SAEUNGAE, Taai & Harbach, 2015

Taai, Kritsana & Harbach, Ralph E., 2015, Systematics of the Anopheles barbirostris species complex (Diptera: Culicidae: Anophelinae) in Thailand, Zoological Journal of the Linnean Society 174 (2), pp. 244-264 : 256-258

ANOPHELES ( ANOPHELES ) SAEUNGAE SP. NOV.

Anopheles (Anopheles) barbirostris in part of Reid, 1962 ( Thailand, ♀ * ♂ E* L P*, taxonomy); Harrison & Scanlon, 1975 ( Thailand, ♀ * ♂ * L* P*, taxonomy); Reid et al., 1979 ( Thailand, ♀ L P morphology).

Anopheles barbirostris in part (?) of Harrison et al., 1988 ( Thailand, A L P morphology).

Anopheles barbirostris forms A (in part) and B (in part) of Baimai et al., 1995 ( Thailand, metaphase karyotype).

Anopheles barbirostris Forms A and B (in part) of Saeung et al., 2007 ( Thailand, mitotic karyotype, crossmatings, COI and COII mtDNA, ITS2 rDNA).

Anopheles barbirostris species A2 of Saeung et al., 2008 ( Thailand, mitotic karyotype, cross-matings, COI and COII mtDNA, ITS2 rDNA); Suwannamit et al., 2009 ( Thailand, cross-matings, metaphase karyotype, COI and COII mtDNA, ITS2 rDNA); Thongsahuan et al., 2011 ( Thailand, Plasmodium susceptibility); Otsuka, 2011 ( Thailand, ITS2 rDNA).

Anopheles barbirostris Clade IV (unknown species) of Paredes-Esquivel et al., 2009 (Sumatran Indonesia, Thailand, COI mtDNA, ITS2 rDNA); Paredes-Esquivel & Townson, 2014 (Sumatran Indonesia, Thailand, ITS2 rDNA).

Diagnosis

Adult females of An. saeungae resemble the adult females of An. campestris in having a similar pattern of pale scales on the abdominal sterna, but the scaling of the wings is paler, as in An. barbirostris . This combination of characters, along with COI and ITS2 sequences (see below), readily distinguish An. saeungae from other species of the Barbirostris Complex. Some additional potentially differential morphological characters are denoted below, but for practical purposes An. dissidens is nearly isomorphic with other species of the complex.

Description

Female

Overall similar to An. barbirostris , but generally smaller, as indicated by measurements of the proboscis, maxillary palpus, antennal flagellum, wing, and forefemur listed in Table 1: lengths of proboscis, maxillary palpus, wing, vein R 4+5, forefemur, and width of wing statistically significantly shorter ( Table S2); apical pale band of hindtarsomere 3 0.04–0.18 mm (mean 0.10 mm), extended across joint onto base of hindtarsomere 4 in 20% of females examined.

Male

As described for An. barbirostris but generally smaller, as indicated by measurements of the gonocoxite, distal parabasal setae, internal seta, gonostylus, claspette club, and aedeagus listed in Table 2, but means of measurements not significantly different ( Table S3).

Pupa

As described for An. barbirostris , indistinguishable; setal branching in Table S8; branching of seta 2 compared with other species of the complex in Table 3.

Larva, fourth instar

As described for An. barbirostris ; setal branching in Table S9; differing in having seta 13-II with eight to 13 (eight) branches; sum of branches of pair of 13- P = 11–18, pair of seta 10-III = 4, 5 (4).

Mitotic karyotype

Three types of X chromosome (X 1, X 2, X 3) and two types of Y chromosome (Y 1, Y 2) comprising two karyotypic forms (X 1 X 2 X 3 Y 1, X 1 X 2 X 3 Y 2) have been identified in the early fourth-instar larval brains of An. saeungae ( Baimai et al., 1995; Saeung et al., 2008; Suwannamit et al., 2009).

Cross-matings

The results of crosses between An. saeungae (as An. barbirostris species A2) and An. dissidens (as species A1) are summarized under An. dissidens above. Suwannamit et al. (2009) obtained similar results from cross-matings between An. saeungae (as species A2) and An. barbirostris (as species A4), i.e. incomplete hatching of eggs, asynaptic polytene chromosomes in larvae, reduced pupation, and abnormal reproductive organs in a few adults.

DNA sequence

Specimens identified as An. saeungae are shown in Table S1, together with GenBank accession numbers for ITS2 and COI sequences. The ITS2 subunit for An. saeungae yields a dominant product of 1678 bp. The six interspecifically variable sites of the COI gene at bases 31, 82, 91, 181, 433, and 631 that are unique for this species are shown in Figure 4 . The results of Bayesian analyses of ITS2 and COI sequences are shown in Figures 5 and 6 , respectively. Both trees show that An. saeungae is a distinct member of the Barbirostris Complex. Our ITS2 sequences for An. saeungae (BCLp) fall within a strongly supported clade ( Fig. 5 , BPP 100%) with two sequences (Btr7 and l14) of An. barbirostris Clade IV of Paredes-Esquivel et al. (2009).

