Aeschnosoma hamadae, Fleck, Günther & Neiss, Ulisses G., 2012

Fleck, Günther & Neiss, Ulisses G., 2012, A new species of the genus Aeschnosoma Selys, 1870 (Odonata: Anisoptera: Corduliidae s. s.), Zootaxa 3159, pp. 47-58 : 48-56

Aeschnosoma hamadae sp. nov.

( Figures 2–39 )

Material. Holotype male: Brazil, Amazonas, Presidente Figueiredo, Ramal Urubuí, Sítio Vivenda Fênix, small blackwater stream (02º02'56.2"S / 60º06'08.7"W, at approximately 78 m above msl), F-0 larva 02.V.2008, exuvia dry stored and corresponding reared male adult stored in 92% ethanol (emerged 14.X.2008, put in ethanol three days after emergence), G. Fleck leg. Allotype female: Brazil, Amazonas, Manaus, Fazenda Experimental da UFAM - Grade PPBio, BR 174-Km 38 (02º39'39.9"S; 60º03'49.4"W, at approximately 80 m above msl), 10.XI.2008, dry stored, U.G. Neiss leg.

Paratypes: Brazil, Amazonas, Presidente Figueiredo, one reared Ƥ, Balbina, Reserva Biológica do Uatumã (01º48'58.8"S / 59º13'51.1"W; at approximately 120 m above msl), F-0 larva 04.X.2009, exuvia dry stored and corresponding reared Ƥ dry stored (emerged 18.X.2009), U.G. Neiss leg.; Manaus, one reared Ƥ, Reserva Florestal Ducke, highway AM 010–Km 26, Igarapé Bolívia 12 (02º59'15.1"S / 59º56'31.9"W; at approximately 74 m above msl), F-0 larva 15.X.2009; exuvia dry stored and corresponding reared Ƥ dry stored (emerged 20.X.2009), U.G. Neiss leg.; 2 F-0 Ƥ larvae, same data as holotype, G. Fleck, C. Jr. Monteiro and U.G Neiss leg.; Manaus, 2 F-0 3 larvae and 2 F-0 Ƥ larvae, Reserva Florestal Ducke, 15.X.2009, U.G Neiss leg; Novo Airão, highway AM-352 Km 24, black-water stream, 1 F-0 3 larva and 2 F-0 Ƥ larvae, U.G Neiss leg.

Etymology. Named after our colleague and friend Dr. Neusa Hamada, entomologist at the Instituto Nacional de Pesquisas da Amazônia/INPA, Manaus, Brazil.

Descriptions. Male holotype.

Exuvia of ultimate instar larva. Robustly built ( Fig. 2 ) and somewhat depressed, and except the distal part of the head, the dorsal part of the S9, the S10 and the anal pyramid, remarkably covered by spinelike setae of various size; filiform setae also present and essentially localised on the posterodorsal side of the occiput, the anterolateral sides of prothorax, the tibiae, the abdominal lateral spines, and on lateral and distal margins of S9; general colour light brown with anterodorsal part of head and ring near the apex of all femora more sombre, and with abdomen darkened toward posterior part and patterned as showed in Figs. 2–3 .

