Empis (Enoplempis) geneatis (Melander)

Sinclair, Bradley J., Brooks, Scott E. & Cumming, Jeffrey M., 2025, Revision of the western Nearctic species of Empis subgenus Enoplempis (Diptera: Empididae), Zootaxa 5615 (1), pp. 1-200 : 91-93

Empis (Enoplempis) geneatis (Melander)

( Figs 12, 13 , 181, 182 , 185 , 192 )

Empimorpha geneatis Melander, 1902: 329 . Type locality: California ( USA).

Empimorpha geneatis : Melander, 1928: 179 (checklist); Kessel & Karabinos, 1947: 181 (behaviour); Kessel, 1955: 101 (behaviour).

E. (Empidomorpha) [sic] geneatis : Cumming (1994) (behaviour).

Empis geneatis : Melander, 1965: 459 (catalogue); Yang et al., 2007: 134 (catalogue).

E. (Enoplempis) geneatis : Turner, 2012: 26 (phylogeny).

Type material examined. HOLOTYPE ♂, labelled: “Calif./ Baron”; “ W.M. Wheeler,/ collection.”; “ TYPE / No./ A.M.N.H. [red label]; “ Am. Mus . Nat. Hist./ Dept. Invert. Zool./ No. 919”; “ HOLOTYPE / Empimorpha ♂ / (= Empis )/ geneatis/ Melander/ teste WJ Turner ’82 [red label]” [dissected] ( AMNH).

Additional material examined. USA. California: Alameda County: Patterson Res. Del Valle Lk. [37°35′N 121°43′W], 15.iii.1973, JAP (1♂ with Sciaridae prey on balloon, EMEC); Redwood Pk E Oakland [37°48′N 122°09′W], 22.iv.1956, Ceanothus, M. Wasbauer (1♀, EMEC). Contra Costa County: Briones Reg. Pk [37.9358°N 122.1374°W], Alhambra Tr. on Ridge, 23.iii.1978, DDW (3♂ with Chalcidoidea and Sciaridae prey on balloons, CAS); same data except, 4.iv.1979 (5♂ with Chalcidoidea and 2♂ with Sciaridae prey on balloons, CAS); Briones Reg. Pk, at Alhambra Valley Rd, 29.iii.1978, DDW (1♂ with Chalcidoidea prey on balloon, CAS). Kern County: Kern Cyn [35°41′N 118°40′W], 2300 ft, 22.v.1967, C. Goodpasture (3♂, LACM). Lake County: Anderson Springs [38°46′N 122°41′W], 25.ii.1951, W. R. Bauer (2♂, CAS). Madera County: San Joaquin Exp. Sta. [37°05′N 119°43′W], 22.ii.1953, P.D. Hurd (1♂, EMEC). Marin County: Carson Ridge [38°00′N 122°38′W], 15.iii.1968, JAP (2♂ with Chalcidoidea and Sciaridae prey on balloons, EMEC); same data except, nr Woodacre, 7.iv.1966 (2♂ with Chalcidoidea and Sciaridae prey on balloons, EMEC); Inverness [38°06′N 122°51′W], 13.ii–6.iii.1964, PHA (1♂ with Chalcidoidea prey on balloon, 1♂, USNM); Mill Valley [37°54′N 122°32′W], 16.iii.1946, E.L. Kessel (1♂ with Sciaridae prey on balloon, AMNH; 2♂ with Chalcidoidea and unknown prey on balloons, USNM); same data except, 15.iii.1946 (1♂, 1♀ mounted as pair, 3♂, CAS; 1♂, USNM); same data except, 17.iii.1946 (1♂, CAS); same data except, 29.iii.1946 (1♂, CAS); same data except, 2.iv.1946 (1♂, CAS; 2♂, USNM); same data except, 4.iv.1946 (2♂, CAS); same data except, 22.ii.1947 (2♂, AMNH); same data except, 24.ii.1947 (3♂, CAS); same data except, 25.ii.1947 (1♂, CAS); same data except, 20.iii.1948 (2♂ with?Cynipoidea and? Sciaridae prey on balloons, CAS; 1♂ with Chalcidoidea prey on balloon, USNM); same data except, 21.iii.1948 (1♂ with? Ceratopogonidae prey on balloon, CAS); same data except, 27.iii.1948 (2♂ with Chalcidoidea prey on balloons, CAS); same data except, 7.iii.1926, M.C. Van Duzee (1♂, CAS); same data except, flight trap, 7–11.iii.1966, PHA (4♂, USNM); Phoenix Lk. [37°57′N 122°34′W], 4.iv.1964, C.N. Slobodchikoff (1♂, CAS). Mendocino County: UC Hopland Field Sta. [39°00ʹN 123°05ʹW], Lookout Pt., 2880 ft, 2.v.1969, WJT (4♂ with? Sciaridae prey on balloons, 2♂, WSU); same data except, Coon Lk., 1900 ft, 26.iv.1975, JAP (1♂ with? Sciaridae prey on balloon, EMEC); same data except, M. Bales (1♀, EMEC); same data except, M. Buegler (1♂ with? Sciaridae prey on balloon, EMEC). Monterey County: Carmel [36°33′N 121°55′W], 25.iii.1919, E.P. Van Duzee (2♂, CAS). Napa County: N side Howell Mt [38°34′N 122°27′W], 2 mi. NNE Angwin, 1300 ft, 6.iii.1978, H.B. Leech (4♂ with Cecidomyiidae, Chalcidoidea and Sciaridae prey on balloons, CAS); same data except, 14.iii.1975 (1♀, CAS). Solano County: Cold Cyn Res. [38°30′N 122°5′W], 9.v.1983, J.L. Stebbins (1♂, UCDC).

