Anax insulanus, Theischinger & Kalnins & Marinov, 2024

Theischinger, Günther, Kalnins, Martins & Marinov, Milen, 2024, Two new species of Anax Leach, 1815 from the Solomon Islands and Tonga (Odonata: Aeshnidae), Zootaxa 5519 (2), pp. 215-242 : 218-230

publication ID	https://doi.org/ 10.11646/zootaxa.5519.2.3
publication LSID	lsid:zoobank.org:pub:BE0CA3E4-3695-403A-AD98-3C279238518B
DOI	https://doi.org/10.5281/zenodo.13940288
persistent identifier	https://treatment.plazi.org/id/03C587C6-CE77-9862-FF24-858F74A0F9C1
treatment provided by	Plazi
scientific name	Anax insulanus
status	sp. nov.

Treatment

Anax insulanus sp. nov.

( Figs 1 View FIGURES 1–6 , 14 View FIGURE 13–17 , 20, 24 View FIGURES 18–25 , 26, 29 View FIGURES 26–31 , 32, 33, 36, 39, 41, 43, 45–47)

Holotype: ♂ (K.646374) Solomon Islands, Guadalcanal Is., Honiara S env., ~ 2 km SE from Barana vill. , Davigori , 9.4827°S / 159.9828°E, ~ 400 m, gardens in semi-open landscape with small basin, 21 April 2023, Martins Kalnins leg. (in AM). GoogleMaps

Paratypes: Solomon Islands, 2♂♂, 14 May 2023, other data as for holotype: (1♂ ( K.646375 ) in AM, 1♂ ( Odo_2023_033 ) in LINC) GoogleMaps .

2♀♀ ( K.646377 , K.646379 ), New Georgia, Munda, 30 June 1999, together with 1♂ ( K.646378 ) of A. guttatus (in AM), D.M. Reeves & J.H. Bryan leg. ; 1♂ ( K.646376 ), same locality, 1 July1999, D.M. Reeves leg.; (all deposited in AM) .

Other material: Anax insulanus sp. nov., formerly identified as Anax sp. cf gibbosulus : 1 ♀ ( NZAC 04145767) SOLOMON ISLANDS, RAP-GUADALCANAL 2015 Valevahalo base camp, 9.6468°S, 160.0447°E, 810 m a.s.l., 10 September 2015, M. Marinov leg.

Etymology. The name refers to the presence of the species on several of the Solomon islands; insulanus is Latin for ‘island inhabitant’ and is used as a noun in apposition to the generic name.

Description of holotype

Head. Labium and base of mandibles largely brownish yellow; remainder of mandibles and genae largely black; labrum brown, merging ventrally into brownish black; anteclypeus yellowish to pale greyish green, postclypeus and widely angulate (c. 140°) antefrons yellowish grey with suffusion of orange and greyish green; postfrons with a brownish black wide-based, moderately thick-stemmed T-mark contrasting with the dull yellow ground area, black base of ‘T’ extending laterally and ventrally, transverse anterior bar of ‘T’ laterally not well defined; antennal base, scape, pedicel, occipital triangle and postgenae narrowly along eye margin black; vertex and antennal flagellum black merging into brown; most of postgenae orange yellow. Eyes dark brown (green in life).

Thorax. Prothorax largely brownish black and greyish yellow. Pterothorax with antealar sinus pale green and pleura greyish green without any distinct pattern except ventral edge of mesepimeron and metepimeron narrowly yellowish merging into brown and black. Terga largely pale green. Sterna greyish yellow. Legs: coxae pale brown, trochanters and base of femora reddish brown, remainder of femora and all of tibiae, tarsi and claws black.

Wings. Humeral sclerites pale green and axillary sclerites bright yellow; intermediary pieces black. Venation largely black, costa greyish brown with very thin yellow median ray. Membrane largely hyaline, Hw slightly pale brownish tinged between level anal loop and MA. Nodal index 10–20 / 18– 10 in Fw and 11–13 / 14– 10 in Hw; Ax1 and Ax7 or Ax8 thickened in Fw, Ax1 and Ax 6 in Hw; wing triangles with 6 cells in Fw, 5 cells in Hw; Arc at or very close to level Ax2; Pt braced, black, overlying 2 and 1/2 cells; 8 double cells between MP and CuA of Hw, one of them triple; anal loop with 11–12 cells; 4 rows of cells between largely dark greyish brown membranule and anal loop.

