Amygdalops nigrinotum Sueyoshi & Rohác, 2003

Jindr, Rohác, ich & ek, 2004, Revision of the genus Amygdalops Lamb, 1914 (Diptera: Anthomyzidae) of the Afrotropical Region, African Invertebrates 45, pp. 157-221 : 189-194

Amygdalops nigrinotum Sueyoshi & Rohác ˘ek, 2003

( Figs 66–76 , 128 )

Amygdalops nigrinotum Sueyoshi & Rohác ˘ek, 2003: 18–21, Figs 1a–g, 2a, 3 [description, relationships]. Amygdalops thomasseti: Hardy & Delfinado 1980: 225–227 , Figs 94a–e [misidentification].

Type material: Holotype male, labelled: ‘ Sueyoshi Park , Naha City, Ryukyu, Japan, 26.iii.2000, H. Nakayama leg.’ (lime green circle), ‘ An 1081’ ( BLKU). For paratypes see Sueyoshi & Rohác ˘ek (2003).

Other material examined: SEYCHELLES: Mahe, Beau Vallon, 4.xi.1997, 1 male 1 female ; Mahe, Jardin botanique, 11.xi.1977, 1 male 1 female; Mahe, Anse Royale, 13.xi.1977, 3 males 1 female ; Mahe, Rivière aux Poules Bleues, 13.xi.1977, 1 male 1 female; Mahe, Cascade, 18.xi.1977, 1 male , all J. David & L. Tsacas leg. (Mission Seychelles C.N.R.S.-R.C.P. 318, Novembre 1977) ( BMNH, 1 male 1 female SMOC). Most specimens with genit. prep .

Description: Male. Total body length 1.74–2.07 mm. Body bicolorous, brown and yellow. Head somewhat higher than long. Occiput brown to ochreous brown, usually paler medially and around bases of vte and vti. Frontal triangle reaching to anterior third of frons, with very narrowed anterior corner, largely bare and shiny, including ocellar triangle. Frons brown with yellow anterior third; stripes between frontal triangle and orbits distinctly darker brown than other parts of frons, greyish microtomentose and dull. Orbit bicolorous, its anterior third yellow and dull, posterior two-thirds brown and more shining. Face yellow to pale ochreous; parafacialia and gena whitish yellow to almost white, with silvery white microtomentum; also postgena pale yellow, contrasting with brown occiput. Mouthparts yellowish orange including palpus. Cephalic chaetotaxy: pvt distinct and strongly crossed; vti about two-thirds of length of vte, the latter longest of cephalic setae; oc about as long as vti; 2 long ors, posterior as long as vte or slightly shorter, anterior distinctly shorter but always longer than oc; 2 (rarely only 1) microsetulae in front of anterior ors, anterior orbital microsetula only half length of posterior one; usually 2 pairs of microsetulae medially in front of frontal triangle; 1 long vi and 1 subvibrissa, about two-thirds to three-fourths of vi; peristomal setulae longer anteriorly, short posteriorly; postocular setulae very minute; palpus with usual subapical seta. Eye very convex, with longest diameter 1.5 times as long as shortest one. Gena anteriorly very narrow; its smallest height 0.07 times as long as shortest eye diameter. Antenna yellow to yellowish ochreous; usually more or less darkened on outer side of pedicel and around base of arista. Arista 1.9 times as long as antenna, long pectinate.

Thorax narrower than head, bicolorous, brown and yellow. Mesonotum including scutellum brown, more rarely with a pair of pale ochreous spots medially just behind neck. Humeral and notopleural areas yellow or orange yellow; pleural part of thorax with brown dorsal band extending from propleuron to haltere and sharply delimited from pale yellow to whitish yellow ventral portion of pleura. Thoracic chaetotaxy: 1 very small and fine prs; 2 dc, posterior very long (about as long as apical sc), anterior short and weak, less than one-third of posterior dc; 2 sc, apical long and strong, laterobasal yet shorter than anterior dc; 1 ppl, reduced to fine microsetula; 2 stpl, posterior longer; additional setae on sternopleuron rich on ventral part with some hair-like setulae inserted also close to stpl macrosetae. Scutellum rounded triangular with slightly convex dorsal surface. Legs completely yellow to pale yellow, with the same chaetotay as in A. thomasseti , but f 1 and f 3 with longer and more numerous setae in posteroventral rows. Wing ( Fig. 128 ) with pattern and venation of A. thomasseti type, but darkened stripe along R 4+5 usually less distinct and also pale spot between R 2+3 and R 4+5 not as whitish as in A. thomasseti , thus more similar to that of A. simplicior sp.n. R 4+5 and M subparallel, very slightly convergent apically; r-m situated near middle of discal (dm) cell. Wing measurements: length 1.62–2.00 mm; width 0.50–0.62 mm, Cs 3:Cs 4 = 2.12– 2.40, r-m\dm-cu: dm-cu = 3.18–3.78. Haltere with ochreous stem and brown knob.

Abdomen. Preabdominal terga large, brown to dark brown, T4 with small, T5 with larger yellow or ochreous laterobasal spot on each side. T6 weakly sclerotised, short and very pale. Preabdominal sterna small and narrow, pale ochreous and becoming somewhat wider posteriorly, S5 the largest. S6–S8 dorsolaterally fused, S6 ventrally shortened, transversely band-like, S8 relatively long.

