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Trichoptera: Phryganeidae of Gunnison County, Colorado

Agrypnia deflata
Giant Case Maker Caddisflies

(Milne 1931)
Updated 1 March 2024
TSN 188492
This is an Agrypnia deflata larvae or pupae partially buried in the bottom sediment.
The aquatic plants nearby are a quillwort, Isoetes bolanderi that larvae use to build their spiral cases.
A. deflata larvae easily use other materials to construct their cases,
but prefer Isoetes when it is available.

Good Links

Other Websites:
Photos, Map, Museum specimens, DNA - Barcodinglife.org

University of Alberta Entomology Collection Species page
     Has description, habitat information, range and more.

Caddisfly Agrypnia deflata pupal_case, usually buried in the sediment

Agrypnia pupal case from a permanent subalpine pond in the Elk Mountains of Colorado August, 2011.
After a year of development in the pond,
A. deflata larvae burrow into the sediment barely enough to cover their case while they pupate :-)
The empty pupal case was netted out of the muck in the bottom of a permanent pond.


Balik,JA; Greig,HS; Taylor,BW and Wissinger,SA 2023 Consequences of climate-induced range expansions on multiple ecosystem functions. Communications Biology, 6(1), p.390. HTML
     Abstract: "Climate-driven species range shifts and expansions are changing community composition, yet the functional consequences in natural systems are mostly unknown. By combining a 30-year survey of subalpine pond larval caddisfly assemblages with species-specific functional traits (nitrogen and phosphorus excretion, and detritus processing rates), we tested how three upslope range expansions affected species' relative contributions to caddisfly-driven nutrient supply and detritus processing. A subdominant resident species (Ag. deflata) consistently made large relative contributions to caddisfly-driven nitrogen supply throughout all range expansions, thus "regulating the caddisfly-driven nitrogen supply. Whereas, phosphorus supply and detritus processing were regulated by the dominant resident species (L. externus) until the third range expansion (by N. hostilis). Since the third range expansion, N. hostilis's relative contribution to caddisfly-driven phosphorus supply increased, displacing L. externus's role in regulating caddisfly-driven phosphorus supply. Meanwhile, detritus processing contributions became similar among the dominant resident, subdominant residents, and range expanding species. Total ecosystem process rates did not change throughout any of the range expansions. Thus, shifts in species' relative functional roles may occur before shifts in total ecosystem process rates, and changes in species' functional roles may stabilize processes in ecosystems undergoing change."

Curtis,J 1835 British Entomology being Illustrations and Descriptions of the Genera of Insects found in Great Britain and Ireland Containing Coloured Figure from Nature of the Most Rare and Beautiful Species, and in Many Instances of the Plants Upon Which They are Found. Richard Taylor, London. vol. IV, 530-577.
     Curtis describes the genus Agrypnia in this book.

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."

Herrmann,SJ 1990 New record and range extension for Rhyacophila wallowa (Trichoptera: Rhyacophilidae) from Rocky Mountain National Park, Colorado. Entomological news (USA).
     While studying R. wallowa, the author found A deflata adults near the cold streams Fall River and Chiquita Creek at 2640m or 8660ft amsl in Rocky Mountain National Park in Colorado.

Hinchliffe,R and Palmer,AR 2010 Curious chiral cases of caddisfly larvae: handed behavior, asymmetric forms, evolutionary history. Integrative and comparative biology, 50(4) 606-618. HTML

