Chilelimnophila (Chilelimnophila) parva Krzemiński, Kania-Kłosok, 2024

Krzemiński, Wiesław, Kania-Kłosok, Iwona, Arillo, Antonio, Kopeć, Katarzyna, Santos, Daubian & Soszyńska, Agnieszka, 2024, The evolutionary history and biogeographical distribution of the Mesozoic relic genus Chilelimnophila (Diptera, Limoniidae), Zoological Journal of the Linnean Society 202 (1), pp. 1-16 : 7

Chilelimnophila (Chilelimnophila) parva Krzemiński, Kania-Kłosok et Arillo, sp. nov.

( Fig. 4A–E )

Zoobank registration: urn:lsid:zoobank.org:act:8B72FF8DEA83-4A2F-9085-7F5892A658BD

Diagnosis: Tip of vein R 1 approximately at fork of R 2 + 3+4; sc-r situated before tip of Sc, approximately two times the distance from the tip of Sc; gonocoxite very elongate, approximately 4× as long as wide, widened in 0.3× of its length and folded to the internal part of hypopygium; outer gonostylus narrow, slightly sclerotized, elongate, longer than half the length of gonocoxite, slightly curved to the internal part of hypopygium; inner gonostylus short and massive, round at apex, shorter than half the length of outer gonostylus, slightly curved to the internal part of hypopygium.

Material examined: Holotype No. MP/4509 (male), coll. Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland (ISEA PAS). Specimen well preserved.

Horizon and locality: Lowermost Cenomanian, Hukawng Valley , northern Myanmar. The mining is done at a hill named Noije Bum, near Tanai Village (26° 21′ 33.41′′ N, 96° 43′ 11.88′′ E) .

Description: Body ( Fig. 4B ) 2.56 mm long, brown, wings without colour pattern, pterostigma absent.

Head: Antenna ( Fig. 4A ) 1.03 mm long, longer than head, longer than palpus; scape cylindrical, slightly elongate, comparative length to pedicel; approximately 2× as long as wide, pedicel ovoid, constricted at base, first flagellomere fused with second and third; flagellomeres 4–16 elongate, tiny, approximately 2–3× as long as wide, become more slender to the apex of antenna, first flagellomere as long as wide, second and third flagellomeres rather short, fused with the first one; last flagellomere as long as penultimate one; each flagellomeres with two elongate setae, longer than segments bearing them; maxillary palpus foursegmented, short, 0.2× the length of antenna, 0.24 mm long, palpomeres rather ovoid, short, only slightly longer than wide, third palpomere comparable length to the second, all palpomeres slightly widened in the mid length; all palpomeres with few not very elongate setae, as long or shorter than segments bearing them.

Thorax ( Fig. 4B ): Almost as long as high; wing 3.40 mm long, 1.13 mm wide ( Fig. 4B, E ); h vein situated between the base of wing and fork of Mb and Cu; Sc ending on C before the level of bifurcation of Rs and tip of A 1; sc-r situated at approximately two of its length from the tip of Sc; Rs slightly curved, originating well proximally to the level of the tip of A 2, only slightly longer than R 2 + 3+4, R 1 reach 0.25× the length of petiole; fork of R 2 + 3+4 situated just beyond the level of d-cell, R 3 approximately 0.6× the length of R 4; R 4 longer than R 2 + 3+4, longer than Rs; section of R 5 between its origin and point of contact with crossvein r-m almost straight; vein M 3 almost straight, approximately 2× the length of d-cell; d-cell 2× as long as wide; crossvein m-cu shorter than d-cell; A 1 almost straight, tip of A 1 situated beyond fork of Mb; A 2 slightly curved; tip of A 2 just before the level of m-cu, just before the level of fork of Mb, beyond the level of fork of Rb; haltere: stem narrow, elongate, slightly longer than knob.

Abdomen: Male terminalia ( Fig. 4D )—hypopygium 0.53 mm long, elongate and narrow, gonocoxite approximately 4× as long as wide, tip of gonocoxite and outer gonostylus slightly sclerotized, brown, outer gonostylus narrow, pointed, slightly curved to internal part of hypopygium, inner gonostylus rather slender but lobe-shaped.

Etymology: The specific name is derived from ‘ parva ’ (Latin)—small.

