Trichoptera: Lepidostomatidae of Gunnison County, ColoradoIntroduction to the Caddisfly genus Lepidostoma
Lepidostomatid Case Maker Caddisflies, Little Plain Brown SedgeRambur, 1842
Updated 8 October 2024
TSN 116793
Provisional Species List
Description
Lepidostoma larvae are small cased larvae found in streams and rivers. The caddis family Lepidostomatidae are identified by their antennae being very close to the eye as well as missing the median dorsal hump on their first abdominal segment. We have one genus of Lepidostomatidae, Lepidostoma in the county. The Gunnison Basin larvae I've seen so far have cases of small sand grains, although other species may have cases constructed of plant pieces and could be present in our area. Keys to the larvae have not been developed yet. For adults, see Weaver's publications.
Good Links
On this website:
Species not reported from the county yet but possibly present:
Lepidostoma ormeum (Pitkin County)
Lepidostoma unicolor (Saguache County)
Other Websites:
Adult Photo - by Tom Murray Lepidostoma adult
References
Brinkman,SF and Johnston,WD 2012 Acute toxicity of zinc to several aquatic species native to the Rocky Mountains. Archives of environmental contamination and toxicology, 62(2) 272-281.
Canton,SP and Chadwick,JW 1983 Seasonal and longitudinal changes in invertebrate functional groups in the Dolores River, Colorado. Freshwater Invertebrate Biology 2(1) 41-47. PDF
Quote from page 46:"Shredders exhibited a downstream pattern of relative abundance that was highly dependent on season. They dominated the benthic invertebrates in spring, having the greatest numerical importance at the upper stations and gradually decreasing in abundance downstream. Shredders were relatively less abundant at all the stations during summer and fall. This spring abundance of shredders differs from the study by Hawkins and Sedell (1981), which reported a shredder predominance in third-order streams during all seasons, with a fall maximum in abundance. The spring abundance observed in the present study appears to be primarily due to the life history patterns of shredding stoneflies such as Prostoia besametsa and Capnia spp. These winter stoneflies were abundant in spring and are the predominant shredders in Colorado mountain streams (Short and Ward 1980a, b, 1981; Short, Canton and Ward 1980). The small rise in shredder importance at the lowest station in spring was due to the caddisfly Lepidostoma sp. rather than stoneflies."
Canton,SP and Ward,JV 1981 The aquatic insects, with emphasis on Trichoptera, of a Colorado stream affected by coal strip-mine drainage. Southwestern Naturalist 25 (4) 453-460.
They studied Trout Creek where it runs through the Edna Coal Mine in northwestern Colorado. The mine spoils were 30 meters from the edge of the creek (approximately a 100 foot buffer zone). They found the aquatic insect density (numbers per square meter) and biomass (weight in grams per square meter) did not change above and below the mine. The Shannon-Weaver Diversity index also showed no difference between sites. However the community structure (which species were present and proportions) did change. Since there were irrigation water and cattle influences at their downstream site, their results may reflect these additional water uses. They note the biggest visible change at this mine is the loss of willow and alder trees downstream of the mine. The caddisfly population changed the most between sites, shifting from a mix of families above the mine to dominance by Hydropsychidae and Glossosomatidae below the mine.
Quote from page 457: "Lepidostomatidae (primarily Lepidostoma moneka) was more abundant at C2 (above the mine), comprising 37% of the density of Trichoptera at this site, but only 4% at C4 (below the mine)." They suggest L. moneka is less common below the mine because they are shredders and don't have leaves from the willows and alders to eat.
Clements,WH; Carlisle,DN; Lazorchak,JM and Johnson,PC 2000 Heavy metals structure benthic communities in Colorado mountain streams. Ecological Applications 10(2)626-638. PDF
Quote from page 633: "Rhyacophila sp.(Fig.5j) was the only caddisfly that showed a significant response to metal level and was lower at medium-metal sites. Differences among metal catagories in abundance of the three other dominant caddisflies, (Brachycentrus americanus, Hydropsyche sp., and Lepidostoma sp.) and the blackfly Simulium sp. were not significant (Fig. 5g, h, i, k)."
