Andrena (Andrena) ladakha, Wood & Jacobs, 2024

Andrena (Andrena) ladakha nov.sp. ( Figs 1-16 View Figs 1-8 View Figs 9-16 )

M a t e r i a l e x a m i n e d: Holotype: India: Ladakh , Leh Tehsil, Rumbak [34.0600 oN, 77.4200 oE], 3850 m, 1.ix.2015, 1♀, leg. M. Jacobs, coll. Biologiezentrum Linz ; Paratypes: India: same information as holotype, 1♁, coll. Biologiezentrum Linz.

D i a g n o s i s. Andrena ladakha is a little tricky to classify within the Andrena , as at first glance it does not unambiguously fall into a single subgenus. The two possible options are within Andrena s. str. FABRICIUS, 1775 and the subgenus Leucandrena HEDICKE, 1933 . Due to the male characters of the pronotum with a strongly produced humeral angle, the gena broadened and produced into a roughly 90 o rounded angle postero-ventrally ( Fig. 9 View Figs 9-16 ), the somewhat elongate and weakly falciform mandibles ( Figs. 10-11 View Figs 9-16 ), and the simple genital capsule ( Fig. 16 View Figs 9-16 ) it could fall into either subgenus. Indeed, the genital capsule has only very weak lateral hyaline extensions on the penis valves basally (usually more strongly produced in Palaearctic Andrena s. str.), and hence resembles members of the Leucandrena such as A. parviceps KRIECHBAUMER, 1873 and A. argentata SMITH, 1844 (see photographs in WOOD 2023a). However, the female morphology is less convincingly associated with the Leucandrena due to the lack of distinct tergal hairbands (terga instead covered with thick though slightly abraded hairs, Fig. 8 View Figs 1-8 ), the shape of the clypeus which is not evenly domed (only very weakly domed) and is covered with dense hairs that obscure the underlying surface ( Fig. 2 View Figs 1-8 ), the propodeal triangle is unsculptured ( Fig. 6 View Figs 1-8 ), and the process of the labrum is truncate with its apical margin weakly emarginate ( Fig. 3 View Figs 1-8 ; in Leucandrena typically with the process of the labrum rounded-triangular).

In frontal view, the apical margin of the clypeus is broadly rounded or emarginate, and very weakly upturned ( Figs 2-3 View Figs 1-8 ). This is reminiscent of the state in A. (incertae sedis) fumea WOOD, 2023 ( Kyrgyzstan only) and to a lesser extent A. ( Hoplandrena ) cephalgia WOOD, 2023 (Central Asia). Based on data from Ultra-conserved Element sequencing, both of these species are actually found within the Andrena s. str. (BOSSERT, PISANTY, WOOD, unpublished data) despite their unusual morphology for this subgenus based on "typical" species from the Palaearctic. In direct comparison, A. ladakha and A. fumea share the same short and broad sub-triangular head that has the face covered with dense pale pubescence ( Fig. 2 View Figs 1-8 , compare photographs in WOOD 2023c) and the broadly emarginate and weakly upturned fore-margin of the clypeus and truncate roughly trapezoidal process of the labrum with emarginate apical margin ( Fig. 3 View Figs 1-8 ). In this context, and in light of the genetic reclassification of A. fumea as an Andrena s. str. (BOSSERT, PISANTY, WOOD, in prep.), it is best to classify A. ladakha as an Andrena s. str. It can be immediately recognised in combination with the aforementioned characters by the elongate malar space, this space equalling or slightly exceeding the length of the 4th antennal segment, whereas in A. fumea the malar space is much shorter, and moreover the basal 1/3rd of the propodeal triangle is covered with coarse raised rugae (predominantly smooth in A. ladakha with only a few weak rugae basally), the terga have sparse pale and dark hairs which do not obscure the underlying surface (terga covered with dense pale-orange-brown hairs which obscure the underlying surface), and the scutum is covered with black hairs (scutum covered with pale hairs in A. ladakha ).