Diagnosis. This species is distinguished from other species of the E. (En.) geneatis species group by males with long, dark facial setae, in addition to similar long black setae on the palpus and scape ( Fig. 181 ), and the male cercus is broader than the epandrium, prolonged dorsally.

Redescription. Wing length 4.3–5.2 mm. Male. Head dark in ground-colour, with greyish pruinescence. Holoptic, eye with upper ommatidia enlarged. Frons small, triangular, without setulae. Face with long, black setae, longer than scape and pedicel combined ( Fig. 181 ). Ocellar triangle elevated, dark, subshiny, with pair of thin ocellar setae, similar in size and length to occipital and facial setae; pair of similar posterior setulae. Occiput bearing long, wavy black setae on lateral and ventral surfaces, similar to facial setae; postocular setae not differentiated; upper posterior surface with few setae. Antenna dark; scape 3× longer than pedicel, with long, wavy black setae, longer than segment; pedicel with thin wavy setae, 1.5× length of segment; postpedicel longer and tapered, more than 5× longer than basal width; stylus slightly longer than basal width of postpedicel. Palpus black, with elongate, wavy black setae, similar to facial setae, similar in length to palpus. Proboscis largely dark; length of proboscis 1.5× to more than twice head height; apex of labrum reddish brown; labellum with short, dark setae.

Thorax dark brown in ground-colour, densely grey pruinescent ( Fig. 181 ). Scutum with pair of distinct greyish vittae between acr and dc rows (viewed anteriorly); clothed in long silky setulae, except vittae and prescutellar depression bare. Proepisternum with long, wavy dark setae on lower section; upper proepisternum in front of spiracle with similar, shorter setae. Prosternum bare. Antepronotum with row of dark setae, longer laterally. Postpronotum with 1 long seta and numerous long, silky setae. Scutum with multi-serial acr setae, increasing in length posteriorly; dc similar to acr, increasing in length posteriorly; 1 posterior npl; presut spal undifferentiated; psut spal undifferentiated; 1 pal. Scutellum with pair of long sctl, with several pairs of marginal setae; disc bare. Laterotergite with numerous long, dark setae. Anterior and posterior spiracles brown.

Legs long, entirely dark brown ( Figs 181, 182 ). Fore and mid coxae with long, wavy anterior setae, twice width of coxa; hind coxa with long, wavy anterior, lateral and posterior setae. Hind trochanter with long, slender, unmodified wavy setae. Fore femur clothed in long, wavy setae, longer dorsally and posteriorly. Fore tibia with long posterodorsal setae similar to femur; ventrally with fine, dense setae, length half width of segment, continuing on tarsomeres 1–4. Fore tarsomere 1 slender, not swollen; all tarsomeres without spine-like ventral setae; tarsomeres 1–3 with apicolateral pair of spine-like setae, longer than width of segment. Mid femur with similar setae to fore femur, longer dorsally and anteroventrally. Mid tibia with long posterodorsal setae similar to femur; ventrally with long, dense setae, longer than twice width of tibia. Mid tarsomere 1 with strong ventral setae, slightly longer than width of tarsus; tarsomeres 2–5 with ventral spine-like setae; tarsomeres 2–4 with apicolateral pair of spine-like setae, longer than width of segment. Hind femur slightly swollen distally, clothed in fine setae, longer posteriorly; on apical half ( Fig. 182 ). Hind tibia broader than femur distally, longest of dorsal setae twice width of tibia; 1 long seta in posteroapical comb ( Fig. 182 ). Hind tarsomeres distinctly swollen compared to fore and mid legs; tarsomere 1 with long dorsal setae, similar to tibia; tarsomeres 2–5 with anteroventral and posteroventral spine-like setae; tarsomeres 1–4 with apicolateral pair of spine-like setae, longer than width of segment.