Cummins,KW; Wilzbach,MA; Gates,DM; Perry,JB and Taliaferro,WB 1989 Shredders and riparian vegetation. BioScience, 39(1), pp.24-30. PDF
DeWalt,RE; Stewart,KW; Moulton,SR and Kennedy,JH 1994 Summer emergence of mayflies, stoneflies, and caddisflies from a Colorado mountain stream. Southwestern Naturalist 39 3, 249-256.
Dodds GS and Hisaw FL. 1925. Ecological studies on aquatic insects. IV. Altitudinal range and zonation of mayflies, stoneflies and caddisflies in the Colorado Rockies. Ecology 6(4)380-390. Abstract PDF
Flint,OS and Wiggins,GB 1961 Records and descriptions of North American species in the genus Lepidostoma, with a revision of the Vernalis group (Trichoptera: Lepidostomatidae). The Canadian Entomologist, 93(4) 279-297.
Gaufin,AR; Clubb,R and Newell,R 1974 Studies on the tolerance of aquatic insects to low oxygen concentrations. Great Basin Naturalist 34:45-59. PDF
The authors studied the acute short term tolerance of aquatic insects to low oxygen. They used the 96 hour Median Tolerance Limit. They did not find a TLm96 for Lepidostoma sp.. The authors had 80% survival from 3-4 mg/l of oxygen with their experimental apparatus.
Kerr,JD and Wiggins,GB 1993 Larval taxonomy in North American Lepidostomatidae. Proceedings of the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), pp 117-121. Leiden: Backhuys Publishers.
Larson,EI; Poff,NL; Atkinson,CL and Flecker,AS 2018 Extreme flooding decreases stream consumer autochthony by increasing detrital resource availability. Freshwater Biology, 63(12), pp.1483-1497. PDF
Quote: "Functional Feeding Group Community Composition
Two study streams lost a functional feeding group following the 2013 flooding. No shredders were found at Black Canyon in 2014, the stream with the highest shear stress value. Shredders had comprised 6% of the stream insect community there by numbers of individuals in the 2011 sampling, consisting of the nemourid stonefly Zapada sp. and the lepidostomatid caddisfly Lepidostoma sp., which were not found at the stream during 2014 sampling."
Mebane,CA; Schmidt,TS; Miller,JL and Balistrieri,LS 2020 Bioaccumulation and toxicity of cadmium, copper, nickel, and zinc and their mixtures to aquatic insect communities. Environmental toxicology and chemistry, 39(4) 812-833. PDF
Mihuc,TB and Mihuc,JR 1995 Trophic ecology of five shredders in a Rocky Mountain stream. Journal of Freshwater Ecology 10 3, 209-216. PDF
Abstract: "The trophic ecology of five shredder taxa found in Mink Creek, Idaho was determined in laboratory food quality experiments to assess the obligate or facultative nature of resource utilization among lotic taxa commonly referred to as detritivores. The experiments tested resource assimilation for each taxon among three major resources available to primary consumers in streams; periphyton, fine particulate detrital material (FPM) and coarse particulate detrital material (CPM). Growth of each taxon was determined on each resource in laboratory experiments conducted at 10°C.
Growth results indicate that only one of the five taxa (middle-late instar Dicosmoecus atripes) was an obligate CPM detritivore. The remaining four taxa (Amphinemura banksi, Lepidostoma sp., Podmosta delicatula, and Zapada cinctipes) were generalists capable of growth on at least two of the three resource types. All four generalists exhibited growth on periphyton and CPM resources suggesting that these taxa can utilize both autochthonous and allochthonous resources. Our results do not support the idea that taxa with similar mouthpart morphology, specifically shredders, exhibit similar trophic relationships."
Peckarsky,BL 1986 Colonization of natural substrates by stream benthos. Canadian Journal of Fisheries and Aquatic Sciences 43, 700-709. PDF
Rambur,JP 1842 Histoire naturelle des insects néveroptères. - Libairie Encyclopédique de Roret, Paris, xviii + 534 p.
