• U. of Minnesota Insect Collection
• Clemson University Arthropod Collection
• NMNH Entomolgy Department

First described in genus Stenophylax.

• McLachlan, R. 1871. On new forms, etc., of extra-European trichopterous insects. Zool. J. Linn. Soc., 11:98-141.

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Eastern North America from southern Canada to northern Georgia and Alabama (Wojtowicz 1982). No central database for Pycnopsyche gentilis is known.

• Wojtowicz, J.A. 1982. A review of the adults and larvae of the genus Pycnopsyche (Trichoptera: Limnephilidae) with revision of the Pycnopsyche scabripennis (Rambur) and Pycnopsyche lepida (Hagen) complexes. PhD dissertation, University of Tennessee. 292 pp.

From:  Betten, C.  1950.  The genus Pycnopsyche (Trichoptera).  Annals of the Entomological Society of America 43: 508-522.

The species of Pycnopsyche are, as Trichoptera go, fairly common and conspicuous insects of yellow color with some brown markings, from 15 to 23 mm. in length to the wing tips, occurring as adults in August, September, and October, with a few records in July and November. The larvae also are conspicuous among aquatic insects because of their size and in some species because of a slender stick, sometimes two, or even more, which may be laid alongside the wooden case, projecting beyond the rear end. In the pupal case small stones may replace the wood to some extent, the stick at the end may disappear, and the anterior end is fastened to a submerged stone or often to a submerged branch of a tree or shrub. Not many life histories have been described and even the case-building habits of the various species are not fully known. Larvae of either P. lepida or P. subfasciata were observed to have the stick attached when the overall length of the case was but 4 or 5 mm. Larvae of P. gentilis had cases made of pebbles when observed three or four weeks before pupation and very possibly these have stone cases throughout the larval life. Much may depend on what materials are available.

CHARACTERS COMMON TO THE ADULTS OF Pycnopsyche

Sometimes ringed darker, basal joint about equal to the head in length. Head covered with numerous yellow hairs and stouter bristles, the latter arranged in areas often referred to as warts. On either side of the head two such spined areas adjacent to the base of the antenna, a larger one parallel with the posterior margin of the head, and a lunate one posteriorly bordering the eye (figs. 4, 5). Prothorax with a large area of coarse bristles on either side; on the mesonotum (fig. 8) narrow areas of bristles extend longitudinally on either side of the scutum and scutellum. Legs each with a line of bristles along the coxa, a black spot prominent on the trochanter, the femur almost bare, tibia and tarsus with numerous black spines, hind tarsus with one or more such spines (P. gentilis frequently an exception). Tibia1 spurs 1-22, 1-3-3, or 1-3-4. Wings with surface more or less tuberculate, their shape varying somewhat with the species (figs. 1, 2). Color of the wings yellow to orange, sometimes almost unicolorous but always with brown areas which, in so far as they are present, conform to a common pattern which may include the posterior apical margin, a series of spots in the bases of the apical cells, a transverse band in the middle of the wing, and, less well marked, the posterior margin. One species has prominent round, brown spots on the forewing; in another species the spots are small and not at all conspicuous. Anal area of the hindwings covered with long thin hairs, the amount of the covering differing with the species, more conspicuous in males than in females. Venation as in the figures (figs. 1, 2), the difference between the species not great.

Eighth tergite of the males fairly heavily sclerotized, its dorsal posterior margin often set with short, black spines, the shape and location of these spinose areas being often diagnostic of the species, lower posterior angle of the chitinous shield of this tergite sometimes extended as a hook, point, or rounded knob (figs. 19, 36, 79). Ninth segment strongly sclerotized, its dorsal half often telescoped into the eighth segment; seen from the side it is widest in the middle, tapering dorsally and ventrally (fig. 61). Attached to the dorsal part of the ninth segment there is a paired structure (10 in figs. 61, 63), representing doubtless the tenth segment, consisting ordinarily of a pair of broad lateral pieces (dorsal or superior appendages of McLachlan and others) running mesally into a pair of processes (intermediate appendages), these often curved at the tips; generally a sclerotized area on the surface of the ninth segment connects the tenth seg1nen.t with the claspers at about the point where the tips of the latter become free, thus the anal aperture is more or less encircled by these structures (fig. 101). Claspers (inferior appendages) in an upright position in relation to the body axis, broadly united to the ninth segment throughout most of their length, the basal part covered with stout bristles; the tips of the claspers, which are free of the ninth segment, variously shaped and often divided (figs. 51, 57, 69, 75). Aedeagus highly characteristic in form, its general structure much the same throughout the genus; arising in a concavity on the dorsal surface are two appendages (titillators) of several types as figured (figs. 13-18).

