Lepidotrigona satun, Attasopa & Bänziger & Disayathanoowat & Packer, 2018

Attasopa, Korrawat, Bänziger, Hans, Disayathanoowat, Terd & Packer, Laurence, 2018, A new species of Lepidotrigona (Hymenoptera: Apidae) from Thailand with the description of males of L. flavibasis and L. doipaensis and comments on asymmetrical genitalia in bees, Zootaxa 4442 (1), pp. 63-82 : 77-79

Male of L. flavibasis

Lepidotrigona flavibasis ( Cockerell, 1929) , measured as range (Average±SD, n=4).

Figs. 2 : B1–4, 3: B1–4 & 8

Diagnosis. Lepidotrigona flavibasis differs from the other two species as follows: S4 apicolaterally bisinuate with medial convexity ( Fig. 2 : B1) (angularly emarginate in L. satun , weakly concave in L. doipaensis ( Fig. 2 : A1, C1)); S5 with apicosubmedial lobes pointed apically (as in L. doipaensis , rounded in L. satun ), with one or two very short setae (generally only one very long seta and a much smaller seta in L. doipaensis but 4–7 setae of intermediate length in L. satun ); and S5 gradulus mostly diagonal except short transverse section touching the antecosta medially ( Fig. 2 : B2) (gradulus parallel to and in touch with most of antecosta medially in L. doipaensis , but no contact in L. satun ( Fig. 2 : A2, C2)). L. flavibasis also differs in having only greyish yellow hairs on metatibia dorsally ( Fig. 8 : B) (dark brown intermixed with greyish yellow hairs in L. doipaensis , but variably brown, dark brown or greyish yellow hairs in L. satun ). The ratio of the forewing diagonal to the length of the 2nd submarginal cell separates L. flavibasis from L. satun (see diagnosis of L. satun above and Table 1). The gonostyli and penis valves are also clearly different in the three species (see descriptions and Fig. 3 ).

Description. As for the holotype of L. satun n. sp. except as follows:

Structure: Body length 4.8–4.94 (4.91±0.07) mm. Head width 1.76–1.78 (1.78±0.01) mm; head length 1.34– 1.37 (1.35±0.01) mm; eye width 0.56–0.57 (0.56±0.005) mm; gena width 0.18–0.2 (0.19±0.01) mm; interocellar distance 0.34–0.35 (0.35±0.01) mm; ocellocular distance 0.2–0.22 (0.21±0.01) mm; upper interorbital distance 1.1–1.11 (1.1±0.01) mm, lower interorbital distance 0.75–0.78 (0.77±0.01) mm; scape length excluding basal bulb 0.51–0.52 (0.51±0.005) mm, with basal bulb 0.57–0.59 (0.58±0.01) mm; 1 st flagellomere length 0.08–0.13 (0.11±0.02) mm; 2nd flagellomere length 0.17–0.18 (0.18±0.005) mm, width 0.14–0.15 (0.14±0.004) mm; 3rd slightly shorter than 2nd; 4th longer than broad; malar space length 0.03–0.04 (0.03±0.005) mm. Forewing length 4.39–4.48 (4.42±0.04) mm, width 1.6–1.61 (1.6±0.01) mm; forewing diagonal 1.23–1.29 (1.26±0.03) mm, length of 1 st submarginal cell 0.3–0.33 (0.31±0.01) mm, 2nd submarginal cell length 0.58–0.61 (0.6±0.01) mm. Metatibia length 1.4–1.42 (1.41±0.01) mm, width 0.54–0.56 (0.55±0.01) mm; metabasitarsus length 0.58–0.59 (0.59±0.01) mm, width 0.37–0.39 (0.38±0.01) mm. S4 convex apicomedially, gradulus of S4 weakly concave medially, with small apicolateral angulation; S5 apical margin with two long, narrow processes bearing one or two very short thick setae, processes delimit an emargination ~0.54 times as deep as length of sternum and as long as wide, apicolateral lobe well developed, bearing long curved setae, gradulus touching antecosta medially; S6 with acute triangular apicomedial process; S7 approximate twice as wide as long, apical margin weakly emarginate. Genital capsule dark brown to black except base of penis valve, apical half to 2/3 of gonostylus and gonocoxa anteriorly pale brown to brown; the right penis valve overarches the left one and has two right angles directed to the right, so that the tip of the valve ends to the right of the midline of the bee, and generally posterior and often dorsal to the tip of the left penis valve. In the left penis valve the first angle is less acute and the second angle is missing but replaced by a curvature directed to the right, hence also bringing the tip of the left valve to the right of the midline, the tip is anterior and often ventral to the tip of the right penis valve. In addition, the final fourth or fifth of the valves is sinuous, the tips diverging from each other. Gonostylus sclerotized basally, approximately 12 times longer than wide (length 0.91–0.96 mm, width 0.073–0.080 mm) hairs equally dense throughout the apically expanded portion.