Ross,HH 1946 A review of the nearctic Lepistomatidae (Trichoptera). Annals of the Entomological Society of America 39:265-291. PDF
Abstract: "The males of this caddis fly family are unusual in the number of very odd structural developments of many appendages. Noteworthy of these secondary sexual characters are enlargement or folding of the wings, plate-like expansion of some of the leg segments, oddly shaped branches, grooves or twisted regions of the basal antennal segment, and many diverse shapes assumed by the maxillary palpi. None of these characters has any similar counterpart in the female. Until recent years, these unusual male structures were used as a basis for generic definition. So abundant are these characters that in 1936 about 15 genera had been erected for the reception of the less than 25 Nearctic species recognized in the family at that time. Few of these genera or species were recognizable in the female sex."
Ruiter,DE 1990 A new species of Neotrichia (Trichoptera: Hydroptilidae) from Colorado with additions and corrections to the distributions and records of Colorado Trichoptera. Entomological News 101:88-92.
Quote from page 90:"Lepidostoma grisea (Banks) originally included by Herrmann et al.
(1986) is removed from the Colorado distribution list. This record was questioned by John Weaver (personal communication) and after a diligent
search, this specimen could not be located. Weaver (1988), also synonymized several species of Lepidostoma occurring in Colorado (L. moneka Denning 1968 = L. ormea Ross 1946; L. mira Denning 1954 = L. cascadense (Milne) 1936; L. strophis Ross 1938 = L. cinereum Banks 1899; L. veleda Denning 1948 = L. pluviale (Milne) 1936)."
Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
Lepidostoma sp nymphs were found with all 4 of the species used to make leaf packs; alder, willow, aspen and pine.
Vieira,NK; Clements,WH; Guevara,LS and Jacobs,BF 2004 Resistance and resilience of stream insect communities to repeated hydrologic disturbances after a wildfire. Freshwater Biology, 49(10) 1243-1259. PDF
Weaver III,JS 1983 The evolution and classification of Trichoptera, with a revision of the Lepidostomatidae and a North American synopsis of this family. Ph.D. dissertation, Clemson Univ. Clemson, South Carolina 411 pages.
Weaver III,JS 1988 A synopsis of the North American Lepidostomatidae (Trichoptera). Contributions of the American Entomological Institute 24, 1-141.
Weaver III,JS 2002 A synonymy of the caddisfly genus Lepidostoma Rambur (Trichoptera: Lepidostomatidae), including a species checklist. Tijdschrift voor Entomologie, 145(2), 173-192. PDF
Abstract: "The synonymy of the genus Lepidostoma Rambur is revised to include 25 new synonyms. The genus is divided into four branches as indicated in the species checklist that is provided. The transferrals of species to Lepidostoma have resulted in 222 new combinations. New names are proposed for six species to avoid secondary homonymy: Lepidostoma kimminsi nom. n., replacing Agoerodes orientalis Mosely; Lepidostoma martynovi nom. n., replacing Dinarthrum modestum Martynov; Lepidostoma ylesomi nom. n., replacing Adinarthrella brunnea Mosely; Lepidostoma navasi nom. n., replacing Crunoeciella hirta Navás; Lepidostoma qilini nom. n., replacing Dinarthrum pilosum Huang; and Lepidostoma wigginsi nom. n., replacing Lepidostoma serratumFlint & Wiggins."
Quote from page 175: "Classification
In Lepidostoma, four large species groups are recognized based on the general types of male forewings that differ primarily in the anal region. These different general types of forewings represent a transitional series that probably evolved in the sequence presented below. I believe that the L. vernale and L. hirtum branches are each monophyletic, but now suspect that the L. podagrum branch is not. Preliminary results of phylogenetic analysis, using mtDNA and mostly North American species, by Myers & Sperling (2002) suggest that the L. vernale + L. podagerum branches together are monophyletic, but that the L. podagerum branch itself is not. Their data also suggest that the L. ferox and the L. hirtum branches are sister groups. Therefore, I do not recognize these groups as subgenera, as previously proposed for the North American Lepidostomatidae (Schmid 1998, Weaver 1988).