Female with posterior margin of the seventh ventral segment. Female with posterior margin of the seventh ventral segment bordered with fine hairs (fig. 29). Genital opening at the posterior margin of what appears to be the eighth segment; seen from the side its upper and lower lips are conspicuously protruding, the lower lip forming a subgenital plate which may be rounded, mucronate, or lobed, its appearance differing greatly according to the exact line of vision. Dorsally a terminal segment, perhaps a modified ninth and tenth, is sclerotized, sometimes heavily so; seen from above, its rear margin is in many cases slightly cleft (fig. 23). The anal aperture with its surrounding structures differs considerably with the species, often oval in shape (fig. 41), with varying degrees of sclerotization in its margin; in several species the opening is large, almost rectangular (fig. 31). In well-cleared specimens the outline of the spermatheca may be seen through the body wall (figs. 9-12).

Pycnopsyche gentilis McLachlan
Figs. 9, 17, 67-72
1871. Stenophylax gentilis McLachlan, Jour. Linn. Soc. London, Zool., 11: 108.
1916. Eustenace gentilis Banks, Can. Ent., 48: 122.
1926. Stenophylax gentilis Sibley, Bull. Lloyd Library, No. 27, ,Ent. Ser. 5:107,
218, figs. 100-102, 109.
1934. Stenophylax gentilis Betten, N.Y. State Mus. Bull., 292: 342, pl. 48,
figs. 3, 4.
1943. Pycnopysclze perplexa Banks nec Betten and Mosely, Harvard Mus. Comp.
Zool., Bull., 92: 346, fig. 35.
1944. Pycnopsyche gentilis Ross, Bull. 111. State Nat. Hist. Surv., 23: 299 (listed).

The male of this species is easily recognized by the median scabrous area on the rear margin of the eighth tergite and by the heavy appendages of the aedeagus. The female has the subgenital plate more distinctly trilobed than any other species. The wings of this rather large species are shiny and transparent, the veins of the anastomosis, particularly in its posterior part, are darker than the remainder of the venation and stand out because of the lack of color in the wings. The species is reported from Nova Scotia, New York (Aug. 22-Sept. 28), from most of the northeastern states, Pennsylvania, New Jersey, North Carolina, and Georgia (Oct. 23).

From: Flint, O.S., Jr. 1960. Taxonomy and biology of Nearctic limnephilid larvae (Trichoptera), with specieal reference to species in eastern United States. Entomolgica Americana 40: 1-117.
Genus Pycnopsyche Banks
Pycnopsyche Banks, 1905, Trans. Amer. Ent. Soc. 32: 9.
Type species : Limnephila scabripennis Rambur 1842 (by original designation).

Pycnopsyche, containing fourteen species, is limited to the cooler parts of Eastern North America,. This is the only genus endemic to the East that has undergone extensive speciation. The immature stages of several species have been described by various authors. Unfortunately most of these writers had mixed series, and mis-determinations of adults were so common before Betten's paper (1950) that the specific names assigned are very suspect. Separation of the larvae is often very difficult and many species cannot be definitely placed with any species. Frequently the shape of the case is as good a specific character as any facet of larval morphology. The larvae are practically identical with those of H. argus, differing only in the following ways. Though they may be very close or touching, the anterior metanotal plates are not fused for their entire width. The ventral ring on the second abdominal segment is lacking, and the larvae are smaller, rarely exceeding 23 mm.