Head transverse, subrectangular, nearly twice as wide as long ( Fig. 4 ); frontal margin weakly developed, without spinelike setae, and bearing instead about 60 hairlike setae separated into two groups, one on each side of sagittal plane ( Fig. 5 ); right antenna 5-segmented (aberration), left antenna 7-segmented with following anterodistal relative length of the antennomeres: 0.5, 0.6, 1.0, 0.9,1.0, 0.9, 0.7 ( Fig. 4 ); functional part of the eyes globular and well developed (particularly uncommon for corduliids, Fig. 4 ); posterior occipital margin straight; dorsolateral part of occiput with a pair of low tubercles with a few filiform setae and armed with 4 or 5 strong spinelike setae and a few additional weaker ones ( Fig. 4 ); lateral part of occiput also armed with fields of spinelike setae, those of upper part comprising well aligned setae; mask robustly built, prementum-submentum articulation situated between the mesocoxae ( Fig. 3 ); ventral side of prementum with premental groove short but very distinct (see Theischinger & Fleck 2003) ( Fig. 3 a); lateral margin of prementum bordered by row of ventrally directed setae, replaced distally by hairlike setae ( Fig. 6 ); anterior dorsolateral part of prementum with strongly developed spinelike seta at each palp articulation, and slightly overlapping it ( Figs. 6, 7 ); prementum with two sets of 8 premental setae, the four more lateral ones of each set being distinctly more developed than others ( Fig. 7 ); distal margin of prementum slightly undulated, undulations separated by setae increasing in size toward apex ( Fig. 7 ); between long premental setae and distal margin, two fields of very small setae present, more proximal one made by thin and rigid setae directly implanted on cuticle, the distal one consisting of extremely thin and rather soft setae, each implanted into a small circular excavation ( Fig. 7 ); labial palps each with short and rather strong seta at internal side, close to articulation, followed distally by field of 7 distinctly smaller setae ( Fig. 7 ); basal 2/5 of dorsal margin of labial palps with row of 13–15 spinelike setae ( Fig. 7 ); labial palps with 7 palpal setae each ( Fig. 7 ); distal margin of labial palps with 14 deeply incised indentations, most of them bearing each three raptorial setae, the most dorsal one of these generally strongly reduced ( Fig. 8 ); mandibular formula R 1234 y’ ab’b with incisor 2 small, y’ small and smooth, b well developed, and b and b’ fused at base, L 1234 y abd with y well developed, d well developed and fused with b at base ( Fig. 9 ).

Thorax strong, slightly wider than long; pronotal shield moderately developed, its posterior margin rounded and with rather well marked posterior edge bearing distinct spinelike setae; propleuron with episternum poorly developed and bearing on its lateral margin a clump of filiform setae, epimeron better developed and bearing on its lateral margin aligned small spinelike setae; wing pads short and not reaching posterior margin of S6 (exuvia) ( Fig. 2 ); legs moderately long and strong with femora bearing two fields—one dorsolateral and one ventrolateral—of small spinelike setae, tibiae bearing filiform setae and rows of rather strong and well aligned spinelike setae ( Figs. 2–3 ); metatibiae with distinct subapical clump of long, strong setae ( Figs. 3 b, 10); apex of protibiae and metatibiae with mall field of specialised trifid setae reaching tarsus articulation; ventral side of tarsomeres with two rows of well developed setae, most of these trifid.

Abdomen distinctly broadened posteriorly and slightly depressed with dorsal side rounded and ventral side flat; dorsal hooks absent; strong, long and acutely pointed lateral spines, bearing strong spinelike setae and filiform setae, present on S8 and S9 ( Figs. 2–3 , 11 ); lateral spines of S8 very slightly divergent and about as long as S8 along sagittal plane; lateral spines of S9 slightly upturned, almost parallel and about as long as S9 along sagittal plane, distance between apices distinctly greater than length of spines ( Figs. 2–3 , 11 ); lateral and posterior margins of abdomen bordered by strong spinelike setae that increase distinctly in size posteriorly ( Figs. 3 , 4 , 11 ); tergites covered by spinelike setae, those of lateral parts and those bordering posterior margin distinctly better developed than dorsal ones ( Fig. 11 ); S9 without anterior small dorsal spines, with a few small dorsolateral ones, and with very strong marginal ones (lateral margins, and ventral distal margin) ( Figs. 11–12 ); dorsal basal half of each lateral spine and adjacent surface slightly proximal to it covered by strong spinelike setae, about 11–14 for each lateral spine of S8, and about 12–13 for each lateral spine of S9 ( Fig. 11 ); S10 very small, bare except for several very small indentations at posterior margin, embedded in S9, and completely fused with it (no intersegmental soft membrane) ( Figs. 11, 14 ); anal pyramid rather small with all elements acute and slightly ventrally directed, and with apical half of epiproct and paraprocts slightly downcurved ( Figs. 11, 14 ); epiproct cordiform, with theca of future male inferior appendage rather well marked, reaching apical 2/3 of epiproct and apically rounded ( Figs. 11, 14 ); cerci well developed, reaching apical 2/3 of epiproct ( Fig. 11 ); antepleurites present on S4, S5 and S9, those of S4 and S9 rather small.