A noticeably elongate malar space is also found in the very rare A. (incertae sedis) rupshuensis which is known only from Rupshu in Ladakh at an elevation of 16,000 ft (= c. 4,900 m), and which was described only in the female sex ( COCKERELL 1911). However, A. rupshuensis is immediately recognisable (type photographs available on the Smithsonian Collections website) due to the terga which have clear and narrow white apical hairbands and due to the head which is 1.2 times wider than long, whereas in A. ladakha the terga are densely covered with a mixture of pale-orange-brown hairs and the head is 1.4 times wider than long.

In the male sex, in addition to the aforementioned characters, A. ladakha can also be recognised due to the elongate malar space that approaches the length of the 4th antennal segment. All other Andrena s. str. species in the region have a much shorter malar space that is barely noticeable. The males of A. fumea and A. rupshuensis are unknown, and so cannot be compared. Andrena cephalgia is radically different (leading to its placement in the subgenus Hoplandrena PÉREZ, 1890 ) with a genital capsule displaying clear pointed lateral hyaline extensions on the penis valves and with the gonostyli apically pointed with their apexes covered with stiff apically-projecting hairs (see photographs in WOOD 2023d).

D e s c r i p t i o n. Female. Body length 12 mm ( Fig. 1 View Figs 1-8 ). Head: Dark, 1.4 times wider than long ( Fig. 2 View Figs 1-8 ). Clypeus very weakly domed, variably punctate, punctures almost confluent in basal ½, separated by 0.5 puncture diameters apically, with impunctate longitudinal midline; underlying surface shagreened, weakly shining. Fore margin of clypeus broadly rounded, giving impression of wide slightly upturned emargination ( Fig. 3 View Figs 1-8 ). Process of labrum trapezoidal, slightly wider than long, apical margin slightly humped, with medial emargination. Malar space elongate, at longest slightly exceeding length of A4. Gena slightly exceeding width of compound eye; ocelloccipital distance slightly exceeding diameter of lateral ocellus. Foveae dorsally occupying majority of space between lateral ocellus and compound eye, separated from lateral ocellus by distance subequal to its own diameter; foveae filled with black hairs ( Fig. 4 View Figs 1-8 ). Face medially covered with long white to pale hairs, hairs becoming black laterally and along apical margin of clypeus, longest hairs exceeding length of scape; gena and vertex with intermixed black and pale hairs. Antennae basally dark, A4-12 ventrally lightened by presence of grey-brown scales; A3 long, subequal to A4+5+6.

Mesosoma: Scutum and scutellum with fine granular microreticulation, predominantly dull, sculpture becoming weaker medially, here weakly shining; surface covered with shallow punctures, punctures separated by 0.5-1 puncture diameters ( Fig. 5 View Figs 1-8 ). Pronotum with strong humeral angle. Mesepisternum finely shagreened and weakly shining, surface covered with shallow punctures, punctures separated by 1-2 puncture diameters. Dorsolateral parts of propodeum very finely shagreened, surface covered with hair-bearing wrinkles, wrinkles separated by 2-3 wrinkle diameters; propodeal triangle delineated by change in surface sculpture, internal surface with fine granular shagreen, surface more strongly shining, basally with irregular pattern of weakly raised rugae ( Fig. 6 View Figs 1-8 ). Mesepisternum covered with long black hairs, hairs exceeding length of scape, hairs becoming pale on scutum, scutellum, and propodeum. Propodeal corbicula incomplete, dorsal fringe composed of mixture of pale weakly plumose hairs in dorsal part, becoming black strongly plumose hairs in ventral part; internal surface with scattered simple long hairs. Legs predominantly dark, apical tarsal segments of fore and mid legs and entire all tarsal segments of hind legs lightened orange, pubescence orange to brownish ( Fig. 7 View Figs 1-8 ). Flocculus complete, composed of strongly plumose dark brown hairs; femoral and tibial scopae composed of dark brown simple hairs. Hind tarsal claws with strong inner tooth.

Wings hyaline, stigma and venation dark brown, nervulus weakly antefurcal.

