Trichoptera: Limnephilidae of Gunnison County, ColoradoHesperophylax occidentalis - Silver Striped Sedge(Banks) 1908Updated 22 February 2026
TSN 116006 NotesScientific papers from the first 60 years of the 20th century refer to this animal as Platyphylax occidentalis.Good LinksOn this website:Introduction to the Limnephilidae Introduction to Hesperophylax Other Websites: Photos, Map, Taxon Identifier Numbers - from the Global Biodiversity Information Facility Hesperophylax occidentalis at GBIF Photos, Map, Museum specimens, DNA - Barcodinglife.org Seriochemicals of the genus Hesperophylax http://www.pherobase.com/database/genus/genus-Hesperophylax.php ReferencesAl Mousa,MDA 2020 Studies on the Odonata and Trichoptera of high-elevation lakes of northern Colorado and southern Wyoming. MS Thesis, Colorado State University, Fort Collins, Colorado. 187 pages. PDFQuote from page 84: "The Nearctic H. occidentalis (Banks, 1908) was recorded and collected from 21 locations between 1980 and 2020 (Fig. 3.7, Appendix 4) in Boulder (7), Clear Creek (1), Grand (7), Jackson (1), and Larimer (5) Counties lentic habitats from an elevation range of 2,545—3,565m. Bushnell et al. (1987) collected larvae of this species from five localities (Green Lakes and Albion Lake) in Boulder County. Wissinger et al. (2003) also listed this species from permanent high elevation lakes in Colorado." Al Mousa,MDA; Nachappa,P; Ruiter,DE; Givens,DR and Fairchild,MP 2022 Caddisflies (Insecta: Trichoptera) of montane and alpine lakes of northern Colorado (USA). Western North American Naturalist, 82(3), pp.563-576. PDF Quote from page 571: "Four species of the Nearctic genus Hesperophylax Banks, 1916, were recorded in this study (Table 2, Supplementary Material 1). Species of this genus usually inhabit lotic habitats but can occur in cold springs and lakes where they inhabit shallow water (Parker and Wiggins 1985, Wissinger et al. 2003, Wiggins 2014). The transcontinental H. occidentalis (Banks, 1908) and H. designatus were common and frequently encountered." Balik,JA; Taylor,BW; Washko,SE and Wissinger,SA 2018 High interspecific variation in nutrient excretion within a guild of closely related caddisfly species. Ecosphere, 9(5) p.e02205. PDF Banks,N 1908 Neuropteroid insects - notes and descriptions. Transactions of the American Entomological Society 34:255-267. Described as Platyphylax designata var. occidentalis. 
Bergey,EA and Ward,JV 1989 Upstream-downstream movements of aquatic invertebrates in a Rocky Mountain stream, Hydrobiologia, Volume 185( 1) 71-82. Abstract Helicopsyche borealis and Hesperophylax occidentalis were the only species to show a net upstream movement during the course of this study. Blinn,DW and Ruiter,DE 2006 Tolerance values of stream caddisflies (Trichoptera) in the lower Colorado river basin, USA. The Southwestern Naturalist 51(3):326-337. Abstract Bjostad,LB, Jewett,DK and Brigham,DL 1996 Sex pheromone of caddisfly Hesperophylax occidentalis (Banks) (Trichoptera: Limnephilidae). Journal of Chemical Ecology 22:103-121. Abstract: "The main component of the sex pheromone of the caddisfly Hesperophylax occidentalis (Banks) (Trichoptera: Limnephilidae) was identified as 6-methylnonan-3-one (enantiomeric composition has not yet been determined). Extracts of adult females elicited strong electroantennogram (EAG) responses from adult male antennae, but elicited significantly smaller EAG responses from adult female antennae. Extracts of adult males did not elicit appreciable EAG responses from antennae of either sex. Racemic 6-methylnonan-3-one was synthesized and elicited EAG responses from male antennae as strong as those obtained with female extracts. In field tests with baited sticky traps near lakes and streams, traps baited with synthetic racemic 6-methylnonan-3-one caught significantly more males than control traps. Female adults contained approximately 1 µg of 6-methylnonan-3-one per individual. Related ketones and alcohols of other chain lengths were also tentatively identified, being present in tiny amounts in female extracts. Extraction of different body parts showed that 6-methylnonan-3-one occurs only in a region near the intersegmental membrane between the fourth and fifth abdominal sternites of the female (no discrete glands were observed). Extracts of males did not contain 6-methylnonan-3-one, nor did pupae of either sex." Enders,D and Schüßeler,T 2000 First asymmetric synthesis of 6-methyl-3-nonanone, the female-produced sex pheromone of the caddisfly Hesperophylax occidentalis. New Journal of Chemistry, 24(12), pp.973-975. Abstract: "The asymmetric synthesis of the female-produced sex pheromone of the caddisfly Hesperophylax occidentalis, (S)- and (R)-6-methyl-3-nonanone, starting from the simple starting materials propanal, propyl iodide and 2-butanone, in good