Key to known larvae of Pycnopsyche
1. Dorsal tubercle of the first abdominal segment lacking ; head marked only with dark-bordered muscle scars………………………………gentilis
All tubercles present, though often flattened; head with some dark blotches anteriorly and dark scars posteriorly………………………………………………2

2. Case composed mainly of sand grains; first abdominal segment with 40-50 setae ventrally……………………………………………lepida group
Case composed mostly of plant matter ; first abdominal segment generally with less than 30 setae ventrally...……………………………………………………...3

3. Ventral margin of posterior femora with 3-4 setae………………………4
Ventral margin of posterior femora with 2 setae……………………....................5

4. Head marked mostly with discrete spots; first abdominal segment with more than 15 setae ventrally; case made of roughly quadrate plant remains without larger pieces laterally (fig. 71) ……………………………divergens
Head with blotches anteriorly plus spots; first segment generally with less than 15 setae ventrally; case with long sticks laterally, and small pieces dorsally and ventrally (fig. 77)…………………………………………...luculenta and sonso

5. Case made partially of sticks extending freely, often arranged obliquely at anterior end (fig. 75) ; first abdominal segment ventrally with more than setae……guttifer
Case made of roughly quadrate fragments of wood, etc. attached firmly to case (fig. 73); first segment ventrally often with less than 15 setae……….scabripennis

Pycnopsyche gentilis (McLachlan)
(Fig. 39, 72-74)
1871. Stenophylax gentilis, McLachlan, Jour. Linn. Soc. Lond., Zool. 11: 108.
1950. Pycnopsyche gentilis, Betten, Ann. Ent. Soc. Amer. 43 : 516, figs. 67-72.
1953. Pycnopsyche gentilis, Kimmins and Denning, Ann. Ent. Soc. Amer. 44: 126, 128, fig. 16.

P. gentilis is widespread over the East being known from Nova Scotia to Georgia throughout the Appalachian system. Of the species of Pycnopsyche reared to date, the larvae of this species are the most distinctive. Lloyd (1921) described the larva under the name Arctoecia consocia. Sibley (1926) also described aid figured the larva and pupa.
Larvae from Chesterfield, Massachusetts, Dryden, New York, and several localities on the Blue Ridge Parkway in Virginia and North Carolina have been reared in this study. In addition, metamorphotypes collected in Virginia and North Carolina have been studied.
LARVA. Length 20-22 mm., width 4 mm. Head: Yellow-brown; muscle scars with dark borders. Setae 13 and 16 modified into short, broad blades. A band of long spicules on the genae dorsally, paralleling frontal sutures, becoming exceptionally long in southern larvae. Thorax: Nota yellow-brown, with dark-bordered muscle scars. Pronotum with short, blade-like setae anteriorly. Metanotum with many setae on membrane. Femora of all legs with 2 setae on ventral margins. Abdomen: First segment lacking dorsal spacing hump ; 35-40 setae on each side both dorsally and ventrally. Eighth segment with 12-16 setae dorsally.

GILLS. Dorsal: II 0, 1; III 1,1; IV 1, 0-1. Dorso-lateral: III 1, 0. Ventro-lateral: I1 0, 1 ; III 0, 0-1. Ventral: II 0, 1; III 1, 1 ; IV, 1, 1 ; v 1, 1 ; VI 0-1, 1 ; V11 0, 0-1.

CASE. Cylindrical; made of large, often flattened, pieces of mineral matter (fig. 74).

MATERIAL EXAMINED. MASSACHUSETTS : East Amherst, Williamsburg, Cummington, Chesterfield, Sunderland. MAINE : Mount Katahdin. NEW HAMPSHIRE: Pinkham Notch. NEW YORK : Dryden, Slaterville Springs. NORTH CAROLINA: Highlands, Mount Mitchell, Crabtree Meadows. PENNSYLVANIA: Hopwood. VIRGINIA : Waynesboro, Shanandoah National Park, Vesuvius, and Natural Bridge.