Corresponding reared adult. Medium-sized dragonfly; general body coloration brown to black with yellow markings, and with some light bluish metallic reflection on synthorax ( Figs. 15–18 ).

Head voluminous with eyes in contact over a long distance dorsally; labium pale yellow with prementum and inner margin of palps brown ( Fig. 16 ); labrum dark brown with diffuse paler mark ventromedially; clypeus yellowish; anteclypeus darker yellow; postclypeus yellow with two short oblique furrows brownish ( Fig. 16 ); frons dark brown, without metallic reflection and with yellow spot below insertions of antennae ( Fig. 16 ); antennae with scape and pedicel very short and flagellum very long and thin; vertex swollen, very slightly flattened on top, and without any indentation or tubercle; occiput black with inconspicuous copper reflection; posterior margin of eyes with ‘corduliid indentation’ poorly indicated ( Fig. 16 ).

Prothorax yellowish, with hind margin not darker, and with posterodorsal rounded margin whitish and covered by minute setae; synthorax patterned with brown and yellow as indicated in Figs. 16 and 17 , and with light bluish metallic reflection on brown surfaces of lateral and anterodorsal parts ( Fig. 16 ); legs moderately long, mainly black or dark brown except prothoracic legs with trochanter and anterior part of femur yellow ( Fig. 16 ); ventral side of meso- and metafemora with two longitudinal and parallel fields of equal short spines; apex of femora with a ventral sublateral spine distinctly stronger than the other spines; all tibiae with keels, that of prothoracic leg occupying distal 1/2, that of mesothoracic leg occupying distal 2/3, and that of metathoracic leg occupying distal 9/10 of the tibia; tarsal claws moderately developed and with ventral tooth rather poorly developed and situated between 1/2 and distal 3/5 of claw. Wings slightly saffron-tinged with veins dark brown to black, membranules grayish-brown and pterostigmata short and brown ( Figs. 15, 19 ); left FW antenodal crossveins 17 of the first rank (between C and ScP) and 17 of the second rank (between ScP and R); right FW antenodal crossveins 17 (first rank) + 16 (second rank); FW antenodals of the first rank generally aligned with those of the second rank but only Ax1 and Ax2 distinctly reinforced and bracketlike; HW antenodals 11 + 11 with those of first rank and those of second well aligned, and, except the most distal ones, reinforced and bracketlike; FW postnodal crossveins 8; HW postnodal crossveins 10–11; cross veins distal to pterostigma: 4; FW hypertriangles with 3–4 crossveins; HW hypertriangles with 1–2 crossvein(s); discoidal triangles 2-celled; FW subtriangles 3-celled, HW subtriangles simple; FW subdiscoidal spaces with 3–4 crossveins, HW subdiscoidal spaces with 1–2 crossveins; Rspl well defined and covering one row of about 8 cells on FW and one row of about 9–10 cells on HW; Mspl well defined and covering one row of 7 cells on FW and one row of 6 cells on HW; anal loop with 21–22 cells; anal triangle well marked and 2-celled; anal angle (tornus) with 8–9 minute spines ( Fig. 20 ); dorsal part of anteroproximal angle of anal triangle (AAa/ (AAb+AP) bifurcation) with strong spine perpendicular to wing plane.