Jannot,JE; Bruneau,E and Wissinger,SA 2007 Effects of larval energetic resources on life history and adult allocation patterns in a caddisfly (Trichoptera: Phryganeidae). Ecological Entomology, 32(4), 376-383.
     Abstract: "1. How populations respond to environmental change depends, in part, on the connection between environmental variance during early life stages and its effect on subsequent life-history traits. For example, environmental variation during the larval stage can influence the life histories of organisms with complex life cycles by altering the amount of time spent in each stage of the life cycle as well as by altering allocation to life-history traits during metamorphosis.
2. The effects of larval energetic resources on developmental timing, adult mass, fecundity, mating success, and allocation to adult body structures (thorax, abdomen, wings) were examined in an aquatic caddisfly (Agrypnia deflata Milne, Trichoptera: Phryganeidae). Larval energetic reserves were manipulated by removing larval cases just prior to pupation. In the first experiment, cases of all individuals were removed just prior to pupation; experimental individuals were required to build a new case whereas control individuals were allowed to re-enter their case without building. In the second experiment, energy differences were maximised between the two treatments by supplementing the larval diet of the control group and removing cases and not supplementing the diet of the experimental group.
3. Male and female development time, adult mass, and female fecundity were not influenced by case removal or diet supplementation. In contrast, allocation to adult body parts indicated a trade-off between abdominal and thoracic mass among case-removal females, suggesting that, under larval resource stress, females adjust resource allocation during metamorphosis to alleviate potential negative impacts on clutch size. In addition, latency to copulation increased when cases were removed, indicating larval resource stress could influence male mating success.
4. This study suggests that, under larval energetic stress, the negative impacts on female reproduction might be mitigated by re-allocating resources during metamorphosis, whereas male allocation strategies might not be as flexible as female strategies."

McCullagh,BS; Wissinger,SA and Marcus,JM 2015 Identifying PCR primers to facilitate molecular phylogenetics in Caddisflies (Trichoptera). Zoological Systematics, 40(4) 459 PDF
     Abstract: "The molecular phylogenetics of the Lepidoptera (butterflies and moths) is well studied, but that of Trichoptera (caddisflies), the sister clade of Lepidoptera, is less studied. The PCR primer libraries developed for lepidopteran phylogenetics might work in Trichoptera. DNA from 8 caddisfly species (Asynarchus nigriculus (Banks, 1908), Grammotaulius lorettae Denning, 1941, Hesperophylax occidentalis (Banks, 1908), Limnephilus externus Hagen, 1861, Limnephilus picturatus McLachlan, 1875, Limnephilus secludens Banks, 1914, Limnephilus sublunatus Provancher, 1877 and Agrypnia deflata (Milne, 1931)) was used to screen for amplification. 107 primer pairs for 45 nuclear and 3 mitochondrial genes were tested. Primers for 1 new gene (40S ribosomal protein S2 (RPS2)) and 8 genes previously used in Trichopteran phylogenetics were recovered (16S rRNA, 18S rRNA, carbamoyl-phosphate synthetase (CAD), cytochrome oxidase I (COI), cytochrome oxidase II (COII), elongation factor-1 alpha (EF-1 alpha), isocitrate dehydrogenase (IDH), and RNA polymerase-II (POL-II)). New primer pairs extended the genomic region sampled for many genes. Evolution rates among loci varied by 2 orders of magnitude. Differences among evolution rates and modes of inheritance offer flexible tools for resolving phylogenetic questions and examining genome evolution in the Trichoptera. Screening libraries of PCR primers is a useful approach for identifying PCR primers in related taxa with limited molecular genetic resources."

Milne,LJ 1931. Three new Canadian Prophryganea (Phryganeidae, Trichoptera). Canadian Entomologist 63
     Original description as Prophryganea deflata

