Anopheles (Cellia) tessellatus Theobald

Harbach, Ralph E. & Wilkerson, Richard C., 2023, The insupportable validity of mosquito subspecies (Diptera: Culicidae) and their exclusion from culicid classification, Zootaxa 5303 (1), pp. 1-184 : 75-78

Anopheles (Cellia) tessellatus Theobald

subspecies kalawara Stoker & Waktoedi Koesoemawinangoen, 1949 —original combination: Anopheles (Myzomyia) tessellatus var. kalawara (subspecific status by Harbach & Howard 2007). Distribution: Indonesia [Celebes = Sulawesi] ( Stoker & Waktoedi Koesoemawinangoen 1949; Waktoedi Koesoemawinangoen 1954).

subspecies orientalis ( Swellengrebel & Swellengrebel de Graaf, 1920) —original combination: Neomyzomyia punctulata var. orientalis (subspecific status by Harbach & Howard 2007). Distribution: Indonesia ( Wilkerson et al. 2021).

subspecies tessellatus Theobald, 1901a [often misspelled tesselatus ]—original combination: Anopheles tessellatus [first published in error as Anopheles punctulatus D̂nitz, see below]. Distribution: Bangladesh, Bhutan, Cambodia, Guam, India, Indonesia, Laos, Malaysia, Maldives, Myanmar, Nepal, Papua New Guinea, People’s Republic of China, Philippines, Solomon Islands, Sri Lanka, Taiwan, Thailand, Timor, Vietnam ( Wilkerson et al. 2021).

Bourke et al. (2021) analyzed COI sequences from populations of An. tessellatus sensu lato from Sri Lanka, Southeast Asia, Indonesia to the Philippines and identified six genetically diverse OTUs (operational taxonomic units), which they called the Tessellatus Complex (Tessellatus Group of Rattanarithikul et al. 2006b). The complex currently consists of the nominotypical tessellatus and subspecies kalawara and orientalis , with six associated synonyms.

The nominotypical form was first described from a single female from Taipang [= Taiping], Perak, Malaya [ Malaysia]. Townsend (1990) documented the presence of the holotype in the Natural History Museum, London. Theobald originally described the species as Anopheles punctulatus D̂nitz, to which he gave the manuscript name tessellatus . He incorrectly believed that tessellatus was the same as punctulatus D̂nitz, 1901. However, punctulatus is a different allopatric species found in the Australian Region. Stanton (1913) recounted the history as follows: “The species here referred to under the name tessellatus was first described by Theobald from specimens taken in Malaya . In his manuscript he gave it the name Anopheles tessellatum , but before publication, having seen D̂nitz’ description of his Anopheles punctulatus , he considered the two to be identical and used his description as that of Anopheles punctulatus , D̂nitz. In a later volume of his monograph (iii, p. 55) Theobald states that, as pointed out by D̂nitz, tessellatus is distinct from punctulatus ; the former species he includes in the genus Myzomyia and the latter in the genus Cellia —to this opinion he adheres in his volumes iii and iv. In volume v I can find no reference to tessellatus , but punctulatus is again referred to under the genus Cellia .” Some confusion persisted as various authors continued to use punctulatus instead of tessellatus .

Theobald’s description is accompanied by illustrations of the scutum, wing, hindtibia and hindtarsomeres. There is also a color drawing of the adult female in a separate accompanying volume (plates). Selected characters from the original description follow.

[Diagnosis] Thorax brown with frosty-grey tomentum, two dark spots in front and another near the scutellum; abdomen almost black with golden hairs [setae]; costa yellow, with four large and four small black spots, wing field with very numerous dark spots. Legs yellow with dusky scales, banded; [Theobald used “metatarsis” for what is now tarsomere 1 and his “tarsus” refers to tarsomeres 2–5] fore tarsi apically and basally pale banded; mid and hind tarsi apically pale banded only.

♀. Head black, with white scales in front, black scales behind and at the top; eyes black... proboscis yellow with black scales towards the base and a small dark ring near the apex; palpi black scaled at the base, then a small ring of white scales, then a broad ring of black, the remainder white, with two small rings of black; the apical joint yellowish.

Thorax... scutellum dusky towards the middle....

Abdomen dark brown, almost black, with golden hairs.

[Next paragraph omitted here.]

Halteres pure white.

Anterior legs with the femora much swollen, yellow with dusky scales, showing more or less banding; tibiae yellow, with dark scales scattered about [speckled]; metatarsus [tarsomere 1] dark scaled at the base, white at the apex, and with several white bands towards the apex; first three tarsal joints apically and basally banded white, last apically white only; the femora and the tibiae of the mid legs as in the fore ones; metatarsus mostly black scaled, the apex banded yellow; tarsi [tarsomeres 2–5] all apically yellow banded; hind legs with the tibiae more or less banded; metatarsus very long and banded, the apex white; and the tarsi apically whitish-yellow.

