Leioproctus idiotropoptera Packer

Packer, Laurence, 2006, A new Leioproctus with unique wing venation in males (Hymenoptera: Colletidae: Paracolletinae) with comments on unusual wing modifications in bees, Zootaxa 1104, pp. 47-57 : 48-55

Leioproctus idiotropoptera Packer , new species

Diagnosis: Males of the new species can easily be differentiated from all other bees by the unusual modification of the forewings with the 2nd recurrent vein being deeply concave outwardly, at its closest, being separated from the first recurrent vein by only slightly more than two vein widths. The females are not so distinctive but the following combination of of characters would seem to separate them from females of any other Australian Leioproctus : two submarginal cells, dorsal surface of propodeum distinct (although short), jugal lobe of hind wing extending well beyond vein cu­v and inner hind tibial spur pectinate with 5 long, narrow teeth.

Description

Male: Body length 6.3mm, forewing length 3.8mm, head width, 1.7mm.

Colouration: Black, lacking any areas of metallic colouration and yellow or red markings on metasoma; metasoma and legs dark brown; following parts testaceous: mandibles (except basal ¼ dark brown and apical margin reddish), anterior surface of flagellomeres 8–9 and all of flagellomeres 10–11 and apical impressed areas of metasomal terga; tegula and wing veins pale amber; forewing with complex pattern of dusky markings which also extends to some portions of wing venation (fig. 3).

Pubescence: white, with numerous short branches, appearing woolly especially on gena, areas of appressed golden hairs or tufts of dense pubescence are entirely lacking; labrum with apical row of strong setae <2MOD; hairs mostly matted on face of sole specimen, but erect, pale brown and moderately long (1.5MOD) on vertex; genal beard long, 2MOD throughout; anterior margin of mesoscutum, lateral margins of mesoscutellum, entire metanotum, dorsolateral portions of propodeum and anterior (declivous) surface of T1 with long hairs, 2MOD; rest of mesoscutum, mesoscutellum and propodeum with shorter hairs 1MOD; lateral surface of thorax with hairs of intermediate length, 1.5MOD; foretibia with double row of very robust, closely appressed, testaceous bristles, ~1MOD, 6 in inner row, 3 in outer row, bristles in each row converge apically; basal concavity of mesofemur with short row of curved, stiff hairs proximally, more normal, but similarly curved hairs on distal margin of concavity; mesotibia with dense tuft of apically directed hairs near base of tibial spur; hairs of forewing dense, dark and robust, of normal length except beyond apical cells where they are extremely short, hairs especially dense around first recurrent vein and towards apex of 2nd medial cell; disc of T1 with hairs strongly curved posteriorly, 1MOD anteriorly, becoming gradually shorter posteriorly to 0.5MOD; erect hairs on T2–4 short, 0.5MOD; those of T5 and T6 longer and suberect ~1MOD; terga with submarginal hair row of long, weakly branched hairs 1.5MOD; S3 and S4 with subapical row of dense, long, pale brown hairs, 1.5MOD, that completely obscure underlying integument.

Surface sculpture: surface shiny, microsculpture weak on head and abdomen, lacking on thorax; labrum impunctate; clypeus with dense, deep punctures, i~d; supraclypeal area with longitudinal ridges; frons with dense, deep punctures, i~0.5d, becoming sparser but larger on vertex; gena distinctly and irregularly punctate, i=0.2–1d; mesoscutum, mesoscutellum and lateral surface of thorax with punctures irregular in size i~d; metanotum densely punctate; ventral surface of thorax almost impunctate; dorsal area of propodeum reticulate, posterior surface punctate, i~d, lateral surface with smaller, more widely spaced punctures i>d; metasomal terga distinctly punctate, i<d on disk of T1 with punctures becoming smaller and less dense posteriorly both on each segment and among segments; apical impressed areas narrowly impunctate.

Structure: head: length and width equal, but due to widest point being just below median ocellus, appearing somewhat elongate; glossa not deeply bilobed, labial palps 4 segmented, maxillary palps 6 segmented; labrum 3.5 times broader than medial length, with apical margin of basal box concave, sharply set off from narrow marginal area; mandible very deep, depth at midlength almost half maximum length (17:40), but thin and comparatively flat; clypeus longer than broad (36:26), somewhat protruding with longitudinal ridge parallel to epistomal suture laterally, these ridges extending onto supraclypeal area where they meet; epistomal suture separating clypeus and supraclypeal area poorly defined; supraclypeal area with median narrow ridge; subantennal suture as long as diameter of antennal socket; malar space entirely absent; compound eyes strongly converging below UOD:LOD 60:40; OOD=IOD; ocelli at summit of vertex; facial fovea a long narrow groove close to upper inner eye margin; hypostomal carinae strongly developed into diverging flanges; breadth of gena less than that of compound eye (24:28); scape slightly more than three times as long as greatest breadth, not extending beyond ¾ distance to lower margin of median ocellus; pedicel and F1 slightly shorter than broad, dorsoventrally flattened, F2 almost twice as broad as long, remaining flagellomeres slightly longer than broad, apex of F11 conical.

