Neocordulia santacatarinensis, Costa & Ravanello & Souza-Franco, 2008

Costa, J. M., Ravanello, C. T. & Souza-Franco, G. M., 2008, Description of a new species of Neocordulia Selys, 1882 (Odonata: Libellulidae, Corduliinae) from southern Brazil, Zootaxa 1704 (1), pp. 64-68 : 65-68

Neocordulia santacatarinensis sp. n.

( Figures 1–9 )

Material. Holotype male: BRAZIL, SANTA CATARINA, Irani River, Ponte Serrada (26 o 55'49,86" S; 52 o 51'52,02" W), IX.2006, C. T. Ravanello & M.E. Anselmini leg. (emerged IX.2006).

Etymology. The name refers to the type locality.

Male (holotype). Head ( Figs.1–3 ). Postfrons, antefrons, postclypeus, anteclypeus and labium yellowish, with long black setae uniformly distributed, but more concentrated on postfrons; mandibles and maxillae light brown; frons divided by a deep median furrow with flattened facets. Vertex dark brown, rounded, with regularly distributed setae. Occipital triangle large, brown, with sparsely distributed setae. Antennae brown, the first segment black; ocellus pale amber; rear of head light brown.

Thorax ( Figs. 1–6 ). Prothorax ( Fig. 4 ) yellowish; anterior lobe undulate and smooth in dorsal view; medial lobe with two dark brown spots, bearing some short setae on dorsal surface; posterior lobe poorly developed, with narrow base laterally and bearing a row of short setae on posterior border. Pterothorax ( Figs. 1–2 ) brown and iridescent metallic green with blue reflections uniformly covered with brown and golden yellow setae. Mesepisternum with a longitudinal light brown stripe and blue and green reflections; longitudinal green stripe of metepisternum wider than half of this sclerite, regularly covered with golden yellow setae; metepimeron green with whitish-yellow stripe extended along ventro-lateral border. Legs yellowish except for black hind tibiae and tarsi, and all pretarsal claws. All tibiae with a prominent ventral keel along distal third. Wings hyaline, golden yellow along costal-medial region; venation black; costa pale in all wings; pterostigma yellow with almost parallel sides; membranule enlarged, pale, ending before apex of anal triangle. Wing margin at distal end of anal triangle entire, without a distinct excavation. Anal angle rounded.

Venation ( Fig. 1 ). Antenodals in FW 9/9; in HW 6/7; postnodals in FW 8/9, in HW 10/11. Arculus proximal to second antenodal. Sectors of arculus not stalked, originating at basal third of arculus. All triangles free. One CuA crossvein in FW, two in HW. Discoidal field in FW with two rows of cells except 3 rows on distal end. Discoidal field in HW with one row of cells for a distance of 3 cells distally to triangle. Mspl indistinct. RP 2 not undulate. Rspl distinct with one row of cells between it and IR 2. Anal loop elongate surpassing level of distal angle of triangle, with 14/15 cells. Space between anal loop and anal triangle with one cell at base. Space between posterior border of anal area and distal end of anal loop with 2 rows of cells. Posterior border of anal loop with 3 cells.

Abdomen ( Fig. 1 ). S7–8 moderately widened, depressed dorsoventrally; dorsolateral carinae present on S3–7; sternum of S8 with a prominent biconical protuberance ( Fig. 6 ) which surpasses half of segment length and has a bifid distal end with divergent tips. S1–9 yellowish with dark brown spots distributed as follows: one small elongate spot on postero-lateral border of S1; one pair of small spots along distal half of S2; one elongate spot extending latero-ventrally along distal third of S3; paired dark brown triangular lateral spots posterior to transverse carinae on S4–9. S10 lacking spots. Genital lobe ( Fig. 5 ) smoothly rounded posterodistally; hamule long, surpassing half the height of genital lobe; inner branch of hamule wider than outer branch, with 4 small teeth, outer branch pointed at distal end. Cerci slightly divergent at tips, longer than S9+10, covered with long setae, with a small basal tubercle visible in lateral and ventral view ( Figs. 7–9 ).

Measurements (mm): Total length (incl. anal appendages) 51.8; maximum width of head 6.8; total length of thorax 8.4; length of metepisternal stripe 5.5; length of femur I 4.8, II 6.6, III 7.3; tibia I 5.2, II 7.1, III 8.2; tibial keel I 3.4, II 4.0, III 6.1; length of FW 34.7, HW 33.3; maximum width of HW 10.2; FW pterostigma length 2.9, HW 3.1; distance from base to nodus 17.0, distance from nodus to apex 17.6; total length of abdomen (incl. anal appendages) 33.5; length of hamule 1.4; maximum width of hamule 0.6; length of genital lobe 1.6, width of genital lobe 0.9; length of cerci 3.1, length of epiproct 2.4, length of biconical sternal protuberance 2.8.

