Aedes (Neomelaniconion) lineatopennis (Ludlow)

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 : 26-28

Aedes (Neomelaniconion) lineatopennis (Ludlow)

subspecies aureus Gutsevich, 1955 —original combination: Aedes (? Aedes) aureus (subspecific status by Danilov 1977).

Distribution: Russia, Russian Federation ( Wilkerson et al. 2021).

subspecies lineatopennis ( Ludlow, 1905) —original combination: Taeniorhynchus lineatopennis . Distribution: Australia, Bangladesh, Borneo (island), Cambodia, India, Indonesia, Laos, Malaysia, Nepal, Pakistan, People’s Republic of China, Philippines, Russia, South Korea, Sri Lanka, Thailand, Timor, Vietnam ( Wilkerson et al. 2021).

The taxonomic study of Huang(1985) provides a prelude to the treatment of these nominal taxa.Multiple identifications of lineatopennis in Africa have complicated the definition of this species. Huang, based on detailed morphological comparison of African specimens with type specimens and other material collected in the Philippines, determined that records of lineatopennis in Africa pertained to a previously unrecognized species, which she described and named Ae. mcintoshi. Since Huang excluded lineatopennis from Africa, all references to lineatopennis in Africa require re-evaluation (e.g. Ingram & de Meillon 1927; Edwards 1941; Gutsevich 1973).

The nominotypical subspecies was described from two adult females captured at Camp Gregg, Bayambang, Pangasinan, Luzon, Philippines. Knight & Hull (1953) designated a lectotype, which was later validated by Stone & Knight (1956a). Its most distinctive features include the head with median golden scales, scutum dark brown with broad golden lateral stripes, legs unmarked, abdominal terga with pale basal bands and wings with pale scales on some veins. A condensed version of the original description ( Ludlow 1905) follows.

Taeniorhynchus lineatopennis , n. sp. — ♀. Head dark brown, with brassy yellow curved scales on median portion and extending from occiput to vertex... dark brown flat lateral scales, and a few forked scales... antennae dark brown... palpi... proboscis... clypeus dark brown....

Thorax: prothoracic lobes dark brown... no scales; mesonotum dark brown, the median portion covered with dark brown curved scales bordered by a heavy band of brassy yellow curved scales, extending cephalad from one wing joint (inverted “U”) across to the other, a very distinct and easily-recognized marking. …pleura brown and clothed only with a few brown hairs [setae]; scutellum dark brown, with brassy yellow curved scales....

Abdomen dark brown, with broad basal bands of “dirty white” scales hardly extending the full width of the terga; the first segment is dark, and the second has merely a median light spot, while on the ultimate segment the band is quite narrow; venter dark.

Legs are brown throughout; coxae and trochanters and ventral side of femora somewhat lighter than the rest, a light spot near the apex of fore femora on dorsal side, i. e., the ventral colour runs up... more distal joints are darker, ranging from purplish to fawn colour....

Wings clear, clothed with brown and light typical Taeniorhynchus scales. The costa is dark throughout, the subcosta and first longitudinal [vein R 1] are mostly light scaled from the base of the wing to about the junction of the subcosta, and the stem of the fifth long vein [vein CuA] is also light, with some light scales on the lower fork. …halteres have a light stem and dark knob.

Knight & Hull (1953) described the male genitalia and larva, Tanaka (2003) described the pupa and Choochote et al. (2001) described the egg of subspecies lineatopennis . Gutsevich (1955) described aureus from Kraskino, Russia, which is an urban locality in the Khasansky District of Primorsky Krai, located on the shore of Posyet Bay, 282 km southwest of Vladivostok, near the border with North Korea. If or where a type series was deposited is not known. An unpublished (1973) translation by B. F. Eldridge of the original Russian description follows.

Aedes ( Aedes ?) aureus Gutzevich , sp. n.

Distinguishing features: Intense golden scales on lateral part of mesonotum. Large clearly outlined golden spot on occiput, presence of light scales on wings, irregularly shaped light spot on abdominal tergites [terga], entirely dark proboscis and tarsi.

