Devadatta yokoii, Phan, Quoc Toan, Sasamoto, Akihiko & Hayashi, Fumio, 2015

Phan, Quoc Toan, Sasamoto, Akihiko & Hayashi, Fumio, 2015, Description of two new species of the genus Devadatta from northern Vietnam and central Laos (Odonata: Devadattidae), Zootaxa 3941 (3), pp. 414-420 : 418-419

Devadatta yokoii sp. nov.

( Figs. 1 B, 2B, 3B, 4B)

Devadatta ducatrix [nec. Lieftinck, 1969]; Yokoi, 1999, Gekkan-Mushi 342: 3, Fig. 4 .

Material examined. Holotype ( Fig. 1 B): male; Laos PDR, Vientiane Province, Vangvieng, submontane forests east of Route 13 (18° 58’ 53” N, 102° 27’ 14” E, ca. 370 m a.s.l.); 01-VIII-1998; Naoto Yokoi leg. (in TMUZ). Paratype: 1 male, same site and date as holotype (in SAC).

Etymology. The new species is named after its discoverer Dr. Naoto Yokoi, an enthusiastic odonatologist who has investigated the odonate fauna of Laos since the 1990s. He kindly gave us the opportunity to examine and describe this new species.

Description of holotype male. Head ( Fig. 1 B): Labrum, clypeus, frons and upper surface of head metallic dark brown; mandibles pale yellow; antennae black; vertex black, with pair of oval yellow spots at sides of lateral ocelli; occipital area black.

Thorax ( Fig. 1 B): Prothorax black; anterior lobe with pair of prominent oval pale yellow spots dorsolaterally; posterior lobe with pale yellow stripe along posterior margin. Synthorax matte black with lateral yellow stripes. Stripe on humeral suture rudimentary and largely interrupted in the middle; that on first lateral suture slender, irregularly constricted; that on second lateral suture broader, a little constricted in the middle, connecting with the ventral stripe of metepimeron. Mes- and metinfraepisternum matte black with pale yellow patches posterolaterally; ventral side of synthorax yellow. Legs brown, coxa with yellow in anterior and posterior surface; femur and tibia with strong but slender spines.

Wings ( Fig. 2 B): Hyaline, venation black with the tips of both wings brown; petiolated at about level of 4th costal vein; 10–11 antenodal crossveins in Fw, 9–10 in Hw; 39–42 postnodals in Fw, 33–35 in Hw; subcostal veins proximal to subnodus 5 in both wings; arculus situated at 4th antenodal crossvein in both wings; quadrangle with 3 or 4 crossveins in Fw, 2 or 3 in Hw; cubital space with 3–4 veins in Fw and 4–5 before anal crossing in Hw, respectively; first anal vein meets wing margin at level of about equal to nodus in Fw, while extending beyond nodus to about 2nd postnodal level in Hw. Only one or two cell rows in space between first anal vein and wing margin in both wings. Pterostigma dark brown, covering 5 cells in both wings. Tip of wing with brown patch covering a little less than half of space between distal end of pterostigma and wing apex in Fw, about a quarter of same in Hw.

Abdomen: Reddish brown, with basal and distal segments of darker coloration. S2–3 with small whitish semioval spot baso-laterally. Other segments lacking maculation. Anal appendages ( Fig. 3 B) black; superior appendage a little more than twice as long as inferior in lateral view; superior appendage in dorsal view gently curved at middle and distal portion a little expanded internally, turning obliquely inwards; tip slightly swollen; apices of superior pair never overlapping each other. The inferior appendage short and gradually tapering in lateral view; tip a little hooked inwards. Penile organ ( Fig. 4 B) similar to that of D. ducatrix and D. kompieri , but lobule attached to apex of distal segment an elongated oval shape.

Measurements (mm). Hw 32; abdomen including appendages 38.

Variations in paratype male. The paratype specimen also has a spot on S4 similar to those of S2 and S3 on the abdomen. Wing venation of the paratype is as follows: in Fw, antenodal veins 11, postnodal 40 and 42; in Hw, antenodal 9 and 11, postnodal 33 and 35. Measurements, Hw 33, abdomen including appendages 37.5 mm.

Female. Unknown.

Notes on biology. Yokoi (1999) described the environment where this new species was observed as follows: “The habitat is dark on small stream in the dense forests. At the same site, Burmargiolestes melanothorax (Selys, 1891) was found.” Interestingly, the locality is near that of D. glaucinotata , about 12 km measured directly.

Differential diagnosis. Devadatta yokoii is similar to D. ducatrix and D. kompieri . but differs from them in the following characters: (1) D. kompieri ( Fig. 1 A) is smaller (Hw 31–34; abdomen including appendages 32–37) than the more robust D. ducatrix (Hw 33; abdomen including appendages 39 mm in our specimen ( Fig. 1 C), and each 40 and 43.3 mm in holotype (Lieftinck 1969)), and D. yokoii ( Fig. 1 B) is intermediate between these two species (Hw 32–33; abdomen including appendages 37.5–38). (2) D. yokoii has pale maculation on prothorax, synthorax, and basal abdominal segments, which are absent in D. ducatrix and D. kompieri ( Fig. 1 ). (3) Wings of D. kompieri and D. yokoii ( Fig. 2 A, B), compared with those of D. ducatrix ( Fig. 2 C), are proportionally shorter and have a less rounded apex and a narrower dark marking at tip (narrowest in D. yokoii ). The pterostigma is proportionally longer and narrower in D. kompieri but is shorter in D. yokoii than in D. ducatrix . The venation of D. kompieri and D. yokoii is less dense, especially in the space between first anal vein and posterior wing margin in the Hw, which consists of two cell rows at most, whereas there are two to three rows in D. ducatrix . (4) Superior appendages of D. kompieri and D. yokoii are slimmer, while those of D. ducatrix are broader ( Fig. 3 ). (5) Lobes of the distal segment of penile organs are slightly elongated and oval in D. yokoii , whereas these are non-elongated and semicircular in D. ducatrix and D. kompieri ( Fig. 4 ).

Figures

FIGURE 1. Devadatta spp. A, holotype of D. kompieri (male). B, holotype of D. yokoii (male). C, D. ducatrix of the specimen collected at Tu Le Community, Mu Cang Chai District, Yen Bai Province, northern Vietnam. The scale is marked in mm and the same for A and C.

FIGURE 2. Male fore- and hindwings of Devadatta kompieri. (A), D. yokoii (B), and D. ducatrix (C, same specimen shown in Fig. 1 C).

FIGURE 3. Male caudal appendages of Devadatta kompieri (A), D. yokoii (B), and D. ducatrix (C, rearranged from Lieftinck 1969, p. 207, Fig. 2) in lateral, dorsal, and ventral views.

FIGURE 4. Male penile organs of Devadatta kompieri (A), D. yokoii (B), and D. ducatrix (C, rearranged from Lieftinck 1969, p. 207, Fig. 2) in lateral and ventral views.