overall yields is described. The stereogenic centre at the C-6 position of the pheromone was generated via α-alkylation employing the SAMP/RAMP hydrazone method with high asymmetric induction (ee = 94 and 92%)." Ferry,EE; Hopkins,GR; Stokes,AN; Mohammadi,S; Brodie Jr,ED and Gall,BG 2013 Do all portable cases constructed by caddisfly larvae function in defense?. Journal of Insect Science, 13(1), p.5. html Abstract: "The portable cases constructed by caddisfly larvae have been assumed to act as a mechanical defense against predatory attacks. However, previous studies have compared the survival of caddisflies with different cases, thereby precluding an analysis of the survival benefits of "weaker" case materials. The level of protection offered by caddisfly cases constructed with rock, stick, or leaf material, as well as a no-case control, was investigated against predatory dragonfly nymphs (Anax junius Drury (Anisoptera: Aeshnidae)). A valid supposition is that the cases made of stronger material are more effective at deterring predators. Yet, observations revealed that there was no difference in survival between the case types. All caddisflies with a case experienced high survival in comparison to caddisflies removed from their case. In addition, larvae with stick-cases experienced fewer attacks and captures by dragonflies. These results showed that the presence of a case, regardless of the material used in its construction, offers survival benefits when faced with predatory dragonfly nymphs." Gall,BG and Brodie,ED, Jr. 2009 Behavioral avoidance of injured conspecific and predatory chemical stimuli by larvae of the aquatic caddisfly Hesperophylax occidentalis. Canadian Journal of Zoology 87: 1009-1015. PDF Abstract: "Prey animals often encounter situations that hinder their ability to conduct normal fitness-enhancing behaviors. Mating and foraging are frequently interrupted by predator vigilance and avoidance, and antipredator behavior. Many caddisfly larvae build protective cases that are carried with them throughout the aquatic life cycle. However, they are still vulnerable to predation, yet it is unknown the extent caddisflies use chemical cues for predator recognition and avoidance. We exposed larval caddisfly Hesperophylax occidentalis (Banks, 1908) to predatory, conspecific, and heterospecific chemical cues to determine if caddisfly larvae can use chemical stimuli alone for predator recognition and avoidance. Exposure to predator and injured conspecific chemicals elicited significant decreases in activity, while exposure to injured and uninjured heterospecific chemicals yielded no significant change in activity. The extended latency to move following exposure to predator kairomones indicates larval caddisflies utilize chemical cues for predator recognition and avoidance, and a similar decrease in movement associated with exposure to injured conspecifics suggests the presence of a chemical alarm cue." Herrmann,SJ; Ruiter,DE and Unzicker,JD 1986 Distribution and records of Colorado Trichoptera. Southwestern Naturalist 31 4, 421-457. The authors show this species is present in Gunnison County. Hornig,CE and Brusven,MA 1984 Effects of Mount St. Helens volcanic ash on leaf utilization by Hesperophylax occidentalis (Trichoptera: Limnephilidae). Journal of the Idaho Academy of Science 20:1-10. Hornig,CE and Brusven,MA 1986 Effects of suspended sediment on leaf processing by Hesperophylax occidentalis (Trichoptera: Limnephilidae) and Pteronarcys californica (Plecoptera: Pteronarcidae). Western North American Naturalist 46 (1) 33-38 PDF Abstract: "The effects of suspended sediments on stream invertebrate detrital processing were investigated under replicated conditions in light and temperature-controlled chambers in the laboratory. The leaf-shredding insects Pteronarcys californica and Hesperophylax occidentalis were studied. Mean daily ingestion rates were lower among insects subjected to suspended sediments (1.5 and 3.0 g/l) than insects held in suspended sediment-free environments for seven of the eight trials. In five of the eight trials, mean ingestion rates were suppressed by 41% when compared to insects held in suspended sediment-free environments. Feeding inhibition was typically greater at the end of the feeding trials (14 days) than at the beginning (0-4 days). The effects of suspended sediments on ingestion were apparently related to the feeding status of the insects at the time of a trial. Insects in an active feeding mode were less influenced by suspended sediment than those in an inactive feeding mode. We conclude that, depending on the season and the duration of impact, suspended sediment can suppress processing of coarse particulate organic matter and thus adversely influence important nutrient and energy pathways in low-order streams." Jewett,D; Brigham,DL