Diplonevra florescens ( Turton, 1801 )

Lee, Jun-Ho, Lee, Jun-Gi & Kim, Sam-Kyu, 2022, A taxonomic study on the South Korean Diplonevra (Diptera: Phoridae), Zootaxa 5138 (3), pp. 238-260 : 245-248

Diplonevra florescens ( Turton, 1801)

( Figs. 1G–J , 4G–I , 5D, 5E , 6F, 6G , 8E, 8F )

Musca florescens Turton, 1801: 636 . Type locality: Germany (replacement name of Bibio florea preoccupied by Linnaeus, 1758— Musca florea , currently Myathropa florea in family Syrphidae ).

Diplonevra florescens: Thompson & Pont, 1994: 76 (emendation).

Bibio florea Fabricius, 1794: 255 . Type locality: “ Germania ” (preoccupied by Linnaeus, 1758: 591).

Trineura abdominalis Fallén, 1823: 5 . Type locality: Sweden ( Diplonevra , synonymy).

Trineura palpina Zetterstedt, 1848: 2868 . Type locality: “Esperöd, Tranas Scaniae” ( Sweden) ( Diplonevra , synonymy).

Trineura fulviventris Boheman, 1852: 208 . Type locality: Ronneby, Sweden (synonym of D. abdominalis ).

Phora flexuosa Egger, 1862: 1233 . Type locality: Austria (synonymy).

Phora sororcula van der Wulp, 1871: 209 . Type locality: Amsterdam, The Netherlands (synonym of D. abdominalis ).

Dohrniphora florea var. versicolor Schmitz, 1920: 105 . Type locality: Limburg, The Netherlands (variety of D. florea ) (synonymy).

Diplonevra versicolor Schmitz, 1920: 105 (elevated from variety of D. florea ) (synonymy).

Diagnosis. This species can be distinguished from other Diplonevra species by the combination of the following characteristics: inner face of male hind trochanter with 2 or 3 short, broad setae, one row of short setae, and single long, pipette-shaped seta on ventral margin; ventrobasal area of inner face of male hind femur slightly extending proximally, with one row of stout setae at tip of extension and several hairs on surface; hind tibia with two dorsal longitudinal setal palisades and two anterodorsal strong setae; wing vein M 1 sinuate; cercus long, entirely yellow.

Description. Male. Body length 2.74–3.89mm (n=8). Head ( Fig. 1G ). Frons blackish brown, shiny. Flagellomere 1 brown but anteroventral face yellow, as large as about one-fifth of compound eye, subglobose, slightly pointed apically. Arista dark brown. Palpus yellow, as wide as maximum width of flagellomere 1, with six bristles apically and some short hairs ventrally. Labrum and labella yellow. Thorax ( Fig. 1H ). Scutum and scutellum blackish brown. Posterior margin of scutum with one pair of long prescutellar bristles. Scutellum with two pairs of long bristles of subequal length; anterior scutellar bristles convergent; posterior scutellar bristles convergent and sometimes apically crossing each other. Pleuron ( Fig. 1G ) dark brown. Legs ( Fig. 1G ) dark brown except fore, mid-tibiae and entire tarsi brown. Fore tibia with single strong dorsal seta on basal half and 2 or 3 short setulae arranged in one row on apical half. Midtibia ( Fig. 4G ) with two dorsal longitudinal setal palisades; anterodorsal one extending three-quarters of midtibial length while posterodorsal one extending entire length of midtibia. Both of two dorsal midtibial bristles protruding at basal one-fifth of midtibia. Inner face of hind trochanter ( Fig. 6F, G ) with 2 or 3 short, broad setae, one row of short setae, and single long, pipette-shaped seta on ventral margin. Ventrobasal area of inner face of hind femur ( Fig. 6F, G ) slightly extending proximally, with four long, narrow setae (three peg-like and one pointed) arranged in one row at tip of extension and several hairs on surface. Hind tibia ( Fig. 4H, I ) with two dorsal longitudinal setal palisades, two anterodorsal strong setae and one row of posterodorsal fine setae. Wing ( Fig. 5D ). 2.49–3.26mm long (n=8). Costal index 0.55–0.59. Mean costal ratio 4.2:2.0:1; range 3.9–4.5:1.8–2.2:1. Costal setae of costal section III 0.05–0.07mm long. Vein of costal sections II–III not thickened. Base of Rs with single short hair. Vein M 1 sinuate. Vein dark brown and membrane with pale brown tinge. 4–7 (mostly 6) alular setae present, 0.11–0.16mm long. Halter brown to dark brown. Abdomen ( Fig. 1G, H ). Tergites blackish brown. Venter of abdomen grayish brown. Hypopygium ( Fig. 8E, F ) dark brown, shiny. Epandrium without hairs dorsally. Left side of epandrium ( Fig. 8E ) with finger-shaped epandrial lobe bearing one long seta apically. Right side of epandrium ( Fig. 8F ) sharply extended posteroventrally, with some hairs on posterior margin and minute, hooked lobe curved inward on posteroventral corner. Hypandrium tomentose. Left plate of hypandrium ( Fig. 8E ) with broad, transparent posterior margin. Right plate of hypandrium ( Fig. 8F ) tapering, with slightly curved, narrow posterior margin. Aedeagus with transparent, rounded apex protruding beyond posterior margin of hypandrium. Cercus with one pair of yellow sclerites mounted dorsally on yellow stalk; length of cercus 6.5 times as long as maximum width of cercus; stalk with two pairs of hairs on ventral apex which distinctly longer than other hairs on cercus.

