Rhizophagus, Herbst, 1793

Barnouin, Thomas, Vincent, Alexis & Soldati, Fabien, 2025, Rhizophagus atticus Tozer, 1968 in France: synonymy with R. diaboli Dodelin, 2021, distribution and ecology (Coleoptera: Monotomidae), Zootaxa 5691 (2), pp. 329-340 : 331-336

Taxonomic comparison of Western Palaearctic Rhizophagus of subgenus Eurhizophagus

Type material examined. Rhizophagus atticus Tozer, 1968 , holotype ♂ and 2 ♀ paratypes, Natural History Museum of the United Kingdom (NHMUK).

Holotype ♂ ( Fig. 1 ), dissected, with the following labels: « Type [round label, white circled in red] / In bark of Pinus / Greece, Parnes Mts, X. 1965, C. Nicolopoulos / Brit. Mus., 1965-598 / Holotype, Rhizophagus atticus sp. n. ♂, E. R. Tozer, 1967 / NHMUK014485018 ».

Paratype ♀ ( Fig. 2 ), with the following labels: « Paratype [round label, white circled in yellow] / In bark of Pinus / Greece, Parnes Mts, X. 1965, C. Nicolopoulos / Brit. Mus., 1965-598 / Paratype, Rhizophagus atticus sp. n. ♀, E. R. Tozer, 1967 / NHMUK014663279 ».

Paratype ♀ ( Fig. 3 ), with the same labels as above but barcode « NHMUK014485021 ».

Other material examined agreeing with the original description of Rhizophagus diaboli . ALPES-DE-HAUTE-PROVENCE (04)—Selonnet (04203), 1060 m, 26.VII.–04.VIII. 2022, 1 ex. HAUTES-ALPES (05)— Veynes (05179), 840 m, 05.VIII.–19.VIII. 2021, 19 ex. ARDENNES (08)—Semide (08410), 120 m, 13.VII.– 05.VIII. 2021, 1 ex. AVEYRON (12)—Saint-Chély-d’Aubrac (12214), 910 m, 05.VIII.–19.VIII. 2021, 3 ex.; Sévérac - le-Château (12270), 820 m, 13.VII.–25.VII. 2022, 1 ex. DSF leg. CHARENTE (16)—Touvérac (16384), 90 m, 24.VIII.–05.IX. 2022, 1 ex. CORRÈZE (19)—Brive - la - Gaillarde (19031), 150 m, 03.VIII.–07.X. 2021, 15 ex. CÔTE-D’OR (21)—Arcenant (21017), 490 m, 24.VI.–05.VII. 2022, 5 ex.; Plombières - lès - Dijon (21485), 350 m, 05.VII.–28.VII. 2022, 7 ex. CÔTES-D’ARMOR (22)—Saint - Brieuc (22278), 20 m, 29.VI.–31.VIII. 2022, 1 ex. DSF leg. DORDOGNE (24)—Montrem (24295), 150 m, 31.VIII.–26.X. 2022, 2 ex.; Lèches (24234), 90 m, 12.VIII.–22.IX. 2022, 3 ex. DOUBS (25)—Rigney (25490), 250 m, 09.VIII.–18.VIII. 2021, 1 ex. DRÔME (26)— Cliousclat (26097), 450 m, 23.VII.–02.VIII. 2021, 2 ex. EURE (27)—Forêt domaniale de Bord-Louviers, 120 m, 26.VII.–16.VIII. 2021, 11 ex. GIRONDE (33)—Escaudes (33155), 20 m, 22.VIII.–06.X. 2022, 2 ex.; Mérignac (33281), 40 m, 13.IX.–23.IX. 2021, 12 ex. ILLE-ET-VILAINE (35)—Gaël (35117), 120 m, 26.VII.–30.VIII. 2022, 5 ex.; Iffendic (35133), 100 m, 22.VII.–26.VII. 2022, 1 ex. JURA (39)—Salins - les - Bains (39500), 360 m, 29.VII.– 18.VIII.2021, 2 ex. LANDES (40)—Bégaar (40031), 20 m, 04.VII.–15.VII. 2022, 1 ex.; Mont - de - Marsan (40192), 50 m, 18.VIII.–30.VIII. 2021: 2 ex., 10.VIII.–23.VIII. 2022: 1 ex. LOIRE-ATLANTIQUE (44)—Joué-sur - Erdre (44077), 20 m, 2022, 4 ex. LOT (46)—Salviac (46297), 220 m, 19.VII.–29.VII. 2021, 2 ex.; Saint - Denis - Catus (46264), 340 m, 29.VII.–09.VIII. 2021, 1 ex. LOT-ET-GARONNE (47)—Fargues - sur - Ourbise (47093), 110 m, 26.VIII.–28.X. 2021, 4 ex. LOZÈRE (48)—Mende (48095), 740 m, 05.VIII.–17.XIII.2021, 3 ex. MAINE-ET-LOIRE (49)—Lézigné (49174), 50 m, 02.VIII.–20.VIII. 2021, 10 ex.; Montreuil - sur-Loir (49216), 30 m, 20.VIII.– 03.IX. 2021, 7 ex. MOSELLE (57)—Volmerange-les-Mines (57731), 320 m, 15.VII.–25.VII. 2022, 1ex. ORNE (61)—Orée-d’Écouves (61228), 400 m, 02.VIII.–10.VIII. 2022, 1 ex. HAUTES-PYRÉNÉES (65)—Ayros - Arbouix (65055), 450 m, 29.VII.–13.IX. 2022, 2 ex. BAS-RHIN (67)—La Vancelle (67505), 430 m, 23.VIII.–09.IX. 2021, 4 ex. HAUT-RHIN (68)—Habsheim (68118), 250 m, 12.VII–29.VII. 2021, 2 ex.; Rixheim (68278), 240 m, 29.VII.– 23.VIII. 2021, 10 ex. SEINE-MARITIME (76)—Arelaune-en-Seine (76401), 50 m, 01.VI.–10.VI. 2022, 1 ex.; Eu (76255), 70 m, 01.VI.–10.VI. 2022, 1 ex. VIENNE (86)—Bonneuil - Matours (86032), 60 m, 12.VIII.–27.X. 2022, 88 ex.; Usseau (86275), 140 m, 11.VIII.–06.X. 2022, 12 ex. YONNE (89)—Chassignelles (89087), 190 m, 26.VII.–16.VIII. 2021, 106 ex.; Gurgy (89198), 50 m, 26.VII.–16.VIII. 2021, 1 ex.