and Bjostad,LB 1996 Hesperophylax occidentalis (Banks) (Trichoptera: Limnephilidae) sex pheromone structure-activity study with electroantennograms. Journal of Chemical Ecology 22: 123-138. Abstract: "Electroantennogram (EAG) analyses of Hesperophylax occidentalis male and female antennae were used to generate dose-response curves for synthetic, racemic 6-methylnonan-3-one and to demonstrate the chemical specificity of male antennal olfactory cells. Male antennae responded to 6-methylnonan-3-one, the main female pheromone component. Females also demonstrated a response to 6-methylnonan-3-one, but a smaller one than males. The chemical specificity of male antennal receptors was determined by comparing EAG activity of synthetic, racemic 6-methylnonan-3-one and a series of structural analogs. The three structural parameters considered, including keto position, chain length, and methyl-group position, were demonstrated to contribute significantly to the reception of synthetic, racemic 6-methylnonan-3-one by male antennae. For straight-chain nonanones with keto groups at different positions, nonan-3-one elicited the greatest EAG responses from male antennae. For straight-chain alkan-3-ones with different chain lengths, the EAG responses of male antennae to nonan-3-one and decan-3-one were the same, but greater than those to other chain lengths. For methyl-branched nonan-3-ones, 6-methylnonan-3-one elicited greater EAG responses from antennae than analogs with the methyl group at another position." Kolar,CS and Rahel,FJ 1993 Interaction of a biotic factor (predator presence) and an abiotic factor (low oxygen) as an influence on benthic invertebrate communities. Oecologia 95(2) 210 - 219 DOI: 10.1007/BF00323492 PDF Abstract: "We examined the response of benthic invertebrates to hypoxia and predation risk in bioassay and behavioral experiments. In the bioassay, four invertebrate species differed widely in their tolerance of hypoxia. The mayfly, Callibaetis montanus, and the beetle larva, Hydaticus modestus, exhibited a low tolerance of hypoxia, the amphipod, Gammarus lacustris, was intermediate in its response and the caddisfly, Hesperophylax occidentalis, showed high tolerance of hypoxia. In the behavioral experiments, we observed the response of these benthic invertebrates, which differ in locomotor abilities, to vertical oxygen and temperature gradients similar to those in an ice-covered pond. With adequate oxygen, invertebrates typically remained on the bottom substrate. As benthic oxygen declined in the absence of fish, all taxa moved above the benthic refuge to areas with higher oxygen concentrations. In the presence of fish mayflies increased activity whereas all other taxa decreased activity in response to hypoxia. Mayflies and amphipods remained in the benthic refuge longer and endured lower oxygen concentrations whereas the vertical distribution of caddisflies and beetle larvae was not influenced by the presence of fish. As benthic oxygen declined in the presence of fish, all but the beetle larva reduced activity over all oxygen concentrations compared to when fish were absent. As benthic oxygen continued to decline, mayflies and amphipods moved above the benthic refuge and were preyed upon by fish. Thus, highly mobile taxa unable to tolerate hypoxia (mayflies and amphipods) responded behaviorally to declining oxygen concentrations by migrating upward in the water column. Taxa that were less mobile (beetle larvae) or hypoxia-tolerant (caddisflies) showed less of a response. Taxa most vulnerable to fish predation (mayflies and amphipods) showed a stronger behavioral response to predator presence than those less vulnerable (caddisflies and beetle larvae). Because invertebrates differ in their ability to withstand hypoxia, episodes of winter hypoxia could have long-lasting effects on benthic invertebrate communities either by direct mortality or selective predation on less tolerant taxa." Martinson,RJ and Ward,JV 1982 Life history and ecology of Hesperophylax occidentalis (Banks) (Trichoptera: Limnephilidae) from three springs in the Piceance Basin, Colorado. Freshwater Invertebrate Biology 1:41-47. Abstract: "The limnephilid caddisfly Hesperophylax occidentalis was collected from July 1978 through June 1979 from spring sources in the Piceance Basin, Colorado. H. occidentalis preferred the spring habitats to area streams downstream from spring sources. H. occidentalis exhibited a univoltine life cycle with extended emergence (April-October) and hatching (June-December) periods. Growth occurred mainly during autumn or winter depending on the time of egg laying. Gut analyses and laboratory observations showed that H. occidentalis can obtain food by several methods and will consume the most available food item." McCullagh,BS; Wissinger,SA and Marcus,JM 2015 