The wing has the full complement of costal spots as defined by Wilkerson & Peyton (1990). Of possible key character significance, the accessory sector pale spot is present on the costa and all of the posterior veins end in pale fringe spots. The accessory sector pale spot is not present on the costa in depictions of tessellatus from Indonesia ( Stoker & Waktoedi Koesoemawinangoen 1949) or Taiwan ( Tanaka et al. 1979).

In Theobald’s original description of the proboscis—“yellow with black scales towards the base and a small dark ring near the apex”—differs somewhat from subsequent descriptions which indicate that the apical third to half of the proboscis is distinctly pale.

The following are distinguishing characters of adult females and larvae summarized from Reid (1968, Malaysia and Borneo) and Rattanarithikul et al. (2006b, Thailand).

Adult. Proboscis with pale scales on apical half; maxillary palpus with four pale bands; antepronotum without scales; upper proepisternal seta present; tibio-tarsal articulation with a narrow, white band; femora and tibiae speckled; hindtarsomeres 3–5 mostly dark but with narrow apical pale bands [ Reid 1968]; hindtarsomeres 1–4 with narrow apical pale bands [ Rattanarithikul et al. 2006b]; abdominal sterna without tufts of black scales.

Larva. Seta 2-C not closely approximated, distance between their bases about 1.5–2.0 times distance between bases of 2-C and 3-C; seta 3-C slender, at least apically without branches or aciculae; seta 1-P reduced, 2–5- branched, arising from small, lightly pigmented basal tubercle not attached to tubercle of seta 2-P; setae 9,10-P and 9,10-M all single, not aciculate; abdominal seta 1-II not palmate, with filamentous branches; abdominal tergal plates on segments IV–VII small, not as wide as the distance between the bases of each pair of palmate setae, small tergal plates not enclosing small median posterior plates.

Stoker & Waktoedi Koesoemawinangoen (1949) are currently credited with naming subspecies kalawara , as Anopheles (Myzomyia) tesselatus (sic) var. kalawara . They stated: “This illustrated map of the Anopheline Imagines [adults] of Indonesia is a corrected and supplemented edition (English translation of the Indonesian text) of the „Kaart [sic] en determinatietabel der Anophelinen in Ned. Oost Indie” (edition Public Health Service, section malariacontrol [sic] 1938).” We have not seen the original 1939 publication, and we do not know, as Harbach & Howard (2007) noted, what status was intended for kalawara (infrasubspecific or other). Two articles are mentioned in the translation that we have not seen but which could shed light on the question. The translation of Stoker & Waktoedi Koesoemawinangoen (1949) does not indicate that kalawara was intended to be a new variety, but the name was distinctly listed as a variety of tessellatus . It is noteworthy that Stoker & Waktoedi Koesoemawinangoen placed “( Brug 1938)” directly after the name kalawara in their key to the Anopheles of subgenus “ Myzomyia ” in Indonesia. This appears to be an indication of prior taxonomic treatment rather than an indication of taxon authorship, which is further indicated by citations of non-authors that follow many other species names in the key.

Apparently, Brug (1938) was the source of the only differential character used in the putative 1949 original description. He did not mention the name kalawara , but described a palpal difference later used by Stoker & Waktoedi Koesoemawinangoen (1949) to distinguish kalawara and tessellatus: Presence of pale scales dorsally on palpomeres 2 and 3 in tessellatus , all dark dorsal scaling on those palpomeres in tessellatus var. kalawara —“In nine females, bred from larvae collected at Kalawara” (see below). Brug (1938) referred to these morphotypes as tesselatus [sic] “normaal” and tesselatus “abnormaal”. Presumably, “abnormaal” corresponded to variety kalawara .

We translated Brug (1938) and report here a type-written, annotated, anonymous translation included with our copy of Waktoedi Koesoemawinangoen (1954). That translation and ours closely agree. In summary, the scattered pale scales supposedly found dorsally on palpomeres 2 and 3 of tessellatus versus no pale scales on those palpomeres of kalawara , are either variable and/or other concordant characters have not yet been noted.

The anonymous translator: “Here is the text on which Waktoedi based Anopheles tesselatus [sic], the variety name kalawara .” And, “He just uses the village name, even in the key there is no differentiation from the other variety [ orientalis ] or the type either [ tessellatus ].”

Translation of Brug (1938) [figure numbers as in original]:

Introduction. “In the investigation of the transmitters of Filaria malayi in Kalawara (this magazine, 1937, LXXVII, 1462) and of Filaria bancroffi at Kabaena 1) (the results will be published in the Med. D.V.G., 1938) showed some aberrant Anophelines found, which will be described in more detail below.”

Description of An. tesselatus [sic]. “The palps [maxillary palpi] of the female usually show, viewed from above, in addition to four light bands, two light spots, one located between the basal band pair [middle of palpomere 2] and the other between base and first band [middle of palpomere 1] (fig. 4a). In nine females bred from larvae collected at Kalawara, these spots were missing and the decoration of the palps therefore consisted exclusively of four pale bands (fig. 4b). Only one female showed the [extra] spots. The hypopygia [genitalia] of the males, bred from the same brood, showed no difference from those of males from other regions van den [from the] Archipelago, where, as far as our collection showed, the female palps as shown in Fig. 4a. However, there was some [some had a] peculiar nodule on the grasping pincers [gonostyli] (fig. 3), but this was far from constant, sometimes only present on [one] the side. Barraud (1934, p. 318) describes the same deviation too, occurring inconstantly, in Armigeres kuchingensis and A. obturbans ).”

