Amygdalops Lamb, 1914

Jindr, Rohác, ich & ek, 2004, Revision of the genus Amygdalops Lamb, 1914 (Diptera: Anthomyzidae) of the Afrotropical Region, African Invertebrates 45, pp. 157-221 : 159-165

Genus Amygdalops Lamb, 1914

Amygdalops Lamb, 1914: 357 , Fig. 39 , Pl. 21, Figs 48–51 [description]; Rohác˘ek & Freidberg 1993: 64,

Figs 64–93 , 119–120 [key]; Rohác˘ek 1998 b: 276, Figs 22.6–7, 22.18–20 [key].

Type species: Amygdalops thomasseti Lamb, 1914: 358 by original designation.

Diagnosis:

(1) Head ( Figs 1 , 20 ): Slightly higher than long to slightly longer than high. (2) Eye large, very convex, elongately ellipsoid, with longest diameter oblique. (3) Occiput strongly concave. (4) Frons very narrow; frontal triangle long, narrow and shining. (5) Frontal lunule reduced, indistinct. (6) Antenna strongly geniculate between pedicel and 1st flagellomere; pedicel overlapping base of 1st flagellomere. (7) Arista very long pectinate, with longest rays dorsoproximally. (8) Palpus slender, with 1 distinct subapical seta. Cephalic chaetotaxy: (9) pvt short but crossed or strongly convergent; (10) vte longest of cephalic setae; (11) vti markedly shorter than vte, about as long as oc; (12) 2 long ors, the posterior in the middle of orbit, the anterior close to fore margin of frons; 2 (less often 1) microsetulae just in front of anterior ors; (13) a single row of minute postocular setulae; (14) 1 long vi and 1 somewhat shorter subvibrissa; (15) peristomal setulae few in number, short, but at least twice as long as postoculars.

(16) Thorax ( Fig. 1 ): Distinctly narrower than head, subshining. (17) Pleura with dark, longitudinal band at dorsal margin. Thoracic chaetotaxy: (18) 1 hu, 2 npl (anterior longer); (19) 1 short sa, 1 longer pa; (20) 1 small prs; (21) 2 postsutural dc, both in prescutellar portion of scutum, the posterior very long, the anterior short to very small; (22) ac microsetae in 4 rows in front of suture; (23) 2 sc, the apical long, the laterobasal small; (24) 1 minute (to invisible) ppl; (25) 2 stpl, the anterior always shorter and weaker. Legs: (26) Fore leg always unicolorous, yellow; (27) f 1 without ctenidial spine; (28) t 2 with distinct ventroapical seta; (29) male f 3 with posteroventral row of setae which are shortened and thickened in distal third. (30) Wing ( Figs 122–132 ) long and very narrow; (31) wing membrane usually ornamented by dark subapical spot and some whitish areas; unicolorous in most primitive members only; (32) C without distinct spinulae; (33) R 2+3 long, sinuous, ending about twice further from apex of R 4+5 than M; (34) R 4+5 straight to strongly sinuous; (35) R 4+5 and M slightly to strongly convergent in apical fourth of wing; (36) M usually straight but sometimes sinuous; (37) discal (dm) cell short and narrow, with cross-vein r-m situated near its middle (38) CuA 1 shortened, not reaching wing margin; (39) A 1 and anal lobe reduced, anal cell narrow; (40) alula small and very narrow.

Male abdomen: (41) T1 separate from T2, at least dorsally; (42) T2–T5 large and broad. (43) S1–S5 much narrower and usually paler than associated terga. Male postabdomen: (44) T6 small, transverse, weakly sclerotised; (45) S6–S8 fused dorsolaterally; (46) S6 strongly asymmetrical and its ventral part very short; (47) S7 asymmetrical, placed laterally; (48) S8 relatively long, less asymmetrical and situated dorsally.