Coloration of integument: Head black except as follows: yellowish brown on basal bulb and extreme apex of scape, labrum, and apical half of mandible; F2–F11 dark brown. Mesosoma black except pronotal lobe and tegula dark brown; fore and mid legs dark brown except medio- and distitarsi yellowish brown; hind leg black except tarsus yellowish brown (sometimes metabasitarsus dark brown). Metasomal terga black except basal depression of T1 transparent brown and apex of T6 and T7 brown. S1–S3 dark brown except posterior half of S1, posterior margin of S2, and apex of S3 whitish translucent; S4 brown except apical margin and most of disc medially translucent; S5 with apical and apicolateral lobes brown; S6 with anterolateral brown spot; S7 translucent except gradulus narrowly brown.

Pubescence: Face with short plumose dense appressed white hairs; vertex with erect long pale whitish brown hairs. Mesoscutum with long and very short pale whitish brown hairs; mesoscutum, pronotal lobe and mesepisternum lacking distinct band of short plumose scale-like yellow hairs on margins; mesoscutellum with erect long pale whitish brown hairs longest on posterior margin; mesepisternum, metepisternum and metanotum with brownish white hairs; coxa and trochanter of all legs and ventral surface of all femora with long pale brownish white hairs, rest of femora with brownish white hairs intermixed with pale brown hairs; pro- and mesotibiae with dark brown hairs intermixed with brownish white hairs; metatibia with short greyish yellow hairs, coloration and density approximately the same on dorsal and ventral margins; all tarsi with whitish brown hairs intermixed with yellowish brown hairs, metatibia with short sparse brown keirotrichia. Posterolateral margin of T3–T7 with fine brownish white hairs progressively longer from T3–T7.

Surface sculpture: All legs with fine dense punctures. T1 with sparse fine shallow punctures except impunctate on basal depression; metasomal sterna with coarse shallow crowded punctures intermixed with sparse coarse punctures.

Material examined. Type material: Holotype (worker, AMNH); Type locality: THAILAND; labelled as follows: “Doi Sutep./Siam/ Feb. 9 / Alice Mackie”, “ Trigona / flavibasis / TYPE. CKll”, “acc 35740”. [Images examined (provided by AMNH, 2017)].

Additional material: Measured male specimens included in description and Table 1 (collected from wild nests): THAILAND, Chiang Mai Prov., Doi Suthep : 6.iv.2017, H. Bänziger (Nest SHQ2, 4 males, caught leaving nest [not swarming]). Measured worker specimens included in Table 1 (collected from wild nests): Chiang Mai Prov. : Doi Suthep , 26.xii.2015, K. Attasopa (Nest PHPL1, 2 workers); Doi Suthep-Pui, 1080 m, 6.iv.2017, H. Bänziger (Nest SHQ2, 2 workers). Non-measured specimens (collected from wild nests): Chiang Mai Prov.: Doi Inthanon , 17.i.2016, K. Attasopa (Nest MYAL1 , 3 workers; MKLL3 , 3 workers) ; Doi Suthep , 26.xii.2015, K. Attasopa (Nest DSTL1 , 2 workers; nest PHPL1 , 3 workers); Doi Suthep-Pui, 1080 m , 1.iv.2017, H. Bänziger (Nest SHQ2, 6 workers), 6.iv.2017, H. Bänziger (Nest SHQ2, 16 males, 9 workers, caught leaving nest [not swarming]). Nonmeasured specimens (collected by H.B. while they sucked his sweat): Chiang Mai Prov., Doi Inthanon, above Mae Ya Noi, 1700 m, 22.ii.1993 (4 workers).

Genitalia examined: GP 3296, 3297, 3298, 3299, 3300, 3301, 3302, nest SHQ2 of type locality, Doi Suthep, 6.iv.2017.

Figures

FIGURE 2. Male metasomal sterna, ventral aspect labelled as: (A), (B), and (C) refer to L. satun n. sp. (Paratype, H.B.- GP3311), L. flavibasis (H.B.-GP3322), and L. doipaensis (H.B.-GP3183) respectively, with the number following as (1), (2), (3), and (4) refer to S4, S5, S6, and S7 respectively. All subfigures are shown at the same scale and magnification. Diagonal lines indicate the characters treated in the diagnoses.

FIGURE 3. Male genital capsules, labelled as: (A), (B), and (C) refer to L. satun n. sp. (Paratype, H.B.-GP3311), L. flavibasis (H.B.-GP3322), and L. doipaensis (H.B.-GP3183) respectively, with the number following as (1), (2), (3), and (4) refer to dorsal, ventral, lateral, and caudal aspect respectively. All subfigures are shown at the same scale and magnification. Diagonal lines indicate the right penis valve.

FIGURE 8. Male of L. flavibasis from the type locality (Doi Suthep, Chang Khian, Chiang Mai, Thailand). (A) dorsal habitus, (B) lateral habitus, and (C) head, frontal view.