Amygdalops silaceus, ROHÁČEK J., 2008
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publication ID |
https://doi.org/ 10.5281/zenodo.12584953 |
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persistent identifier |
https://treatment.plazi.org/id/A2710835-FFB0-8C38-9B1B-B162FE3CFD22 |
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treatment provided by |
Felipe |
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scientific name |
Amygdalops silaceus |
| status |
sp. nov. |
Amygdalops silaceus View in CoL sp. n.
( Figs 14–25 View Figs 14–19 View Figs 20–25 , 162 View Figs 161–162 )
Type material: Holotype male labelled: “ Pt. Oca, GUAM, Mariana Is., May 31, 1945, Light Trap, G. E. Bohart, J. L. Gressitt ” (intact, USNM) . Paratypes: MARIANA Is. : Guam I., same data as for holotype but 28.v.1945, 1 female and 4.vi.1945, 1 female ; Guam I., Tumon Bay , iv.1946, 1 male (damaged, abdomen lost), N. L. H. Krause leg. ; Guam I., Pt. Ritidian, 1.viii.1945, 1 female, J. L. Gressitt leg. ; Rota I., Rota, 20.vi.1946, 1 male, Townes leg. ; Saipan I., ex Off. s’ mess [= Officer’s mess], 7.ix.1944, 4 females (1 damaged), Saipan Med Bn [= Medical Battalion], 2nd Mar. Div. [= 2nd Marine Division] leg. ( USNM, 1 female paratype SMOC, 1 male 2 female paratypes with genit. prep.) .
Etymology – The species is named for its prevailing colour of thorax ( silaceus = Lat. ochreous yellow).
Description – Male. Total body length 1.67–1.75 mm. Body bicolourous, ochreous-yellow and brown. Head about as long as high, distinctly angular in profile. Frons relatively long and narrow, whitish yellow and ochreous-brown. Occiput ochreous-yellow medially and brown laterally, bare, medial pale area sparsely whitish microtomentose. Frontal triangle narrowly elongate, distinctly depressed, reaching to anterior third of frons, ochreous to ochreous-brown and dull. Ocellar triangle brown between ocelli, ochreous laterally, distinctly shining. Medial stripe in front of frontal triangle dark ochreous-brown, rest of frons including orbits whitish yellow, sparsely whitish microtomentose and subshining. Face narrow, with a pair of brown medial stripes, laterally paler brown; parafacialia, gena and postgena whitish, sparsely silvery white microtomentose. Mouthparts (including palpus) whitish yellow. Cephalic chaetotaxy: pvt small, convergent but not crossed; vti distinctly shorter than vte, the latter and posterior ors longest of cephalic setae; oc about as long as vti; 2 long ors (posterior as long as vte, anterior shorter) and 1 short ors (= enlarged microsetula, inserted close to anterior ors) plus 1 microsetula in front of the latter; 1–2 medial microsetulae in front of frontal triangle; 1 long vi and 1 shorter subvibrissa (about two-thirds of vi); 4–5 weak peristomal setulae; postocular setulae minute; palpus with 1 dark seta as long as subvibrissa. Eye strongly convex, elongately ellipsoid; its longest diameter 1.6 times as long as shortest one. Gena narrow, markedly widened posteriorly; its smallest height about 0.07 times as long as shortest eye diameter. Antenna with pedicel ochreous; 1st flagellomere with large area around base of arista ochreous-brown, rest white and whitish ciliate on anterior corner. Arista only 1.5 times as long as antenna.
