Trichoptera Research Articles

Disponibilidade de invertebrados aquáticos para peixes bentófagos de dois riachos da bacia do rio Iguaçu, Estado do Paraná, Brasil

Analyzing aquatic organisms present in fish stomachs is a good way to determine their availability in the environment. This paper aims to determine aquatic organism availability (especially benthos) for bentophagous fishes and to analyze spatial, temporal and ontogenetic changes in their diets. Samples were monthly taken from March 2000 to February 2001, through electrofishing, in two streams of the Iguacu River. The stomachs were analyzed (329 units) and the results expressed through volumetric method. The diet was composed of benthic invertebrates, especially insects from several orders, being Ephemeroptera (3 families), diptera (11 families) and Trichoptera (9 families) the most consumed ones. Therefore, these groups were the most available for fish feeding. The Spearman rank correlation results were highly significant, showing high spatial, temporal and ontogenetic similarity. The high aquatic resources availability may explain the genus Trichomycterus (Siluriformes, Trichomyspteridae) abundance in the streams.

Biologically inspired model of adaptive searching behavior

The computer model of searching adaptive behavior is constructed and investigated. The model describes searching behavior of caddis fly larvae which inhabit creek bottoms and build their cases using hard particles of different size. Using large particles, the larva can build cases more quickly and effectively than with small particles, so it prefers large ones. Inertial switching between search tactics takes place. The model is compared with results of biological experiment. The results of simulation are adequate to biological data.

Glass buildings on river banks as “polarized light traps” for mass-swarming polarotactic caddis flies

The caddis flies Hydropsyche pellucidula emerge at dusk from the river Danube and swarm around trees and bushes on the river bank. We document here that these aquatic insects can also be attracted en masse to the vertical glass surfaces of buildings on the river bank. The individuals lured to dark, vertical glass panes land, copulate, and remain on the glass for hours. Many of them are trapped by the partly open, tiltable windows. In laboratory choice experiments, we showed that ovipositing H. pellucidula are attracted to highly and horizontally polarized light stimulating their ventral eye region and, thus, have positive polarotaxis. In the field, we documented that highly polarizing vertical black glass surfaces are significantly more attractive to both female and male H. pellucidula than weakly polarizing white ones. Using video polarimetry, we measured the reflection-polarization characteristics of vertical glass surfaces of buildings where caddis flies swarmed. We propose that after its emergence from the river, H. pellucidula is attracted to buildings by their dark silhouettes and the glass-reflected, horizontally polarized light. After sunset, this attraction may be strengthened by positive phototaxis elicited by the buildings' lights. The novelty of this visual-ecological phenomenon is that the attraction of caddis flies to vertical glass surfaces has not been expected because vertical glass panes do not resemble the horizontal surface of waters from which these insects emerge and to which they must return to oviposit.

A bionic model of adaptive searching behavior

The adaptive behavior line of investigation, which is considered as a bionic approach to development of systems of artificial intelligence, is characterized. One of the topical problems in the framework of this approach is the simulation of searching animal behavior. A general scheme of searching adaptive behavior with inertial switching between search tactics is presented. A particular model of searching behavior of larvae of caddis flies building a case-house from particles of different size and searching for gathering of suitable particles is investigated. The adequacy of the model to biological experimental data is shown, which is characterized by its specificity reflecting the memory data of larvae about both the sizes of last-processed particles and the general properties of the inertial switching.

New species of Cheumatopsyche (Trichoptera: Hydropsychidae) from North Sulawesi, Indonesia

Sulawesi Island has a high density of endemic animal species, including insects in the order Trichoptera. We describe the males of four new species of Cheumatopsyche (Trichoptera: Hydropsychidae) from North Sulawesi (Provinsi Sulawesi Utara), and provide a checklist of the Cheumatopsyche species from the Indonesian archipelago. Describing the aquatic insect fauna is an important step toward establishing biomonitoring protocols in Indonesia, which is experiencing rapid development and water pollution problems.

