Peltoperlopsis cebuano, Stark & Sivec, 2007

Stark, Bill P. & Sivec, Ignac, 2007, New Species And Records Of Asian Peltoperlidae (Insecta: Plecoptera), Illiesia 3 (12), pp. 104-126 : 119-120

Peltoperlopsis cebuano sp. nov.

( Figs. 50-57 )

Material examined. Holotype ♂, and 3 ♀ paratypes from the Philippines, Mindanao , Mt. Agtunganon, 1050 m, 28 May-7 June 1996, W. Mey ( MNB).

Adult habitus. Biocellate. General color brown. Head with a distinctive mask over ocelli, but with pale halo surrounding ocellar pair and paler areas around eyes and at anteromedian margin ( Fig. 50 ). Pronotum pale but with large irregular darker rugosities. Wing membrane brown, veins darker but costal area pale. Femora pale brown at base, darker toward apex; tibiae dark brown.

Male. Forewing length 10 mm. Tergum 10 with posterior U-shaped brown mark and dark transverse anterior band constricted in median field ( Fig. 51 ). Basal cercal segment curved and about 2X long as wide; inner setal fringe well developed at least on middle segments. Vesicle about as long as wide and with sclerotized base extending beyond lateral margins of structure ( Fig. 53 ). Aedeagus asymmetrical and armed with variably sized spination; sinistral lobe apically rounded, membranous at tip and base, lightly sclerotized in mesal section, and armed ventrally with sparse patch of small spines and microtrichia ( Fig. 52 ); dextral lobe with a major dorsal and ventral lobe; ventral lobe with sparse microtrichia. In dorsobasal aspect, much of surface covered with fine irregular ridges ( Fig. 55 ). Female. Forewing length 12-13 mm. Subgenital plate large and broadly rounded; U-shaped sclerite and transverse band of microtrichia visible from internal vaginal structure ( Fig. 54 ). Sternum 9 reaches beyond sternum 10 and covers bases of paraprocts; mesal field of sternum 9 bare and weakly sclerotized.

Egg. Outline barrel shaped with nipple-like collar surrounded by depressed ring. Chorion covered with FCIs ( Fig. 56 ); those near collar obscure ( Fig. 57 ), but becoming gradually more prominent near anterior pole. FCI floors depressed, rims thin near collar but thick near anterior pole. Micropyles not observed.

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, honors the people of the Cebuano ethnolanguage group.

Diagnosis. This species is closely related to P. mindanensis but the two species clearly differ in egg morphology with the surface of P. mindanensis eggs covered with similar FCIs over most of the chorion ( Stark 1989) and those of P. cebuano becoming progressively more distinct opposite the collar. They also appear to differ in aedeagal armature with P. mindanensis having a fairly large apical patch of spines on the dextral lobes and these being smaller and less abundant in P. cebuano . Banks (1924) also emphasizes the very dark blackish wings and dark brown head and pronotum of P. mindanensis whereas in the present sample, P. cebuano is a slightly larger and paler appearing species.

Figures

Figs. 50-55. Peltoperlopsis cebuano. 50. Head and pronotum, 51. Male terminalia, dorsal, 52. Aedeagus, ventral, 53. Male sternum 9, 54. Female terminalia, 55. Aedeagus, dorsal.

Figs. 56-57. Peltoperlopsis cebuano micrographs of eggs. 56. Egg, lateral, 57. Egg collar, lateral.