Mesosoma: dorsal surface of pronotum poorly developed, lacking horizontal collar, but with anterior declivous portion more horizontally oriented than usual; anterior portion of mesoscutum strongly raised above level of pronotum; mesoscutum broader than long (67:60); mesoscutellum very large, fully half as long as mesoscutum; metanotum half as long as mesoscutellum; dorsal surface of propodeum slightly longer than metanotum; metanotum strongly convex but not markedly produced; ventral surface of thorax concave; fore­ and midlegs highly modified as follows: foretrochanter with elongate beak­like ventral projection; forefemur short and deep with strong basal projection truncate in apical view, with semicircular concavity beyond projection and rounded convexity beyond; foretibia short and robust with bigibbous ventral surface, cavity between convexities bearing two rows of strong bristles; forebasitarsus somewhat dorsoventrally flattened, remaining foretarsomeres unmodified; mesotrochanter long and narrow, length 3 times median depth; mesofemur swollen just basal to midpoint, almost triangular with transverse basal concavity; mesotibia swollen ventrally; mesobasitarsus robust, slightly curved; hind leg robust but otherwise unmodified, two hind tibial spurs, inner spur ciliate, half as long as basitarsus; basitibial plate entire, defined by strong carinae, with a few, fine, simple hairs; tarsal claws with strong inner tooth; arolia present; stigma half as long as marginal cell; marginal cell with apex rounded and separated from costal margin by three vein widths; basal vein at an angle of less than 30o to costal margin; 2 submarginal cells; first recurrent vein slightly basal to first submarginal cross­vein; 2nd recurrent vein very long and strongly outwardly concave, arising near middle of second submarginal cell; Cu1 reduced in length to accommodate development of 2nd recurrent vein; jugal lobe of hind wing 4/5 as long as vannal lobe.

Metasoma: broadest at second segment, gradually tapering posteriorly; first segment large with anterior (declivous) surface longer than dorsal horizontal portion; pygidial plate not defined by ridges or carinae but apicomedial portion of T7 glabrous; S7 with 4 apical lobes but seemingly with 6 due to bifid nature of apical lobe with inner portion of this lobe narrower than its outer one; anterior lobe broad and flat with posteriorly oriented apical angulation; S8 with lateral lobes very short, anterior apodemes elongate and apical process broad, narrowed towards base, strongly hirsute, with apex somewhat rounded and membranous; gonobase long, ¾ as long as greatest width, gonostylus long, well sclerotised, and slightly medially oriented.

Female: as in male except for usual secondary sexual characteristics and as follows:

Colouration: antennal flagellum with anterior surface of annuli 4–10 pale orange; wing veins uniformly testaceous; tegula somewhat darker than in male; apical impressed areas of metasomal terga paler.

Pubescence: somewhat shorter than in male except on dorsolateral portion of propodeum, 3MOD, and metasomal sterna which bear long, branched scopal hairs>4MOD on S2 and S3, 3MOD on S4 and 2MOD on S5; hind leg with long scopal hairs, up to 3MOD on coxa and trochanter, up to 4MOD on femur and tibia, these hairs branched on one side only; all hairs whitish except on dorsal margin of hind tibia where they are dark brown.

Surface Sculpture: finer, more even in size and density than in male, i<d; punctures shallower and somewhat effaced on lateral surface of mesosoma; dorsal surface of propodeum with irregular longitudinal striae.

Structure: head: broader than long (58:47); glossa deeply bilobed; labrum more than 4 times as broad as medial length; mandibles unmodified; clypeus with distinct apical rim, evenly rounded, lacking lateral ridge, length to breadth 30:49; epistomal suture clearly separating clypeus from supraclypeal area; compound eyes less convergent below, UOD:LOD 36:30; facial fovea not impressed, represented by broad shiny area almost devoid of punctures; gena one­third as broad as compound eye; hypostomal carina not unusually developed but divergent; scape not attaining median ocellus; flagellomeres broader than long except F1 and F10 with length and breadth subequal;

Mesosoma: mesoscutellum normal in size, one­third length of mesoscutum; dorsal surface of propodeum shorter than in male, subequal in length to metanotum; wings and legs unmodified, hind tibial spur with 5 long, narrow teeth;

Metasoma: with well developed pygidial plate; apical margin of S6 narrowly and shallowly concave;

Sting apparatus: 7th hemitergite with median portion of marginal ridge outwardly concave, lateral portion of ridge somewhat divergent, hemitergite somewhat expanded posteriorly, posterior margin simuate, lateral process short, at slightly obtuse angle to lateral portion of marginal ridge basally, somewhat posteriorly curved, spiracle closer to lateral ridge and apical margin of lamina spiracularis than its shortest diameter; 8th hemitergite with apodeme deeply semicircular, body of plate strongly shifted medially in comparison to apodeme with apodeme extending laterally beyond plate for ¼ of its length and plate extending beyond apodeme medially for 1/3 of length of plate; first valvifer triangular with ventral angle much longer than dorsal one; second valvifer with postarticulatory portion of anterior ridge slightly convex, apodeme shallowly semicircular, incisura postarticularis parallel­sided, pars articularis weakly expanded in comarison to rostral process; gonostylus digitiform without transverse membranous region with setae denser towards apex and equal in length to subapical diameter of gonostylus; furcula Yshaped with dorsal and ventral arms subeequal in length; sting shaft with basal bulb strongly swollen, dorsal margin of bulb concave, ventral margin of shaft weakly curved dorsally.

Etymology: The specific name combines idiotropos, Greek for bizarre or whimsical, with ptera, from pteron: wing. The name refers to the unusual form of the forewing of males.

Material studied: holotype male, allotype and one paratype female: AUSTRALIA, N[orthern] T[erritory]; Litchfield National Park, 20.i.1998, A. Zwich. All three specimens are in good condition, although the male is missing the left hind wing, the right foreleg is glued to the pin separately beneath the rest of the body, the hairs are somewhat matted in places, and a muddy substance covers much of the lower portions of the pronotum. The holotype and allotype are to be housed in the CSIRO collection, Canberra, Australia, the paratype female will remain in the authors collection but will be bequeathed to CSIRO.