Female: Scales behind eye brown, abutting [eyes abutting? abutting eyes?]. Occiput with large spots of upright golden scales and hairs [setae]. Proboscis and palpi with unicolored brown scales; sometimes with middle third of proboscis having a single light scale. Proboscis as long as front femur. Length of antennae about 1/5 of length of proboscis. Antennae brown. Mesonotum with a longitudinal expanding [posteriorly?] stripe of chocolate-cinnamon scales. Lateral part of mesonotum with golden scales. Body of thorax devoid significantly of accumulated scales; the last forming a small spot on sternopleuron and mesepimeron. Bristles [Setae] (their arrangement and quantity play a part in the classification of the Oriental species of the subgenus Aedes ): Proepimeral 6–8, parastigmatic [postspiracular] 5–7, upper mesepimeral 7–9, lower mesepimeral 3–5. Wing: costal vein covered with dark scales, subcosta mostly clear, cream-colored; base of radial, medial, and cubital vein with light scales, which vary among particular wings; anal vein with dark scales. Legs usually with dark scales; light longitudinal streak on posterior surface of femur, tibia, and first segment of tarsus. Tarsi without light rings. Claws equal on the anterior and middle tarsi and with teeth, the posterior tarsi without teeth. Abdomen from above usually with brown scales. Lighter yellowish-gray concentrated mainly in the middle and the anterior edge of the tergites, formed as indistinct spots. Abdominal hairs long, golden. Cerci very short. Length of body with proboscis 7–8 mm.

Material (13 females) collected by K.P. Chaginem north of the Kraskino Primorskovo region in August 1947 .

Gutsevich (1973), after comparison of aureus with lineatopennis from South Africa [= Ae. mcintoshi Huang, 1985], determined that aureus belonged in Aedes subgenus Neomelanoconion , thus removing the initial doubt expressed in the original description.

Danilov (1977) [summarized from a translation of the Russian] compared four aureus females from near the type locality with a female of lineatopennis from an undetermined [by us] locality in China (from the “IMP & TM collection”). To separate lineatopennis from aureus, Danilov determined that since there was a wide range of variation in the key character of the extent of basal pale scaling on the abdominal terga of putative aureus specimens, and also a wide range in the number of setae on the frontal stripe, that the characters were unreliable. He cited the wide distribution of lineatopennis, Afrotropical to South Korea, to conclude that aureus was simply a variant on the peripheral distribution of lineatopennis . He then decided, without explanation, that this distribution merited subspecies status for aureus . Of probable diagnostic significance, Danilov noted that aureus was much larger than lineatopennis .

The larva and male genitalia of aureus were later described and illustrated by Shestakov (1980) from specimens collected near the type locality. To further our understanding of his description, we generated a rough translation of his paper using Google Translate. Most informative to us, however, are his illustrations of the head and terminal segments of the larva and the male genitalia. We compared Shestakov’s illustrations of the larva with the larva of lineatopennis illustrated by Mattingly (1961) and Knight & Hull (1953), and his illustrations of the male genitalia with the male genitalia of lineatopennis illustrated by Huang (1985). In the larval stage, the antenna of aureus has large spines on the inner surface but in lineatopennis the large spines are distributed over all surfaces. The siphon of aureus is short (index about 1.5) and widened medially whereas in lineatopennis it is longer (index about 2.5) with the widening more basal. The anal papillae of aureus are about 1.5 times the length of the saddle, gradually narrowing, while in lineatopennis they are about 2.5 times the length of the saddle, slender and tapered to a point. In the male genitalia, the stout subapical spines of the gonocoxite appear to be shorter and more numerous in aureus (the aureus illustration is a bit stylized so it is difficult to confidently compare them). Huang (1985) used differences in the nature of these spines to distinguish Ae. mcintoshi from lineatopennis . Also, tergum IX of aureus is somewhat rounded, while in lineatopennis it is slightly emarginate.

The siphon of the lineatopennis larva illustrated by Lee (1999) and the siphon of aureus illustrated by Shestakov (1980) are both short and mesally expanded. Also, both nominal taxa exhibit peak activity in August and September ( Shestakov 1980; Hwang et al. 2020). Since both are found in temperate climates in the same geographic region, we suspect that they are conspecific and the correct name for the form found in Korea is probably aureus , not lineatopennis . The name lineatopennis appears in all recent keys for the identification of mosquitoes that occur in the Republic of Korea ( South Korea) ( Lee & Egan 1985; Lee & Zorca 1987; Lee 1999; Ree 2003). The nominal taxon aureus has only been treated as a species by Gutsevich (1955, 1971, 1973, 1974) and Danilov (1977), and has only been designated and treated as a subspecies of lineatopennis by Danilov (1977).

The nominal taxon lineatopennis apparently has a wide tropical distribution that extends from India to Australia. The nominal taxon aureus is only known from temperate areas ranging from the Korean peninsula to western Russia and probably China. In view of distinct ecological and morphological differences, we hereby restore subspecies aureus to species status: Aedes (Neomelanoconion) aureus Gutsevich, 1955 . Aedes aureus is currently listed as a species in the Encyclopedia of Life. Synonyms: None.

Aedes (Neomelanoconion) lineatopennis ( Ludlow, 1905) has one synonym: Pseudohowardina linealis Taylor, 1913 . Synonymy by Taylor (1916).