Phanoperla occipitalis, Sivec & Stark, 2010

Sivec, Ignac & Stark, Bill P., 2010, Seven New Species Of Phanoperla Banks From Vietnam And Thailand (Plecoptera: Perlidae), Illiesia 6 (10), pp. 98-112 : 105-106

Phanoperla occipitalis sp. n.

( Figs. 19-23 )

Material examined. Holotype ♂ and 2♂ paratypes from Thailand, Chiang Mai Province, Doi Suthep-Pui National Park, Namtok Monthatarn , 98° 55’ N, 18° 49’ E, 700 m, 5-6 May 2002, Blacklight trap, Chiang Mai University Team ( PMSL). Additional paratypes: Thailand: type locality, 27 May-6 June 2002, Malaise trap, Chiang Mai University Team, 1♀ ( PMSL). Chiang Mai Province, Doi Inthanon National Park , 98° 27’ N, 18° 31’ E , 1060 m, Huai Sai Lueng, 7-8 May 2002, Blacklight trap, Chiang Mai University Team, 1♀ ( PMSL). Chiang Mai Province, Doi Inthanon National Park, Nam Mae Klang at Ban Sop Aep , 98° 36’ N, 18° 31’ E , 630 m, 7-8 June 2002, I. Sivec, 1♂ ( PMSL). Doi Suthep- Pui National Park, Huai Kaew above Monthratarn , 800 m, 6-26 May 2002, I. Sivec, 1♂ ( PMSL). Khampaeng Phet Province, Khlong Lan National Park, namtok Khlong Lan , 99° 16’ N, 16° 07’ E , 310 m, 21 February 2002, 1♀, Chiang Mai University Team ( PMSL). Same location, 7-8 March 2002, 6♂, 7♀, Chiang Mai University Team ( PMSL). Same location, 19-20 June 2002, 3♂, 2♀, Chiang Mai University Team ( PMSL). Same location, 21-22 August 2002, 1♂, Chiang Mai University Team ( PMSL). Same location, 19-20 October 2002, 1♂, 1♀, Chiang Mai University Team ( PMSL) .

Adult habitus. Biocellate with ocelli separated by at least one ocellar diameter. Occiput yellow, contrasting with dark frons; M-line pale, epicranial suture dark ( Fig. 19 ). Pronotum brown with pale rugosities.

Male. Forewing length 11 mm. Tergum 8 without mesal lobe. Tergum 9 with large mesal patch of sensilla basiconica almost divided by thin bare area devoid of structures; hind margin of tergum 9 produced as a small mesal lobe ( Fig. 20 ). Processes of hemitergal lobes short and wide but acute at apex. Aedeagal tube with slender ventral sclerite and ventroapical membranous lobe; aedeagal sac bearing a dorsobasal and a smaller, distal ventral lobe; both lobes covered at least partially by small spines ( Fig. 21 ); apex and subapex of sac armed with a continuous broad band of spines; largest spines form an almost complete, close-set, subapical ring.

Female. Forewing length 12 mm. Subgenital plate wide, slightly produced over anterior margin of sternum 9 and shallowly notched ( Fig. 22 ).

Egg. Outline tear drop-shaped, with long slender collar, flanged rim and short, petiolate anchor ( Fig. 23 ).

Larva. Unknown.

Etymology. The species name refers to the distinctively pale occiput of this species.

Diagnosis. This relatively large species is similar to P. sertispina Jewett in external male genitalic and aedeagal characters. It differs in having the sensilla patch of tergum 9 united on the anterior margin and in having the ventral and dorsal lobes of the aedeagal sac covered with spines. In P. sertispina no dorsobasal lobe is shown by Zwick (1982) and the midventral sac lobe is membranous and lacks spines. The eggs of the two species also differ, with P. occipitalis eggs lacking markedly raised “meshes” on the collar.

Figures

Figs. 19-23. Phanoperla occipitalis. 19. Head and pronotum. 20. Male terminalia, dorsal. 21. Aedeagus, lateral. 22. Female terminalia. 23. Egg.