Thorax narrower than head, with distinctive bicolourous pattern. Mesonotum with broad ochreous-yellow medial area (between dc and sc setae) extended from thoracic neck to apex of scutellum; only lateral sides with (dark) brown longitudinal band reaching onto basal corners of scutelum; humeral and notopleural areas narrowly ochreous-yellow. Pleural part with brown longitudinal band along dorsal margin (from anterior spiracle to haltere); rest of pleura yellow to whitish yellow. Thoracic chaetotaxy: 1 prs reduced to microseta; 2 dc (anterior short and weak, posterior very long); 4–5 rows of ac microsetae on suture but only 2 rows behind posterior dc; 2 sc, apical yet longer than posterior dc, laterobasal short; ppl indistinct; 2 stpl, anterior weak and short; ventral part of sternopleuron with about 5 pale hair-like setae. Scutellum ochreous-yellow, with only basal corners brown. Legs yellow, coxae, trochanters and tarsi usually paler. f 3 with posteroventral row of 7–8 densely arranged setae in distal third, the most distal 4–5 thickened and shortened. Wing ( Fig. 162 View Figs 161–162 ) narrow, with almost unicolourous pale ochreous membrane faintly brownish darkened only at Cs 3, more diffuse beyond this. Veins pale brown. R 2+3 subparallel and running close to C, with slightly upcurved apex terminating far from apex of R 4+5. R 4+5 and M close to each other, subparallel or slightly convergent apically. Cell dm short and narrow; r-m situated near its middle. CuA 1 and A 1 not reaching wing margin, the former less than half length of the latter. Alula strongly reduced but anal lobe distinct. Wing measurements: length 1.47–1.63 mm; width 0.47–0.51 mm, Cs 3: Cs 4 = 2.25–2.90, r-m\dm-cu: dm-cu = 3.71–4.43. Haltere with dark yellow stem and brown knob.
Abdomen. Terga moderately wide, rather sparsely and shortly setose. T1-T3 almost entirely brown (or paler brown at anterior margin of T3); T4 and T5 brown, with large anterolateral semicircular yellow spots (in T5 almost meeting anteromedially). T6 reduced, desclerotized and unpigmented, bare. Sterna (S1-S5) simple, relatively wide, becoming slightly wider posteriorly (S5 largest), pale yellow, with finer setae than on terga. S6-S8 asymmetrical, all partly fused together. S6 most transverse; S7 on left side of postabdomen, 1.5 times as long as S6. Both S6 and S7 ochreous-brown, with anterior darkened marginal strip-like swelling and each with 2 microsetae. S8 longer than S7, dark brown as epandrium and similarly setose as T5. 7th left spiracle large, embedded in S7 near its anterior margin laterodorsally.
Genitalia. Epandrium ( Figs 14–15 View Figs 14–19 ) relatively wide, with strong setae, 1 dorsomedial, 1 dorsolateral and 1 caudal longest; anal opening moderate ( Fig. 14 View Figs 14–19 ). Cercus large, slightly shorter than gonostylus. Medandrium ( Fig. 14 View Figs 14–19 ) small compared to epandrium. Gonostylus ( Fig. 18 View Figs 14–19 ) shorter than epandrium, narrow, suboblong, with tapered but rounded apex slightly bent inside (cf. Fig. 14 View Figs 14–19 ); its outer side with a few setulae and reduced micropubescence (restricted to posterodorsal area); inner view. Scales: 0.05 mm
side of gonostylus with longer setae, particularly near anterior margin. Hypandrium ( Fig. 16 View Figs 14–19 ) simple, slender, with weak unpigmented internal lobes; transandrium ( Fig. 17 View Figs 14–19 ) strongly bent medially, with deeply concave ventral margin; caudal process only indicated by medial dark-pigmented stripe. Pregonite ( Fig. 16 View Figs 14–19 ) very low, fused with hypandrium, incurved, posteriorly internally separated from hypandrium by an incision; its posterior part slightly projecting ventrally and with 1 long and 1 short seta, its anterior part with 3 setae. Postgonite ( Fig. 16 View Figs 14–19 ) short, simply tapered, with rounded apex and 1 setula near middle of its outer side; basal sclerite of postgonite small. Aedeagal part of folding apparatus ( Fig. 19 View Figs 14–19 ) not darkened dorsally, externally provided with flat lenticular tubercles (enlarged ventrally) and some fine spines among them. Connecting sclerite slender, elongate, darker pigmented dorsally. Basal membrane overgrown by short broad spines particularly posteroventrally ( Figs 16–17 View Figs 14–19 ). Aedeagal complex ( Fig. 19 View Figs 14–19 ) with slender phallapodeme, having strongly widened forked base, slender ventral fulcrum and short apex. Saccus of distiphallus not large, only basally and ventrally somewhat sclerotized and darker pigmented, otherwise membranous and provided with fine acute spines basally, ventrally and subapically and with small blunt tubercles dorsolaterally preapically. Filum of distiphallus relatively short, formed by 2 dark stripe-like sclerites being closely affixed but diverging in proximal and distal end and terminating in dilated membranous apex ( Fig. 19 View Figs 14–19 ). Ejacapodeme small, pale-pigmented, with digitiform projection.
