered from An. cracens. An. campestris-like Forms B and E (Chiang Mai) were high-potential vectors for P. vivax because 66.67 percent and 64.29 percent sporozoite rates were obtained, respectively, in comparison to 90 percent sporozoite rates recovered from An. cracens.

Karyotypic variation and geographic distribution of Anopheles campestris-like (Diptera: Culicidae) in Thailand

Seventy-one isolines of Anopheles campestris-like were established from wild-caught females collected from human-biting and animal-biting traps at 12 locations in Thailand. All isolines had an average branch summation of seta 2-VI pupal skins ranging from 20.3-30.0 branches, which is in the range of An. campestris (17-58 branches). They showed three different karyotypes based on the amount of extra heterochromatin in the sex chromosomes, namely Forms B (X2, Y2), E (X1, X2, X3, Y5) and a new karyotypic Form F (X2, X3, Y6). Form B has been found only in Chaing Mai and Kamphaeng Phet populations, while Forms E and F are widely distributed throughout the species range. Genetic crosses between the 12 isolines, which were arbitrarily selected as representatives of An. campestris-like Forms B, E and F, revealed genetic compatibility that provided viable progeny through F2 generations, suggesting a conspecific nature of these karyotypic forms. These results are supported by the very low intraspecies variation (genetic distance < 0.005) of ITS2, COI and COII from genomic DNA of the three karyotypic forms.