Paraleucopidae Wheeler

Wheeler, Terry A. & Sinclair, Bradley J., 2019, Systematics of Paraleucopis Malloch with proposal of Paraleucopidae, a new family of acalyptrate Diptera, Zootaxa 4668 (3), pp. 301-328 : 302-303

publication ID	https://doi.org/ 10.11646/zootaxa.4668.3.1
publication LSID	lsid:zoobank.org:pub:804E2985-0444-4C04-B5F9-02D7B196E990
persistent identifier	https://treatment.plazi.org/id/FD3487D1-A55F-C741-FF47-F965FAECF854
treatment provided by	Plazi
scientific name	Paraleucopidae Wheeler
status

Treatment

Paraleucopidae Wheeler View in CoL View at ENA fam. nov.

urn:lsid:zoobank.org:act:6C5CDF47-77C9-4B5F-AF2B-FC3545D64B7C

Paraleucopidae View in CoL : Brown et al., 2009: 52 (nomen nudum); Buck et al., 2009: 131 (nomen nudum); Borkent & Rotheray, 2009: 157 (nomen nudum); Wheeler, 2010: 1009 (nomen nudum); Marshall, 2012: 359 (nomen nudum); Máca & Otranto, 2014: 3 (nomen nudum); Brooks et al., 2015: 51 (nomen nudum); Amorim et al., 2018: 24 (nomen nudum).

Type genus: Paraleucopis Malloch (by present designation).

Other included genera: Mallochianamyia Santos-Neto , Schizostomyia Malloch.

Diagnosis. Clypeus prominent and protuberant; face with vertical median sulcus; postocellar bristles absent; vibrissa absent or weakly developed; subcostal vein complete or incomplete; costa extending to M 1; cells dm and bm separate; cell cua present; male postabdomen asymmetrical; male spiracle 7 absent; female postabdomen very narrow, mostly membranous and rugose with long, slender cerci.

Description. Diptera, Schizophora. Small , compact, dark, shiny metallic flies. Head with inner and outer vertical bristles strong, other cephalic setae often reduced or absent; postocellar bristles absent; proclinate interfrontal setulae evenly distributed over frons; frons broad, striate, ocelli present; lunule broad, bare; face broad, sclerotized with vertical median sulcus; vibrissa absent or weakly developed; antenna porrect with dorsal arista, scape and pedicel short, postpedicel round; eye bare or short haired; clypeus prominent and protuberant, palpus present, short, prementum narrow, usually short, labellum short, fleshy.

Prosternum trapezoidal, precoxal bridge absent; scutal bristles few, variable; scutal setulae dense, not differentiated into acrostichal, dorsocentral, or intra-alar rows; scutellum with 2 pairs of marginal bristles; subscutellum convex; thoracic pleurites mostly bare, katepisternal bristle present. Legs without outstanding setae except for posterior and posteroventral setae on fore femur and apicoventral bristle on mid tibia; hind femur occasionally with preapical anteroventral setae. Wing well-developed, clear; costa extending to apex of M 1, subcostal break present as weakening, distinct only at high magnification; Sc complete or incomplete distally, not fused with R 1; R 1 short, R 2+3, R 4+5, M 1 and M 4 long; crossveins r-m, bm-m and dm-m present, cell cua complete, anal vein (CuA+CuP) usually long.

Abdomen oval, tergites 1–5 broad, sternites 1–5 narrow, sternite 1 large, sternite 2 transversely divided into narrow anterior and broad posterior regions. Spiracles 1–6 present in both sexes.

Male postabdomen asymmetrical; tergite 6 present, variable; sternite 6 ventral or lateral, asymmetrical (symmetrical in Schizostomyia ); spiracles of segment 6 variable in location; tergite 7 present, small (absent in Schizostomyia ); sternite 7 asymmetrical, shifted to left side; spiracles of segment 7 absent; tergite 8 absent; sternite 8 dorsal; epandrium simple, small, offset to right side of midline at rest; hypandrium U-shaped; surstylus freely articulated or fused with epandrium; subepandrial sclerite (bacilliform sclerite) well-developed, connecting surstyli to hypandrial arms anteriorly, and to each other across midline; phallapodeme short, phallic guide present; pregonite and postgonite present, variable; basiphallus short, round; distiphallus tubular, membranous; ejaculatory apodeme long, curved (reduced in Paraleucopis ); cerci distinct, weakly sclerotized, setulose, located in ventral part of anal membrane.

Female postabdomen telescopic posterior to segment 5, narrow, mostly membranous and rugose ( Fig. 10 View FIGURES 8–10 ); tergite 6 well sclerotized, variable in shape; sternite 6 usually distinct sclerite (reduced in Paraleucopis ); spiracle 6 in lateral region of segment 6, spiracle 7 absent; tergite 7 reduced to indistinct median sclerite and group of posterior setae; sternite 7, tergite 8 and sternite 8 reduced to posterior setae; tergite 10 triangular, setose; sternite 10 rounded, setose; cerci long, narrow, setose; spermathecae 2 or 3, variable in shape and degree of sclerotization; ventral receptacle present, unsclerotized.

Remarks. The Paraleucopidae are defined and recognized by the following suite of characters (possible synapomorphies marked with “*”): antennae widely separated; clypeus prominent and protuberant* ( Fig. 18 View FIGURES 15–18 ); face with vertical median sulcus* ( Fig. 11 View FIGURES 11–14 ); frons broad, parallel-sided with proclinate interfrontal setulae; postocellar bristles absent; vibrissa absent or weakly developed; subcostal vein complete or incomplete; basal cells separate and complete; cell cua present; subcostal break present as weakening; vibrissa absent or weakly developed; tergites 1 and 2 separate, male postabdomen asymmetrical; male spiracle 7 absent; female postabdomen very narrow, mostly membranous and rugose* ( Fig. 10 View FIGURES 8–10 ); female cerci long, slender* ( Fig. 10 View FIGURES 8–10 ); 2–3 spermathecae.

Biology. Details on biology are only available for adults of species of Paraleucopis , which have been recorded as swarming persistently around humans, seabirds and other vertebrates, often in great numbers ( Smith 1981). Paraleucopis mexicana Steyskal is locally referred to as “bobos” and can be extremely annoying, crawling over skin, hair and face. At the type locality of Kino Bay, Mexico the extreme numbers and annoying behaviour during the flies’ peak periods has a significant impact on tourism in this region ( Smith 1981). The flies appear to be attracted to the eyes and superficial wounds, but do not bite ( Figs 1, 2 View FIGURES 1–2 ) ( Smith 1981; Marshall 2012). In this habit Paraleucopis closely resembles some genera of oscinelline Chloropidae . It is not known whether any species of Paraleucopidae act as disease vectors. Adults of Paraleucopis species have also been collected hovering at cactus flowers ( Cactaceae ) (K.N. Barber, pers. comm.). Specimens of two Nearctic species of Paraleucopis have been reared from birds’ nests ( Malloch 1913; Wheeler 1959; Smith 1981) indicating that it may be a preferred habitat for the larvae. Immature stages of the family have not been described, although rearing records suggest that they are saprophagous.