A checklist of the Anopheles mosquito species (Diptera: Culicidae) in Bhutan

A multiplex PCR assay for the identification of 5 sibling species of the Lindesayi Complex of the genus Anopheles (Diptera: Culicidae) in Bhutan

Five sibling species of the Lindesayi Complex of the genus Anopheles have been discovered in Bhutan: An. druki Somboon, Namgay & Harbach, An. himalayensis Somboon, Namgay & Harbach, An. lindesayi Giles, An. lindesayi species B, and An. thimphuensis Somboon, Namgay & Harbach. The species are morphologically similar in the adult and/or immature stages. This study aimed to develop a multiplex PCR assay to identify the 5 species. Allele-specific primers were designed for specific nucleotide segments of ITS2 sequences previously reported for each species. The assay provided products of 183 bp for An. druki, 338 bp for An. himalayensis, 126 bp for An. lindesayi, 290 bp for An. lindesayi species B, and 370 bp for An. thimphuensis. The use of the assay produced consistent results. The assay is relatively inexpensive, enables the rapid identification of a large number of specimens, and will foster further studies of the Lindesayi Complex.

The Anopheles lindesayi Species Complex (Diptera: Culicidae) in Bhutan

This paper deals with species A, C, D, and E of the Lindesayi Complex of Anopheles subgenus Anopheles (Diptera: Culicidae) that were recently recorded from Bhutan. Species B is not included due to insufficient data. Species A is Anopheles lindesayi sensu stricto, and species C, D, and E are new species that are formally described and named herein as Anopheles druki Somboon, Namgay & Harbach, Anopheles himalayensis Somboon, Namgay & Harbach and Anopheles thimphuensis Somboon, Namgay & Harbach, respectively. Morphological characteristics of the adults, larval and pupal stages of each species are provided and compared with An. lindesayi from Bhutan.

The Anopheles baileyi species complex (Diptera: Culicidae: Anophelinae) in Bhutan

This paper deals with three species (informal species A, B and C) of the Baileyi Complex of Anopheles subgenus Anopheles (Diptera: Culicidae) that were recently reported from Bhutan. Species A is An. baileyi sensu stricto, while species B and C are new species which are formally described and named herein as An. monticola Somboon, Namgay & Harbach and An. bhutanensis Somboon, Namgay & Harbach, respectively. Morphological characters of the adults, male genitalia, larval and pupal stages of the two new species, and the chaetotaxy of the immature stages, are provided and compared with An. baileyi from Bhutan. Although the patterns of wing spots of the adults and the pupal setae of the three species are very similar, significant differences in structures of the male genitalia distinguish them. Larvae of An. baileyi and An. monticola are similar, but differ from the larva of An. bhutanensis in the development of setae 3- and 13-T. The first antennal flagellomere of females of An. baileyi and An. bhutanensis has a distinct patch of pale scales, which is absent in An. monticola.

Reinertia, a New Subgenus of the Genus Aedes Meigen and Its Type Species Aedes (Reinertia) suffusus (Diptera: Culicidae), Newly Recorded From Bhutan

A new subgenus, Reinertia Somboon, Namgay & Harbach, of the genus Aedes Meigen and its type species, Ae. suffusus Edwards, are described from specimens reared from larvae and pupae found in a tree hole in Bhutan. The scutum of the adults is mostly covered with narrow pale falcate scales. The proboscis, maxillary palpus, tibiae, and tarsi are dark-scaled. The gonocoxite of the male genitalia bears a unique setose basomesal sclerite. The larva closely resembles larvae of the subgenus Downsiomyia Vargus in having setae 4-6-C with numerous branches and inserted more or less on level with seta 7-C, abdominal seta 12-I is present and the comb is composed of 6-10 spine-like scales arranged in an irregular row. Surprisingly, Reinertia shares features of the adult habitus, male genitalia, and larva with the Palearctic subgenus Dahliana Reinert, Harbach & Kitching. However, in phylogenetic analyses of the mitochondrial COI gene of species representing 38 subgenera of Aedes and six other genera of the tribe Aedini Neveu-Lemaire, Reinertia was not associated with Dahliana or Downsiomyia. In both maximum likelihood and Bayesian analyses of the data, Ae. suffusus was recovered as the weakly supported sister of a clade composed of five species of the subgenus Protomacleaya Theobald. In the absence of strong support, and because Protomacleaya is an unnatural group of species that resemble each other phenetically by virtue of what they lack, Ae. suffusus cannot be placed in the subgenus Protomacleaya. Thus, the morphological and molecular data attest the uniqueness of Ae. suffusus and its recognition as a monobasic subgeneric lineage.

