Peltoperlopsis anomala, Stark & Sivec, 2007

Stark, Bill P. & Sivec, Ignac, 2007, New Species And Records Of Asian Peltoperlidae (Insecta: Plecoptera), Illiesia 3 (12), pp. 104-126 : 117-119

Peltoperlopsis anomala sp. nov.

( Figs. 44-49 )

Material examined. Holotype ♂ (pinned) from Indonesia, East Kalimantan, Kec. Pujangan, Kayan- Mentarang Nature Reserve , 500 m, 2 ° 52’ N, 115 ° 49’ E, October 1994, Malaise trap, D.C. Darling, Rosichon U., llS 940606 ( MZB) . Additional material: Indonesia: East Kalimantan: Kayan-Mentarang Nature Reserve, Nggeng River, 2 ° 51’ N, 115 ° 49’ E, 378 m, 30 March 1994, B. Hubley, D.C. Darling, llS 940510, 8 larvae ( ROM). Bulungan, Kayan-Mentarang Nature Reserve , Lalut Birai Res. Sta., 2 ° 51’ N, 115 ° 48’ E, 355 m, 20 February-4 March 1993, D.C. Darling, llS 930003, 2 larvae ( MZB) .

Adult habitus. Biocellate. General color brown. Head with dark brown over most of occiput; pale areas encircle anteromedian margins of ocelli but dark brown continues from interocellar area to M-line and forward as a small brown triangle; lappets and pronotum brown. Wings brown with slightly darker veins. Femora and tibiae brown but somewhat paler along ventral margins.

Male. Forewing length 9 mm. Tergum 10 with Ushaped mesal sclerite. Basal cercal segment ca. 1.25X long as basal width ( Fig. 44 ). Segments clothed laterally with short fringe setae. Vesicle a poorly defined arc about 4X wide as long ( Fig. 45 ). Aedeagus membranous, asymmetrical and armed with variably sized spines; basal third armed with dense microtrichia patch completely ringing structure; sinistral lobe bifurcate at tip with lateral lobe somewhat thumb shaped ( Figs. 46-47 ); apical half of sinistral lobe armed with minute spines along ventrolateral margin and basal half with a small lateral patch of 5-6 large triangular spines and a dorsomesal patch of 2 large triangular spines; dextral lobe much shorter than sinistral lobe, consisting of three small, more of less rounded lobes; outer dextral lobe armed with a few (<10) large spines and inner dextral lobes armed with finer and more numerous spines.

Female. Unknown.

Larva. Pre-emergent body length 7-8 mm. General color brown to red brown without conspicuous pattern. Long slender gills project from beneath prosternal and mesosternal plates ( Fig. 48 ) and similar supracoxal gills occur on mesothorax and metathorax under wingpads; gills on paraprocts long, slender and sharply upturned ( Fig. 49 ), median gill on ventroapical margin of tergum 10 delicate. Metasternum concave on posterior margin and completely fringed with small bristles; lateral margins with longer fringe bristles around coxal bases which continue onto plate as a short row of about five mesal bristles ( Fig. 48 ). Mesosternum with

45 44

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46 47 49

only a few small posterolateral, bristles, lateral bristles around coxal bases and about 4 mesal bristles from continuation of lateral row onto plate. Prosternum with complete anterior row of erect bistles, mesolateral bristles absent. Cerci without enlarged blade setae, but segments 11-28 each with a single long seta in ventral whorls; long whorl setae generally less than half as long as next segment.

Etymology. The species name refers to the asymmetry of the internal male genitalic structure.

Diagnosis. This species is similar to P. concolor ( Banks 1931; Stark 1989) but is slightly darker, has shorter cercal fringe setae and the vesicle is arcuate rather than tab shaped. The aedeagus of P. concolor has a similar asymmetry (based on a specimen from Kinabalu National Park in the USNM collection) but the detailed lobe pattern and armature distribution are different. Specifically, the sinistral lobe of P. concolor is apically trifurcate and bears no large spines along the outer margin; however a small spherical lobe on the inner margin base has a few moderate sized spines. Other differences are apparent when the dextral lobes are compared. Unfortunately, eversion of the aedeagus for Peltoperlopsis males is difficult to achieve in fixed specimens, consequently collectors may need to routinely squeeze male specimens in the field to facilitate their study. Larvae can be distinguishedfrom those of P. concolor on the basis of

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the absence of flattened blade setae on the mesal cercal segments and perhaps by the presence of a delicate median ventroapical gill on abdominal tergum 10.

Figures

Figs. 44-49. Peltoperlopsis anomala. 44. Male terminalia, dorsal, 45. Male sternum 9, 46. Aedeagus, dorsal, 47. Aedeagus, ventral, 48. Larval thoracic sterna, 49. Larval abdominal apex and cerci.