Srayko,SH; Mihalicz,JE; Jardine,TD; Phillips,ID and Chivers,DP 2023 Overwintering capacity of water boatmen (Hemiptera: Corixidae) and other invertebrates encased in the ice of shallow prairie wetlands. Canadian Journal of Zoology, 101(6), pp.434-447. PDF
     Abstract: "Overwintering in shallow habitats presents a serious obstacle for aquatic invertebrates. Here we investigated the little-known ability of water boatmen (Hemiptera: Corixidae), an aquatic insect, to survive the winter encased in air pockets within the ice of shallow wetlands. We extracted and experimentally thawed large blocks of ice from prairie wetlands in Saskatchewan, Canada, from which we examined the species composition and revival of corixids. While multiple corixid species were present in wetlands prior to freeze-up, a single species, Cymatia americana Hussey, 1920, comprised the vast majority of corixids that were found within the ice later in winter. Only 4%-9% of corixids, all Cymatia americana, revived after ice thawing over both study years. Being encased within an air pocket appeared to be necessary for the survival of corixids in the ice, with up to 300 individuals grouped together. Other invertebrate taxa also revived after thawing, including Haliplidae and Dytiscidae (Coleoptera) encased within air pockets both alongside corixids and on their own, as well as Coenagrionidae (Odonata), Phryganeidae and Leptoceridae (Trichoptera), Chironomidae (Diptera), and Physidae and Planorbidae (Basommatophora), which appeared to be encased in solid ice. The ability to overwinter inside ice represents a little understood survival mechanism of aquatic invertebrates in shallow wetlands, which could confer energetic and reproductive advantages to those that endure until spring."

Tigreros,N and Davidowitz,G 2019 Flight-fecundity tradeoffs in wing-monomorphic insects. Advances in insect physiology, 56, pp.1-41. PDF

Wiggins,GB 1960 The unusual pupal mandibles in the caddisfly family Phryganeidae (Trichoptera). The Canadian Entomologist, 92(6), pp.449-457.

Wiggins,GB 1998 The Caddisfly family Phryganeidae (Trichoptera). University of Toronto Press, Toronto Buffalo London.

Wissinger, SA 2004 Population fluctuations in caddisflies inhabiting high-elevation wetlands in central Colorado . Presented at the NABS Annual meeting, Vancouver, British Columbia, in Population Ecology 2 Abstract

First or second instar of an Agrypnia deflata larvae

This is a first or second instar larval case built from Isoetes fragments, pine needles and a spruce bud scale.
The spiral shape of the case is in preliminary stages.
The larvae is hidden from view.
Note the adult Dipteran built into its case.

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). PDF
     "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."

Wissinger,SA; Whissel,J; Eldermire,C and Brown,W 2006 Predator defense along a permanence gradient: roles of case structure, behavior, and developmental phenology in caddisflies, Oecologia, Pages 1 - 12. Pdf Icon (311 KB)
     Abstract: "Species replacements along freshwater permanence gradients are well documented, but underlying mechanisms are poorly understood for most taxa. In subalpine wetlands in Colorado, the relative abundance of caddisfly larvae shifts from temporary to permanent basins. Predators on caddisflies also shift along this gradient; salamanders (Ambystoma tigrinum nebulosum) in permanent ponds are replaced by predaceous diving beetles (Dytiscus dauricus) in temporary habitats. We conducted laboratory and field experiments to determine the effectiveness of caddisfly cases in reducing vulnerability to these predators. We found that larvae of a temporary-habitat caddisfly (Asynarchus nigriculus) were the most vulnerable to salamanders. Two relatively invulnerable species (Limnephilus externus, L. picturatus) exhibited behaviors that reduced the likelihood of detection and attack, whereas the least vulnerable species (Agrypnia deflata) was frequently detected and attacked, but rarely captured because cases provided an effective refuge. Vulnerability to beetle predation was also affected by cases. The stout cases of L. externus larvae frequently deterred beetle larvae, whereas the tubular cases of the other species were relatively ineffective. Two of these vulnerable species (A. nigriculus and L. picturatus) often co-occur with beetles; thus, case construction alone is insufficient to explain patterns of caddisfly coexistence along the permanence gradient. One explanation for the coexistence of these two species with beetles is that they develop rapidly during early summer and pupate before beetle larvae become abundant. One species (L. picturatus) pupates by burying into soft substrates that serve as a refuge. The other (A. nigriculus) builds stone pupal cases, which in field experiments, more than doubles survival compared to organic pupal cases. The combined results of these experiments suggest that caddisfly distributions along permanence gradients depend on a suite of primary and secondary predator defenses that include larval and pupal case structure, predator-specific escape behaviors, and the phenology of larval development."

Brown,WS 2005 Trichoptera of Gunnison County, Colorado, USA