Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae 
(Pictetiella expansa (Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
http://zoobank.org/ urn:lsid:zoobank.org:pub:D9C73EE7-52F4-42EF-8FA7-91CB3BC157E8 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 1 
 
 
DESCRIPTION OF THE MALE TERMINALIA OF TWO WESTERN NEARCTIC 
PERLODINAE (PICTETIELLA EXPANSA (BANKS) AND SALMOPERLA 
SYLVANICA BAUMANN & LAUCK) 
 
Chris J. Verdone1 & Boris C. Kondratieff2 
 
Department of Bioagricultural Sciences and Pest Management, Colorado State University, 
Fort Collins, Colorado, 80523 U.S.A. 
1 E-mail: verdonec@gmail.com 
 
2 E-mail: Boris.kondratieff@colostate.edu 
 
 
 
 
ABSTRACT 
The male epiproct and aedeagus of Pictetiella expansa (Banks) and Salmoperla sylvanica Baumann & Lauck 
are described and supported by scanning electron micrographs and color images. 
 
Keywords: Plecoptera, Pictetiella, Salmoperla, male genitalia 
 
 
 
 
INTRODUCTION 
Banks (1920) described Perla expansa from 
Grant, Park County, Colorado. The original 
description was based on a single adult female. 
Needham and Claassen (1925) putatively described 
the male, which was possibly incorrectly associated 
(Ricker 1952, Baumann 1973). Claassen (1931) 
putatively described, but did not illustrate, the 
nymph, but this was again apparently incorrectly 
associated (Ricker 1952, Baumann 1973). Ricker 
(1952) provided the first apparently valid 
description of “Isogenus (Pictetia) expansus” by 
dissecting the male genitalia from a pre-emergent 
nymph collected in Wyoming, but the illustration 
was “rather general” (Baumann 1973). Illies (1966) 
replaced the homonym Pictetia with the 
replacement name Pictetiella. Gaufin et al. (1966) 
provided illustrations of the dorsal and lateral 
view of male terminalia and ventral view of the 
female terminalia. Gaufin et al. (1972) used the 
same illustrations originally from Gaufin et al. 
(1966) except the lateral view of the male 
terminalia. Baumann (1973) provided descriptions 
of the adult male and female, an illustration of the 
nymphal habitus, and scanning electron 
micrographs of the egg. Baumann et al. (1977) 
illustrated the wings and reproduced the Baumann 
(1973) illustrations of the dorsal view of the male 
terminalia and the ventral view of the female 
terminalia. Stark & Szczytko (1984) placed P. 
expansa in the tribe Diploperlini based on the 
presence of submental gills and the triangular 
shape of the eggs. Nymphs of P. expansa occur in 
small to medium-sized high elevation streams in 
the Rocky Mountains (Baumann et al. 1977, 
Kondratieff & Baumann 2002). Detailed images of 
the male epiproct and aedeagus are not currently 
available. 
Baumann & Lauck (1987) described Salmoperla 
sylvanica from the Willow Creek drainage in 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 2 
Humboldt County, California. In their original 
description, based on 33 nymphs and two adult 
male specimens, illustrations were provided for the 
male terminalia, nymphal habitus, and several 
other nymphal characters. Stark & Baumann (2006) 
described and illustrated the female terminalia and 
forewing and provided scanning electron 
micrographs of the egg. Stark & Baumann (2006) 
placed S. sylvanica in the tribe Arcynopterygini 
based on the presence of paired gill structures on 
the 2nd and 3rd thoracic segments. Salmoperla 
sylvanica is known from few locations and appears 
to be restricted to smaller streams in the 
mountainous regions of northern California and 
southern Oregon (Baumann & Lauck 1987, Nelson 
& Stark 1988, Stark & Baumann 2006, Stark et al. 
2015). Detailed images of the male terminalia and 
aedeagus are not currently available. The purpose 
of this paper is to provide complementary 
descriptions further detailing the male epiproct 
and aedeagus of P. expansa and S. sylvanica using 
high quality color images and scanning electron 
micrographs (SEM). 
 
 
 
Fig. 1. Head and pronotum dorsal, Pictetiella 
expansa ♂, Boulder Co., Colorado, North Fork 
Middle Boulder Creek, 29 Aug. 2015. 
MATERIALS AND METHODS 
A JEOL JSM-6500F Field Emission Scanning 
Electron Microscope (FESEM), Central Instrument 
Facility, Imaging Laboratory (http://cif.colostate.edu/ 
imaging-laboratory/), Colorado State University 
was used for the SEM images. Samples were 
critical point dried and coated with 20 nm gold. 
Color images were captured using a Canon EOS 
7D digital camera with a Nikon model K2 SE lens 
and CF3-CF10 lens adapters. Images resulted from 
batches of ≈ 60 photomicrographs taken at 
progressively deeper focal planes using Camlift 
and were edited together using Zerene Stacker 
version 1.04. Photographic adjustments were made 
using Adobe Photoshop CS6. Specimens listed in 
this study are deposited in the C.P Gillette 
Museum of Arthropod Diversity, Colorado State 
University, Fort Collins, Colorado (CSUC). 
 