Female. Body length 3.58–4.90mm (n=3). Head ( Fig. 1I ) similar to male except flagellomere 1 smaller, palpus broader, clypeus elongated, and labrum robust, slightly elongated (length of clypeus plus labrum about twice as long as palpal length). Thorax ( Fig. 1J ) similar to male. Legs similar to male, except without structures on inner face of hind trochanter and femur. Wing ( Fig. 5E ) similar to male, 2.56–4.73mm long (n=3). Costal index 0.56–0.58. Mean costal ratio 3.9:2.1:1; range 3.8–4.0:2.0–2.2:1. Costal setae of costal section III 0.05–0.06mm long. 6–8 (mostly 6) alular setae present, 0.06–0.14mm long. Halter dark brown. Abdomen ( Fig. 1I, J ). Tergites present only on abdominal segments 1–4 and 9. Tergite 1 fully developed, blackish brown. Tergite 2 blackish brown, inverted trapezoidshaped, with slightly extended anterolateral margin and trapezoid-shaped anteromedial incision (width of incision variable). Tergite 3 narrower than width of posterior margin of tergite 2, blackish brown. Tergite 4 longer than wide, slightly narrower than width of maximum width of tergite 3, blackish brown. Membranous area of dorsum and venter of abdominal segment 1–7 blackish to grayish brown. Abdominal segment 8 membranous, grayish brown, with one pair of narrow, dark brown sclerites laterally. Abdominal segment 9 yellow, flattened, tapering apically; tergite 9 with median ridge bearing one pair of long hairs posteriorly; sternite 9 with erected short hairs on surface. Cercus yellow, rounded, with two long hairs apically.

Specimens examined. South Korea: 1♂, Gangwon-do , Yangyang-gun , Seo-myeon , Seorim-ri, Seorim Valley, 37°56′44.1″N, 128°30′50.6″E, 10–23.v.2018, Malaise trap, S. Nam leg. ( KNU) ; 1♂, Gangwon-do , Pyeongchanggun , Yongpyeong-myeon , Nodong-ri, Nodong Valley, 37°42′31″N, 128°29′03.8″E, 16.vi–31.viii.2019, Malaise trap, M. Lee & Park leg. ( KNU) ; 1♂, Gangwon-do , Inje-gun , Buk-myeon, Hangye-ri, 38°08′46.5″N, 128°15′47.5″E, 16.iv–1.v.2020, Malaise trap, Lim et al. leg. ( KNU) ; 2♂, ditto ( NIBR) ; 1♂ 2♀, Gangwon-do , Pyeongchang-gun , Jinbu-myeon , Mt. Odaesan, near Sangwonsa Temple, 37°47′03.9″N, 128°33′45.2″E, 15.vii–14.viii.2020, Malaise trap, J. H. Lee et al. leg. ( KNU) ; 1♂, Gangwon-do , Pyeongchang-gun , Jinbu-myeon , Mt. Odaesan, near Odae Mountain Cabin, 37°45′53″N, 128°34′45.2″E, 15.vii–14.viii.2020, pitfall trap, J. H. Lee et al. leg. ( KNU) ; 1♀, Gangwon-do , Pyeongchang-gun , Jinbu-myeon , Mt. Odaesan, streamside near Sinseongam Temple, 37°46′49″N, 128°34′33.5″E, 15.vii–14.viii.2020, pitfall trap, J. H. Lee et al. leg. ( KNU) ; 1♂, ditto, 14.viii–18.ix.2020, Malaise trap, J. H. Lee et al. leg. ( KNU) .