All material collected by DSF staff. Some of this material has been deposited at the ONF’s National Forest Entomology Laboratory (LNEF-ONF).

Key to Western Palaearctic Rhizophagus of subgenus Eurhizophagus

1 Larger, 4.5–5.5 mm; pronotum broader as long; microreticulation longitudinally elongated and sinuate, always clearly visible................................................................................... R. grandis Gyllenhal (Naturally rare species in mountain spruce forests but widely disseminated for biological control in many mountain and lowland stands.).

- Smaller, < 4 mm; pronotum as wide as long or barely longer than wide; polygonal microreticulation or absent............ 2

2 Antennal club globose, 11 th antennomere clearly visible ( Fig. 13 ); median lobe of genitalia long, curved over the first basal third and then sub rectilinear, with a small tuft of long setae on its ventral side, in the anterior third ( Fig. 19 ); body slender and on average larger (2.8–4.2 mm, median 3. 3 mm) ( Fig. 6 )....................................... R. depressus (Fabricius) (Common and widely distributed species, especially in lowland and mountain pine forests.).

- Antennal club subtruncate, 11 th antennomere inconspicuous, embedded in the 10 th ( Figs. 11, 12 ); median lobe of genitalia short, regularly curved, without long tuft of setae on ventral side ( Figs. 17, 18 ); body more compact and on average smaller (2.5–3.6 mm, median 2. 9 mm) ( Figs. 1, 2, 3 , 5 )............................... R. atticus Tozer (= R. diaboli Dodelin , syn. nov.)

Figures

FIGURES 1–4. Figures 1–3. Habitus and labels—1. R. atticus, holotype ♂, 2.8 mm. 2. R. atticus, paratype ♀, 2.5 mm. 3. R. atticus, paratype ♀, 2.5 mm. (Photos: Alexis Vincent). Figure 4. French distribution of R. atticus (=diaboli, syn. nov.) and R. depressus based on 2021–2022 pinewood nematode monitoring data.

FIGURES 5–13. Figures 5–6. Habitus—5. R. atticus from France, ♀, 3.0 mm. 6. R. depressus from France, ♀, 3.6 mm. Figures 7–10. Pronotum—7. R. atticus, holotype ♂. 8. R. atticus, shiny form, from France, ♂. 9. R. atticus, microreticulate form, from France, ♀. 10. R. depressus, from France, ♀. Figures 11–13. Antennal club—11. R. atticus, holotype ♂. 12. R. atticus, from France. 13. R. depressus, from France. (Photos: Alexis Vincent).

FIGURES 14–19. Figures 14–16. Median lobe of aedeagus with internal sclerites (dorsal view)—14. R. atticus, holotype ♂. 15. R. atticus, from France. 16. R. depressus, from France. (Photos:Alexis Vincent). Figures 17–19. Median lobe of aedeagus (lateral view)—17. R. atticus, holotype ♂. 18. R. atticus, from France. 19. R. depressus, from France. (Photos: Alexis Vincent).