Lepidostoma vernale branch. ̶ Figs. 1-3. This group is based on the venation of the male forewing, having anal and cubital veins converging at the arculus and differing only slightly from venation in the female. This primitive type of forewing is exhibited by species from eastern North America, most of which were previously placed in the subgenus Mormomyia Banks (Schmid 1998, Weaver 1988).
Lepidostoma podagrum branch. ̶ Figs. 4-6. This group is exemplified in having male forewing with Cu2 atrophied and the configuration of anal and cubital veins is altered, being quite different from that of the female which retains the typical configuration. This type of forewing is exhibited by a majority of North American species previously placed in the subgenus Nosopus McLachlan (Schmid 1998, Weaver 1988).
Lepidostoma ferox branch. ̶ Figs. 7-9. This group is characterized by the anal groove, a fold that originates near the base of A1 and runs adjacent to the basal portion of A1 and then diverges anterad, becoming the anterior margin of a closed pseudocell. Species often differ with respect to the length of the pseudocell and the different number of open cells that are between it and the posterior margin. The anal groove is never present in the female. A large number of the Palearctic and Oriental species exhibit this type of forewing (most of the species previously placed in Dinarthrum McLachlan, Dinarthrodes Ulmer, Agoerodes Mosely, Adinarthrum Mosely, and Anacrunoecia Mosely by various authors), and a small number of western North American species previously placed in the sub-genus Neodinarthrum Weaver, 1988 (Schmid 1998). This group can usually be distinguished from the L. hirtum branch by having parameres present and lacking lateral straps attached to the phallobase. However, a few species of this group do not have parameres.
Lepidostoma hirtum branch. ̶ Fig. 10-12. This group is defined by having male forewing with the anal groove remaining adjacent to A1 and hence, the closed pseudocell (of the L. ferox branch) is absent. The Lepidostoma hirtum branch is the most widely distributed group within Lepidostomatidae, including a large portion of Oriental and Palearctic species, most of the species from southeastern Asian islands, all of the Afrotropical species (most of the Old World species previously placed in Lepidostoma Rambur, Goerodes Ulmer, Lasiocephala Costa, Maniconeura McLachlan, and Crunoeciella Ulmer, by various authors), and five North American species previously placed in the subgenus Lepidostoma Rambur (Schmid 1998, Weaver 1988). This group is also characterized by having male genitalia with parameres absent and a pair of heavily sclerotized, lateral straps attached to the phallobase and the anteriolateral corners of segment X."
Wiggins, GB 1996 Larvae of the North American Caddisfly Genera (Trichoptera). 2nd Edition. University of Toronto Press, 457 pages.
Williams,DD, Tavares,AF and Bryant,E 1987 Respiratory device or camouflage? A case for the caddisfly. Oikos 50(1): 42-52. PDF
Abstract:"Two hypotheses exist as to the function of the tubular cases constructed from silk and debris by caddisfly (Trichoptera) larvae. One proposes that they provide protection for the larvae by camouflaging them against their background or by providing resistance to the jaws of predators. The other proposes that the case acts as an aid to respiration as, by undulating its abdomen, the larva can create a flow of water through the case and over its gills. We measured, in respirometer chambers at 13°C, the uptake of dissolved oxygen by larvae of 22 species of caddisfly representing a variety of habitat types and phylogenetic lines. Oxygen uptake by larvae in their cases was compared with that of larvae without cases and the species fell into three basic groups: in Group A, representing seven families, the cases appeared to confer a respiratory advantage upon the larvae through reduced levels of oxygen uptake and moderation of respiration rates (i.e., by optimizing rather than maximizing oxygen consumption); in Group B, representing two families, the cases appeared to be a disadvantage to respiration (larvae in their cases consumed more oxygen than they did in the absence of their cases); and in Group C, representing the largest family, the Limnephilidae, for most of the species tested the cases appeared to confer no respiratory advantage (no differences between the amounts of oxygen consumed by larvae in their cases and alone). Given the many uses to which silk has been put in the Trichoptera, it seems reasonable to suppose that construction of a tubular case does not dictate a single function across all case-building species. Our data point to a respiratory function in some species but to a non-respiratory function (probably protection from predators) in others, particularly in the Limnephilidae."
|