Culex ( Lophoceraomyia ) spiculosus Bram & Rattanarithikul, 1967

5. Culex ( Lophoceraomyia) spiculosus Bram & Rattanarithikul, 1967 View in CoL

A single fourth-instar larva (Le 14936), although somewhat damaged, was collected from a tree hole on 28.VIII.2022 at Shillong Peak ( 25.539624 N; 91.848479 E, 755 m a.s.l) in Meghalaya State and was identified as Cx. spiculosus . Identification was made by comparing the specimen with the description provided by Sirivanakarn (1977c) and with reference specimens of Cx. raghavanii Rahman, Chowdhury & Kalra, 1969 and Cx. uniformis ( Theobald, 1905b) housed in our museum collection. Culex spiculosus was originally described from Thailand and later reported by Bram (1967) from Malaysia.

Diagnosis. The presence of strong spicules on the thorax and abdominal segments places the larva of Cx. spiculosus in close resemblance with Cx. kuhnsi King & Hoogstraal, 1955 , Cx. raghavanii and Cx. uniformis ; however, each species is distinctly separated by other larval characters. Culex kuhnsi differs notably by possessing 4–6 branched spicules on the thorax and abdomen, whereas Cx. raghavanii , Cx. spiculosus and Cx. uniformis have unbranched spicules. In Cx. raghavanii , seta 8-P is double and subequal in length to seta 7-P, while in Cx. spiculosus seta 8-P is single ( Fig. 3a).

Culex spiculosus larvae can be easily distinguished from those of Cx. uniformis by the following features: Seta 5-C is double (although not clearly visible due to damage); the posterior caudal margin of the saddle is lightly spiculate; seta 2-X is single ( Fig. 3b); and seta 8-P is single and subequal to seta 7-P. In contrast, Cx. uniformis exhibits 3- or 4-branched seta 5-C; the posterior caudal margin of the saddle bears numerous strong spicules; and seta 8-P is minute and 4- or 5-branched. The pecten spines of Cx. spiculosus are illustrated in ( Fig. 3c).

The known distributions of Cx. raghavanii and Cx. uniformis include the Western Ghats and southern India, while Cx. spiculosus is reported from Thailand and Malaysia. Species of the subgenus Lophoceraomyia are difficult to identify based on morphological characters of adult females, but they can be reliably separated by features of the male genitalia and larvae. In most cases, reared associated specimens are essential for accurate species confirmation. Sirivanakarn (1977c: 8) and Belkin (1962: 250) both emphasized that larval characters are more useful for identification than characters of the male genitalia. However, as the present diagnosis is based on a single larva, additional specimens with associated life stages are necessary to validate the presence of Cx. spiculosus in India.