Abdomen. Dorsally largely black, ventrally in different shades of brown. S3 Index c. 6.25; S1 dorsally largely brown, basally and laterally and ventrally dull yellow; S2 with dull greyish yellow (green in life) basal ring covering approximately 1/5 of segment length, its median 1/5 produced backward in form of shallow rounded triangle, remainder dorsally largely black, laterally dull blue, black, orange and grey; anterior half of S3 laterally also dull blue, black, orange and grey, S3 otherwise and S4 black, S4 without any clearly detectable pale pattern elements on one side, with barely detectable very small pale patch on the other side; only S5–8 with pair of very small, barely detectable and ill-defined dull white to pale yellow to greenish subapical dorso-lateral patches; S9 and S10 black.

Terminalia. Brown to black. Cerci with style slightly arched, outer margin almost straight and inner margin sinuously and evenly convex; about 4 times as long as greatest width; apico-lateral spike small (very short and thin), directed strictly backward, basal inferior tooth wide-based. Epiproct trapezoidal, c. 1/4 as long as cerci, apically barely emarginate; two pairs of small low dorsal tubercles.

Measurements (mm). Abdomen (including cerci) 66.8, cerci 6.5, Hw 54.2.

Description of female (Paratype K.646377).

Head. Labium and base of mandibles largely brownish yellow; remainder of mandibles and genae black; labrum brown, merging basally and ventrally into brownish black; anteclypeus pale greyish to greenish yellow, postclypeus and widely angulate (c. 140°) antefrons yellowish grey with areassuffusion of orange; postfrons with brownish black thick-stemmed T-mark contrasting with the dull yellow ground area, black base of ‘T’ extending laterally and ventrally, transverse anterior bar of ‘T’ laterally not well defined; antennal base, scape, vertex, occipital triangle and postgenae narrowly black along eye margin; pedicel and antennal flagellum brown; most of postgenae orange yellow. Eyes dark brown.

Thorax. Prothorax largely brownish black and yellowish to greyish brown. Pterothorax with pleura and antealar sinus yellowish to brownish grey without any distinct pattern except ventral edge of mesepimeron and metepimeron narrowly yellowish merging into brown and black. Terga largely dull yellow to pale greenish, greyish and brownish. Sterna pale greyish brown. Legs: coxae, trochanters and base of femora brown, remainder of femora, tibiae, tarsi and claws black.

Wings. Humeral and axillary plates partly pale greenish and pale yellow, partly pale orange to dark brown; intermediary areas blackish brown. Venation greyish brown to black, costa without median ray. Membrane largely hyaline, Fw barely tinged, Hw tinged slightly pale brownish between base and MA. Nodal index 10–19 / 18– 9 in Fw and 11–14 / 13– 11 in Hw; Ax1 and Ax7 thickened in Fw, Ax1 and Ax 6 in Hw; wing triangles with 6 cells in Fw, 5 cells in Hw; Arc very close to level Ax2; Pt braced, 4.6–4.9 mm, greyish to blackish brown, overlying 1 and 1/2 to 2 and 1/2 cells; 6–8 double cells between MP and CuA of Hw; anal loop with 12 cells; 4 rows of cells between dark greyish brown membranule and anal loop.

Abdomen. Dorsally largely black, ventrally in different shades of brown. S3 Index c. 4.0. S1 largely dull yellow, basally and laterally blackish brown; S2 with dull yellow basal ring covering approximately 1/6 of segment length, its median 1/5 produced backward to form a rounded subtriangular shape, remainder with small and larger yellow and whitish smudges each side of large black strongly pimpled median area; S3 with whitish lateral smudge in anterior half, otherwise as S4–S8 with only pair of small ill-defined dull yellow subapical dorsolateral spots each; S9 laterally with dull yellowish brown smudge; S10 black, mid-dorsally with narrow dull yellow to orange patch. Subgenital plate greyish brown with many short mostly flat lying black spines.

Terminalia. Cerci brownish black, markedly longer than width of S10, leaf-shaped with inner margin markedly more strongly convex than outer margin.

Measurements (in mm). Abdomen (including cerci) 55.6, cerci 4.2, Hw 52.2.

Variation in the paratypes

Three male paratypes and one female paratype are available. Their overall coloration ranges from distinctly paler to barely darker than that given in the description of holotype and female.