Male genitalia ( Figs 2–4 , 6–11 , 26–29 ): (49) Epandrium moderately broad, with relatively sparse setae, 1–2 pairs of setae usually longer. (50) Medandrium variable in size, usually relatively high; (51) cercus moderate to long, weakly sclerotised, finely setose. (52) Gonostylus with longest setae in anterior half of inner side, micropubescence on outer side usually well developed. (53) Hypandrium with internal dorsally projecting lobes flat and membranous; (54) transandrium ( Fig. 11 ) with caudal process usually represented by a pair of band-like sclerites. (55) Pregonite fused to hypandrium, only posteriorly separated by narrow notch ( Figs 9 , 26 ), either incurved or somewhat projecting ventrally. (56) Postgonite usually simple and slender, more or less flattened and with characteristic basal sclerite attached to its proximal part. (57) Aedeagal part of folding apparatus ( Fig. 7 ) dorsally dark and sclerotised, attached to base of phallapodeme, laterally provided by lenticular or tuberculate armature; (58) connecting sclerite ( Figs 7 , 26 ) usually slender and long, pale pigmented. (59) Basal membrane usually with sclerotised structures (short spines or tubercles). (60) Phallapodeme with distinctly bifurcate base and more or less distinct lateral projections in front of it ( Fig. 10 ). (61) Aedeagus with short phallophore and (62) distiphallus composed of voluminous membranous saccus and slender sclerotised filum. (63) Membrane of saccus overgrown by rich spines of various length and thickness; (64) filum formed by 2 long, dark, slender and twisted band-like sclerites, terminating into membranous apex. (65) Ejacapodeme small, with slender digitiform projection.

(66) Female abdomen: With broader terga (T2–T6) and narrower sterna (S2–S5). (67) Postabdomen ( Figs 12–19 ) relatively broad and short, terga and sterna (except S6) well sclerotised and dark. (68) T6 and also S6 relatively large. (69) T7 laterally extended and reaching ventral side, usually embedding spiracles; (70) S7 strongly modified, usually narrow and characteristically pigmented, disparate or partly (anteriorly) fused with T7; (71) T8 plate-shaped, small, transversely suboblong; (72) S8 protruding posteromedially, with narrow, postero(dorso)medial incision. (73) Internal sclerotisation of female genital chamber (uterus) developed ( Figs 17, 18 , 23 ) but usually weakly sclerotised, formed by 2 pairs of posterior crooked sclerites and (74) 1 anteroventral, transversely compressed, fine ring-shaped sclerite. (75) Anterior part of uterus provided with membranous pouch-like ventral receptacle ( Figs 22, 23 ) having a digitiform or vermicular terminal projection. (76) Accessory glands of usual form, subterminally with slightly dilated ducts. (77) Spermathecae (1+1) spherical to shortly pyriform ( Figs 15, 16 ), with simple but distinct cervix, and with body surface carrying dark, usually short and blunt spinulae with minute stalked pale globules. (78) T10 small, at least partly dark, with 1 or (rarely) 2 pairs of dorsal setae; (79) S10 slightly larger and longer than T10, simple, densely micropubescent besides fine setulae. (80) Cerci relatively short and broad, with comparatively short setae, those on apex thicker than others.

Discussion:The genus Amygdalops is best diagnosed by the combination of the character states 2–5, 7, 11, 12, 17, 20, 21, 27, 29, 31, 37, 38, 40, 54–57, 60, 70, 72, 75, 77 and 80. However, some of these features are shared with the recently described Afrotropical genus Margdalops and are considered synapomorphic and demonstrating the sistergroup relationships of these two genera, viz. 2–4, 12, 17, 27, 29, 39, 40, 75 and 80. The genus Margdalops (see Rohác˘ek & Barraclough 2003) differs from Amygdalops in a number of other features, both plesiomorphic with respect to those in Amygdalops (e.g. frontal lunule distinct; arista ciliate; vti long; prs distinct; CuA 1 long; transandrium without medial caudal process; aedeagal part of folding apparatus dorsally membranous; female S7 slightly or unmodified) and autapomorphic (occiput with a pair of silvery microtomentose stripes, dc inserted more anteriorly, wing dark margined anteriorly, dm cell shorter and very narrow, medandrium wide and medially shortened, male cercus strongly sclerotised). Consequently, the monophyly of Amygdalops is substantiated by only the following apomorphies, viz. (5) frontal lunule reduced, (7) arista very long pectinate, (11) vti markedly shorter than vte, (20) 1 small prs, (31) wing membrane usually ornamented by dark subapical spot and some whitish areas (with exception of the most primitive species), (38) CuA 1 shortened, (54) transandrium medially with paired caudal process, (55) pregonite fused to hypandrium and posteriorly separated by a narrow notch, (57) aedeagal part of folding apparatus dorsally sclerotised and attached to base of phallapodeme, (70) female S7 strongly modified.

