Thliptoceras Warren, 1890

Zhang, Dandan, Xu, Jiawen & Li, Jinwei, 2014, Review of the genus Thliptoceras Warren, 1890 (Lepidoptera: Crambidae: Pyraustinae) from the Oriental region of China, Zootaxa 3796 (2), pp. 265-286 : 266-267

Thliptoceras Warren, 1890

Thliptoceras Warren, 1890: 274 . Type species: Thliptoceras variabilis Warren, 1890 (by subsequent designation by Hampson, 1896: 377, but cited as " T. cascale Swinhoe ").

Mimocomma Warren, 1895: 473. Type species: Mimocomma fulvimargo Warren, 1895 , by original designation. Polychorista Warren, 1896: 109. Type species: Thliptoceras calvatalis Swinhoe, 1890 , by original designation. Parudea Swinhoe, 1900: 523. Type species: Parudea fimbriata Swinhoe, 1900 , by original designation.

DIagnosIs. Species of Thliptoceras can be recognized superficially by a hind wing with the postmedial line either parallel with the termen or oblique and straight to behind CuA1, in the male by the modified antenna and in some species by modified, broad scales along the posterior margin of the forewing. In the male genitalia the combination of a narrowly triangular uncus usually with anteriorly directed lateral setae, a finger- to club-shaped editum, a sacculus with a dorsal process, and presence of an anellus are diagnostic for Thliptoceras . The female genitalia are characterized by a sclerotized tubular antrum.

Thliptoceras is superficially similar to Circobotys Butler, 1879 , but can be distinguished by the modified antenna with sinus and scale-tuft or scale-tooth, the minute outer mid-spur on the hind tibia, a finger-shaped editum, absence of sella and presence of anellus in the male, and a tubular antrum in the female. Thliptoceras is definitely close to Toxobotys , as Munroe and Mutuura mentioned (1968), based on similar wing pattern and valva shape. The two genera also share a modified antenna and a hind tibia with outer mid-spur minute in the male, a finger-shaped editum, a process to the sacculus and a sclerotized tubular antrum. However, Toxobotys can be distinguished by an uncus with a distal appendix and a vinculum with a long dorsal process. The sclerotized transverse ridges posterior to the ostium in the female could be another apomorphy for Toxobotys .

DescrIptIon. Head. Frons flat and oblique, seldom conically projecting. Labial palpus sinuate, obliquely upturned, exceeding frons by about length of head or a little less, third segment porrect. Maxillary palpus filiform. Antenna modified at base in male (except in T. gladialis ), usually with sinus and scale-tuft or scale-tooth. Thorax. Hind tibia with inner mid-spur longer than other inner spurs and outer mid-spur minute in male, other outer spurs about 1/3–1/2 of inner. Forewing in males sometimes with frenulum hook extending posterodistad from behind costa (subcostal frenulum hook). Wing venation. Forewing cell about half length of wing; R1 from 2/3 to 4/5 of anterior margin of cell; R3 and R4 stalked at about 3/5–2/3 of distance from cell to apex; discocellulars curved; M1 much closer to R5 at base than to M2; CuA2 from 3/5–2/3 of posterior margin of cell; 2A sometimes absent. Hindwing with cell 1/3 length of wing; Sc+R1 and Rs anastomosed for 1/3– over 1/2 of Rs; CuA2 from 3/5–3/4 of posterior margin of cell. Abdomen. Posterior margin of 7th sternite bordered by modified scales. Male genitalia. Uncus slender and long, narrowly triangular or inverted T-shaped, usually with anteriorly directed setae along margin and dorsal surface. Valva narrow and long, costa usually with excavation and apex with spine; editum arising from base or middle of valva, curved, finger- to club-shaped, with apex sparsely setose; sella absent; sacculus inflated, with dorsal process submedially, sometimes with a process distally. Anellus usually developed. Aedeagus cylindrical, usually with spine-shaped cornuti. Female genitalia. Ovipositor lobes flat, densely setose. Anterior apophyses longer, posterior apophyses short. Antrum widened and sclerotized, tubular, with ductus seminalis arising from close to its anterior end. Ductus bursae long, parallel-sided and usually more or less spiraled, usually membraneous. Corpus bursae with accessory bursae, signum rhomboid, sometimes bipartite and irregular.

DIstrIbutIon. Thliptoceras occurs in China, Japan, India, Myanmar, Thailand, Sri Lanka, Sumatra, Java, Borneo, Sulawesi, Africa and Costa Rica. In China, the majority of species occurs in the south.

BIology. All Chinese material of Thliptoceras has been collected at light and host information is not available. However, Bänziger (1987) observed mostly males of 5 species of Thliptoceras sucking lachrymal and other body fluids from animals or humans: T. cascale (Swinhoe) sucking at the eye of a sambar deer ( Cervus unicolor Kerr ) and flying around an Indian elephant ( Elephas maximus L.); T. anthropophilum Bänziger sucking perspiration of humans and lachrymal fluid of Indian elephants; T. umoremsugente Bänziger sucking perspiration of a human and lachrymal fluid and blood droplets expelled by mosquitoes on elephant and buffalo; T. lacriphagum Bänziger sucking lachrymal fluid of a zebu ( Bos indicus L.) and elephant’s skin secretions; T. shafferi Bänziger sucking perspiration of a human.

Remarks. Based on external structures, the species of Thliptoceras in the Oriental region of China are divided into three species groups: T. artatalis ( Caradja, 1925) , T. formosanum Munroe & Mutuura, 1968 , T. gladialis ( Leech, 1889) and T. bicuspidatum sp. nov. as the artatalis group; T. caradjai Munroe & Mutuura, 1968 , T. semicirculare sp. nov., T. bisulciforme sp. nov. and T. fulvimargo ( Warren, 1895) as the caradjai group; T. anthropophilum Bänziger, 1987 , T. shafferi Bänziger, 1987 , T. sinense ( Caradja, 1925) , T. filamentosum sp. nov. and T. impube sp. nov. as the sinense group. Diagnoses for the three groups are given below.

Sexual dimorphism is prominent in Thliptoceras and is expressed in antennal structure, wing shape and colour, wing venation and modified scales on male forewing, as well as in the size of the hind tibial mid-spur. All species in the Oriental region of China except T. gladialis have a modified antennal base. In the hind tibia of males the inner mid-spur is longer than the other inner spurs and the outer mid-spur is minute. Males of the artatalis group have narrowly elongate forewings with an acute apex and a strongly oblique termen. Males of the sinense group have modified scales along the posterior margin of the forewing obliquely extending forward, corresponding with a close approximation of 1A to CuA2 at the wing margin. In T. gladialis and T. bisulciforme sp. nov. the female is in general paler than the male.

Wing shape and venation are usually very uniform at the generic level in the subfamily Pyraustinae. But in Thliptoceras , there is a substantial range of variation in both wing shape and venation (Figs. 3–14). In males of the artatalis group the forewings are narrowly elongate, with a strongly oblique termen and an acute apex, and the hindwings are nearly triangular. Both sexes of T. caradjai and T. semicirculare sp. nov. have the forewing costa arched and the termen obliquely rounded. All other species have the forewing costa straight and the termen oblique, and the hindwing oblong.

Variation of forewing venation is restricted to the course of CuA2, 1A and 2A. In the males of the sinense group vein 1A is closely approximated to CuA2 at the wing margin, and 2A is absent in these species in both sexes. In the artatalis and the caradjai groups 1A and 2A usually form a loop, with both ends of 2A fused with 1A in T. gladialis and T. bicuspidatum sp. nov. but 2A reduced in T. artatalis , T. fulvimargo and T. caradjai .