Identifying PCR primers to facilitate molecular phylogenetics in Caddisflies (Trichoptera). Zoological Systematics, 40(4) 459 PDF Mesick,CF and Tash,JC 1980 Effects of electricity on some benthic stream insects. Transactions of the American Fisheries Society, 109(4), pp.417-422. Abstract: "Pulsed direct current, square-wave alternating current, alternating current, and direct current, at voltages similar to those currently in use for electrofishing, induced drift by Ameletus dissitus, Baetis spp., Cinygmula par, Hesperoperla pacifica, Psychoglypha subborealis, Hesperophylax occidentalis, and Epeorus longimanus under simulated stream conditions. Of nine species of insects shocked at these voltages, only Simulium jacumbae did not drift. There was an inverse relationship between the propensity of an individual to drift and the minimum level of voltage required to induce drift. Threshold body voltages varied among and within species at different body sizes and at different temperatures. Temporary reductions in productivity with potential loss of species will occur in areas that are electrofished so frequently that rates of insect displacement are greater than rates of insect recolonization." Parker,CR and Wiggins,GB 1985 The nearctic caddisfly genus Hesperophylax (Trichoptera: Limnephilidae). Canadian Journal of Zoology 61(10): 2443-2472. Abstract: "Seven species of Hesperophylax are recognized: alaskensis (Banks), consimilis (Banks), designatus (Walker), magnus Banks, minutus Ling, occidentalis (Banks), and mexico n.sp. Hesperophylax alaskensis is reestablished as a valid species distinct from occidentalis. Hesperophylax incisus Banks is placed as a junior subjective synonym of designatus. Hesperophylax oreades Saether is placed as a junior subjective synonym of Psychoronia costalis (Banks). Keys are provided for identification of males, females, and larvae. A hypothesis of phylogeny is proposed in which consimilis is the sister group of all other Hesperophylax; magnus and mexico are sister species and together are the closest relatives of occidentalis, designatus, and alaskensis; designatus and alaskensis are sister species. An interpretation of biogeography is offered, suggesting how geological events affected the origin and distribution of Hesperophylax species. Data on food, life cycle, habitat, and distribution are given. All species appear to be univoltine with extended flight periods. Larvae are opportunistic omnivores, but magnus is more predaceous than the other species. Differences in mandibular morphology between consimilis and the other species are not reflected in the food habits of the larvae. Among Trichoptera the species of Hesperophylax are little differentiated morphologically and most species vary within unusually broad limits; most species occur in a wider range of habitat types than do other Trichoptera. Perhaps those factors represent a genetic plasticity selected for generalized adaptability rather than the habitat specialization of other Trichoptera." Sultanov,RM; Khafizov,IF; Shutov,NV; Ozden,IV and Khafizov,FS 2018 Catalytic Reductive Β-Metalloethylation in the Synthesis of 6-Methylnonan-3-One and 3-Methylheptanoic Acid, Racemic Analogs of Hesperophylax occidentalis and Coleoptera scarabaeidae Pheromones. Chemistry of Natural Compounds, 54(1), pp.161-162. Abstract: "Previously, the syntheses of 4-methyloctanoic acid, an aggregation pheromone component of an Oryctes rhinoceros beetle [1], and 6-methyloctan-3-one, a racemic analog of an alarm pheromone of a Crematogaster ant [2], were used as examples to demonstrate the potential of the reductive E-metalloethylation of 1-alkenes in the presence of tantalum (Ta) complexes that was discovered by us [3–7]. Herein, this synthetic approach is expanded to the syntheses of 6-methylnonan-3-one (1), a racemic analog of the sex pheromone of the caddisfly Hesperophylax occidentalis, and 3-methylheptanoic acid (2), a racemic analog of the aggregation pheromone of the beetle Coleoptera scarabaeidae. The sex pheromone of H. occidentalis was first isolated by Bjostad et al.[8] and identified as 6-methylnonan-3-one. Multistep syntheses of this compound as a racemate and enantiomers are known [8–10]. An effective synthetic pathway to the racemic analog of pheromone 1 was based on the new regioselective reductive E-zinc-ethylation of 1-alkenes using Et2 Zn and TaCl" Wissinger,SA; Brown,WS and Jannot,JE 2003 Caddisfly life histories along permanence gradients in high altitude wetlands in Colorado (U.S.A.). Freshwater Biology 48(2). Abstract  (427 KB)