RESULTS 
 
Pictetiella expansa (Banks) 
(Figs. 1-11) 
 
Perla expansa Banks (1920:317.) 
Perla expansa: Needham and Claassen, (1925:81., 313., 
325.) [♂ possibly incorrectly associated? (Ricker, 
1952:120., Baumann, 1973:97.)] 
Perla expansa: Claassen, (1931:55.) [nymph incorrectly 
associated (Ricker, 1952:120., Baumann, 1973:98.)] 
Isogenus (Pictetia) expansus: Ricker, (1952:120.) 
Pictetiella expansella: Illies, (1966:375.) 
Isogenus (Pictetia) expansus: Gaufin et al., (1966:62.) 
Isogenus (Pictetia) expanus [sic]: Gaufin et al., 
(1972:110.) 
Pictetiella expansa: Baumann, (1973:98.) 
Pictetiella expansa: Baumann et al., (1977:22., 115.) 
 
Material Examined. COLORADO: Boulder Co., 
North Fork Middle Boulder Creek, 4th of July Rd. 
below 4th of July Campground, 39.99194°N, 
105.63226°W, 29 Aug. 2015, C. Verdone, D. Fuller & 
M. Diesenroth, 18♂, 7♀ (CSUC). 
Description: Male. For a habitus description refer 
to Baumann (1973). Head and pronotum shown in 
(Fig. 1). Hemitergal lobes (HL) rounded produced 
inward, apices with long fine hairs, bearing sparse 
sensilla basiconica anteriorly (Figs. 2, 3). Epiproct 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 3 
 
 
 
Figs. 2-4. Pictetiella expansa ♂, Boulder Co., Colorado, North Fork Middle Boulder Creek, 29 Aug. 2015. 2. 
Epiproct lateral, epiproct cowl (EC), hemitergal lobes (HL), paragenital plates (PP). 3. Epiproct dorsal, 
epiproct cowl (EC), paragenital plates (PP). 4. Epiproct dorsal. 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 4 
 
 
Figs. 5-10. Pictetiella expansa ♂, Boulder Co., Colorado, North Fork Middle Boulder Creek, 29 Aug. 2015. 5. 
Epiproct dorsal. 6. Epiproct anterior. 7. Epiproct apex lateral. 8. Epiproct, scale-like setae. 9. Epiproct, 
bristle-like hairs. 10. Epiproct tip. 
 
 
cowl densely clothed with short bristle-like setae 
(Figs. 2, 3) and flanked by inward pointed finger-
like paragenital plates (PP) (Figs. 2, 3). Epiproct 
sclerotized process bifurcate in lateral aspect (Fig. 
2). Sclerotized process singular, widest at base 
from dorsal aspect (Figs. 3, 4). Fully everted 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 5 
epiproct directed forward. Epiproct long, narrow 
and widest just before apex (Figs. 3-7). Anterior ⅔ 
of epiproct covered in backward directed shingled 
scale-like setae, which appear translucent (Fig. 8). 
Scale-like setae transition into bristle-like setae near 
apex (Fig. 9). Apex of sclerotized process narrow 
with flared blunt tip (Figs. 9, 10). Lateral stylets 
absent. Aedeagus completely membranous, 
bearing only a few sparse hairs and two small 
posterolateral lobes (Fig. 11). 
 
 
 
Fig. 11. Aedeagus lateral, Pictetiella expansa ♂, 
Boulder Co., Colorado, North Fork Middle Boulder 
Creek, 29 Aug. 2015. 
 
Salmoperla sylvanica Baumann & Lauck 
(Figs. 12-17) 
 
Salmoperla sylvanica Baumann & Lauck (1987:825.) 
Salmoperla sylvanica: Stark & Baumann, (2006:24.) 
 
Material Examined. CALIFORNIA: Humboldt Co., 
Willow Creek, 40.931559°N, 123.681118°W, 17 June 
2009, B. Kondratieff & J. Sandberg, 1♂ (CSUC); 
OREGON: Jackson Co., Split Rock Creek, Wagner 
Gap Road, 12 mi S Talent, 42.09480°N, 
122.77397°W, 22 May 2014, B. Kondratieff, C. 
Verdone, J. Sandberg & B. Stark, 2♂, 1♀ (CSUC). 
Description: Male. For a habitus description refer to 
Baumann and Lauck (1987). Head and pronotum 
shown in (Fig. 12). Ninth tergum with pair of lateral 
humps (LH), apices covered in sensilla basiconica, 
 
 
 
Fig. 12. Head and pronotum dorsal, Salmoperla 
sylvanica ♂, Siskiyou Co., Oregon, Split Rock 
Creek, 22 May 2014. 
 
