Neoperla agtouganon, Sivec & Stark, 2011

Sivec, Ignac & Stark, Bill P., 2011, New Species Of Neoperla Needham And Phanoperla Banks (Plecoptera: Perlidae) From The Philippine Islands, Illiesia 7 (24), pp. 264-279 : 264-265

Neoperla agtouganon sp. n.

( Figs. 1-8 )

Material examined. Holotype ♂, PHILIPPINE ISLANDS, Mindanao , Mt. Agtouganon, 1050 m, 28 May-7 June 1996. W. Mey ( ZMB) . Paratypes 1♂, 4♀, same data as holotype (all specimens deposited in the ZMB) .

Adult habitus. General color pale brown. Head without distinctive dark pigment patches; pronotum pale with scattered, thin rugosities ( Fig. 1 ).

Male. Forewing length 14 mm. Tergum 7 process a small, rounded, median lobe; posterior margin of lobe lined with thick sensilla basiconica. Tergum 8 without lobes, but bearing a sparse mesal patch of sensilla. Tergum 9 with a pair of small median sensilla patches. Hemitergal lobes slender and curved laterad near midlength ( Fig. 2 ). Penis tube short, weakly sclerotized along dorsal margin, and bearing a small spiny, dorsoapical lobe in lateral aspect ( Fig. 4 ). Penis sac longer than tube, bearing spines along most of length, and curved ventrad into a wide, subapical, spiny lobe, thumb shaped in lateral aspect and somewhat lunate in ventral aspect; sac additionally bearing two basolateral pairs of spiny lobes and a low pair of subapical, spiny outgrowths dorsad to ventral thumb shaped lobe ( Figs. 3-4 ).

Female. Forewing length 18-21 mm. Subgenital plate poorly developed, not projecting beyond hind margin of sternum 8.

Egg. Outline oval, collar absent. Length ca. 280 μm, width ca. 240 μm. Chorionic surface finely punctate throughout ( Figs. 5-8 ). Micropylar orifices sessile ( Fig. 6 ).

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, is based on Mt. Agtouganon, the type locality.

Diagnosis. This species is a member of the N. oculata Banks, 1924 species complex of the N. montivaga species group ( Sivec 1984; Zwick 1986). Among Philippine members of the complex, the penis of the new species is generally similar to that of N. pallescens Banks, 1937 and N. oculata in having multiple pairs of small, dorsolateral lobes and a minor dorsal projection from the penis tube apex. However, the subapical, ventrally hooked, lunate process on the penis sac is unique to N. agtouganon . The new species will key to couplet 15 in Sivec (1984) where the ventral lunate process can be interpreted as a single “outgrowth” directing to couplet 16. The presence of at least two pairs of dorsolateral outgrowths on the penis sac directs to couplet 17 where the species is identified either as N. pallescens or N. flinti Sivec, 1984 . However, the lobe positions and general shape of the penis sac are inconsistent with either of these choices. The egg is similar to that of N. PH D ( Sivec 1984) in lacking a collar and in being finely punctate, however the egg of that species has a fine opercular line.

Figures

Figs. 1-4. Neoperla agtouganon. 1. Head and pronotum. 2. Male terminalia. 3. Everted penis sac, dorsal. 4. Penis tube and everted sac, lateral aspect.

Figs. 5-8. Neoperla agtouganon egg. 5. Entire egg. 6. Micropyle and chorionic detail. 7. Collar end. 8. Anterior end.