The best diagnostic characters of Amygdalops are the characteristic ellipsoid eyes, position of ors and short vti, combined with long pectinate arista, short prs, dc macrosetae in prescutellar position, pleura with dark dorsal band, wing with subapical dark spot, short and narrow dm cell and shortened CuA 1. These are usually sufficient to affiliate a species to Amygdalops , with the exception of species with unpatterned wings, such as is A. trivittatus whose position is not quite clear because its male is unknown. It is placed in Amygdalops because it lacks synapomorphies of the genus Margdalops and possesses reduced lunule, long pectinate arista, short vti and prs and also its spermatheca, modified female S7 and ventral receptacle resemble most those of Amygdalops species.

In the Afrotropical fauna 11 species of Amygdalops have been recognised which are described or redescribed below. However, at least five additional species have been identified in the material examined but these are left undescribed either because only females are available, or in two cases, because single males are damaged which precludes their description. The species are dealt with below according to presumed systematic order based on the suggested relationships.

Figures

Figs 35–40. Amygdalops simplicior sp.n., male paratype (Cape Verde). 35. External genitalia, caudal view. 36. Same, lateral view.37.Transandrium, caudal view. 38. Hypandrium and associated structures, lateral view. 39. Gonostylus, sublateral view (widest extension). 40. Aedeagal complex, lateral view. Scales: Fig. 39 = 0.05 mm, others = 0.1 mm.

Figs 61–65. Amygdalops acer sp.n., male holotype. 61. External genitalia, caudal view. 62. Same, lateral view. 63. Transandrium, caudal view. 64. Aedeagal complex, lateral view. 65. Gonostylus, sublateral view (widest extension). Scales: Fig. 65 = 0.05 mm, others = 0.1 mm. For abbreviation see text.

Figs 66–70. Amygdalops nigrinotum Sueyoshi & Rohác˘ek, male (Figs 66, 67, 70 - paratype, Japan; Figs 68, 69 - Seychelles). 66. External genitalia, caudal view. 67. Same, lateral view. 68. Transandrium, caudal view. 69. Aedeagal complex, lateral view. 70. Gonostylus, sublateral view (widest extension). Scales: Fig. 70 = 0.05 mm, others = 0.1 mm.

Figs 71–76. Amygdalops nigrinotum Sueyoshi & Rohác˘ek, male (Seychelles), paratype female (Hawaii). 71. Hypandrium and associated structures, lateral view. 72. Postabdomen, dorsal view. 73. Same, ventral view. 74. Spermathecae. 75. Ventral receptacle, ventral view. 76. Left wall of female genital chamber (uterus). Scales: Figs 71–73 = 0.1 mm, others = 0.05 mm.

Figs 77–81. Amygdalops obscurior sp.n., male paratype (Uganda). 77. External genitalia, caudal view. 78. Same, lateral view. 79. Hypandrium and associated structures, lateral view. 80. Gonostylus, sublateral view (widest extension). 81. Aedeagal complex, lateral view. Scales: Fig. 80 = 0.05 mm, others = 0.1 mm.

Figs 82–86. Amygdalops obscurior sp.n., female paratype (Uganda). 82.Spermathecae.83.Ventral receptacle, lateral view. 84. Internal sclerites, ventral view. 85. Postabdomen, dorsal view. 86. Postabdomen + 5th segment, ventral view.