Culex bhutanensis, a new species of the Mimeticus Subgroup of the nominotypical subgenus of the genus Culex Linnaeus (Diptera: Culicidae) from Bhutan

Culex bhutanensis Somboon, Namgay & Harbach is described as a new species of the Mimeticus Subgroup of the subgenus Culex Linnaeus. Based on morphological distinctions and phylogenetic analysis of COI sequences, the new species is a member of the Mimulus Complex. The adults have wing markings similar to those of Cx. mimulus Edwards and Cx. murrelli Lien, but are distinguished by the presence of a line of pale scales or scattered pale scales along the posterior margin of the proximal portion of the costa. The larva is most similar to the larva of Cx. orientalis Edwards from Japan and South Korea, but is distinguished by the form of the comb scales, pecten spines and seta 2-X. The pupa differs from the pupae of other species of the subgroup in having seta 8-C with more branches. The immature stages of the new species were found in rice paddies, stagnant pools and marshes at high altitudes in several districts of Bhutan.

Molecular and morphological evidence of sibling species in Anopheles baileyi Edwards (Diptera: Culicidae) in Bhutan and Thailand

This paper reports the results of a molecular and morphological study of Anopheles baileyi in Bhutan and Thailand. Phylogenetic analyses of ribosomal (ITS2) and mitochondrial DNA (COI) sequences revealed the presence of four genetically distinct clades, three in Bhutan (Clades I, II and III) and one in Thailand (Clade IV). Most of the larvae in the Bhutanese clades differed from those in the Thai clade in having seta 4-C branched, whereas it is single in the latter. The adults of each clade showed variation of wing markings and overlapping characters. The combination of characteristics of thoracic setae 1,2-P and abdominal seta 3-I was found to be useful for distinguishing the larvae. Pupae were inseparable. We provisionally recognize mosquitoes of Clades I, II, III and IV as members of a sibling species complex, the Baileyi Complex, denoted as species A, B, C and D, respectively. Species A is most likely the type form of An. baileyi s.s. because it was found adjacent to the type locality (Yatung, Tibet), and the others are unrecognized species.

Molecular and morphological evidence for sibling species within Anopheles (Anopheles) lindesayi Giles (Diptera: Culicidae) in Bhutan

This paper reports the results of a comparative molecular and morphological study of An. lindesayi collected from various districts of Bhutan and An. l. cameronensis from Thailand, compared with GenBank accessions and publications for An. l. japonicus from Japan, South Korea and China, An. l. pleccau from Taiwan, and An. lindesayi from India. Phylogenetic analyses based on ribosomal (ITS2) and mitochondrial (COI) DNA sequences using the Maximum Likelihood method revealed five genetically distinct clades (A, B, C, D and E) in Bhutan. Specimens in Clade A correspond to the original description of An. lindesayi, particularly in wing markings, the pattern of basal pale scales on the hindfemur and the single seta 4-C of larvae, and their COI sequences were closely related to one Indian sequence. Larvae of Clades B, C, D and E are similar in having seta 4-C branched rather than single. The adults of Clades C, D and E (B not available) are distinguishable from those of Clade A and other subspecies. Specimens of Clade C are unique in having a long pale spot on wing vein R and the subcosta, scattered pale scales on several veins and a dark spot at the tip of vein R₂. The adults of Clades D and E are similar in having a dark spot at the tip of vein R₂ and no scattered pale scales on all other veins. We provisionally recognize mosquitoes of Clades A, B, C, D and E as species A, B, C, D and E, respectively, of the Lindesayi Complex. Species A is An. lindesayi sensu stricto and the others are unnamed species. Concomitantly, the previous concept of the "Lindesayi Complex", which included An. lindesayi, An. menglangensis, An. nilgiricus and An. wellingtonianus, is now recognized as the Lindesayi Subgroup of the Lindesayi Group (Anopheles Series, subgenus Anopheles) with the five sibling species of An. lindesayi comprising a more apposite Lindesayi Complex within the subgroup.