Female. Similar to male unless mentioned otherwise. Total body length 1.71–2.34 mm. Face with brown pattern composed of 4 more or less distinct longitudinal stripes, lateral pair being as dark as (or darker than) medial pair. f 3 posteroventrally simply finely setulose. Wing measurements: length 1.63–1.87 mm, width 0.52–0.58 mm, Cs 3: Cs 4 = 2.14–2.73, r-m\dm-cu: dm-cu = 3.10–4.00. Preabdominal terga wider and more transverse than in male, brown, with pale yellow spots. T1-T2 with pale yellow medial area, wider on T1, narrower on T2. T3-T5 (and also T6, see below) with large pale yellow anterolateral semicircular spots (smaller on T3, larger on T5). Preabdominal sterna (S1-S5) pale yellow to whitish, S1 shorter and bare; S2-S5 about as long as wide and of almost the same size or S5 slightly wider.
Postabdomen ( Figs 21–22 View Figs 20–25 ). T6 large, markedly broader than T7, densely shortly setose, pale yellow with brown sinuous transverse band ( Fig. 21 View Figs 20–25 ). S6 whitish yellow, as wide as T7, with fine setae in posterior half. T7 narrow, dark brown (darkest of postabdominal sclerites) but with anterior and posterior pale-pigmented marginal area, with dense short setae in posterior half. S7 ( Fig. 22 View Figs 20–25 ) narrow (narrower than S8), with distinctive anterolateral corners, darkened only along anterior and lateral margins, thus, with large unpigmented but microtomentose area, and with 8 fine long setae in posterior half. T8 pale-pigmented, plate-shaped, transversely suboblong, with sparse thin setae along posterior margin. S8 darker posteriorly and paler anteriorly, finely setulose, of usual shape. T10 small, brown like cerci, finely microtomentose in addition to a pair of long medial setae. S10 wider and paler than T10, micropubescent, with setulae at posterior margin. Internal sclerotization of genital chamber ( Figs 20, 24 View Figs 20–25 ) distinctive, pale brown, formed by a pair of elongate, anteriorly wing-like widened sclerites, and by a distinct transversely compressed annular sclerite; vaginal area near genital opening densely finely spinulose. Ventral receptacle ( Fig. 20 View Figs 20–25 ) small, membranous, formed by a pouch projecting in ventrally curved digitiform terminal projection. Accessory gland ( Fig. 20 View Figs 20–25 ) finely granulose, on short, distally widened and ringed duct. Spermathecae almost spherical ( Figs 23, 25 View Figs 20–25 ), without surface spinulae; duct cervix developed but short, pale-pigmented. Cerci ( Fig. 21 View Figs 20–25 ) rather robust, brown, with rich but not long setae.
Discussion – A. silaceus sp. n. is distinguished by its largely yellow head, unusually enlarged “microseta” in front of the anterior ors, mesonotum ochreous-yellow between dc lines and dark brown laterally to them, wing faintly brownish only at Cs 3, R 4+5 and M close to each other, elongate gonostylus with reduced micropubescence, caudal process of transandrium reduced to darkened medial stripe, short postgonite, saccus of distiphallus short, female S7 very narrow and spermathecae without surface spinulae. Cladistically (see Fig. 175 View Fig ) it represents a sister-group clade to all remaining Oriental and Oceanian species except for A. lineola .
Biology – The type specimens were collected in IV-VI, VIII and IX, some of them in a light trap.
Distribution – The species is plausibly endemic to Mariana Is. ( Guam I., Rota I., Saipan I.).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.