Claustropyga alveata, Vilkamaa, 2024

Vilkamaa, Pekka, 2024, Description of two new species of Claustropyga Hippa, Vilkamaa & Mohrig (Diptera, Sciaridae) from the northern Palaearctic, Zootaxa 5463 (1), pp. 137-144 : 138-141

Claustropyga alveata sp. n.

Figs 1–3 , 4 A

Holotype male. FINLAND, Le (Lapponia enontekiensis), Enontekiö, Annjaloanji (Grid 76860:2806), 11–15. VII.2007, 1 male, R. Jussila ( MZH) . Paratype. NORWAY, FN Båtsfjord, Komagdalen , Bajit, Suovka, Malaise trap, 14.VII–21.VIII.2009, T . E. Barstad, 1 male (Sample ID: TSZD-JKJ-103800; TMU) .

Male. Head. Face and antenna concolorous brown, maxillary palpus pale brown. Eye bridge 2 facets wide. Face with 6 scattered strong setae. Clypeus with 1 seta. Maxillary palpus with 3 segments; 1 st segment longer than 2 nd segment, 3 rd segment shortest; 1 st segment with 1 sharp seta, with a large dorsal patch of sensilla. Body of 4 th antennal flagellomere 1.65x as long as wide, the neck shorter than wide, the longest setae as long as the width of flagellomere. Thorax. Brown, setae dark. Scutum with some long and strong laterals and long dorsocentrals. Scutellum with 2–6 long and strong setae and with some short setae. Anterior pronotum with 1–5 setae. Proepisternum with 3–4 setae. Wing. Length 2.1 mm. Width/length 0.45. R 1 /R 0.65–0.95. stM longer or shorter than fork of M. bM longer than r-m. bM non-setose, r-m non-setose or with 3 dorsal setae. Halter pale brown. Legs. Fore coxa yellow, mid- and hind coxae pale brown, coxal setae dark. Fore tibial organ with indistinct patch of few strong setae. Fore tibial spur slightly longer than tibial width. Abdomen. Pale brown, setae long and strong. Hypopygium ( Fig. 1 ). Pale brown, as abdomen. Tergite IX long and wide, nearly covering cerci dorsally. Intergonocoxal area lobe-like produced with roundish medial notch; gonocoxa much longer than gonostylus, with moderately long setosity; with apicoventral elongated seta rather short, gonocoxal apodemes strongly sclerotized, with hook-formed basal extensions; extended caudad forming a V-shaped structure with its closed end pointing caudad ( Fig. 3 C ). Gonostylus ( Figs 2 A , 4 A ) roundish, with short setosity; strongly excavated medially; with straight dorsomedial margin, excavation with central ridge on which 1 megaseta very close to apical tooth and 1 megaseta at middle position; with 1 subapical megaseta at ventral margin; with small pyramidal apical tooth. Tegmen ( Figs 1 A , 3 A, B ) long, constricted subapically, weakly sclerotized laterally; apical part unsclerotized; with divergent ventromedial sclerotizations extended from middle to apical part; with strongly sclerotized V-formed apodeme; with small area of tiny needle-like aedeagal teeth. Aedeagal apodeme strong.

Female. Unknown.

DNA. Barcode COI, BIN BOLD ADL3758. Deposited in The Barcode of Life Data System (BOLD) ( Rathasingham & Hebert 2007)

Discussion. Claustopyga alveata sp. n. has unusual, strongly sclerotized, vertically superimposed structures on the medial part of the hypopygium ( Fig. 3 A–C ); dorsally the V-shaped gonocoxal apodeme is extended caudally, ventral to this the apodeme of the tegmen is also V-shaped, and at the ventralmost position, two rod-like medial sclerotizations of the tegmen extend from the basal part to the apical part of the tegmen. Whether these ventral rods are united into the apodeme of tegmen, is not detectable in the preparations. Usually in Sciaridae , the apodeme of tegmen, mediad of the usually strongly sclerotized lateral parts (which are usually called ‘apodemes of tegmen’), is a transverse or apically smoothly curved variably sclerotized bridge. In general, the basal part of the gonocoxal apodeme consists of a transverse ‘bridge’ uniting the left and right apodemes, with simple longer or shorter proximally orientated rods, not the hook-like structures present in Claustropyga alveata . The combination of sclerotized structures in the hypopygium of this species is unique among Sciaridae .

By its subapically constricted tegmen, Claustopyga alveata resembles only C. stupenda Hippa & Vilkamaa, 2016 , but the latter has two very long basal megasetae on its gonostylus instead of one short one and lacks the characteristic medial sclerotizations of C. alveata in its hypopygium. Moreover, the gonostylus of C. alveata is much smaller. In its small, globular gonostylus with a very small apical tooth, Claustropyga alveata differs from all other species of the genus. Claustropyga alveata has a long and unusually wide tergite IX, in dorsal aspect nearly covering the cerci ( Fig. 1 B ). The length of tergite IX is variable amongst Sciaridae genera and amongst species of Claustropyga , with C. caetrata sp. n, C. abblanda ( Freeman, 1983) , C. clavulata Hippa & Vilkamaa, 2016 , C. subcorticis ( Mohrig & Krivosheina, 1985) and C. tumida Hippa, Vilkamaa & Mohrig, 2003 having a long tergite IX.

Etymology. The name is a Latin adjective, alveata , hollowed, referring to the roundish, deeply excavated gonostylus.

Figures

FIGURE 1. Claustropyga alveata sp. n. (A holotype, B paratype). A. Hypopygium, ventral. B. Hypopygium, dorsal. Scale 0.1 mm.

FIGURE 2. Claustropyga alveata sp. n. (holotype). A. Gonostylus, dorsal. B. Apical part of fore tibia, prolateral. Scale for A 0.1 mm, for B 0.05 mm.

FIGURE 3. Claustropyga alveata sp. n. (paratype). Medial structures of hypopygium, ventral. A. Focus on ventral portion of tegmen. B. Focus on dorsal portion of tegmen. C. Focus on apodeme of gonocoxa. Scale 0.1 mm.

FIGURE 4. Gonostylus, ventral. A. Claustropyga alveata sp. n. (holotype). B. C. caetrata (holotype). Scale 0.1 mm.