Microgomphus jurzitzai Karube, 2000

Phan, Quoc Toan & Keetapithchayakul, Tosaphol Saetung, 2023, First descriptions of the final stadium larva of Heliogomphus chaoi Karube, 2004 and the adult female of Microgomphus jurzitzai Karube, 2000 from Vietnam (Odonata: Gomphidae), Zootaxa 5318 (1), pp. 83-96 : 90-92

Microgomphus jurzitzai Karube, 2000

( Figs. 8–9 )

Specimens examined. 1♁, 3♀♀, Nam Nung Nature Reserve (12.2026 N, 107.7583 E, altitude 862 m), Dak Nong Province, 9.v.2020, Q. T. Phan & Q.P. Ngo leg. ; 1♁, 2♀♀, Cu Mot Commune (13.1537 N, 108.0608 E, altitude 557 m), Ea H’leo District, Dak Lak Province, Vietnam, 8.vi.2022, Q. T. Phan & Q.P. Ngo leg. ; 2♁♁, Cu K’Bang Commune (13.1884 N, 107.9639 E, altitude 216 m), Ea H’leo District, Dak Lak Province, Vietnam, 9.vi.2022, Q. T. Phan & Q.P. Ngo leg.

Notes. Karube (2000) described M. jurzitzai based on two males from Lam Dong Province, southern Vietnam. Recently we collected several males and females of M. jurzitzai from neighboring provinces including Dak Nong and Dak Lak Provinces. The female of this species is described here for the first time. In Nam Nung Nature Reserve, we observed that males often perch on sand bars in the middle of open stream with many large rocks ( Fig. 6B ). Females were observed carrying large clusters of blue eggs at the end of their abdomens; the female appears suddenly and flies down to drop her egg cluster into water near the resting male and then flies up and away very quickly.

Description of female. (based on a specimen from Nam Nung Nature Reserve) ( Fig. 8 ).

Head ( Fig. 9A–C ). Labium black with a pair of lateral yellowish-green spots; anteclypeus black with a large central spot, postclypeus, antefrons and genae entirely black, postfrons black with a thick, transverse, pale yellow stripe; mandible yellowish-green; anteclypeus black with a large central spot; antennae entirely black; postfrons black with a thick transverse pale yellow stripe. Vertex and occiput all black with yellowish ocelli; two robust erect horns adjacent to lateral ocelli. Occiput with two small sharp horns.

Thorax ( Fig. 8 ). Prothorax black with anterior pronotal lobe yellowish and two large yellow spots to each side of pronotal midlobe. Pterothorax black, antehumeral stripe broadened anteriorly and yellowish, the remaining whitish; humeral stripe reduced to a small spot at dorsal end; mesepimeron and metepisternum black with large yellow bands; metepimeron yellow.

Legs ( Fig. 8 ). Stoutly built, entirely black.

Wings ( Fig. 8 ). Forewing with 13–14 Ax, 10 Px; hindwing with 11 Ax and 10 Px. Pterostigma brown, covering about 3.5–4 underlying cells.

Abdomen ( Figs. 8 , 9D–F ) black with yellowish green marking as follows: S1 with a large lateral spot; side of S2 with large bands, S3–S6 with marking smaller toward the end of each abdomen; a spot in anterior part of S7; S8–10 entirely black. Cerci yellowish, conical, twice the length of S10 ( Fig. 9D, E ). Vulvar lamina divaricated for about half the length, about 1/2 the length of S9 ( Fig. 9F ).

Measurements (in mm). Total length 45.0; Hindwing length 30; Hind femur length 14.5; Abdomen length (including appendages) 32.0.

Distribution. ( Fig. 7 ). Vietnam: Dak Lak (Ea H’Leo), Dak Nong (Nam Nung Nature Reserve) & Lam Dong (Bao Loc) Provinces ( Karube 2000; this study).

Diagnosis. This study brings the number of species known from female of the genus Microgomhus to nine. Females of M. jurzitzai can be separated from congeneric species in the genus Microgomphus by a combination of characters as follows (in parentheses other species): Occipital horns (absent in M. chelifer and M. farrelli ; not mentioned in M. lilliputians , M. loogali , and M. wijaya ). S7 with basal ring (S4–7 with basal rings in M. chelifer , M. farrelli and M. lilliputians ; S7 with large anteriolateral spots in M. alani ). Postfrons entirely pale (pale yellow peaked in middle with shallow cleft in M. phewataali ; large pale spot on both sides in some M. alani , M. loogali , M. chelifer , and M. svihleri ; pale band with upper margin concaved centrally in M. lilliputians ; not mentioned in M. wijaya ).

Figures

FIGURE 6. Habitat of (A) Heliogomphus chaoi (Hoa Trung) and (B) Microgomphus jurzitzai (Nam Nung).

FIGURE 7. Distribution of Heliogomphus chaoi (red circles) and Microgomphus jurzitzai (blue circle) in Vietnam.

FIGURE 8. Female habitus of Microgomphus jurzitzai.

FIGURE 9. Structures of Microgomphus jurzitzai, female. (A) head in frontal view; (B) two robust horns adjacent to lateral ocelli; (C) two small horns on occiput; abdominal tip in (D) dorsal, (E) lateral, and (F) ventral view.