Rhagoletis Loew, 1862

Korneyev, S. V., Smith, J. J., Hulbert, D. L., Frey, J. E. & Korneyev, V. A., 2022, A New Species Of Rhagoletis (Diptera, Tephritidae) From Switzerland, With Discussion Of Its Relationships Within The Genus, Zoodiversity 56 (1), pp. 1-20 : 5-7

Rhagoletis Loew, 1862

Rhagoletis Loew, 1862 b: 44 .

T y p e s p e c i e s: Musca cerasi Linnaeus, 1758 (by monotypy).

Zonosema Loew, 1862 b: 43 .

Type species: Tephritis alternata Fallén, 1814 (by subsequent designation of Rondani, 1870: 6). Microrrhagoletis Rohdendorf, 1961: 187 .

T y p e s p e c i e s: Microrrhagoletis samojlovitshae Rohdendorf, 1961 (by original designation).

Megarrhagoletis Rohdendorf, 1961: 196 .

T y p e s p e c i e s: Megarrhagoletis magniterebra Rohdendorf, 1961 (by original designation).

Diagnosis. Medium-sized (3.0–8.0 mm) fruit flies with 3 frontal and 2 (rarely 1) orbital setae, pale or dark postocellar seta, short head, first flagellomere usually with pointed apex (rarely rounded); thorax entirely orange to entirely black; postpronotal lobe usually pale yellow; scutellum orange to black with creamy white or yellow disc (black in R. psalida ); surstylus of male with long and variously shaped, usually acute, posterior lobe; oviscape with T-shaped desclerotized posteromedial area ventrally; aculeus usually uniformly tapered apically. Third instar larva with variable number (from 3 to 20) of oral ridges and stomal sensory organ with or without preoral teeth.

Remarks. The morphological diagnosis of Rhagoletis almost entirely overlaps with that of Carpomya , which sometimes cannot be undoubtedly differentiated (except the mesonotum pattern and number of frontal setae; both variable). Current concepts of these genera need revision based on a sound multi-locus DNA reconstruction of phylogenetic relationships among the genera of Carpomyini .

Key to the Rhagoletis species similar to R. merzi sp. n.

This key includes R. merzi and the species similar to it, having a black body with postpronotal lobe and major part of scutellum yellow or white, the wing with 4 bands, of which the apical band is connected to the subapical band and separated from the apical wing margin by a crescentic marginal hyaline area: Rhagoletis juniperina Marcovitch, 1915 , R. zernyi Hendel, 1927 , R. flavigenualis Hering, 1958 (the juniperina group), R. tabellaria (Fitch, 1855) , R. persimilis Bush, 1966 , R. electromorpha Berlocher, 1982 , R. bushi Hulbert et al., 2018 ( tabellaria group), R. ebbettsi Bush, 1966 , R. ribicola Doane, 1899 ( ribicola group), and the following species unassigned to groups, R. scutellata Zia, 1938 , R. batava Hering, 1958 , R. mongolica Kandybina, 1972 ), and R. bagheera Richter & Kandybina, 1997 .

1. Dark subbasal and discal bands widely connected in posterior part of wing (see Foote et al., 1993: figs 378–379). Nearctic Region only. .............................................................................. tabellaria group, part 2

— Dark subbasal and discal bands widely separated or connected by a pale grey, indistinctly darkened area ( fig. 1 ). Palearctic and Nearctic Regions. ......................................................................................................... 4

2. Apical crescentic hyaline area (cr) shorter, reaching at most to posterior 1/3 of costa in cell r 4+5; subapical band uniformly dark, crossvein dm-m pale emarginated (see: Foote et al., 1993: fig. 379). ................. ................................................................................................................................... R. electromorpha Berlocher

— Apical crescentic hyaline area longer, reaching vein M 1; subapical band uniformly dark, crossvein dm-m not pale emarginated (see: Foote et al., 1993: 359). ........................................................................... 3

3. Aculeus shorter than 0.7 mm. Larvae in fruits of Cornus (Cornaceae) and Vaccinum ( Ericaceae ). ......... ................................................................................................................................................. R. tabellaria (Fitch)

— Aculeus longer than 0.8 mm. Larvae in fruits of Prosartes hookeri (Liliaceae) . ............................................ ................................................................................................................................................... R. persimilis Bush