Order Trichoptera Kirby, 1813 (Insecta), Caddisflies*

The taxonomy, diversity, and distribution of the aquatic insect order Trichoptera, caddisflies, are reviewed. The order is among the most important and diverse of all aquatic taxa. Larvae are vital participants in aquatic food webs and their presence and relative abundance are used in the biological assessment and monitoring of water quality. The species described by Linnaeus are listed. The morphology of all life history stages (adults, larvae, and pupae) is diagnosed and major features of the anatomy are illustrated. Major components of life history and biology are summarized. A discussion of phylogenetic studies within the order is presented, including higher classification of the suborders and superfamilies, based on recent literature. Synopses of each of 45 families are presented, including the taxonomic history of the family, a list of all known genera in each family, their general distribution and relative species diversity, and a short overview of family-level biological features. The order contains 600 genera, and approximately 13,000 species.

Comunidades de Ephemeroptera, Plecoptera eComunidades de Ephemeroptera, Plecoptera e Trichoptera em folhiço de um riacho de montanha da Mata Atlântica do Sudeste do Brasil

The study of Ephemeroptera, Plecoptera and Trichoptera associated with litter in southeastern Brazil streams aimed to answer the following questions: 1) Does richness and composition of EPT fauna differ between riffle and pool mesohabitats despite being associated to the same substratum, litter? 2) Does the similarity of the EPT fauna between both mesohabitats change with time? 3) Does the EPT functional feeding structure differ between both mesohabitats (riffles–pools)? In order to answer these questions, monthly collections, from November 1999 to June 2000, were done in Ribeirao (Stream) Bocaina with a D-net (10 litter patches in riffles and 10 in pools). The EPT fauna at Ribeirao Bocaina was more diversified and more abundant in the litter in riffles than in the litter in pools, although, when richness was standardized for the same number of individuals it became similar in both conditions. EPT fauna was very different between both mesohabitats in terms of faunal composition as well as in terms of function. Probably it was due to differences in water speed, in the time of litter residence and in the concentration of dissolved oxygen between both mesohabitats.

Food Habits of Four Bottom‐Dwelling Gobiid Species at the Confluence of the Danube and Hron Rivers (South Slovakia)

AbstractSince 1997, three newNeogobiusspecies (Neogobius kessleri,N. fluviatilisandN. melanostomus) have been regularly recorded in the Slovak part of the Danube River, formerly inhabited only by one native gobiid species (Proterorhinus marmoratus). The study of their food habits proved that the amphipodCorophium curvispinum,chironomid larvae and pupae, caddis fly larvae (Hydropsychesp.) and mayfly nymphs (Ephoron virgo,Potamanthus luteus) were the most important food items contributing to the similarity of the diets of the gobiid species. Fish (0+Zingel zingelandSander lucioperca) appeared in the diet ofN. kesslerionly. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Strategy‐switching in the gaffing bat

AbstractForaging in Daubenton's bats Myotis daubentonii, at two altitudinal locations along a river gradient in North Wales was investigated in relation to aerial insect density and to the density of prey on the water surface. Prey capture in Daubenton's bats consisted of aerial hawking, where prey was taken in the air, and trawling, where bats gaffed invertebrates from the water surface. Aerial hawking accounted for 86% of all prey capture attempts, despite aerial insect availability falling close to zero for much of the night. Conversely, prey density on the water surface was an order of magnitude higher than aerial prey density and increased through the night due to aquatic invertebrate drift. At the higher altitude site, M. daubentonii switched prey capture strategy to gaffing, possibly to reflect this change in prey availability on the water's surface, but at the lower altitude site, they maintained aerial hawking as the preferred strategy. The switch to gaffing may be inhibited by the significant downstream accumulation of large numbers of inedible exuviae of caddis flies, Trichoptera, at the low‐altitude site, which form both acoustic clutter and increase the probability of capturing inedible prey, making foraging less efficient. These small altitudinal differences in foraging strategy should be factored into the design of future altitudinal bat foraging studies and if found to be a widespread strategy, taken into consideration by conservation planners when reviewing the habitat requirements of Daubenton's bats in river valleys within the United Kingdom.

