Systropha (Systropha) sirikitae de Silva & Packer, 2016

Silva, Nicholai de & Packer, Laurence, 2016, A new species of Systropha from Thailand (Hymenoptera: Halictidae: Rophitinae), Journal of Melittology 2016 (61), pp. 1-9 : 3-5

Systropha (Systropha) sirikitae de Silva & Packer , new species

ZooBank: urn:lsid:zoobank.org:act:C4A22A9D-26B0-4245-AA8A-943986827960

( Figs. 1, 2 , 5 , 6, 8, 9 , 10 )

DIAGNOSIS: Males can be differentiated from all other congeners globally by the combination of the nature of the antennal flagellum and that of S2. The flagellum has six well-defined flagellomeres of normal size and an additional two or three that are minute ( Figs. 1, 2 ). The second metasomal sternum has a well-defined transverse ridge ( Fig. 10 ). Only S. glabriventris Friese , from Namibia and Zimbabwe, has a similarly structured flagellum but it lacks protuberances on S2. Systropha glabriventris also differs in having a lateral tooth on each of T6 and T7 ( Patiny & Michez, 2006: cf. their figure 4 and Fig. 7 ); S. sirikitae lacks such teeth ( Figs. 5 , 6 ). There are only two known Systropha from southeastern Asia: S. difformis Smith known only from the Republic of the Union of Myanmar [ Burma] and S. inexspectata from Thailand. The males of these both have the normal 11 flagellomeres ( Fig. 4 ) (although the apical ones are narrow and form a spiral in both species), and a single, median process on S2 (e.g., Fig. 11 ; see also Ebmer, 1994: figures 10, 11 therein).

DESCRIPTION: ♂: Body length 11 mm, forewing length 6.8 mm, intertegular width 1.8 mm, head width 2.3 mm.

Coloration. Black except as follows: F7–F9 very pale to light brown; tegula brown, translucent posteriorly and laterally; wing veins translucent brown; T6 entirely red-brown, somewhat translucent apically; pretarsal claws red-brown; metatibial spurs brown, becoming darker distally; antennal cleaner almost entirely transparent.

Structure. Head broader than long, width to length ratio 4:3. Labrum slightly shiny, basal area with irregular carinulae, apical area distinctly punctate. Mouthparts long; length of labial palpus approximately 1.5X length of head; glossa approximately 1.5X as long as labial palpus. Clypeus basal two fifths with dense, small punctures, i<d, rest shiny with large, sparse, longitudinally effaced punctures, i<d; with dull yellow hairs. Supraclypeal area densely and finely punctured (i<d). Frontal area densely punctate, i<d; upper paraocular area minutely and sparsely punctate, ocellocular area largely impunctate. Scape minutely and densely punctate; F1 twice as long as greatest breadth. Antenna reduced apically, F7–F9 minute, superficially appearing as if with only 7 flagellomeres. Genal area shiny, obscurely and sparsely punctate (i>3d); genal beard long (L<2D).

Mesoscutum doubly and finely punctate, i<1.5d between median and parapsidal lines; large punctures sparse except on anterior one third (i=1–3d); pubescence sparse, short (L<1.3D, somewhat longer anteriorly L<2D). Mesoscutellum with punctures as on mesoscutum except smaller and somewhat sparser. Metanotum with transversely effaced punctures i<2d. Metapostnotum imbricate, dull, margins smooth, lacking microsculpture, side of propodeum shiny, distinctly punctate, i=2d; pubescence long (L<2D). Mesosoma lacking ventral protuberances. Fm1 and Fm3 thickest at basal one quarter, Fm2 thickest at midlength. Tb1 and Tb2 unmodified, Tb3 somewhat swollen, thickest subapically. Anterior metatibial spur curved apically, shorter than posterior spur.

Terga without lateral spines or teeth. T1 distinctly and regularly punctate (i ≈ d), apical impressed area more finely and sparsely punctate (i>d); pilosity pale, longest apicolaterally (L ≈1.5D), remaining hairs short (L<D). T2–T3 as for T1 except basal areas depressed and with punctures similar to those on apical impressed areas, apical impressed area longer, hairs towards side of disc short, thick, and dark brown; T4–T6 lacking basal depressed areas, punctures on discs smaller. Hairs increasing in length from T2 to T6, on T6 ≈3D, proportionately more dark brown hairs on more posterior terga; hairs simple except somewhat plumose towards sides of terga. Sterna shiny, with row of hairs subapically; sparsely and irregularly punctate (i>2d). S2 with a pronounced transverse ridge extending almost entirely across exposed portion of sternum. S5 weakly concave basomedially. S6 with raised area medially ending in short blunt process. Erect hairs longest on S1 and towards sides of S3–S4 (L<2D). T7 lacking lateral tooth but with broadly rounded convexity on either side.

♀: Unknown.

HOLOTYPE: ♂, THAILAND: Chaiyaphum, Pha Hin Ngam NP. 15°37.683’N 101°23.323’E 681 m. malaise trap. 19–26.ix.2006. coll: Sa-nog & Adnafai. T856 B. To be deposited in Queen Sirikit Botanical Gardens ( QSBG).

PARATYPE: ♂, THAILAND: Loei, Phu Kradeung NP. 16°49.099’N 101°47.624’E 275m . MT. 14.xi.2006. coll: S. Gong-lasae. T1074 A. Deposited in PCYU .

VARIATION: Paratype as in holotype except: only 8 flagellomeres, F7–F8 minute, forming a hook, and bee slightly smaller, head width 2.2 mm. Terminalia as in figures 8–9.

ETYMOLOGY: The species is named after the botanical gardens where the holotype will be deposited, QSBG, Thailand.

COMMENTS: In the locality labels, NP refers to ‘National Park’: both of the known specimens are from national parks. The two localities are less than 150 km apart.

Figures

Figure 5. Holotype of Systropha sirikitae, new species, in lateral view (scale bar = 2 mm).

Figures 1–4. Antennae of species of Systropha to show variation in number of flagellomeres. 1. Systropha sirikitae, new species, holotype, with six normal-sized flagellomeres and three minute apical ones forming a small hook (scale bar = 0.5 mm). 2. Paratype of S. sirikitae with the api- cal hook formed from two flagellomeres (scale bar = 1 mm). 3. S. punjabensis Batra & Michener, paratype, with 10 flagellomeres (scale bar = 0.5 mm). 4. S. inexspectata Ebmer, with the normal condition of 11 flagellomeres, right antenna (on the left) in the normal, spiral-horned position; left antenna with the spiral straightened after relaxing (scale bar = 2 mm).

Figures 6–9. Apical metasomal terga and terminalia of species of Systropha (all scale bars = 1 mm). 6. Systropha sirikitae, new species, paratype, T7 to show lack of spines. 7. S. tropicalis Cockerell, oblique view to show spines (indicated by red lines). 8. S7 and S8, not separated, of paratype of S. sirikitae. 9. Genital capsule, dorsal view, of S. sirikitae.

Figures 10–13. Metasomal S2 or S2 and S3 of select species of Systropha (all scale bars = 0.5 mm). 10. Transverse process on S2 in profile (black line) of Systropha sirikitae, new species, paratype. 11. Elongate, medial process on S2 (black line) of S. inexspectata Ebmer, or a closely related, undescribed species. 12. absence of processes on S3 (green line), and weak paired convexities on S2 (red line) of S. punjabensis Batra & Michener, paratype. 13. More strongly developed convexities on S3 (blue line), than S2 (red line) of S. tropicalis Cockerell.