Figs 88–93. Amygdalops sparsus sp.n., male paratype (Uganda). 88. External genitalia, caudal view. 89. Same, lateral view. 90. Hypandrium and associated structures, lateral view. 91. Gonostylus, sublateral view (widest extension). 92. Hypandrium and associated structures, ventral view. 93. Aedeagal complex, lateral view. Scales = 0.1 mm.

Figs 116–121. Amygdalops poecilus sp.n., female paratype (South Africa). 116. Postabdomen, dorsal view. 117. Spermatheca. 118. Ventral receptacle, lateral view. 119. Internal sclerites, ventral view. 120. Postabdomen, ventral view. 121. Spermatheca. Scales: Figs 116, 120 = 0.1 mm, others = 0.05 mm.

Figs 21–25. Amygdalops trivittatus Frey, female holotype. 21. Postabdomen + 5th segment, dorsal view. 22. Ventral receptacle, lateral view. 23. Genital chamber with internal sclerites and S8, ventral view. 24. Postabdomen + 5th segment, ventral view. 25. Spermathecae. Scales: Figs 21, 24 = 0.1 mm, others = 0.1 mm. For abbreviations see text.

Figs 1–5. Amygdalops thomasseti Lamb, male (Israel). 1. Head and thorax, dorsal view. 2. Genitalia, lateral view (hypandrium not dotted). 3. Gonostylus, sublateral view (widest extension). 4. External genitalia, caudal view. 5. Hind femur, posterior view. Scales: Figs 1, 5 = 0.2 mm, Fig. 3 = 0.05 mm, others = 0.1 mm. For abbreviations see text. Illustration according to Rohác˘ek & Freidberg (1993).

Figs 12–20. Amygdalops thomasseti Lamb, female, male (Israel). 12. Female postabdomen, dorsal view. 13. Same, lateral view. 14. Same, ventral view. 15, 16. Spermathecae. 17. Female internal sclerites (ring-shaped sclerite omitted), lateral view. 18. Same, ventral view. 19. Female S8, caudal view. 20. Male head, lateral view. Scales: Figs 12–14 = 0.1 mm, Fig. 20 = 0.2 mm, others = 0.05 mm. For abbreviations see text. Illustration according to Rohác˘ek & Freidberg (1993).

Figs 122–125. Wings of Amygdalops species. 122. A. trivittatus Frey, female holotype. 123. A. thomasseti Lamb, male (Uganda). 124. A. obtusus sp.n., male paratype (Kenya). 125. A. simplicior sp.n., male paratype (Nigeria). Scales = 0.5 mm.

Figs 126–128. Wings of Amygdalops species. 126. A. major sp.n., male paratype (Madagascar). 127. A. acer sp.n., male holotype. 128. A. nigrinotum Sueyoshi & Rohácek, male (Seychelles). Scales = 0.5 mm.

Figs 129–132. Wings of Amygdalops species. 129. A. obscurior sp.n., male paratype (Uganda). 130. A. sparsus sp.n., male paratype (Uganda). 131. A. undulatus sp.n., male paratype (Madagascar). 132. A. poecilus sp.n., female paratype (South Africa). Scales = 0.5 mm.

Figs 6–11. Amygdalops thomasseti Lamb, male (Israel). 6. Apex of filum, ventral view. 7. Aedeagal complex, lateral view. 8. Hypandrium and associated structures, lateral view. 9. Same, ventral view. 10. Basal part of phallapodeme, dorsal view. 11. Transandrium, caudal view. Scales = 0.05 mm. For abbreviations see text. Illustration according to Rohác˘ek & Freidberg (1993).

Figs 26–29. Amygdalops obtusus sp.n., male paratype (Kenya). 26. Genitalia, erect position, lateral view. 27. Gonostylus, outer side, sublateral view (widest extension). 28. Same, inner side. 29. External genitalia, caudal view. Scales: Figs 27–28 = 0.05 mm, others = 0.1 mm. For abbreviations see text.