Nursery Production of Golden Perch, Macquaria ambigua, at Two Densities in Ponds

ABSTRACT Golden perch, Macquaria ambigua (Richardson), is a freshwater percichthyid native to inland eastern Australia. Growth and feeding of this fish in pond aquaculture conditions was studied in nursery phase at high (95,300/ha) and low (32,800/ha) density over 126 days. Mean growth of golden perch at both densities was similar, but there were significantly more small fish in the high-density treatment. Coefficient of variation was high in both treatments (72–79%). After 126 days, 67% of the fish in both treatments reverted to natural foods. Reversion from pelleted diet to natural foods was very rapid in the low-density treatment (<14 days), but slower in the high-density treatment. Golden perch were found to be selective feeders. The smallest fish selectively ate water fleas, Moina sp., from the zooplankton, and larger fish ate chironomids and caddis flies (Trichoptera). Golden perch, which fed predominantly on pellets, grew 54% faster than those eating natural foods. Three to four months of an intensive nursery period, followed by grading for grow-out, is recommended to separate fast growing pellet feeding fish from slower growing fish that have reverted to eating natural foods.

Caddis flies (Insecta: Trichoptera) in the collection of the State Museum of Natural History, National Academy of Sciences of Ukraine in Lviv

SZCZESNY B., GODUNKO R. J. 2007. Caddis flies (Insecta: Trichoptera) in the collection of the State Museum of Natural History, National Academy of Sciences of Ukraine in Lviv. Acta zoologica cracoviensia, 50B(2): 27-43. Abstract. The collection includes 1429 specimens representing 177 species/subspecies; 159 specimens belonging to 32 species are determined herein, and determinations of fur- ther 174 specimens of 54 species are corrected. The largest share of caddis flies were col- lected, identified and prepared by J. DZIEDZIELEWICZ from the second half of 19 th century to 1916. All specimens had been originally preserved dry but were moved to alcohol prior to the current identification. The collection comprises 177 specimens of all Carpathian species described by DZIEDZIELEWICZ (seven taxa), by KLAPALEK (three taxa) and by SCHMID (two taxa). Among them there are lectotypes of two species (Chionophylax czar- nohoricus (DZIEDZIELEWICZ), and Drusus carpathicus DZIEDZIELEWICZ (), syntypes of 2 taxa (Chionophylax subradiata KLAPALEK, Isogamus aequalis (KLAPALEK)), Apata- nia carpathica SCHMID. There are also 33 paralectotypes representing six species and 33 specimens of five species with the status locus typicus. A list of incorrectly identified or labelled taxa is presented.

Aquatic tetrasporoblastic microsporidia from caddis flies (Insecta, Trichoptera): Characterisation, phylogeny and taxonomic reevaluation of the genera Episeptum Larsson, 1986, Pyrotheca Hesse, 1935 and Cougourdella Hesse, 1935

Seven microsporidian species infecting caddis fly larvae, corresponding to conventional genera Episeptum, Pyrotheca and Cougourdella were studied using light and electron microscopy. Parts of their small subunit, ITS and large subunit ribosomal RNA genes were sequenced and compared with sequences of rDNA obtained from syntype slides of Cougourdella polycentropi Weiser 1965 and Pyrotheca sp. from Hydropsyche pellucidula. All studied caddis fly microsporidia form a closely related group. Their developmental stages in trichopteran hosts are restricted to fat body cells and oenocytes and have isolated nuclei. In late merogony, uninucleate meronts and binucleate plasmodia are formed. In sporogony a sporogonial plasmodium with four nuclei gives rise by rosette-like budding to four sporoblasts within a non-persistent sporophorous vesicle. Sporoblasts mature into pyriform to lageniform spores. The shape and size of spores, the number of polar filament coils, the structure of the polaroplast and of the exospore, together with morphometric characters present a set of markers unique for respective species. Four new species are established. The new genus Paraepiseptum is proposed to replace the tetrasporoblastic Pyrotheca and Cougourdella species from caddis flies. The genus Episeptum is redefined. Field and laboratory examinations as well as the phylogenetic position within the aquatic clade of microsporidia suggest that the life cycle of trichopteran microsporidia probably involves an alternate (copepod?) host and (or) transovarial transmission.

