Anacroneuria pakaraima, Stark, 2012

Stark, Bill P., 2012, Anacroneuria Pakaraima And A. Wokomung, Two New Stonefly Species From Guyana (Plecoptera: Perlidae), Illiesia 8 (10), pp. 114-118 : 114-115

Anacroneuria pakaraima sp. n.

( Figs. 1-5 )

Material examined. Holotype ♂, 6♂, 6♀ paratypes (all pinned) from Guyana, District 8 , Mount Wokomung, 1234 m, 05 ° 06’ 34.8” N, 59 ° 49’ 15.3” W, Mercury vapor light, 27 October-1 November 2004, ROM 2004515 , B. Hubley ( ROM).

Adult habitus. General appearance pale yellow brown with obscure darker markings. Head entirely pale except for pale brown antennae; pronotum pale over most of disk but with narrow, dark brown pigment bands near lateral margins. Legs pale except for narrow, dark bands at distal end of femora. Wings pale but with slightly darker yellow-brown longitudinal band over bases of anal veins, extending to apical margin but with an obscure pale circular area beyond cord; first cubital vein and cord crossveins slightly darker.

Male. Forewing length 10-11 mm. Hammer long and slender, posteromesal margin of sternum 9 prolonged ( Fig. 1 ). Aedeagal apex conspicuously narrower than shoulders, and bearing a poorly defined pair of ventral membranous lobes ( Fig. 3 ); dorsal keel poorly defined, consisting of a short stem and a pair of divergent arms which circumscribe upturned tip ( Fig. 5 ); keel lines interrupted along length, consisting of a linear series of small raised areas. Apex turned ventrad giving a smoothly curved lateral profile ( Fig. 4 ). Aedeagal hooks slender.

Female. Forewing length 12-13 mm. Subgenital plate 4-lobed ( Fig. 2 ); mesal lobes larger than lateral ones and separated by a relatively deep, V-shaped notch; lateral lobes separated by shallow V-shape notches from mesal lobes. Mesal sclerite of sternum 9 with a pair of prominent lateral patches of setae, separated by a median, triangular patch of fine short setae. Posterior transverse sclerite obscure.

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, is based on the Pakaraima Mountain range of Guyana.

Diagnosis. This species is similar in pigment pattern to A. wokomung , described below, however, the pattern is not as distinct in the specimens available, and might be overlooked. Adults of these two Mount Wokomung species are separated on the basis of genital structures; externally A. pakaraima has the hammer long and slender ( Fig. 1 ), whereas that of A. wokomung is wide with parallel margins ( Fig. 8 ). The aedeagal apex of the two species are also quite distinctive with A. wokomung having a short, but conspicuous dorsal keel line ( Fig. 11 ) and A. pakaraima having inconspicuous keel lines that diverge and circle around a portion of the curved aedeagal tip ( Fig. 5 ). The female subgenital plates of the two species are also distinct with A. pakaraima having a much deeper mesal notch ( Figs. 2 , 13 ).

Figures

Figs. 1-5. Anacroneuria pakaraima structures. 1. Male sternum 9. 2. Female abdominal sterna 8-9. 3. Male aedeagus, ventral. 4. Male aedeagus, lateral. 5. Male aedeagus, dorsal.

Figs. 6-13. Anacroneuria wokomung structures. 6. Head and pronotum. 7. Forewing. 8. Male sternum 9. 9. Male aedeagus, ventral. 10. Male aedeagus, lateral. 11. Male aedeagus, dorsal. 12. Egg outline. 13. Female abdominal sterna 8-9.