Diagnosis. Neocordulia santacatarinensis is placed in the genus Neocordulia Selys, 1882 as it conforms to the characters mentioned for it by May (1991), Costa & Santos (2000a, 2000b), Machado (2005) and Garrison et al. (2006): 1) fore wing discoidal field parallel sided; 2) two rows of cells throughout discoidal field of FW; 3) subtriangle of FW free; 4) anal loop elongate, lacking sole; 5) apex of anal loop separated from posterior border of HW by three cells; 6) midrib distinct; 7) anal area in HW with three rows of cells; 8) presence of a prominent biconical protuberance on the sternum of abdominal segment 8; 9) distal segment of vesica spermalis with one apical flagellum; 10) posterior margin of anterior lamina with medial arched rim bearing a tuft of setae on each lateral end; 11) posterior hamule bifid.

This new species differs from other species of the subgenus Neocordulia which have a protuberance on sternum 8 by the distinct biconical shape of the protuberance, shape of caudal appendages and of anterior lobe of prothorax, and by the inner branches of hamules bearing 4 teeth.

Larva. ( Figs. 10–15 ). General shape of body typical of Libellulidae , very similar to N. androgynis . General coloration dark brown ( Fig. 10 ).

Head ( Figs. 10–11 ). Small, 1.5 times as wide as long; general shape rhomboidal, as wide as thorax in dorsal view; eyes small, with rounded outer margin. Dorsal crest covered with long setae. Occiput rounded, rear slightly concave; posterior corner on each side with more than 20 long setae and with many short setae nearer eyes ( Figs. 10–11 ). Postocular region with spiniform setae ( Fig. 11 ). Antennae 7 segmented, segment 5 the longest. Labrum rectangular, fringed with long hairs. Mandibular formula ( Figs. 13–14 ): L122'34 0 abd/ R1234 y abd. Labium long and wide, reaching mesocoxae; prementum ( Fig. 12 ) with 11 setae of varying length on each side, ligula smooth; no spines at junction of labial palp with prementum. Labial palp ( Fig. 12 ) triangular with 7 setae; movable hook small; distal margin of palp with 7 crenulations, each bearing 5–7 spiniform setae; internal and external margins with many setae.

Thorax. Prothorax rectangular. Wing pads parallel reaching distal margin of S5. Legs long, posterior pair longer than abdomen.

Abdomen. Cylindrical ( Fig. 10 ), widest at S5 (1.8 mm), middorsal hooks absent. Short lateral spines on S9–10. Anal appendages triangular ( Fig. 15 ), acuminate; epiproct and cerci similar in length; paraprocts longer than epiproct and cerci.

Measurements (mm): Total length 24.7; width of head 7.01, length 4.57; mesofemur 7.24, mesotibia 8.0, mesotarsus 3.38; anterior wing pads 7.38, posterior wing pads 7.74.

Habitat. The larva was collected in a stream with substrate composed of pebbles, abundant alloctonous organic material (leaves, twigs, etc.), at an average of about 0.2 m depth and clear water. Marginal vegetation on the right margin was undisturbed while the left was used for camping. This stretch is located at 520 m altitude, with a measured pH of 7, average conductivity of 35.40 S.cm -1, yearly average water temperature of 15.23 o C, and dissolved oxygen of 8.80 mg. L -1.

Discussion. This new species can be distinguished from all other species of the genus by the biconical shape of the protuberance of sternum S8, Rspl with 9 cells in FW and 11 cells in HW, and inner branch of hamule with 4 teeth.

Based on shape of cerci and similarity of larvae we believe that N. santacatarinensis shows closer affinities to N. androgynis (described by Selys, 1871 as Gomphomacromia androgynis ) but differs (characters for N. androgynis in parenthesis) by its undulated anterior lobe of prothorax (straight), distal end of cerci slightly divergent (strongly divergent), outer branch of hamule surpassing half the length of genital lobe (not surpassing), protuberance on S8 biconical (robust and blunt) and presence of 4 small teeth on inner branch of hamule (1–2). Ultimate instar larva of N. santacatarinensis has 11 mental setae (12) and lateral spines on S9–10 longer (shorter).

Figures

FIGURE 1–4. Neocordulia santacatarinensis sp.n.: (1) adult, dorsal view; (2) adult, lateral view; (3) head, dorsal view; (4)prothorax, anterior lobe.

FIGURE 5–15. Neocordulia santacatarinensis sp.n.: (5) hamule and genital lobe, lateral view; (6) segment 8, ventral view (biconical protuberance); (7) cerci, dorsal view; (8) cerci and epiproct, ventral view; (9) cerci and epiproct, lateral view. (10) larva, dorsal view; (11) head, dorsal view; (12) labium and labial palp, ventral view; (13) right mandible, inner view; (14) left mandible, inner view; (15) anal appendages, dorsal view.