Vulnerability of alpine stream biodiversity to shrinking glaciers and snowpacks

AbstractClimate change poses a considerable threat to the biodiversity of high latitude and altitude ecosystems, with alpine regions across the world already showing responses to warming. However, despite probable hydrological change as alpine glaciers and snowpacks shrink, links between alpine stream biota and reduced meltwater input are virtually unknown. Using data from the French Pyrénées, we demonstrate that taxonomic richness and total abundance of stream macroinvertebrates increase significantly as meltwater (snow melt and glacier melt) contributions to river flow decrease. Macroinvertebrate species showed a gradation of optimum meltwater conditions at which they persist. For example: Habroleptoides berthelemyi (Ephemeroptera), Perla grandis (Plecoptera) and Rhithrogena spp. (Ephemeroptera) increased in abundance when meltwater contributions to streamflow decrease, whereas in contrast, Rhyacophila angelieri (Trichoptera) and Diamesa latitarsis spp. (Diptera) decreased in abundance. Changes in alpine stream macroinvertebrate community composition as meltwater contributions decline were associated with lower suspended sediment concentration, and higher water temperature, electrical conductivity and pH. Our results suggest α diversity (at a site) of streams presently fed by meltwaters will increase with future meltwater reductions. However, β diversity (between‐sites) will be reduced as snow melt and glacier melt decrease because the habitat heterogeneity associated with spatiotemporal variability of water source contributions will become lower as meltwater contributions decline. Extinction of some endemic alpine aquatic species (such as the Pyrenean caddis fly R. angelieri) is predicted with reduced meltwater inputs, leading to decreases in γ diversity (region). Our identification of significant links between meltwater production and stream macroinvertebrate biodiversity has wider implications for the conservation of alpine river ecosystems under scenarios of climate change induced glacier and snowpack loss.

Caddisflies: Architects Under Water

Caddisflies: Architects Under Water

Zoobenthos of salmon rivers in the Kola Peninsula and Karelia (north east Fennoscandia)

Based on the study of zoobenthos in the salmon rivers of the Kola Peninsula and Karelia for 1978–2001, the abundance of food for young Atlantic salmon Salmo salar L. is assessed. Aprevailing group in density (73%) and biomass (66%) of zoobenthos are larvae of amphibian insects such as chironomids and black flies, mayflies, stoneflies and caddis flies regarded as food objects for juvenile salmonid fishes. On average, quantitative characteristics of bottom communities of the rivers of the Kola Peninsula and Karelia vary from 4 up to 16 thousand ind m−2 and from 5.5 up to 15.5g m−2. The food conditions for juvenile salmon in the rivers of the Kola Peninsula and Karelia can be estimated as averag

Trophic structure of invertebrate communities in ecosystems of salmon rivers in the southern Far East

The formation of trophic structure has been studied in communities of amphibiotic insects (mayflies, stoneflies, caddis flies, and dipterans) and gammarids accounting for 90% of the total benthos biomass. The results show that the trophic groups prevailing by biomass in the metarithral subzone of small rivers are as follows: filtering collectors in rivers of the moderately cold-water type, collectors and scrapers in rivers of the cold-water type, and scraping predators and scrapers in rivers of the moderately warm-water type. Predators, scraping predators, and scrapers show seasonal changes in abundance and biomass. In the rithron of Far Eastern rivers, the abundance of predators regularly decreases in a south-north direction. The change of dominant groups along the longitudinal profile of the river is related to its zones and subzones. In the trophic structure of rivers exposed to anthropogenic impact, the number of trophic groups decreases and the remaining groups undergo changes in their qualitative composition and the ratio of their individual members.