lateral margins covered in long fine hairs (Fig. 13). 
Tenth tergum deeply cleft, membranous with a 
large basal anchor (BA) which extends to base of 
the epiproct cowl (Fig. 14). Epiproct cowl (EC) 
membranous with sparse setae (Fig. 13) and 
flanked by two rectangular paragenital plates (PP) 
at base (Fig. 14). Hemitergal lobes (HL) rounded 
produced inward, sclerotized and flattened at 
apices bearing sensilla basiconica anteriorly and 
fine hairs posteriorly (Fig. 14). Epiproct short, box-
like in dorsal aspect, basal portion slightly 
narrowed, covered in backward directed scale-like 
setae, setae absent on apex (Figs. 15, 16). Lateral 
stylets short, broad and darkly sclerotized 
terminating in outward directed hooks, present 
laterally at epiproct base (Fig. 16). Aedeagus with 
pair of large posterolateral lobes at base (Fig. 17). 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 6 
 
 
 
 
Figs. 13-14. Salmoperla sylvanica ♂, Siskiyou Co., Oregon, Split Rock Creek, 22 May 2014. 13. Terminalia 
lateral, lateral humps (LH), epiproct cowl (EC). 14. Terminalia dorsal, basal anchor (BA), hemitergal lobes 
(HL), paragenital plates (PP). 
 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 7 
 
 
 
 
Figs. 15-17. Salmoperla sylvanica ♂, Siskiyou Co., Oregon, Split Rock Creek, 22 May 2014. 15. Epiproct 
dorsal, scale-like setae. 16. Epiproct lateral, lateral stylet (LS). 17. Terminalia, aedeagus dorsal. 
 
 
Verdone, C.J. & B.C. Kondratieff. 2016. Description of the male terminalia of two western Nearctic Perlodinae (Pictetiella expansa 
(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
Illiesia – http://illiesia.speciesfile.org      Volume 12 – Number 1 – Page 8 
Basal portion of aedeagus covered with uniformly 
spaced spinulae (Fig. 17). Apex of aedeagus 
bulbous, glabrous (Fig. 17). 
 
DISCUSSION 
Pictetiella is currently represented by four 
species, P. expansa (Banks), P. lechleitneri Stark & 
Kondratieff (2004), P. asiatica Zwick & Levanidova 
(1971), and P. zwicki Zhiltzova (In Levanidova and 
Zhiltzova 1976) (DeWalt et al. 2016). The male 
terminalia of P. expansa is most similar to P. 
lechleitneri, which is the only other Nearctic species. 
The epiproct of these species are widest just before 
the apex and bear scale-like setae. However, the 
epiproct of P. expansa is longer and narrower near 
the apex than P. lechleitneri. 
The function of the scale-like setae covering the 
epiproct of both Pictetiella and Salmoperla is 
unknown. Typical of all Perlodinae, P. expansa and 
S. sylvanica possess both an aedeagus and epiproct. 
The aedeagus is functionally equivalent to a penis 
and is ultimately the structure through which 
sperm is transferred (D. Murányi, personal 
communication). The epiproct in this case does not 
support sperm transfer as it does in the families 
Nemouridae and Capniidae (Zwick 1973). Several 
hypotheses are possible in regards to the purpose 
and complexity of the epiproct. The backwards 
directed scale-like setae may help to keep the 
epiproct inserted, or the setae may play a role in 
sexual stimulation (P. Zwick, personal 
communication). There does seem to be a general 
concensus among stonefly workers that the 
Perlodinae epiproct serves to open the female 
ducts to allow insertion of the aedeagus. Further 
insight into the epiproct question may be 
elucidated by examining specimens preserved in 
copula or by disecting and examining internal 
female genitalia. 
 
ACKNOWLEDGEMENTS 
We thank Dr. John Sandberg, California State 
University, Chico, for his assistance in collecting 
specimens of S. sylvanica and providing locality 
information for P. expansa, which led to the large 
series collected for this study, Dr. Bill Stark, 
Mississippi College, Clinton, for his diagnostic 
interpertation of the Salmoperla terminalia, Kim 
Vanderpool, Colorado State University, 
Department of Biomedical Sciences for the 
excellently prepared SEM images, Joseph Benzel, 
Colorado State University, Department of 
Bioagricultural Sciences & Pest Management for 
photographing and preparing all the color images 
and finally, Dr. Peter Zwick, Schlitz, Germany and 
Dr. Dávid Murányi, Hungarian Natural History 
Museum, Budapest for their contributions to the 
discussion of the function of the epiproct. 
 
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(Banks) and Salmoperla sylvanica Baumann & Lauck). 
Illiesia, 12(01):1-9. Available online: http://illiesia.speciesfile.org/papers/Illiesia12-01.pdf 
 
 
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Submitted 13 January 2016, Accepted 30 January 2016, 
Published 11 February 2016 
 
Hosted and published at the University of Illinois, Illinois 
Natural History Survey, Champaign, Illinois, U.S.A.