Comparison: The main differences between Recent and Cretaceous species of Chilelimnophila are the morphology of the hypopygium ( Figs 2–4 ) and wing venation ( Fig. 5 ). In these newly described Cretaceous species, the gonocoxite is narrow and elongate, in C. (R.) amorimi subgen. et sp. nov. and C. (C.) wangi sp. nov. the coxite is approximately 3× as long as wide, in C. (C.) parva sp. nov. it is approximately 4× as long as wide, while in C. (C.) lyra the gonocoxite is massive and wide, but relatively shorter, at most 2× as long as wide. In C. (R.) amorimi subgen. et sp. nov. the tip of the gonocoxite and outer gonostylus are strongly sclerotized, almost black, while in C. (C.) lyra they are only slightly sclerotized and pale. In C. (C.) parva sp. nov. the gonocoxite is folded inwards in 0.3× of its length, the outer gonostylus is longer than half the length of the gonocoxite, the inner gonostylus is rounded at its apex, and shorter than half the length of outer gonostylus. In comparison, in C. (C.) wangi sp. nov. the outer gonostylus is shorter than half the length of the gonocoxite, the inner gonostylus is sharpened at the apex, longer than half the length of the outer gonostylus. Moreover, in C. (C.) lyra vein Sc ends on C at the level of bifurcation of Rs and tip of A 1 while in C. (R.) amorimi subgen. et sp. nov. it ends before, and in C. (C.) wangi sp. nov it ends at the level of bifurcation of Rs and before the level of tip of A 1. In C. (R.) amorimi subgen. et sp. nov. and C. (C.) wangi sp. nov. the tip of A 1 is positioned even beyond half the level of the d-cell, while in C. (C.) lyra the tip ends before its level. Position of sc-r in these three species is different also, in Cretaceous species C. (R.) amorimi subgen. et sp. nov. and C. (C.) wangi sp. nov. crossvein sc-r is situated far before the tip of Sc and before half the length of Rs, while in C. (C.) lyra even if the position of sc-r is variable, this vein occurs more or less near the tip of Sc and the fork of Rs. Rs in C. (C.) lyra is elongate, while in Cretaceous species it is rather short. Crossvein m-cu in C. (C.) lyra is situated distinctly beyond half the length of the d-cell, while in newly described species m-cu occurs before half the length of the d-cell. In addition, M 1 and M 2 are quite short in C. (C.) lyra in relation to the length of its petiole, the petiole is approximately 3× longer than M 1 or M 2, in C. (R.) amorimi subgen. et sp. nov. Cell M 1 is longer than its petiole, while the petiole and M 2 are of comparable length. In C. (C.) lyra the basal section of R 5 between its origin and point of contact with r-m is curved, in C. (R.) amorimi subgen. et sp. nov. this is straight and perpendicular to fork of Rs, while in C. (C.) wangi sp. nov. the basal section of R 5 is slightly curved and shifted to the apex of wing, but not so far as in C. (C.) lyra .

Figures

Figure 2. Chilelimnophila (R.) amorimi subgen. et sp. nov. (Limoniidae), inclusions in Spanish amber, holotype No. MCNA 9845 (male). A, body, latero-frontal view, drawing A. Arillo; B, body, latero-frontal view. C, antenna.D, palpus. E, part of hypopygium: gonocoxite and gonostyle; F.wing venation. Abbreviations: gx, gonocoxite; ing, inner gonostylus; oug, outer gonostylus; scp, scape; ped, pedicel; I–IV, palpomeres 1–4.

Figure 3. Chilelimnophila (C.) wangi sp. nov. (Limoniidae), inclusions in Kachin amber, holotype No. MP/4449 (male). A, antenna. B, palpus. C, part of hypopygium: gonocoxite and gonostyle. D, body, lateral view. E, wing venation.Abbreviations:gx, gonocoxite; ing, inner gonostylus; oug, outer gonostylus; scp, scape; ped, pedicel; I–IV, palpomeres 1–4.

Figure 4. Chilelimnophila (C.) parva sp. nov. (Limoniidae), inclusions in Kachin amber, holotype No. MP/4509 (male). A, antenna. B, body, latero-dorsal view.C, head, ventral view. D, hypopygium, dorsal view. E, wing venation. Abbreviations: gx, gonocoxite; ing, inner gonostylus; oug, outer gonostylus; scp, scape; ped, pedicel; I–IV, palpomeres 1–4.

Figure 5. Comparison of wing venation of recent and fossil species of Chilelimnophila. A–D, comparison of the position of fork M1 + 2 on M1 and M2. E–H, position of fork of Rs and basal section of R5 vein. I–L, position of cross-vein sc-r.A, E, I, Chilelimnophila (C.) lyra. B, F, J, Chilelimnophila (C.) wangi sp. nov. C, G, K, Chilelimnophila (R.) amorimi sp. nov. D, H, L, Chilelimnophila (C.) parva sp. nov. M, wing venation of fossil and recent species of Chilelimnophila and Zelandomyia.