" SUMMARY 1. Larvae of cased caddisflies (Limnephilidae and Phryganeidae) are among the most abundant and conspicuous invertebrates in northern wetlands. Although species replacements are often observed along permanence gradients, the underlying causal mechanisms are poorly understood. In this paper, we report on the distributional patterns of caddisflies in permanent and temporary high-altitude ponds, and how those patterns reflect differences in life history characteristics that affect desiccation tolerance (fundamental niches) versus constraints related to biotic interactions (realised niches). 2. Species (Hesperophylax occidentalis and Agrypnia deflata) that were encountered only in permanent ponds are restricted in distribution by life history (no ovarian diapause, aquatic oviposition, and/or inability to tolerate desiccation). Although the egg masses of H. occidentalis tolerate desiccation, the larvae leave the protective gelatinous matrix of the egg mass because adults oviposit in water. 3. Three species (Asynarchus nigriculus, Limnephilus externus and L. picturatus) have life history characteristics (rapid larval growth, ovarian diapause and terrestrial oviposition of desiccation-tolerant eggs) that should facilitate the use of both permanent and temporary habitats. However, A. nigriculus is rare or absent in most permanent ponds, and L. externus and L. picturatus are rare or absent in most temporary ponds. Experimental data from a previous study on the combined effects of salamander predation and interspecific interactions among caddisflies (e.g. intraguild predation) suggest that biotic interactions limit each species to a subset of potentially exploitable habitats. 4. Many wetland invertebrates exhibit species replacements along permanence gradients, but few studies have separated the relative importance of the effects of drying per se from the effects of biotic interactions. Our results emphasise the complementary roles of comparative data on life histories and experimental data on competition and predation for understanding invertebrate distributions along permanence gradients." Wissinger,SA; Eldermire,C and Whissel,JC 2005 The role of larval cases in reducing aggression and cannibalism among caddisflies in temporary wetlands. Wetlands 24(4) 777-783. PDF Abstract: "Larvae of wetland caddisflies supplement their detrital diets with animal material. In some species this supplement is obtained by preying on other caddisflies. In this study, we conducted a series of laboratory experiments to a) compare intraspecific aggression and the propensity for cannibalism among six caddisfly species that occur along a gradient from vernal to autumnal to permanent high-elevation wetlands, and b) determine the importance of cases in preventing or reducing cannibalism and intraguild predation. We predicted that cannibalism and overall levels of aggression should be highest in species that occur in temporary habitats. We found that all of the species that use temporary habitats (Asynarchus nigriculus ,Hesperophylax occidentalis, Limnephilus externus, Limnephilus picturatus, Limnephilus secludens) were extremely aggressive towards and cannibalized conspecifics without cases. Species that typically occur in short-duration temporary wetlands were more aggressive than those in long-duration temporary wetlands. Cases prevented cannibalism in four of these temporary-habitat species, and reduced cannibalism among Asynarchus larvae. The latter species occurs in extremely ephemeral habitats where cannibalism provides a dietary supplement that probably facilitates emergence before drying. Asynarchus also preys on Limnephilus spp., and we found that cases dramatically reduced vulnerability to intraguild predation. Larvae of Agrypnia deflata, a species that occurs only in permanent wetlands, were least aggressive and rarely cannibalized conspecifics. Our results are consistent with the hypothesis that intraspecific aggression and the potential for cannibalism are highest in species that live in habitats with developmental time constraints. Many wetland invertebrates face developmental time constraints and selection for aggression in temporary habitats should be especially strong for taxa that rely on animal material to supplement a mainly detrital diet." Zuellig,RE; Heinold,BD; Kondratieff,BC and Ruiter,DE 2012 Diversity and Distribution of Mayflies (Ephemeroptera), Stoneflies (Plecoptera), and Caddisflies (Trichoptera) of the South Platte River Basin, Colorado, Nebraska, and Wyoming, 1873-2010. U.S. Geological Survey Data Series 606, 257 p. PDF - caution 46MB Quote from page 86: "The type locality for this species is Florissant, Colorado (Banks, 1908), near the type locality of Hesperophylax consimilis. This is another widespread Hesperophylax species in the SPRB that occurred from the lower foothills to nearly timberline. This species is typically found in permanent ponds and streams (Wissinger and others, 2003), often among moss (Parker and Wiggins, 1985)." The elevation range is 5,000-12,150 feet and the adults emerge from March-December. |