Anopheles, Meigen, 1818

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 : 258-259

ANOPHELES ( ANOPHELES ) CAMPESTRIS REID

Anopheles (Anopheles) campestris Reid, 1962 (♀ * ♂ * E P L*). Holotype ♀ LePe : Rantau Panjang, Klang, Selangor, Malaysia (BMNH).

Anopheles (Anopheles) campestris of Reid, 1968 (peninsular Malaysia, southern Thailand, ♀ * ♂ * E P L*); in part (?) of Harrison & Scanlon, 1975 (southern Thailand only, ♀ * ♂ * L* P*, taxonomy); Reid et al., 1979 ( Malaysia, Thailand, L P morphology).

Diagnosis

Adults of An. campestris generally have more darkly scaled wings and paler scaling on the abdominal sterna than the adults of An. barbirostris . The pupa and larva are normally distinguishable by having some setae with more numerous branches. DNA sequences are not avail- able for this species, but the mitotic karyotype of larval brain cells (see below) is distinctive in having a telocentric Y chromosome.

Description

Female

Anatomical features compared with other species of the Barbirostris Complex in Table 1: wing statistically significantly shorter than wing of An. barbirostris ( Table S3); forefemur/proboscis ratio 0.88–0.95 (mean 0.91); pleura with three or four upper proepisternal setae, four to seven prealar setae, three to six upper and two to five lower mesokatepisternal setae, and nine to 14 upper and zero to six lower mesepimeral setae; wing scaling generally darker than wing scaling of An. barbirostris ; cubital vein often with more dark scales than pale scales; apex of wing frequently with bar of pale scaling extending posteriorly from preapical pale spot across veins R 1, R 2, R 3+4, and M 1; wing without pale fringe spot at apex of vein R 2; foretarsomere 3 usually without apical pale band, midtarsomeres usually without pale bands, apical pale band of hindtarsomere 3 0.08–0.10 mm (mean 0.08 mm), not extended across joint onto base of hindtarsomere 4 in 10% of females examined; sterna II–VII with numerous pale scales in median patch and lateral row, and scattered between median patch and lateral rows; posterior margin of sternum VI rarely with dark scales.

Male

Like female except for sexual differences and as follows: distal 0.5 of abdominal tergum VIII usually with central patch of dark scales and pale scales on lateral aspects; characters of genitalia listed in Table 2: lengths of gonocoxite and aedeagus statistically significantly shorter and longer, respectively ( Table S3).

Pupa

As described for An. barbirostris ; setal branching in Table S10; branching of seta 2 compared with other species of the complex in Table 3; differences include seta 1-II with five to 15 branches; sum of branches of pair of seta 1-II = 12–24, pair of seta 3-III = 15–19 (15).

Larva, fourth instar

As described for An. barbirostris ; similar to An. wejchoochotei , setal branching in Table S11; differences include seta 14-P with four to eight (six) branches; seta 8-M with nine to 22 (11) branches; seta 2-T with one to three (one) branches; seta 13-II with nine to 19 (14) branches; seta 5-V with four to seven (five) branches; sum of branches of pair of seta 13- C = 18 or 19, pair of seta 7-P = 24–39, pair of seta 8-M = 22–31, pair of seta 2-I = 20–33, pair of 2-VIII = 16– 20(16), pair of seta 5-IV = 8–11(11).

Mitotic karyotype

The mitotic karyotype of An. campestris is only known from a single male larva collected in Bangpa-in of Ayutthaya Province, located in the central plains area north of Bangkok ( Baimai et al., 1995). The karyotype consists of a metacentric X chromosome, which differs from the metacentric X 1, and a telocentric Y chromosome, which is unique among the Y chromosomes of the Barbirostris Complex.

DNA sequence

Not available.

Bionomics

The immature stages are normally found in still, shaded bodies of fresh water containing some vegetation, including rice fields, marshes, swamps, ponds, ground, stream and flood pools, canals and ditches, pits, animal footprints, and wells ( Harrison & Scanlon, 1975; Rattanarithikul et al., 2006). Adult females readily bite humans, more so than other members of the Barbirostris Complex, enter houses, and have been found infected with malaria protozoa. Females are important vectors of malaria in the western coastal plains of peninsular Malaysia ( Reid, 1962) and are known to transmit the nematode Brugia malayi that causes lymphatic filariasis ( Rattanarithikul et al., 2006).

Distribution

Anopheles campestris occurs in low-lying areas normally at elevations less than 200 m a.s.l. It reportedly occurs in Cambodia, China, Malaysia, Thailand, and Vietnam, but its occurrence is only confirmed for populations in peninsular Malaysia and in Thailand. It seems to be confined to the Korat Plateau, Chao Phrya River basin, and the coastal areas of Thailand ( Reid, 1962; Harrison & Scanlon, 1975; Reid et al., 1979). Based on extensive surveys and detailed study of adults with associated larval and pupal exuviae, Harrison et al. (1988) showed that An. campestris does not occur in the plains area of Chiang Mai Province where the type locality of An. wejchoochotei resides. Current evidence suggests that An. campestris is unlikely to occur in China.

Etymology

The specific name is taken from the Latin adjective ( campestris , campestris , campestre) meaning ‘of fields’ or ‘plain-dwelling’. When Reid (1962) described this species, he stated ‘This species appears to be largely confined to broad alluvial plains (thus the name campestris ) along coasts and river deltas’.

Type series

Twenty-seven specimens (5 ♀, 4 ♂, 9 Le, 9 Pe) reared from eggs obtained from wild-caught females, with associated larval and pupal exuviae mounted on micro- scope slides. Holotype, ♀ LePe (L.H. 75/10), mother collected MALAYSIA, Selangor, Klang, Rantau Panjang, 20.vii.1952, coll. J. A. Reid ; Allotype, ♂ LePe [L.H. 75/ 2], same data as holotype; Paratypes, ♀ LePe [L.H. 75/ 21], same data as holotype; ♀ LePe [377/1] and ♂ LePe [377/4], same data but collected 31.iii1949 ; ♂ LePe [L.H. 80/4], same data but collected 24.iii.1952 ; 2 ♀ LePe [L.H. 81/7, /8]; ♂ LePe [L.H. 81], same data but collected 3.viii.1952 . The series is deposited in BMNH.