Genitalia. Epandrium hemispherical, medium-long ( Figs 66, 67 ), moderately setose, with 1 dorsomedial and/or also 1 dorsolateral pair of longer setae; anal opening large, rounded substriangular ( Fig. 66 ). Cercus long, projecting ventrally, almost as long as gonostylus. Medandrium ( Fig. 66 ) comparatively high and wide. Gonostylus ( Fig. 70 ) small, suboblong, with tapered but rounded apex; most of its outer side with dense micropubescence, only anterior margin bare; inner side of gonostylus with longer setae, particularly in apical half. Hypandrium ( Fig. 71 ) moderate, with weak unpigmented internal lobes; transandrium ( Fig. 68 ) simple, slender, with straight ventral margin; caudal process represented by a pair of dorsally separate and weak sclerites each of which has small lateral projection. Pregonite ( Fig. 71 ) very low, fused with hypandrium, incurved and only posteriorly slightly ventrally projecting, with only 3–4 setae, 1 of them longer. Postgonite ( Fig. 71 ) slightly sinuous, proximally slender, widened in the middle, apically tapered but not acute, with only a few minute microsetulae on outer side; basal sclerite attached to postgonite robust, finely dotted and provided by some small teeth posteroventrally. Aedeagal part of folding apparatus attached to base of phallapodeme ( Fig. 69 ) not darkened dorsally, provided by large flat polygonal tubercles; connecting sclerite very slender, long, pale pigmented. Basal membrane densely spinulose, particularly ventrally ( Figs 68 , 71 ).Aedeagal complex ( Fig. 69 ) with moderate phallapodeme, having bifurcate base and apex with short lateral projections. Aedeagus with short frame-like phallophore and large distiphallus. Base of distiphallus bare. Saccus of distiphallus large, except for base membranous and provided by rich thorn-like spines dorsally, laterally as well as subapically; fine spinulae are only close to sclerotised base of saccus. Filum of distiphallus formed by 2 dark stripe-like twisted sclerites which are closely affixed except for proximal and distal end and terminate in very tapered apex. Ejacapodeme small, with very slender projection.

Female differs from male as follows:

Total body length 1.90–2.42 mm.

f 3 posteroventrally simply finely setulose, lacking shortened setae. Wing measurements: length 1.94–2.27 mm, width 0.55–0.68 mm, Cs 3: Cs 4 = 2.00–2.39, r-m\dm-cu: dm-cu = 3.27–3.54. Abdomen with preabdominal terga shorter, more transverse. T1 and T2 completely dark brown, T3–T6 with pale yellow laterobasal spot on each side; spots on T3 smallest, on T5 largest (extended over more than basal third of sclerite). Preabdominal sterna smaller and narrower than in male, pale ochreousyellow; S4 and S5 subequal and as broad as S6.

Postabdomen ( Figs 72, 73 ). T6 large, markedly broader than T7, densely shortly setose, brown with pale yellow laterobasal spots which are medially connected by transverse stripe. S6 whitish yellow, distinctly narrower than T7, with fine setae. T7 narrow, dark brown, anteriorly shallowly emarginate, with dense short setae in posterior half. S7 with pattern similar to that of A. simplicior , thus, with unpigmented central area, darkest anterolateral rounded corners and setose posterior pigmented part, but differing in elongate shape, lacking anteromedial cuspidate structures and richer setosity. T8 paler than T7, plate-shaped, with strongly rounded posterior corners and thin dense setae in posterior half. S8 dark, distinctly narrower than T8, finely densely setulose, posteromedially slightly bulging, with narrow mediodorsal incision as usual. T10 small and relatively short, dark and bare except for small posteromedial microtomentose area, and with of a pair of longer setae. S10 also dark but wider than T10, micropubescent, with setulae at posterior margin. Internal sclerotisation of genital chamber very weak, unpigmented and hardly visible but provided with short thorn-like spines near genital opening ( Fig. 76 ). Ventral receptacle ( Fig. 75 ) membranous, formed by strangled pouch and vermicular, ventrally directed, terminal projection. Spermathecae (1+1) not spherical as incorrectly described by Sueyoshi & Rohác˘ek (2003) but in contrast to all known relatives somewhat pear-shaped ( Fig. 74 ), narrowed at duct insertion, with dense curved spines inserted on basal half of spermatheca; duct cervix developed but short. Cerci ( Fig. 72 ) moderate, with short setae.

Discussion: This widespread species (see below) belongs to the A. thomasseti group and resembles species with dark mesonotum and knob of halter (i.e. A. major sp.n. and A. acer sp.n). Its wing pattern is most similar to that of A. acer sp.n. but it can be recognised from both above species in having paler occiput and spots around bases of vertical setae, yellow or orange humeral and notopleural areas and quite different male and female genitalia.The peculiar caudal process of transandrium with lateral projections, saccus of distiphallus and pyriform spermathecae armed by short thorns and other genital features indicate that A. nigrinotum probably has no close relative among African species of the A. thomasseti group and that its nearest ally could plausibly be found in the Oriental (unfortunately largely unknown) fauna of the genus.

Biology: Sueyoshi & Rohác˘ek (2003) recorded adults collected from March to May and August to December. In Seychelles, the flies were captured in November.

Distribution: The species has only been known from Japan (Izu, Ogasawara, Ryukyu Is.), Hawaii (Oahu I.) and Indonesia (Java), see Sueyoshi & Rohác˘ek (2003). Hardy &Delfinado (1980, sub A. thomasseti ) recorded it also from Hawaii (Oahu I., Kauai I., Molokai I., Hawaii I.). The above record from Seychelles is the first from the Afrotropical Region.

Figures

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 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 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 94–98. Amygdalops sparsus sp.n., female paratype (Uganda). 94. Postabdomen + 5th segment, dorsal view. 95. Ventral receptacle, lateral view. 96. Internal sclerites and S8, ventral view. 97. Postabdomen + 5th segment, ventral view. 98. Spermathecae. Scales: Figs 94, 97 = 0.1 mm, others = 0.05 mm. For abbreviations see text.