Bionomics

Adult females of An. saeungae have been collected in buffalo-baited traps, but are likely to attack humans on occasions when preferred hosts are scarce. Thongsahuan et al. (2011) found that 6.67% of females (as An. barbirostris species A2) had developed sporozoites of P. vivax during experimental infection studies.

Distribution

Based on COI, COII, and ITS2 sequences, An. saeungae is currently only definitely known to occur in Indonesia (Sumatra) and Thailand (Chanthaburi, Lampang, Phetchaburi, Ratchaburi, Sa Kaeo, Trat, Ubon Ratchaburi, and Udon Thani Provinces) ( Saeung et al., 2008; Paredes-Esquivel et al., 2009; Suwannamit et al., 2009; present study).

Etymology

This species is named in honour of Dr Atiporn Saeung ( Department of Parasitology , Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand) for her many contributions to our knowledge of mosquitoes in Southeast Asia, especially her cytogenetic and molecular studies of the Barbirostris Group, which provided information for further studies of these economically important mosquitoes .

Type series

Two-hundred and ninety-seven specimens (135 ♀, 67 ♂, 36 Le, 35 Pe, 24 L) derived from nine molecularly identified progeny broods: BCLp12(1), BCLp16(1), BCLp23(1), BCLp41(1), BCLp43(1), BCLp44(1), BCLp46(1), BCLp50(1), and BCLp52(1). Holotype, ♀ [BCLp16(1)-2], with Le and Pe on microscope slide, offspring of female collected as follows: THAILAND, Lampang Province, Ko Kha District , Ban Don Tham , buffalo-baited trap, 7.xii.2013, coll. Choochote et al. Paratypes, same data as holotype : 20 ♀ LePe [BCLp12(1)-3 to -6, -8, -10, -12; BCLp16(1)-1, -5 to -8, -12; BCLp23(1)-1, -3, -4, -8 to -11] ; 1 ♀ Le [BCLp12(1)- 7] ; 113 ♀ [BCLp12(1)-14, -16, -17, -21, -23, -25 to -29, -32; BCLp16(1)-13, -17, -18, -20, -22 to -49; BCLp23(1)- 13, to -15, -17 -19; BCLp41(1)-1 to -3, -7, -8, -10, -11; BCLp43(1)-8 to -11; BCLp44(1)-2, -3, -5, -7, -9, -11 to -23, -100; BCLp46(1)-2, -3, -5, -7, -12, -14, -15; BCLp50(1)-1, -3, -9 to -11, -13, -14, -16 to -22; BCLp52(1)-6 to -19]; 14 ♂ LePe [BCLp12(1)-1, -2, -9, -11; BCLp16(1)-3, -4, -9 to -11; BCLp23(1)-2, -5 to -7, -12] ; 53 ♂ [BCLp12(1)-13, -15, -18 to -20, -22, -24, -30, -31; BCLp16(1)-14 to -16, -19, -21; BCLp23(1)-16, -18, -20 to -22; BCLp41(1)-4 to -6, -9; BCLp43(1)-1 to -7; BCLp44(1)-1, -4, -6, -8, -10; BCLp46(1)-1, -4, -6, -13, -16; BCLp50(1)-2, -4 to -8, -12, -15; BCLp52(1)-1 to -5]; 24 L [BCLp12(1)-A, -B; BCLp16(1)-A, -B; BCLp23(1)- A, -B; BCLp41(1)-A, -B; BCLp43(1)-A, -B; BCLp46(1)- A, -B; BCLp50(1)-A, -B, -C, -D, -E, -F; BCLp52(1)-A, -B,-C, -D, -E, -F]. The type series is deposited in BMNH .

Figures

Figure 4. Alignment of the polymorphic sites along a 658-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene in Anopheles barbirostris (one female), Anopheles dissidens sp. nov. (13 females), Anopheles saeungae sp. nov. (nine females), Anopheles wejchoochotei sp. nov. (six females), and An. barbirostris species A3 (three females) (Saeung et al., 2008). Codes for the specimens are shown in Table S1. Bases enclosed in boxes represent species-specific differences among the five species.

Figure 5. Bayesian consensus tree for internal transcribed spacer 2 sequences. The tree is rooted on Anopheles (Cellia) dirus. Only Bayesian posterior probabilities greater than 50% are shown on the branches. The bar represents 0.1 substitutions per site.

Figure 6. Bayesian consensus tree for cytochrome c oxidase subunit I sequences. Only Bayesian posterior probabilities greater than 50% are shown on the branches. The bar represents 0.01 substitutions per site.