Pachyleuctra Despax, 1929

Stark, Bill P. & Nelson, Charles H., 2019, First Sem Micrographs Of Representatives Of Pachyleuctra Despax, 1929 And Tyrrhenoleuctra Consiglio, 1957 (Plecoptera: Leuctridae), Illiesia 15 (6), pp. 98-106 : 99

Pachyleuctra Despax, 1929

( Figs. 1–8 )

Leuctra (Pachyleuctra) Despax, 1929: 298 , type species Leuctra (Pachyleuctra) montana Despax = Pachyleuctra benllochi (Navás, 1917)

Adult habitus. Slightly brachypterous to macropterous in available specimens. General color of body and wings dark brown to black without distinctive contrasting pigment.

Male genitalia (n = 3). Epiproct strongly reduced ( Vinçon & Ravizza 2001). A moderately slender pair of long, closely appressed paraprocts (specilla) form a recurved probe that extends from below the cerci to above the apex of the abdomen ( Fig. 3 ); apex of paraprocts recurved over abdomen, tips flattened and bearing a small circular orifice near the inner subapical margins ( Figs. 2–4 ). Apical half of paraprocts bearing long slender setae along caudal surface and lateral surfaces of the apex ( Figs. 3–4 ). Abdominal terga 5, 7–9 bear a median pair of spine-like lobes on the anterior segmental margins. Cerci somewhat conical in shape and bearing a small apical nipple-like process ( Figs. 1–2 ). Sternum 9 bearing a circular, densely hairy vesicle ( Figs. 5–6 ).

Female genitalia (n = 2). Subgenital plate on sternum 8 consists primarily of a pair of ear-like lobes that extend from the basoposterior margin of sternum 8 across most of sternum 9 ( Fig. 7 ). Lobes and much of sternum 8 clothed with long, slender setae.

Mesosternum (n = 1). Mesosternal furcasternum circular in outline ( Fig. 8 ); mesosternal basisternum bearing a narrow, dark, hairless median line that extends across at least half of the basisternum surface ( Fig. 8 ). Mesosternal spinasternum relatively long, slender and distinctly separated from mesosternal postfurcasterna. Metasternal prefurcasterna united ( Fig. 8 ).

Figures

Figs. 1–6. SEM micrographs of Pachyleuctra benllochi male structures (Escrita River basin, Pyrenees Mountains, Spain). 1. Terminalia, dorsal. 2. Details of paraprocts and cerci, dorsal. 3. Terminalia, caudolateral. 4. Paraproct apex caudolateral (arrow indicates orifice). 5. Terminalia, ventral. 6. Details of vesicle. (ce = cerci; or = orifice; pp = paraproct; ve = vesicle)

Figs. 7–10. SEM micrographs of Pachyleuctra benllochi (Escrita River basin, Pyrenees Mountains, Spain) and Tyrrhenoleuctra zavattarii (Rio Pirastzu, Sardinia, Italy) adult structures. 7. P. benllochi female terminalia, ventral. 8. P. benllochi, adult mesosternum, ventral. 9. T. zavattarii, female terminalia, ventral. 10. T. zavattarii, female subgenital plate. (bs2 = mesobasisternum; cx2 = mesocoxa; fs2 = mesofurcasternum; ml = median line; pfs2 = mesopostfurcasternum; sgp = subgenital plate; ss2 = mesospinasternum)