The heads of the male paratypes largely agree with the holotype, but the brownish black T-mark on top of the frons ranges from rather thin-stemmed to very thick-stemmed. The coloration of pterothorax and antealar sinus is pale green and greyish green as in the holotype to pale orange brown or yellowish to brownish grey. The wings are much as in the holotype but humeral sclerites can also be greyish green and axillary sclerites greyish yellow. Venation greyish brown to black. The membrane ranges from Hw only slightly pale brownish tinged between the level of the anal loop and MA, added to which is slight brownish suffusion of almost all remaining Fw. Nodal index 8–9, 19–22 / 20–21, 9–10 in Fw and 10–12, 14 / 12–14, 11–14 in Hw; Ax1 and Ax7 or Ax8 thickened in Fw, Ax1 and Ax6 or Ax 7 in Hw; wing triangles with 6–8 cells in Fw, with 4–6 cells in Hw; Arc from halfway between level Ax1 and Ax2 to very close to level Ax2; Pt braced, greyish brown to black, overlying 2 and 1/3 to 3 and 1/2 cells; 6–10 double cells, if 8 or 10, 3 triple, between MP and CuA of Hw; anal loop with 12–15 cells. The abdomen closely agrees with the holotype, but S3 Index 5.9–7.5. In two specimens much of S2 and anterior half of S3 markedly more vividly whitish, blue and black. S4–8 black and barely detectably smudged with brown along lateral margin, S4–9 or S5–9 each with pair of small ill-defined dull whitish yellow to pale greenish subapical dorso-lateral spots; S9 latero-basally black to black smudged with dull yellowish. The terminalia closely agree with the holotype. Abdomen (including cerci) 63.2–67.0 mm, cerci 6.2–6.5 mm, Hw 52.9–56.0 mm.

The second and only other female paratype (K.646379) largely agrees well with paratype K. 646377 (see above) regarding head, thorax, abdomen and terminalia. The T-mark on top of the frons has a slightly more slender stem. However, the Fw membrane is slightly tinged pale brownish almost all over. Nodal index 9–18 / 19– 10 in Fw and broken-14 / 14– 12 in Hw; Ax1 and Ax7 thickened in Fw, Ax1 and Ax6 or Ax 7 in Hw; Pt overlying 2 and 1/2 cells; 6–8 double cells between MP and CuA of Hw; anal loop with 10–12 cells. The S3 Index is c. 4.5. There is no mid-dorsal yellow to orange patch on S10. Abdomen (including cerci) 59.3 mm, cerci 4.6 mm, Hw 55.6 mm.

Diagnosis. A rather large dark short-bodied Anax (body length c. 85 mm, wingspan c. 110 mm, Abd 63–67 mm, Hw 53–56 mm; Ratio <1.3) with high S3 Index (male: 5.9–7.5, female 4.0–4.5). Mature male in life ( Fig. 36 View FIGURE 36 ) with head, eyes and thorax largely green, legs and most of abdomen largely black, abdomen base bright green, blue and black. Abdominal pattern of male generally made up by pair of small ill-defined dull greenish yellow to pale yellow subapical dorsolateral spots each on S4–8 or 9 or S5–8 or 9, none on S1–3 and 10 in male, on S3–8, none on S1, 2, 9 and 10 in female. Coloration of preserved material ranges from distinctly paler to darker ( Figs 37 View FIGURES 37–38. 37 , 39 View FIGURES 39–40. 39 , 41 View FIGURES 41–42. 41 , 43 View FIGURES 43–44. 43 ) than given above, depending on maturity of the individual when collected and on age and state of preservation of specimens. Anax insulanus may be separated from the very similar A. celebensis and A. piraticus by its very dark abdomen with only a few barely perceptible small paler spots and smudges vs much richer and larger pale maculation.

Habitat. The three males of A. insulanus were captured near a small artificial concrete pool serving to collect rainwater ( Fig. 45 View FIGURE 45 ), located in a highly disturbed open garden landscape ( Figs 46 View FIGURE 46 , 47 View FIGURE 47 ) in the vicinity of secondary forest. One patrolling individual was caught on 21 April 2023. On the following day, 14 May 2023, another patrolling individual was caught there. Later that same day, the vacant territory was occupied by a third individual.

Distribution. Known only from Guadalcanal and New Georgia in the Solomon Islands, where it was found coexisting with A. guttatus . Possibly endemic to the Solomon Archipelago.