Tyrrhenoleuctra Consiglio, 1957 Tyrrhenoleuctra antoninoi, Fochetti & Tierno de Figueroa, 2009

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 : 99-105

Tyrrhenoleuctra Consiglio, 1957

( Figs. 9-–22 )

Strobliella Klapálek, 1903: 13 , Preoccupied ( Kieffer, 1898)

Tyrrhenoleuctra Consiglio, 1957: 1 , novum nomen, type species, Strobliella minuta Klapálek = Tyrrhenoleuctra minuta (Klapálek)

Current species and type localities:

T. antoninoi Fochetti & Tierno de Figueroa, 2009 ,

Mallorca Island, Spain

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:4121

T. lusohispanica Tierno de Figueroa & Fochetti, 2014 ,

Algarve, Portugal

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:464237

T. minuta ( Klapálek, 1903) ,

Sierra Morena, Spain

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:4127

Material examined: T. c.f. minuta : SPAIN: Sevilla, Arroyo del Moro, Sierra Morena, 38˚ 02’ 23” N, 5˚ 56’ 10” W, 347m, 18 February 2015, J.M. Luzón-Ortega, 2♂ 2♀ 1 larva, specimens damaged (UST).

T. tangerina (Navás, 1922) ,

Fondak, Morocco

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:4125

T. zavattarii (Consiglio, 1956) ,

Monte Limbara, Sardinia, Italy

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org: TaxonName:4123

T. zavattarii : ITALY: Sardinia, Sardegus, Rio Pirastzu, Strada, S. Teresa- Costelsordo Ponte, 100m, 6 February 2000, 10♂ 3♀ (UST).

Tyrrhenoleuctra sp. : SPAIN: Estrema Dura, Calera De Leon, Rio Andila, 650m, 24 February 2001, 5♂ 2♀ (UST).

Adult habitus. Brachypterous or macropterous among male specimens examined (3–6 mm), forewings usually reaching midlength of abdomen; females fully winged, forewing length (7.5–8.0 mm). General color of wings and body pale brown, without distinctive contrasting pigment pattern; head with numerous (~30) occipital rugosities ( Fig. 15 ), at least among specimens of Tyrrhenoleuctra sp. listed above. Pronotum with a small number of rugosities (~10). Antennae and palpi hairy ( Fig. 16 ).

DISCUSSION

Based on the postulated apical systematic position of Pachyleuctra in Leuctrinae phylogeny several features of the genitalia examined in this study are likely apomorphies: male epiproct reduced; male paraprocts separated but closely appressed; and female subgenital plate with lobes extending from the basoposterior margin. Recently, as part of a study on Pyrenees Leuctridae, Vinçon & Ravizza (2001) reviewed the species belonging to this genus and observed that P. benllochi closely resembles P. bertrandi . Owing to this close similarity these researchers depicted the lateral view of the male terminalia of both species with one illustration (their fig. 14e, p. 113). Added fine details of the male and female genitalia of P. benllochi are provided by SEM micrographs of this study, but specimens of P. bertrandi were not available for examination. Vinçon & Ravizza (2001), however, determined that these two species can be differentiated by the shape of the tergal process found on male abdominal segments 5, 7–9.