Ecology. The distribution of this species in South Korea seems to be limited to the mountainous region in Gangwon-do. Detailed ecological information of the species in South Korea is unknown because all specimens were collected either by Malaise or pitfall traps. In Europe, adults visit various flowers and females have been observed at vertebrate carrion. The larvae were reported to feed on invertebrate and vertebrate carrion, including human corpses ( Disney 1994; 2006).

Remarks. Both sexes of South Korean specimens of D. florescens match the Russian Far East specimens described by Michailovskaya (1990; 2000), including the male hypopygium. Overall morphology of the South Korean D. florescens specimens was largely congruent with the description of Chinese species ( Liu & Yang 2016), but characteristics of the hind legs of Chinese specimens described by Liu & Yang (2016) somewhat differed from South Korean and Russian Far East specimens that are rather similar to European specimens (illustrated by Disney 1983: figs. 47, 48). There are some differences between Russian Far East + South Korean specimens and European specimens; for example, the strong setae on the ventrobasal area of the inner face of the hind femur are long and slightly pointed (short, blunt in European specimens), and the color of the female abdomen is entirely grayish to blackish brown (extensively reddish, orange or partly black in European specimens, see Disney 1981: 157; 1983: 23). Illustrations of the hind trochanter and femur of European specimens ( Disney 1983: figs. 47, 48) showed some variation in arrangement and size of stout setae. This might implicate character plasticity or possible presence of cryptic species. In the case of the male hypopygium, however, Schmitz’s illustration (1949: fig. 147) of the left side of the hypopygium of D. florescens from Europe was quite similar to South Korean specimens, but the hypopygium has not been described or illustrated for Chinese specimens. To clarify this vague situation of species identity, detailed examination of male genitalia for European and Chinese specimens is warranted.

Distribution. Korea (new record, Gangwon-do), Europe, Russia, China.

Figures

FIGURE 1. Habitus of Diplonevra species from South Korea, lateral view (A, C, E, G, I, K) and dorsal view (B, D, F, H, J, L). A, B, D. abbreviata (male); C, D, D. abbreviata (female); E, F, D. biflagella, sp. nov. (male); G, H, D. florescens (male); I, J, D. florescens (female); K, L, D. hirsuta (male). Scale bars=2mm (A–D, G, I, J), 1mm (E, H, K, L), 0.5mm (F).

FIGURE 4. Mid- and hind tibiae of Diplonevra species from South Korea, anterodorsal view (Midtibia: A, D, G, J, M, P, S), anterior view (Hind tibia: B, E, H, K, N, Q, T) and dorsal view (Hind tibia: C, F, I, L, O, R, U). A–C, D. abbreviata; D–F, D. biflagella, sp. nov.; G–I, D. florescens; J–L, D. hirsuta; M–O, D. incisura, sp. nov.; P–R, D. nigritarsis, sp. nov.; S–U, D. peregrina. Abbreviations: ad=anterodorsal setae, av=anteroventral setae, sp=setal palisade. Scale bars=0.25mm.

FIGURE 5. Wings of Diplonevra species from South Korea, dorsal view. A, D. abbreviata (male); B, D. abbreviata (female); C, D. biflagella, sp. nov. (male); D, D. florescens (male); E, D. florescens (female); F, D. hirsuta (male); G, D. incisura, sp. nov. (male); H, D. incisura (female); I, D. nigritarsis, sp. nov. (male); J, D. nigritarsis (female); K, D. peregrina (male); L, D. peregrina (female). Scale bars=1mm (A, B, D, E), 0.5mm (C, F–L).

FIGURE 6. Inner face of male hind trochanters and femora of Diplonevra species from South Korea, posterior view. A, B, D. abbreviata; C–E, D. biflagella, sp. nov. (C, D: posterior view, E: posteroventral view, arrow: bifurcated setae); F, G, D. florescens; H, I, D. hirsuta. Abbreviation: asp=ascending process. Scale bars=0.2mm (A, F, H), 0.1mm (B, C, G, I), 0.05mm (D, E).

FIGURE 8. Hypopygia of Diplonevra species from South Korea, left view (A, C, E, G) and right view (B, D, F, H). A, B, D. abbreviata; C, D, D. biflagella, sp. nov.; E, F, D. florescens; G, H, D. hirsuta. Abbreviations: cer=cercus, ep=epandrium, epl= epandrial lobe, hpl=left plate of hypandrium, hpr=right plate of hypandrium, scl=sclerite mounted on cercus. Scale bars= 0.25mm (A, B), 0.2mm (C–H).