A walk around the pond: insects in and over the water

A water strider darts across a pond, its feet dimpling the surface tension; a giant water bug dives below, carrying his mate's eggs on his back; hidden among plant roots on the silty bottom, a dragonfly larva stalks unwary minnows. Barely skimming the surface, in the air above the pond, swarm mayflies with diaphanous wings. Take this walk around the pond with Gilbert Waldbauer and discover the most amazingly diverse inhabitants of the freshwater world. In his hallmark companionable style, Waldbauer introduces us to the aquatic insects that have colonised ponds, lakes, streams and rivers, especially those in North America. Along the way we learn about the diverse forms these arthropods take, as well as their remarkable modes of life - how they have radiated into every imaginable niche in the water environment, and how they cope with the challenges such an environment poses to respiration, vision, thermoregulation and reproduction. We encounter the caddis fly larva building its protective case and camouflaging it with stream detritus; green darner dragonflies mating midair in an acrobatic wheel formation; ants that have adapted to the tiny water environment within a pitcher plant; and insects whose adaptations to the aquatic lifestyle are furnishing biomaterials engineers with ideas for future applications in industry and consumer goods. While learning about the evolution, natural history and ecology of these insects, readers also discover more than a little about the scientists who study them.

Caddisflies: the underwater architects

Caddisflies: the underwater architects

A review of Australian long-horned caddisflies in the Oecetis pechana-group (Trichoptera: Leptoceridae), with descriptions of thirteen new species

Wells, A. 2006. A review of Australian long-horned caddisfl ies in the Oecetis pechana-group (Trichoptera: Leptoceridae), with descriptions of thirteen new species. Memoirs of Museum Victoria 63(2): 107–128. This fi nal paper in a series reviewing Australian members of the long-horned caddisfl y genus Oecetis McLachlan (Trichoptera: Leptoceridae) deals with 21 species, 13 of them new, and all assigned here to the pechana-group, so-named for the most common and widespread of Australian Oecetis species. This group is diagnosed as having fork 1 in the forewing sessile and, in the male, scale patches on the forewing and a single internal paramere in the phallus, although in several species one or other of these male features is absent. Keys are given to the Oecetis species groups recognised in Australia and to species in the pechana-group. Established pechana-group species are diagnosed and new species are described. Male genitalic features are illustrated for all species save O. lurida Kimmins which was described from a female and is probably a doubtful name. A homonym created in the name O. dilata Wells, 2004 is replaced with the name Oecetis kimberleyensis nom. nov., and Oecetis cepaforma Wells, 2004 is synonymised with the widespread Oriental-Australian O. hemerobioides McLachlan, 1866. Seventy-four Oecetis species are now recognised in the Australian fauna.

Selenium and other trace metals in fish inhabiting a fly ash stream: Implications for regulatory tissue thresholds

Bluegill sunfish ( Lepomis macrochirus) and caddis flies ( Trichoptera: Hydropsychidae) were collected from a stream receiving fly ash discharge and nearby reference streams to determine tissue levels of selenium (Se) and other metals, and compare these levels to published “no effect” thresholds. Stingy Run samples contained elevated levels of several metals. Mean Se concentrations in bullhead minnow whole body, bluegill whole body, bluegill ovary, and testes tissues were 44.6, 17.3, 32.5, and 37.1 μg/g (dry wt), respectively. These levels were 2–3 times higher than proposed toxic thresholds for fish whole body (7.9 μg/g) and ovary (17 μg/g). Although monitoring indicated a persistent bluegill population, some reproductive impairment may have occurred. Tissue residue data should be treated with caution because feral fish may accumulate several metals. In Stingy Run, persistence of a bluegill population may be explained by antagonistic interactions with other metals that were also elevated in the fish.