A few wingless species, such as the Lake Tahoe benthic stonefly ("Capnia" lacustra[Note 1]) or Baikaloperla, are the only known insects, perhaps with the exception of Halobates, that are exclusively aquatic from birth to death. Some true water bugs (Nepomorpha) may also be fully aquatic for their entire lives, but can leave the water to travel.
If we had a favorite fly, no question it would be the stonefly. Stoneflies, members of the order Plecoptera, are good-sized insects found in clean, fast-moving, gravel-lined streams around the world. Trout, steelhead, grayling, and whitefish find stoneflies irresistible.
These underwater creatures elude most predators by growing during the winter months when most fish are more sluggish. They live only in good quality streams so searching for them tells us about problems in the river and its streams. HRWC does stonefly searches to gauge the health of our streams.
The stonefly pattern proved so successful, I decided to release set of realistic foam body cutters to match our Stonefly Wing, Spent Stonefly Wing, and Universal Bug Wing cutters. With these cutters, you can tie anything from Salmon Flies to small Winter Stones!
The level of realism you can achieve depends on the level of your desire, but in any event, these patterns are really fun and fast to tie. Trust me, only a little practice is needed to crank out any type of stonefly you want to fish!
Stoneflies have incomplete metamorphosis: eggs are placed in masses on the water surface by adult stoneflies and hatch into naiads. Naiads may live underwater for a few years before moving to the water surface to molt into winged adults. Stonefly Naiad (B. Newton, 2004) Stonefly Naiad (B. Newton, 2004) ECOLOGY Stonefly naiads occur in fast moving streams where they are most commonly found clinging to the undersides of rocks. Many stonefly naiads are predators, feeding on other aquatic arthropods. Naiads of other species eat plants and algae. Although stonefly naiads were once very common in streams, they are very sensitive to pollution. These days, stonefly naiads are only common in very clean water. Stonefly adults can't fly very well, and are usually found sitting on rocks near the streams where they emerged. Many stonefly adults do not feed, others feed on algae, pollen, or other plant parts. Stoneflies are a very important food source for fish and birds, and they are also eaten by spiders and predatory insects. PEST STATUS Stoneflies are not considered pests.
FAMILIES: Perlidae, Pteronarcidae, and Taeniopterygidae We have several common stonefly species in Kentucky, but most are very similar in appearance and habits. Pictured below center is a stonefly adult which has just molted. Insects are soft and unable to fly for a short time just after they molt, and are said to be in a "teneral" state.
Unlike some other aquatic insects, stonefly naiads usually do not do well in home aquariums. Most stoneflies need running water with lots of oxygen - a condition that is difficult to maintain in an aquarium.
Like many aquatic insects, stonefly naiads need clean water to live. Because of this, scientists can tell if a stream is polluted or not based on whether stonefly naiads are present. Read more about using insects to determine water quality: -1167/ANR-1167.pdf
The Evolution Stonefly tungsten beadhead is molded after the common stonefly head profile -- broad with prominent eyes at the back where it meets the thorax, and a long, flat nose that tapers to the front.
A fine diameter variegated chenille perfect for tying rubberlegged stones with lead wire underneath while keeping the fly slim. This is the chenille requested in the recipe for Lance's stonefly pattern in the Confidence Flies section of our film Modern Nymphing.
Using the definition of Bybee et al. , stoneflies exhibit a hemimetabolous metamorphosis consisting of egg, nymph or naiad (their preferred term), and adult life stages. Most stonefly researchers use nymph for the immature stage of stoneflies, we retain its use here. The aquatic nymphs grow gradually then transform to usually winged adults. Nymphs feed on decaying leaves and wood, encrusting algae, or on other invertebrates, and some species are known to undergo ontogenetic diet shifts . Stoneflies utilize all stream sizes, inhabit high latitude or elevation lakes, endure a wide range of thermal regimes, and have evolved to complete their life cycles under a broad range of stream permanence conditions . Adults are almost exclusively terrestrial, and approximately half of the species feed during this stage to support maturation of eggs [5,6]. Exceptions to nymphal and adult habitat use occur, for instance, nymphs of Vesicaperla McLellan, 1967 (Gripopterygidae) are terrestrial in New Zealand , and adults of Capnia lacustra Jewett, 1965 (Capniidae) never leave the depths of Lake Tahoe in California and Nevada, USA .