Systematic studies of Anopheles (Cellia) kochi (Diptera: Culicidae): Morphology, cytogenetics, cross-mating experiments, molecular evidence and susceptibility level to infection with nocturnally subperiodic Brugia malayi

Anopheles kochi Dӧnitz (Diptera: Culicidae) is a malaria vector in some countries in South and Southeast Asia. This is the first report to provide clear evidence that two different cytological forms of An. kochi are conspecific based on systematic studies. Two karyotypic forms, i.e., Form A (X₁, X₂, Y₁) and a novel Form B (X₁, X₂, Y₂) were obtained from a total of 15 iso-female lines collected from five provinces in Thailand. Form A was common in all provinces, whereas Form B was restricted to Ubon Ratchathani province. This study determined whether the two karyotypic variants of An. kochi exist as a single or cryptic species by performing cross-mating experiments in association with the sequencing of the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA), and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA). Cross-mating experiments between the two karyotypic forms revealed genetic compatibility by providing viable progenies through F₂ generations. The two forms showed a high sequence similarity of those two DNA regions (average genetic distances: ITS2 = 0.002-0.005, COI = 0.000-0.009). The phylogenetic trees based on ITS2 and COI sequences also supported that four strains (from Bhutan, Cambodia, Indonesia, and Thailand) were all of the same species. Five sensilla types housed on the antennae of female An. kochi were observed under scanning electron microscopy (SEM). In addition, this study found that An. kochi was a refractory vector, revealed by 0% susceptibility rates to infection with nocturnally subperiodic Brugia malayi. The cibarial armature was a resistant mechanism, as it killed the microfilariae in the foregut before they penetrated into the developmental site.

Description of Aedes (Hulecoeteomyia) bhutanensis n. sp. (Diptera: Culicidae) from Bhutan

A new species of the subgenus Hulecoeteomyia of the genus Aedes reared from pupae found with two larvae in a small pool on a log in mountainous forest of Bhutan is diagnosed and formally named Aedes bhutanensis Somboon & Harbach, n. sp. The specific status of the species is supported by differential morphological characters of females, larvae and pupae, and sequences of the mitochondrial COI gene. Dichotomous keys are provided for identification of the adult females and larvae of the species of the subgenus.

Genetic and morphological evidence for a new species of the Maculatus Group of Anopheles subgenus Cellia (Diptera: Culicidae) in Java, Indonesia

BACKGROUND

Anopheles maculatus, a species of the Maculatus Group of subgenus Cellia (Diptera: Culicidae), is an important vector of human malarial protozoa in Java, Indonesia. However, the identity of this species in Indonesia has been questionable because published reports and records are based mainly on morphological identification, which is unreliable for distinguishing members of the Maculatus Group due to overlapping characters.

METHODS

We performed morphological assessments, metaphase karyotype preparations, phylogenetic analyses of ITS2 and cox2 sequence data and cross-mating experiments to determine whether the Javanese form and An. maculatus (s.s.) from Thailand were conspecific.

RESULTS

The adults of the Java strain are similar to those of An. maculatus (s.s.), but the larvae and pupae exhibit significant differences. The metaphase karyotype of Javanese specimens includes a long acrocentric X chromosome and a small telocentric Y chromosome, which are distinct from other members of the Maculatus Group. Cross-mating of the Java strain with An. maculatus (s.s.) revealed genetic incompatibility. Phylogenetic analysis of ITS2 and cox2 sequences revealed that the Java strain forms a single clade that is distinct from clades of other members of the group (Kimura 2-parameter, K2P, genetic distances 3.1-19.2% and 1.6-9.6%, respectively).

CONCLUSIONS

This study provides evidence that the Javanese form of An. maculatus is not conspecific with An. maculatus (s.s.) and constitutes a previously unrecognized species of the Maculatus Group.