Abdomen shaped and patterned with yellow and black as indicated in Figs. 16–18 ; abdomen not compressed laterally and with S5 and S6 slightly depressed dorsoventrally; lateral carina extending from S4 to S8; S7 and S8 triangular in cross section due to distinct dorsal carina; secondary accessory genitalia with prominent genital lobe and smoothly pointed posterior hamule shaped as showed in Figs. 21 and 22 ; anterior part of S8 ventrally with distinct longitudinal brush of long, dark setae ( Fig. 23 ); male superior appendages rather thin and straight, subcylindrical, slightly but distinctly longer than inferior appendage, and bearing near middle of ventral side a small protuberance ( Figs. 23–25 ); male intromittent organ complex, with three terminal prolongations differently sclerotized, coloured and shaped as indicated in Figs. 26–28 .

Measurements (mm). Exuvia: total length 19.3; width of head (between eyes) 6.3; width of abdomen 8.1; left antenna 4.0. Imago: total length (including anal appendages) 52.5, hindwing length 35.0; length of hind femur 7.5; length of abdomen (including anal appendages) 39.0.

Female specimens. The adult females closely resemble the male holotype ( Figs. 29–30 ), with the following main differences: larger size with somewhat broader abdomen; inner margin of labial palps with thinner brown strip ( Fig. 31 ); labrum nearly entirely dark brown with diffuse pale marking almost imperceptible; dorsolateral abdominal yellow markings and S2 ventrolateral yellow markings somewhat better marked and wider ( Fig. 30 ); middorsal spot on S2 bean-shaped, not circular as in holotype male ( Fig. 29 ); anterior ventrolateral spots of S4–S7 less marked ( Fig. 30 ); S8 ventral tergal margins without long setae; terminal abdominal appendages (cerci) robust, subcylindrical, slightly curved inward and about as long as S9, and without indentation ( Figs. 32–33 ).

S9 genital plate large with well marked longitudinal median carina that is increasingly well developed toward posterior margin; presence of well marked transverse undulated strip of strong black setae at base of genital plate; genital plate distal margin rounded and slightly overlapping S10 ( Fig. 34 a); S8 vulvar lamina poorly developed with distinct convex portion in its median part and two lateral membranous structures as indicated in Figs. 34 a and 34b.

Wings hyaline in mature female (both wings brownish tinged at apex and very slightly so distal to nodus in the two immature reared females), with veins dark brown to black; membranule dark grayish; pterostigma short and light (immature specimens) to dark brown (mature specimen) ( Fig. 31 ); FW antenodal crossveins 16–21 of first rank (between C and ScP), 16–19 of second rank (between ScP and R), FW antenodals of first rank generally aligned with those second rank (sometimes most distal ones not or poorly aligned); HW antenodals 11–12 (first rank) and 12–13 (second rank) with those of first and second ranks generally well aligned, and except most distal ones reinforced and bracketlike; FW postnodal crossveins 8–9; HW postnodal crossveins 10–12; anal loop with 25–32 cells; cross veins distal to pterostigma 4, except 5 in two right HW; FW hypertriangles with 3–5 crossveins; HW hypertriangles with 2–3 crossveins; FW discoidal triangles 2–3-celled; HW discoidal triangles 2–4-celled; FW subtriangles 3–4-celled, HW subtriangles 2-celled, except for one right wing with subtriangle simple; FW subdiscoidal spaces with 4–5 crossveins, HW subdiscoidal spaces with 2 crossveins; Rspl well defined and covering one row of about 9–12 cells in FW and one row of about 12–14 cells in HW; Mspl well defined and covering one row of 7–9 cells in FW and one row of 7–8 cells in HW.

Measurements (mm): total length (with anal appendages) 52–57; hindwing length 40–41; length of hind femur 7.5; length of abdomen 39–44.

