Culex (Culex) pruina 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 : 88-89

Culex (Culex) pruina Theobald

subspecies eschirasi Galliard, 1931 —original combination: Culex pruina var. eschirasi (subspecific status by Harbach & Howard 2007). Distribution: Burkina Faso, Cameroon, Central African Republic, Gabon, Côte d’Ivoire, Nigeria, Republic of the Congo, Uganda ( Wilkerson et al. 2021). subspecies pruina Theobald, 1901d —original combination: Culex pruina . Distribution: Cameroon, Central African Republic, Côte d’Ivoire, Democratic Republic of the Congo, Gabon, Ghana, Liberia, Nigeria, Republic of the Congo, Sierra Leone, South Sudan, Uganda ( Wilkerson et al. 2021, but not Sudan, see Simsaa et al. 2021).

With the exception of Burkina Faso, subspecies eschirasi has been recorded from eight of the 12 countries in which the type form has been recorded. The larvae of the two forms, which are apparently sympatric, exhibit significant differences. The larva of the type form was described by Macfie & Ingram (1916), and their description and illustrations of the head and terminal abdominal segments were utilized by Hopkins (1936, 1952), with little additional information. Galliard (1931) illustrated the terminal abdominal segments of eschirasi and noted two major distinctions from the type form. Hopkins (1936, 1952) illustrated a longer siphon for eschirasi and reiterated the differences between the two forms noted by Galliard (1931). In the type form, the posterior surface of the siphon between the pecten of either side is covered with microtrichium-like spicules (aculeae) whereas in subspecies eschirasi the entire surface of the siphon, except narrowly at the base, is covered with aculeae. Both authors indicate that the integument of the thorax and abdominal segments I–VII and part of VIII bears a dense covering of aculeae. Harbach et al. (2017) recorded the presence of thoracic and abdominal aculeae in Cx. pruina , but they did not indicate which subspecific form was examined. Other differences noted in the descriptions and illustrations of the two forms include the following: Comb scales evenly fringed in eschirasi whereas some scales are only fringed at the apex and on one side in the type form; the siphonal setae (seta 1-S) are about 0.6 the diameter of the siphon in the former and about 0.5 the diameter in the latter; seta 1-X is short and single in eschirasi and longer with three branches in the type form; and the anal papillae are equally long in eschirasi , slightly longer than the length of the saddle, whereas the dorsal and ventral papillae are unequal and the dorsal pair is slightly shorter than the length of the saddle in the type form. The male genitalia of the typical form were partially described and illustrated by Edwards (1914, 1929 b, 1941). The genitalia of eschirasi have not been illustrated, but Galliard (1931) noted that they look a little different than those of the type form: “appendices chitineux du tube génital (mésosome) sont profondément divisés en deux” [lateral plates of the genital tube (aedeagus + lateral plates) are deeply split in two]. However, Edwards (1941) stated that he could not find any differences between the genitalia of the two forms. That aside, in view of the morphological distinctions of the larvae and the sympatry of the two forms, it is likely that eschirasi is genetically distinct and should therefore be afforded specific status: Culex (Culex) eschirasi Galliard, 1931 . Culex eschirasi is currently listed as a species in the Encyclopedia of Life.

Culex pruina has a single synonym, Cx. pallidothoracis Theobald, 1909 (type locality: Obuasi, Ashanti Region, Ghana). Until topotypic larvae of this nominal species are available for examination, Cx. pallidothoracis should remain a synonym of Cx. pruina .