Leptoconops, Skuse, 1889

BORKENT, ART, 2001, Leptoconops (Diptera: Ceratopogonidae), the Earliest Extant Lineage of Biting Midge, Discovered in 120 - 122 Million-Year-Old Lebanese Amber, American Museum Novitates 3328, pp. 1-12 : 2-3

LEPTOCONOPS Skuse

Leptoconops Skuse, 1889: 288 . Type­species, Leptoconops stygius Skuse , by monotypy.

DIAGNOSIS AND DESCRIPTION OF ADULTS: As given by Borkent (1995), Clastrier and Wirth (1978), Smee (1966), Szadziewski (1988: 232), and Wirth and Atchley (1973). In addition: females with 10–13 flagellomeres.

Borkent (1995, 2000) and Wirth and Atchley (1973) provided an overview of the distribution, biology and fossil record of the genus. Borkent and Wirth (1997) cataloged 127 extant and 6 extinct species of Leptoconops ; since then a further 7 extant and 3 extinct species (including those newly named here) have been recognized.

Eight fossil species of Leptoconops are now known from the Cretaceous and they may be recognized using the following keys, which are based in part on earlier keys by Borkent (1996) and Szadziewski (1996). A tentatively identified and unnamed male Leptoconops known as a compression fossil from the Lower Cretaceous in Australia is not keyed. Neither is the unnamed female Leptoconops from Upper Cretaceous French amber briefly described by Schlüter (1978).

KEY TO CRETACEOUS MALE LEPTOCONOPS

The males of L. antiquus from Lebanese amber and L. boreus Kalugina from Taimyr amber are unknown.

1. Gonostylus with medial lobe at midlength and subapical, pointed projection about one­third from apex............................... sibiricus Szadziewski (Taimyr amber)

– Gonostylus a single, undivided structure.... .................................. 2

2. Wing with costa well­developed beyond apex of R 3; first tarsomere of hindleg with many (about 10 or more) thick spines (fig. 1B)..... amplificatus , n. sp. (Lebanese amber)

– Wing with costa terminating at apex of R3; first tarsomere of hindleg with no more than 6 thick spines...................... 3

3. Apicolateral process on tergite 9 thick and slightly enlarged apically..................... clava Borkent (Hungarian amber) – Apicolateral process on tergite 9 slender and elongate, tapering to apex............ 4

4. Terminal flagellomere about 2–3 times as long as penultimate flagellomere............... copiosus Borkent (New Jersey amber)

– Terminal flagellomere about 5–6 times as long as penultimate flagellomere........... 5

5. Gonocoxite relatively short and stout........ curvachelus Borkent (New Jersey amber)

– Gonocoxite relatively elongate and slender....... primaevus Borkent (Canadian amber)

KEY TO CRETACEOUS FEMALE LEPTOCONOPS

The female of L. clava Borkent from Hungarian amber is unknown.

1. Antenna with 13 flagellomeres (figs. 1H, 2C)................................. 2

– Antenna with 12 flagellomeres.......... 3

2. First tarsomere of hindleg with more than 15 thick spines (fig. 1I); cercus long and slender (fig. 2A)................................ amplificatus , n. sp. (Lebanese amber)

– First tarsomere of hindleg with a few (about 4–5) thick spines; cercus relatively short and well­developed anteroventrally (fig. 2G)........... antiquus , n. sp. (Lebanese amber)

3. Tarsal claws strongly curved basally, with thick, well­developed inner tooth......... curvachelus Borkent (New Jersey amber), sibiricus Szadziewski (Taimyr amber)

– Tarsal claws more or less evenly curved from base, with at most a very slender, hairlike inner tooth........................ 4

4. Flagellomeres 3–11 somewhat elongate........ primaevus Borkent (Canadian amber)

– Flagellomeres 3–11 spherical.. copiosus Borkent (New Jersey amber), boreus Kalugina (Taimyr amber)