Additional F-0 specimens. The larvae studied are nearly identical to the exuvia of the male holotype, and only a few differences or variations are detectable: colour little darker than holotype exuvia, mainly on distal margins of S4 to S8; antennae 7-segmented; apex of prementum (anterior margin) with pair of setae (the absence of these setae in male holotype is considered therefore as an aberration); two sets of 8 premental setae on dorsal surface of prementum sometimes augmented by one or two very short additional median setae; internal side of labial palp with short and rather strong seta close to articulation followed distally by a field of 6–10 smaller setae; dorsal margin of the labial palps with row of 9–14 spinelike setae; one paratype larva with 8 palpal setae on right palp; HW pads surpassing distal half of S6; S8 lateral spines with about 9–15 dorsal strong spinelike setae and S9 with about 7–13 strong spine-like setae; female anal pyramid with epiproct more acuminate than that of male and with cerci reaching or slightly surpassing 1/2 of epiproct ( Fig. 13 ).

Measurements (mm): F-0 larvae: total length 19.0–20.7, width of head (between eyes) 6.1–6.7; width of abdomen 8.1–9.1; antennae 3.6–4.1.

Figures

FIGURES 2 – 3. Aeschnosoma hamadae sp. nov., last-instar exuvia (holotype): 2) dorsal view; 3) ventral view, the arrows indicate: a) the ventral premental groove of the mask and b) the clump of robust setae on the hind femora.

FIGURES 4 – 9. Aeschnosoma hamadae sp. nov., last-instar exuvia (holotype): 4) head, dorsal view, setae of base of antennae and frons omitted; 5) head, dorsal view, detail of the frons; 6) superior part of the prementum, right lateral view; 7) mask, dorsal view, showing the complex system of setae; 8) labial palps, frontal view; 9) mandibles: a, b: right mandible, c, d: left mandible.

FIGURES 10 – 14. Aeschnosoma hamadae sp. nov., last-instar exuviae: 10) detail of the apex of the metafemora (holotype); 11) three last abdominal segment of the male, dorsal view (holotype); 12) posterior margin of S 9, ventral view (female paratype); 13) female anal pyramid, dorsal view (paratype); 14) male anal pyramid, and dorsal setae of the S 9 lateral spine, right lateral view (holotype).

FIGURES 15 – 20. Aeschnosoma hamadae sp. nov., adult male (holotype): 15) dorsal general habitus; 16) lateral view; 17) thorax and abdomen, dorsal view; 18) abdomen, ventrolateral view; 19) left wings, ventral view; 20) detail of the posterior wing anal angle showing the field of minute spinelike setae.

FIGURES 21 – 28. Aeschnosoma hamadae sp. nov., adult male (holotype): 21) secondary genitalia, left lateral view; 22) secondary genitalia, ventral view; 23) anal appendages and last abdominal segments, left lateral view; 24) anal appendages, dorsal view; 25) anal appendages, ventral view; 26) male intromittent organ, right lateral view, the pale coloration of the apical digitations indicates softer structures, darker coloration indicates more rigid structures; 27) male intromittent organ, right lateral view; 28) male intromittent organ, ventral view.

FIGURES 29 – 31. Aeschnosoma hamadae sp. nov., adult female (paratype): 29) dorsal general habitus; 30) lateral view; 31) left wings, ventral view.

FIGURES 32 – 34. Aeschnosoma hamadae sp. nov., adult female (paratype): 32) anal appendages and last abdominal segments, dorsal view; 33) anal appendages and last abdominal segments, left lateral view; 34) last abdominal segments with S 9 genital plate and S 8 vulvar lamina, ventral view, a) general view, b) detail of the vulvar lamina.

FIGURES 35 – 39. Aeschnosoma spp. 35 – 36 Aeschnosoma elegans, male adult, (after Geijskes, 1970): 35) anal appendages: a: lateral view, b: dorsal view, c: ventral view; 36) secondary genitalia, left lateral view. 37 – 39 Aeschnosoma marizae, adult male, original drawings and photograph: 37) lateral view; 38) anal appendages and last abdominal segments: a: left lateral view, b: dorsal view; 39) secondary genitalia, left lateral view.