Variety kalawara was listed as such in catalogs by Stone et al. (1959) and Knight & Stone (1977), but it was excluded from keys to Indonesian anophelines by O’Connor & Soepanto (1979) due to lack of distributional data and specimens. In compliance with Article 45.6.4 of the International Code of Zoological Nomenclature, kalawara was raised to subspecific rank by Harbach & Howard (2007) because the original designation did not provide any indication that the name was intended for an infrasubspecific form. To our knowledge, kalawara was not explicitly designated as the name of a new taxon, it is based on a single apparently variable character and type specimens do not exist. Until further information might come to light, we believe kalawara Stoker & Waktoedi Koesoemawinangoen, 1949 should be formally treated as a nomen dubium. “ Anopheles kalawara ” should be removed from the list of Anopheles species recorded in the Encyclopedia of Life.

Swellengrebel & Swellengrebel de Graaf (1920) described orientalis as a variety of An. punctulatus (see explanation of the name punctulatus above) from northern Celebes [Sulawesi], Moluccas and eastern Java. Without explanation, Bonne-Wepster & Swellengrebel (1953) cited the type locality as Paleleh, Celebes [a village in Central Sulawesi Province]. The original description follows [figure numbers as in the original]: “This variety is founded on larval characters only, the adult not differing from the type, [sic] Here follow the distinctive character [sic]: 1). The leaflets of the fans [palmate setae] are very slender, not serrate and show pigmentation up to the apex ([pl. 2,] fig. 4). 2). There is no fanshaped [sic] hair [seta] on the 2 nd abdominal segment but only a small cocade [sic; Dutch word veder should instead have been translated as feather] ([pl. 2,] fig. 5).”

The character of the palmate setae (seta 1) on abdominal segments III–VII with smooth or very slightly serrate margins has been used to distinguish orientalis in Indonesia from the “ type ” form of tessellatus by Bonne-Wepster & Swellengrebel (1953), Waktoedi Koesoemawinangoen (1954) and Reid (1968). However, specimens of nominal tessellatus in the Philippines ( Baisas & Dowell 1967) and Taiwan ( Tanaka et al. 1979) were also found to have smooth or slightly serrate margins. The leaflets in Taiwanese larvae appear a bit different in that they are “rather broad, transparent, usually simple...”.

There seem to be multiple character states related to the form of the leaflets of palmate setae in the Tessellatus Complex. Subspecies orientalis has no known type material and only an uncorroborated type locality. Larvae characteristically have the leaflets of palmate setae without serration and adults may or may not have dorsal pale scales on palpomeres 2 and 3.

Subspecies orientalis occurs in an area where Bourke et al. (2021) identified two sympatric OTUs in their molecular study. It is not possible, however, without further study, to determine if one of those refers to orientalis . For now, we think that the name orientalis Swellengrebel & Swellengrebel de Graaf, 1920 should be considered a species inquirenda, i.e. a “species of doubtful identity requiring further investigation” (Glossary, International Code of Zoological Nomenclature, International Commission on Zoological Nomenclature 1999). “ Anopheles orientalis ”, currently recognized as a species in the Encyclopedia of Life, should be removed from the list of Anopheles species until its taxonomic status is resolved.

The nominotypical subspecies currently has six synonyms (type localities from Wilkerson et al. 2021): Anopheles formosae Hatori, 1901 (type locality: Taihoku, Kielun and Tansui, Formosa [ Taiwan]); Anopheles deceptor D̂nitz, 1902 (type locality: Sumatra [ Indonesia]); Myzomyia thorntonii Ludlow, 1904a (type locality: Cottabato [Cotabato], Mindanao, Philippines); Dactylomyia ceylonica Newstead & Carter, 1910 (type locality: Trincomalee, Ceylon [ Sri Lanka]); Anopheles kinoshitai Koidzumi, 1917 (type locality: Ryukokosho, Taihoku (Taipei), Formosa [ Taiwan]); Anopheles taiwanensis Koidzumi, 1917 (type locality: Garden of Central Institute, Formosan government and Banshoryo, Ako Prefecture, Formosa [ Taiwan]).

It is not yet known what differential characters might be associated with the component taxa of the Tessellatus Complex. We should therefore be mindful that published keys and descriptions were sometimes based on characters of specimens from throughout the range of what was assumed to be a single species. For examples see Peyton & Scanlon (1966), Baisas & Dowell (1967), Reid (1968), Basio (1971), Rattanarithikul & Harrison (1973), Tanaka et al. (1979) [characters of Taiwanese specimens], Lee et al. (1987), Darsie & Pradhan (1990), Oo et al. (2006) and Rattanarithikul et al. (2006b).