Wing infuscate with dark veins; all veins complete (except Sc), well sclerotized. Basal costal seta absent. R 5 and M 1 divergent near wing margin; R 5 ending at wing tip; radial fork acute. Halter dark.

Abdomen dark brown, similar to scutum, with long, wavy setae on tergites and sternites of segments 1 and 2; setae sparse on distal tergites; distal sternites with long, fine setae. Pregenital segments unmodified, except sclerites of segment 8 narrowly separated. Terminalia ( Fig. 185 ): dark brown. Cercus broader than epandrium, prolonged dorsally, fused anterolaterally with epandrium; margin invaginated dorsally and posteriorly, inner face clothed in dense, short setae; outer distal half with long setae, longer than epandrial setae. Subepandrial process extended to phallus. Epandrial lamella subquadrate, posterior margin not projecting beyond cercus, bearing apical setae, shorter than cercal setae. Hypandrium slender, prolonged posteriorly with rounded margin, less than half as long as epandrium; without setae. Phallus with base not greatly expanded, with tight, subapical S-shaped curve; apex not emerging beyond cercus; ejaculatory apodeme half-length of epandrium, comprising only flat median keel, without horizontal wings.

Female. Similar to male, except as follows: lacking all long, wavy setae from head, legs, thorax and abdomen; face with dark setae, shorter than scape; frons as broad as antennal sockets, with short setulae long eye margin; scutum with broad brown vittae along acr and dc rows; tarsomeres similar to male; spine-like setae of hind trochanter sometimes less numerous and slightly less stout; halter pale; cercus long and slender, subequal to length of tergite 8.

Geographical distribution and seasonal occurrence ( Fig. 192 ). Empis (En.) geneatis is known from February to May in California.

Nuptial gift presentation. The behaviour of this balloon carrying species was extensively described by Kessel & Karabinos (1947). Males swarm with small to moderate size balloons (about half the length of the fly) that contain a minute inedible dried-up prey item attached (see Kessel 1955, fig. 3). The balloons are presented to females, which do not consume the prey during copulation. The balloon is dense in nature and doesn’t collapse after collection ( Figs 12, 13 ). No circular opening was observed in the balloons, which are possibly not hollow.

Remarks. A spring species that appears to attract the eye of collectors due to the white shiny balloons. In fact, a majority of the material obtained (see “Additional material examined” above) were males collected with balloons, whereas only a few individual females have been collected.

Figures

FIGURES 6–14. Balloons of E. (Enoplempis) species. 6, E. (En.) bigoti Melander (New York Creek, California), mating pair collected with balloon, prey: Psocoptera; 7, E. (En.) aerobatica Melander (3 mi. S Helmer, Idaho), prey: Chloropidae; 8, same, prey: Psyllidae; 9, E. (En.) bigoti Melander (New York Creek, California), prey: Psocoptera; 10, same, paratype of E. bullifera Kessel & Kessel (Novato, California), prey: Chironomidae; 11, same, opposite end of balloon; 12, E. (En.) geneatis (Melander) (Briones Reg. Pk, California), prey: Sciaridae; 13, same (Mill Valley, California), prey: Chalcidoidea; 14, E. (En.) vockerothi Cumming, empty prey-less balloon (Hocking Co., Ohio). Balloons all at same scale, except E. (En.) vockerothi.

FIGURES 181–182. Male habitus and hindleg of E. (Enoplempis) geneatis (Melander). 181, habitus, lateral view; 182, hind femur tibia joint, anterior view.

FIGURES 183–185. Male terminalia of the E. (Enoplempis) geneatis species group, lateral view. 183, E. (En.) fisheri sp. nov.; 184, same, phallus; 185, E. (En.) geneatis (Melander).

FIGURES 192–193. Known geographical distribution of the E. (Enoplempis) geneatis and E. (Enoplempis) manca species groups. 192, E. (En.) fisheri sp. nov., E. (En.) geneatis (Melander), E. (En.) oharai sp. nov. and E. (En.) subgeneatis sp. nov.; 193, E. (En.) bova sp. nov.