HABITS. The larvae are often common in small, cold, spring-fed brooklets only 1 or 2 feet wide. Sometimes they are found in large, cold, mountain torrents. They are often associated with the larvae of P. divergens, and downstream they may overlap with
P. luculenta. The partially grown larva builds a case of roughly circular leaf fragments placed around a central silken cylinder so as to form a triangular cross section (fig. 72). The larvae generally overwinter in this type of ease, changing in the spring to the case of stones. The change is very abrupt; many cases are in part one type and in part the other (fig. 73).

Leaf inputs in temperate forest streams may limit caddisfly production because leaf detritus serves both as a food and case-material resource. We estimated Pycnopsyche gentilis produdion in a stream experimentally decoupled fmm its riparian habitat and a reference stream for 8 y in the southern Appalachians. We also examined laboratory survivorship, growth, and case-building activities of P. gentilis in substrate containing various quantities of leaf material. Pycnopsyche gentilis produdion declined to 0 within 3 y of the start of litter exclusion. Abundance, biomass, and production of P. gentilis were positively related to leaf litter standing naps. Maxixnum individual length, of P. gentilis was reduced when annual leaf standing crops fell below 25 to 50 g AFDM/m2. Observations of case construction for instars removed from their origninal leaf cases and kept in substrate with low leaf standing crop, showed that P. gentilis was capable of rebuilding a case of available substrate and surviving for 3 to 4 wk before dying of starvation Survivorship and growth were significantly greater for larvae reared at high and intermediate leaf standing crops, than at low leaf standing crop. Older instars had higher survivorship rates but lower growth rates than younger instars in the low litter substrates. Survivorship and growth rates were lower for some individuals forced to rebuild new cases, indicating an energetic cost associated with case-building activities. Our results demonsrate that the linkage between terrestrially derived organic matter and production of a caddisfly shredder was a consequence of food availability.

Source

Eggert, Susan L.; Wallace, J. Bruce. 2003. Reduced detrital resources limit Pycnopsyche gentilis (Trichoptera: Limnephilidae) production and growth. Journal North American Benthol. Society 22(3): 388-400

The hatching coincides with autumnal leaf fall in September and October. The larvae are important converters of leaf material. Early instars are found in slow-flowing parts of the stream. After reaching final instar, the larvae will undergo a prepupal quiescent period of 1 to 6 months. Pupation and emergence occur between July and October.

References

• LaFontaine, Gary. 1981. Caddisflies. 336 pages.
• Wiggins, Glenn B. 1996. Larvae of the North American caddisfly genera (Trichoptera). 457 pages.

DNA barcoding data for P. gentilis suggest that this species may be a complex of cryptic species that are not distinguishable by morphological characters.

• Caddisfly Barcode of Life (Webpage in progress)
• Canadian Centre for DNA Barcoding
• Barcode of Life Data Systems

Trichoptera are members of the "EPT" taxa that are used as bioindicators of water pollution.

• Biological Assessment Unit, North Carolina Department of Environment and Natural Resources
• Invertebrates as Indicators, U.S. Environmental Protection Agency
• North American Benthological Society

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread in eastern North America.

Caddisfly cases are used to make jewelry.

• Nature Crafted Jewelry by WildScape Inc.
• Shalaway, Linda. 1999. Wildscape with Caddisflies. Wonderful West Virginia Magazine 63:11.
• Sperry, Shelley. Crafty Little Buggers. National Geographic (May 2005).

P. gentilis has a North Carolina Biotic Index (NCBI) value of 0.8 out of 10, which means it is very sensitive to degraded water quality.

• Lenat, D.L. 1993. A biotic index for the southeastern United States: derivation and list of tolerance values, with criteria for assigning water-quality ratings. J. N. Am. Benthol. Soc. 12(3): 279-290.

• North American Benthological Society
• Entomological Society of America
• Tree of Life Trichoptera page

• Tree of Life Trichoptera page
• Nature Crafted Jewelry by WildScape Inc.
• Shalaway, Linda. 1999. Wildscape with Caddisflies. Wonderful West Virginia Magazine 63:11.
• Sperry, Shelley. Crafty Little Buggers. National Geographic (May 2005).