Metasoma: Terga predominantly dark, apical rims narrowly lightened hyaline yellowbrown; tergal discs finely shagreened and predominantly shining, punctate, punctures separated by 1-2 puncture diameters. Tergal discs and margins covered with dense mixture of pale, orange-brown, and black hairs, obscuring underlying surface when not abraded ( Fig. 8 View Figs 1-8 ). Apical fringe of T5 and hairs flanking pygidial plate dark brown. Pygidial plate roughly triangular, lateral margins weakly constricted medially, surface smooth and featureless.

Male. Body length 11 mm ( Fig. 9 View Figs 9-16 ). Head: Dark, 1.3 times wider than long ( Fig. 10 View Figs 9-16 ). Clypeus very weakly domed, regularly punctate, punctures separated by <0.5-0.5 puncture diameters, underlying surface shining. Process of labrum rounded trapezoidal, anterior margin with weak emargination. Malar space elongate, at its longest subequal to length of A4 ( Fig. 11 View Figs 9-16 ). Gena strongly broadened, clearly exceeding width of compound eye, ventroposteriorly produced into a strong almost 90 o rounded angle; ocelloccipital distance 1.5 times diameter of lateral ocellus. Face medially with pale whitish hairs, hairs becoming black laterally and anteriorly, most hairs not exceeding length of scape; gena and vertex with intermixed black and pale hairs. Antennae basally dark, A4-13 lightened by presence of greyish-brown scales; A3 equalling length of A4, A4-13 long, rectangular, at least 2 times as broad as long.

Mesosoma: Mesosoma structurally as in female ( Fig. 12 View Figs 9-16 ), with exception of propodeum with dorsolateral parts with slightly denser network of wrinkles, propodeal triangle with more pronounced rugae in basal ½ ( Fig. 13 View Figs 9-16 ). Mesepisternum with mixture of long whitish to blackish hairs, hairs exceeding length of scape, hairs becoming white to pale on scutum, scutellum, and propodeum. Legs predominantly dark, tarsi and part of hind tibiae lightened orange, pubescence whitish ( Fig. 14 View Figs 9-16 ). Hind tarsal claws with strong inner tooth. Wings hyaline, stigma and venation dark orange-brown, nervulus weakly antefurcal.

Metasoma: Terga predominantly dark, apical rims narrowly lightened hyaline brown; tergal discs finely shagreened and predominantly shining, punctate, punctures separated by 1-2 puncture diameters. Terga with sparse pale hairs, longest on disc of T1, not obscuring underlying surface ( Fig. 15 View Figs 9-16 ). T6-7 with long light brown hairs overlying pseudopygidial plate of T7. S8 narrow and columnar, ventral surface with dense lateral fan of brown hairs. Genital capsule weakly elongate, gonocoxae produced into moderately projecting rounded teeth, gonostyli slightly constricted medially, apexes slightly broadened and spatulate with inner margins weakly raised. Penis valves with weak and obscure lateral hyaline projections, valves weakly narrowing apically ( Fig. 16 View Figs 9-16 ).

R e m a r k s: The elongate malar space of this species is remarkable, as very few Andrena species show an elongate face or elongate malar space. This elongate malar space in combination with the elongate malar space shown by A. rupshuensis along with several Himalayan species of Colletes (M. Kuhlmann, pers. comm.) suggest that solitary bees found in high elevation sites in Kashmir are under selection pressure to access nectar in flowers with deep corollae. Detailed study of the ecological niches of these very rare species in the field is required to further clarify this point. The collecting locality ( Fig. 17 View Figs 17-21 ) supported flowers with both long (e.g. Lamiaceae ) and short (e.g. Asteraceae ) corollae. Essentially no Andrena species are known to be associated with the collection of Lamiaceae pollen in meaningful quantities, so this potentially intriguing association requires study.

D i s t r i b u t i o n: Northern India (Ladakh).

D e r i v a t i o n o m i n i s: Named after the northern union territory of India from which it was collected.