4. Occiput completely yellow. Wing pattern usually yellowish brown, with bands laterally emarginated with brown ( figs 1 , a–b). Femora mostly or entirely yellow. Larvae in Juniperus fleshy cones. ................. ......................................................................................................................................... juniperina group, part 5

— Occiput with at least medial sclerite above occipital foramen, or often lateral of occipital suture black or brown. Wing pattern with blackish brown bands ( figs 1 , c–e). Femora coloration and host plants variable. .............. 6

5. Discal and subapical bands widely connected at least in cell r 2+3 ( fig. 1 , a). Spain. .......... R. zernyi Hendel

— Discal and subapical bands entirely separated ( fig. 1 , b). Asia: Turkey, Caucasus, Iran, Middle Asia. ..... .......................................................................................................................................... R. flavigenualis Hering

6. Discal and subapical bands connected in cell r 4+5 (see: Bush, 1966: fig. 200; Foote et al., 1993: fig. 381). USA: California ................................................................................................................ R. ebbettsi Bush, 1966

— Discal and subapical bands widely isolated. .................................................................................................... 7

7. Femora yellow. .................................................................................................................................................... 8

— At least mid and hind femora black. ................................................................................................................ 9

8. Only dorsal third of occiput with dark transverse spot. Larvae in Juniperus sabina . Asia: Mongolia, (?) Kyrgyzstan. Genitalia not examined. ...................................................................... R. mongolica Kandybina

— Occiput with wide black horseshoe-shaped pattern reaching its lower half. Lateral surstylus with short posterior lobe. Spermatheca narrow and long, worm-like (see Bush, 1966: fig. 167). Larvae in Ribes spp. North America......................................................................................................................... R. ribicola Doane

9. Occiput with wide black horseshoe-shaped pattern reaching its lower half. Lateral surstylus with long and narrow posterior lobe ( fig. 2 , a). Spermatheca rounded, small, <0.05 mm in diameter, with neck longer than spermatheca itself ( fig. 2 , d)........................................................................................................10

— Occiput black only across upper 1/3. Lateral surstylus with short posterior lobe ( fig. 2 , c) (not known for R. scutellata ). Spermatheca globose, larger,> 0.05 mm in diameter, with neck shorter than spermatheca itself ( fig. 2 f ) (not known in R. scutellata ). Associated with Juniperus (host not known for R. scutellata ). .......................................................................................................................................................... 12

10. Nearctic Region. Scutellum laterally and fore coxa usually black. Larvae in Shepherdia argentea (Pursh) Nutt. (Eleagnaceae) . ................................................................................................ R. bushi Hulbert & Smith

— Palearctic Region. Scutellum laterally and fore coxa usually yellow. Host plants different. .................. 11

11. Smaller: wing length less than 2.8 mm (in Ơ 2.0–2.4, rarely up to 2.7 mm), in ♀ 2.2–2.5 mm). Larvae in Rhamnus pallasii (Rhamnaceae) . Asia: Armenia, Georgia. .................. R. bagheera Richter & Kandybina

— Larger: wing length greater than 2.9 mm (in Ơ 3.0– 3.6 mm, in ♀ 3.3–4.2 mm). Europe, Asia (Caucasus, Middle Asia, Siberia, China). Larvae in Hippophae rhamnoides L. ( Elaeagnaceae ). ..... R. batava Hering

12. Abdominal tergites 2–4 uniformly brown or black, without pale bands on posterior margins. Genital characters not examined. Host plants unknown. China (Gansu). .................................... R. scutellata Zia

— Abdominal tergites 2–4 with pale bands on posterior margins. ................................................................ 13

13. North America. Associated with various Juniperus spp. ................................................................................. ............................................................ R. juniperina Marcovitch (possibly an assemblage of cryptic species)

— Europe: Switzerland. Associated with Juniperus sabina . ....................................................... R. merzi sp. n.

Figures

Fig. 1. Palearctic species of Rhagoletis species similar to R. merzi, wings: a — R. zernyi; b — R. flavigenualis; c — R. merzi, sp. n.; d — R. bagheera; e — R. batava. Bands are marked as follows: A — apical, D — discal, SA — subapical, SB — subbasal. Red arrow shows connection of D and SA; cyan arrow shows cr — crescentic hyaline area. Scale: 1 mm.

Fig. 2. Palearctic species of Rhagoletis species similar to R. merzi, epandrium and surstyli, posterior view (a–c) and spermatheca (d–f): a, d — R. batava; b, e — R. flavigenualis; c, f — R. merzi sp. n.