Phaenandrogomphus safei, Dow, Rory A. & Luke, Sarah H., 2015

Dow, Rory A. & Luke, Sarah H., 2015, Phaenandrogomphus safei, a new species from Sabah, northern Borneo (Odonata: Anisoptera: Gomphidae), Zootaxa 3905 (1), pp. 145-150 : 145-149

Phaenandrogomphus safei sp. nov.

( Figs. 1 , 3, 4, 5, 6 , 7, 8 , 11, 12, 13 , 14, 15, 16 )

Material. Holotype: ♂, Malaysia, Sabah, Kalabakan Forest Reserve, 4 ̊43’N, 117 ̊37’E, 29 iv 2013, leg. S. H. Luke. To be deposited at the Forest Research Centre, Sepilok, Sabah.

Etymology. safei , a noun in the genitive case, formed from the acronym of the Stability of Altered Forest Ecosystems (SAFE) Project, where the type specimen was collected.

Description of holotype male. Head ( Figs. 3–4 ): Labium pale grey centrally, whitish basally and laterally, black along free margin of median lobe and narrowly on apical outer margin of palps. Labrum black with pair of broad pale markings in upper half, narrowly divided centrally. Mandible bases pale, genae mostly olivaceous. Anteclypeus with lower margin slightly concave ( Fig. 3 ), greyish-green coloured. Postclypeus mostly black with pair of pale lateral marks. Ante- and postfrons not very sharply divided, black with green transverse stripe on anterior half of postfrons ( Fig. 4 ). Vertex and occiput mostly black to very dark brown, with poorly defined paler areas behind median ocellus and between eyes at level of their closest approach to one another. Pair of tubercles behind lateral ocelli; ocelli pale yellowish.

Thorax: Prothorax almost entirely dark brown and black, except anterior pronotal lobe, where central part of anterior carina and area behind pale. Synthorax dark brown to black with pale yellow-green markings as follows ( Figs. 5–6 ): short mesothoracic collar, narrowly divided at mid-dorsal carina, joined to narrow antehumeral stripes that extend beyond level of apex of antealar triangle, terminating just short of antealar carina. Small spot below antehumeral marking on mespisternum, near antealar carina. Stripe running length of mesepimeron. Metepisternum with stripe running below spiracle from metinfraepisternum, separated from ca triangular spot at antealar carina. A broad stripe occupying all of metepimeron except narrowly below metapleural suture. Mesinfraepisternum mostly dark brown, metinfraepisternum pale. Venter pale with brown stripe on either side. Legs robust and relatively short with posterior femur not reaching base of S1. Coxae mostly pale, trochanters brown and black, flexor surface of anterior femora, and distal ca one-third of flexor surface of middle femora pale, rest mostly black. Wings ( Figs. 7–8 ): Sectors of arculus separated at origin with 2 cross veins before first bifurcation of superior sector in Fw and 1 in Hw. Discoidal field with 2 rows of cells from origin to level of nodus in both wings. 13 (left) or 15 (right) Ax in Fw, 9 (left) or 10 (right) in Hw, 8 (left) or 9 (right) Px in Fw, 8 (left) or 9 (right) in Hw. Pt very dark brown, covering just over 4 underlying cells in Fw, ca 4-1/2 underlying cells in Hw.

Abdomen: Slender after base of S3, expanding moderately from base of S7, maximum width and height reached apical part of S8, then almost constant. Black with pale markings as follows ( Fig. 1 ): S1 mostly pale yellowish laterally. S2 pale yellowish around and including auricle laterally, except free margin of auricle, another yellowish lateral mark placed posteriorly, narrow yellowish mid-dorsal stripe. S3–6 with small dorso-lateral markings at base, divided dorsally. S3–4 with small elongate oval yellow mark mid-dorsally, this reduced to small spot on S5 and absent on S6. S7 with more extensive yellow dorso-lateral marking at base, occupying slightly less than two-thirds of tergite and narrowly divided dorsally. S8–10 entirely black. Cerci ( Figs. 14–15) curved down and moderately dorso-ventrally expanded in apical ca one-third, bearing robust teeth on inner edge apically. Pale brown at base, darkening towards apices, especially on upper surface where almost black. Epiproct ( Figs. 14, 16 ) black, shorter than cerci, deeply divided, branches running approximately parallel on their inner margins for almost their entire length, apices pointed and slightly out-turned. In lateral view ( Fig. 14) branches curved downward for short distance from base, then straightening, with upper margin abruptly raised at this point, before curving upwards again at ca two-thirds length, finally straightening again apically, where upper margin gently concave before apex. Accessory genitalia as shown in Figs. 11–13 , with anterior hamule moderate sized, directed posteroventrally, apical half narrow and hook shaped, penis with terminal segment ( Figs. 11–12 ) divided centrally and bearing cornua, penis vesicle moderately large, but not extending ventrally beyond level of hamuli, its posterior apex only weakly bifurcate ( Fig. 13 ).

Measurements [mm]: Hw 26, abdomen without anal appendages 31.5, cerci ca 3, epiproct ca 2.7.

Diagnosis. A moderately small gomphid ( Figure 1 ), brightly coloured in life. It differs from all other Phaenandrogomphus species except P. treadawayi in having a smaller penis vesicle with posterior part of apex much less strongly bifurcated (compare with Fig. 3 in Lieftinck (1964)). It also differs in the form of the anterior hamule, which in the mainland species, while ventrally directed at base, makes an abrupt turn posteriad shortly after it emerges from the genital fossa. Additional differences from the mainland species include the less extensive pale markings on thorax and abdomen and sectors of arculus well separated at origin. P. safei can be separated from P. treadawayi by the accessory genitalia with terminal hooked part of anterior hamule longer and penis vesicle differently shaped in lateral view, more flattened terminal segment of the penis, the markings of the synthorax, the more downcurved and expanded apical part of the cerci with large apical teeth, and the epiproct which has the upper margin expanded abruptly and is upturned more apically than in P. treadawayi .

Remarks. The holotype was found flying over a shallow stream, approximately 2 km downstream from its source, and flowing through lowland dipterocarp forest that had previously been selectively logged several times. The stream channel was fairly open following a large flooding event in 2011 that caused long distance transport of logs and extensive erosion of stream banks. In life the pale markings of the synthorax were more blue-green than yellow and the eyes were blue.

Figures

FIGURES 1 – 2. Habitus: (1) Phaenandrogomphus safei holotype; (2) Phaenandrogomphus treadawayi holotype.

FIGURES 3 – 6. Phaenandrogomphus safei holotype: (3) head, anterior view; (4) head, dorsal view; (5) synthorax lateral view; (6) mesepisternum dorsal view.

FIGURES 7 – 10. Wings: (7) left forewing Phaenandrogomphus safei holotype; (8) right forewing Phaenandrogomphus asthenes holotype, flipped to left for comparison; (9) left hindwing Phaenandrogomphus safei holotype; (10) right hindwing Phaenandrogomphus asthenes holotype, flipped to left for comparison.

FIGURES 11 – 13. Phaenandrogomphus safei holotype: (11) accessory genitalia, lateral view; (12) terminal segment of penis, ventral view; (13) penis vesicle, ventral-posterior view, posterior apex indicated by arrow.

FIGURES 15 – 16. Phaenandrogomphus safei holotype, anal appendages: (15) dorsal view; (16) ventral view.