Phanoperla flabellare, Stark & Sivec, 2007

Stark, Bill P. & Sivec, Ignac, 2007, Studies Of Indonesian Perlidae (Plecoptera), With Descriptions Of Three New Species, Illiesia 3 (7), pp. 53-64 : 58-59

Phanoperla flabellare sp. n.

( Figs. 10‐12 , 13‐17 )

Material examined. Holotype ♂ and 2 ♀ paratypes from Indonesia, East Kalimantan, Kayan‐ Mentarang Nature Reserve, Lalut Birai , 2° 52’ N, 115° 49’ E, 378 m, IIS 940507, B. Hubley, D.C. Darling (Holotype MZB, paratypes ROM).

Adult habitus. General color pale yellow brown. Head pale without distinct marking except dark stem suture behind ocelli ( Fig. 13 ); basal eight antennal segments pale brown, rest darker; palpi pale brown. Pronotum pale brown with slightly darker rugosities; margins almost completely ringed with narrow, dark suture lines. Wings pale amber, veins slightly darker; Rs with two branches. Femora pale, tibiae and tarsi slightly darker.

Male. Forewing length 8 mm. Tergum 9 bearing three narrowly separated sensilla basiconica patches; posterior margin produced as a narrow, truncate mesal lobe. Hemitergal lobes rather broad at base and more or less triangular in outline ( Fig. 14 ). Aedeagal tube sclerite narrow, outline of sclerite a slender, prolonged rhomboid; sac shorter than tube and armed with lateral groups of 6 or 7 large, black spines in fan shaped clusters on either side of apical cylindrical lobe ( Figs. 15‐16 ); surface of apical cylinder very densely armed with black, scale‐ like spines; ventroapical tube surface armed with large patch of minute spinules.

Female. Forewing length 10 mm. Subgenital plate slightly produced over base of sternum 9 and notched; midpoint of notch bearing a small projection ( Fig. 17 ). Posterior intersegmental membrane of sternum 9 with microtrichia patch.

Egg. Length ca. 0.31 mm, equatorial width ca. 0.18 mm. Collar short, wide with slightly flanged rim; collar width ca. 0.07 mm. Anchor mushroom shaped with marginal row of globular bodies on short lobes ( Figs. 10‐11 ). Chorionic surface with inconspicuous striations extending from collar rim, area between striae divided into irregular, more or less rhomboid cells with punctate floors; ca. eight striae visible in lateral aspect. Equatorial zone with a narrow belt of larger punctations; lid coarsely punctate with groups of 3‐5 pits per cluster, each cluster associated with an irregular serpentine ridge ( Fig. 12 ).

Larva. Unknown.

Etymology. The species name refers to the fan shaped clusters of spines on the aedeagal sac.

Diagnosis. The aedeagus of this species is generally similar to that of P. flaveola , a species known from Java, Borneo and the Philippines ( Zwick 1982d). It differs from that species in lacking the two secondary rows of large spines on the ventrobasal area of the sac and in having a slender dorsal sclerite. It is also similar to P. tuberosa in having several large, black spines clustered in circumlinear row around the base of an apical, spinous lobe. However in P. tuberosa the apex is strongly curved ventrad and the ventroapical projection of the tube is bilobed with the armature separated into patches on each lobe. The female subgenital plate resembles those of P. flaveola and P. pumilio in having a prominent, almost quadrate median notch, but in P. flabellare there is a distinctive median projection. The egg is of the general P. flaveola or P. malayana Zwick type but differs from both as well as those known from Borneo in specific, but subtle detail. The egg of P. flaveola , for example also has multiple zones of chorionic pits but in that species the “equatorial zone” consists of smaller rather than larger pits and it is shifted distinctly above the equator and onto the lid of the egg ( Zwick 1982d).

Figures

Figs. 7‐12. Neoperla BoM (7‐9) and Phanoperla flabellare (10‐12) eggs. 7. Entire egg. 8. Collar end. 9. Chorionic surface. 10. Entire egg. 11. Collar end. 12. Lid.

Figs. 13‐17. Phanoperla flabellare structures. 13. Head and pronotum, 14. Male terminalia, 15. Aedeagus lateral, 16. Aedeagal apex ventral, 17. Female terminalia.