Male genitalia (n = 6). Epiproct pronounced; in dorsal or caudal view divided by a median groove ( Figs. 11, 12 & 17, 18 ). Tyrrhenoleuctra zavattarii epiproct dorsally or caudally appears triangular ( Fig. 11 ); in profile posteriorly hemispherically-shaped, abruptly becoming flattened to apex. Tyrrhenoleuctra sp. epiproct dorsally or caudally appears caret-shaped ( Fig. 17 ); in profile posteriorly hemispherically-shaped sloping gradually to apex ( Fig. 20 ). Epiproct surface of both species covered by uniformly distributed short peg-like sensilla bearing approximately 80–160 sensilla per epiproct ( Figs. 12 & 18 ). Epiproct sensilla of T. zavattarii in dorsal view ( Fig. 12 ) appear slightly more closely packed and of a more uniform length than those comprising the sparse patch of Tyrrhenoleuctra sp. ( Fig. 18 ). In both T. zavattarii and Tyrrhenoleuctra sp. a single pair of long slender paraprocts (specilla) extend from a ventrobasal plate on the abdominal apex ( Fig. 11 ); paraprocts are closely fused and extend through the median groove of the epiproct as a spear-like structure ( Figs. 11–12 & 17–19 ). Apex of paraprocts emerge from subapical notch in epiproct and the emergent section of the paraprocts bear 5–6 partial, circular annuli formed from densely packed single rows of short setae ( Figs. 12, 14 & 18–21 ). Paraproct tips of T. zavattarii broadly rounded ( Figs. 12, 14 ), those of Tyrrhenoleuctra sp. bluntly pointed ( Figs. 20, 21 ). Cerci oriented vertically to the body axis, and shaped somewhat cylindrically with truncate apices ( Figs. 11, 13 & 17, 19 ). Vesicle small, circular and covered with long hairs throughout ( Fig. 22 ).

Female genitalia (n = 2). Abdominal sternum 7 larger than other segments, overlapping and covering much of sternum 8; sternum 8 with extensive membranous areas on the posteromedian region of the segment ( Fig. 9 ). Median section of posterior margin of segment 7 truncate for a short section of the segment ( Fig. 10 ).

In distinguishing between the three traditional species of Tyrrhenoleuctra, Aubert (1963) considered several characters: body size, wing length, leg color, male epiproct length, male cercal length, color of female sternites 8 and 9 and shape of the female subgenital plate posterior border. Puig et al. (1990), however, described morphological variability in T. minuta adult male and female wing length and the female tenth sternite. Fochetti & Tierno de Figueroa (2009) and Tierno de Figueroa & Fochetti (2014) concluded that “…morphological characters cannot be confidently and consistently used for identification of species of Tyrrhenoleuctra ”. Additionally, they suggested that new species descriptions based entirely on morphology are not reliable because of variation. Instead they relied on differences in the mitochondrial genes cytochrome oxidase subunit-1 (COI) and 12s ribosomal gene to recognize two additional cryptic species belonging to Tyrrhenoleuctra . Nonetheless, Fochetti et al. (2009) did observe that T. zavattari is both genetically as well as morphologically homogenous. SEM images in this study indicate that some ultrastructural and structural features of the epiproct and paraprocts of this species while similar to those of Tyrrhenoleuctra sp. are distinct. Various researchers [e.g. Wiens (2004), Okiwelu & Noutcha (2014), Wanninger (2015)], have suggested that morphology is important and that an integrated or combined approach incorporating both morphological and molecular data is necessary in systematic studies.

In summary, this initial SEM analysis of populations of Pachyleuctra and Tyrrhenoleuctra has identified a few morphological features, especially those involving male and female genitalia that might potentially be useful in subsequent taxonomic investigations. This result, however, is based on limited material and the systematic utility of these characters will need to be corroborated by additional SEM studies of the species of both genera over their known geographic range.

Figures

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)

Figs. 11–16. SEM micrographs of Tyrrhenoleuctra zavattarii (Rio Pirastzu, Sardinia, Italy) and Tyrrhenoleuctra sp. (Rio Andila, Estrema Dura, Spain). 11. T. zavattarii, male terminalia, dorsal. 12. T. zavattarii, details male epiproct, dorsal. 13. T. zavattarii, male cerci and base of paraprocts, caudodorsal. 14. T. zavattarii, apex of epiproct and paraprocts, dorsal. 15. T. sp., head and pronotum, dorsal. 16. T. sp. basal antennal segments and palpus. (ce = cercus; ep = epiproct; pp = paraprocts)

Figs. 17–22. SEM micrographs of Tyrrhenoleuctra sp. (Rio Andila, Estrema Dura, Spain) male structures. 17. Male terminalia, caudodorsal. 18. Male epiproct and paraprocts dorsal. 19. Male epiproct and paraprocts, dorsolateral. 20. Epiproct, lateral. 21. Epiproct and paraprocts, dorsoapical. 22. Vesicle, ventral. (ce = cercus; ep = epiproct; pp = paraprocts; ve = vesicle)