This sensitivity leads to the imperilment of many stonefly species [15,16]. Plecoptera researchers use museum specimens to establish historical assemblages for comparison with contemporary fauna. Currently, there are over 150,000 verifiable, digitized specimen-based occurrence records in museums of the developed world . Many more specimens remain uninvestigated in museums. Using these data researchers have documented extinctions (Illinois, USA: Isoperla conspicua Frison, 1935; Alloperla roberti Surdick, 1981) , regional extirpations [15,18], massive range losses [19,20], and declines of entire guilds of stoneflies (predators and long-lived species) . Myriad reasons exist for these losses including acid precipitation , large scale hydrological modifications (channelization, tiling of fields, and riparian tree removal) , eutrophication , and sedimentation resulting from agricultural practices and regional urbanization . One result of these losses is that smaller species with shorter life cycles have replaced long-lived species with direct egg hatching . These losses are broad enough that entire generations of water quality biologists no longer recognize that multiple species of large, long-lived, predatory stoneflies were once common in streams, resulting in shifted regional baseline expectations (e.g., the shifting baseline syndrome of Soga and Gaston ). Most of the losses to date have not been climate related, though some climate impacts may already be occurring [22,23] and more severe consequences are predicted .
The ecological consequences of these stonefly species losses are not well understood, but others have hypothesized that it could upset the normal flow of nutrients and energy to downstream areas . Of the 16 stonefly families, 11 are shredders of coarse organic matter and comprise a majority of the species in the order . Loss of shredder stoneflies from headwaters due to acid precipitation , climate change , or pesticide application  could dramatically diminish the availability of fine organic matter causing a cascade of losses of downstream invertebrate and vertebrate species  that provide many other ecosystem services.
A breakthrough achievement by Fochetti et al. , compiled a global, electronic checklist of valid names, synonyms, and distribution information. The resultant data were used by Fochetti and Tierno de Figueroa  to publish a global assessment of stonefly diversity, increasing the number of valid, extant species to 3497. The authors also tallied the number of extant species and genera for each biogeographic region and conducted a biogeographical analysis. The article summarized a wealth of other biological, distributional, and biogeographical information, making this one of the most important stonefly papers to date. The database of Fochetti et al.  was not intended to be a catalog and the data available from the website were limited to valid names and distribution information, but still provided data previously unavailable in digital form.
Plecoptera Species File (PSF)  is a global taxonomic database focusing on stonefly nomenclature, and reached 95% completion in 2010. It is currently the most cited stonefly taxonomic resource. It is the source of data for Plecoptera in the CoL and its taxonomic classification is used for stonefly data at GBIF, in the Barcode of Life Database , and in the Encyclopedia of Life . The data are replicated throughout many other sources. Species and literature are continually added to the database. Publications in Illiesia, The International Journal for Stonefly Research  use a life science identifier (LSID) link for new taxa provided by PSF that resolves directly to a taxon page. The PSF is a mature resource and its data may now be used to conduct analyses on global and regional scales for taxonomic and geographic diversity and to relate the results to ecosystem services of stoneflies.
Comparing large conjoined land masses proved to be more challenging. Fochetti and Tierno de Figueroa  reported 350 species for China, noting some uncertainty. We find that China has at least 615 species, 595 of which were described from China. It is unlikely that Fochetti and Tierno de Figueroa  had access to all the literature for China, and of course, the number of published papers has increased dramatically over the past decade. Chinese researchers now publish much of their work in English journals, significantly improving access to the literature. Editors of English journals have also requested that checklists come with Chinese stonefly papers which enhances our understanding of stonefly distribution in the country. As an indication of just how rapidly the Chinese fauna is being discovered and clarified, nearly 200 taxonomic papers have been published recently by the two most productive stonefly researchers in China, Yu-Zhou Du and co-authors (94 since 2001) and Weihai Li and co-authors (103 since 2004), most of them in English journals. A significant advance in our understanding of the Chinese fauna occurred with the publication of two new catalogs [44,45]. 041b061a72