Plecoptera Research Articles

Trophic ecology and reproductive aspects of Trichomycterus areolatus (Pisces, Trichomycteridae) in irrigation canal environments

Twelve of the sixteen species of fishes present in the Itata river basin enter the irrigation canals at least once a year, constituting a habitat that is frequently utilized by the native fish assemblages. However, only Trichomcterus areolatus, a native siluriform, is found in great number throughout the entire year, being the dominant species of such artificial environments. Among the factors that could explain the relative success of T. areolatus are its benthonic habits, adaptation to rithral habitat, an offer of trophic resources that is in line with its feeding habits, and a lower abundance of predators in the canals. In this study, the trophic ecology of this species in 174 individuals inhabiting the Itata river (Octava Región, Chile) and 231 from irrigation canals that arise from this river are analyzed and compared. In addition, the length-weight relationship and seasonal frequencies of reproductive status are analyzed, with the purpose of inferring on the status of these populations and their possible condition of resident in these canals. In canals, its diet includes a greater number of different taxa as well as total number of preys consumed in comparison with the river populations, including items of greater biomass, such as lumbriculides. The selectivity analysis showed that T. areolatus prefer prey items like Chironomidae, Baetidae, Elmidae, Plecoptera and Hyallela. Although both the river as well as canal populations show an isometric type growth, they reach greater body lengths and weights in the latter. According to the reproductive states analysis in different periods of the year, populations inhabiting canal environments reproduce synchronically with those of the river, although these latter tend to show a slight delay in the reproductive activity.

Yearly discharge patterns determine species abundance and community diversity: Analysis of a 25 year record from the Breitenbach

Population size of Ephemeroptera, Plecoptera and Trichoptera (EPT) emergence in a given year and the assemblage of the community are predictable based mainly on the discharge pattern of the previous year. We analysed the relationships between precipitation, discharge, water temperature and the emergence of 41 EPT species over 25 years from the Breitenbach, Central Germany. We assumed that the number of emerging individuals does not depend on a single event but was determined particularly by the annual pattern of key variables during larval development in the previous period. Precipitation, discharge and water temperature were tested for variation among years (predictability), predictable persistence (constancy), and predictable fluctuation (contingency). Water temperature had a clear seasonal pattern, precipitation and discharge were rather constant. Precipitation was mediated through the climatic conditions in the catchment into a seasonal discharge pattern. Discharge strongly affected the community. We classified the yearly discharge patterns (1969-1993) into four different groups: (i) permanent 'good flow', (ii) winter and spring spates, (iii) permanent low flow, and (iv) floods during 'unusual' periods (non-seasonal); patterns were discriminated by mean discharge, the yearly sum of the standard deviation of monthly discharge maximum, and the yearly sum of the monthly coefficient of discharge stability (an inverse of the coefficient of variation) within the respective group. The long-term constancy of the EPT populations was determined using the inverse of the coefficient of variation as well. Caddis flies with heavy mineral cases, large stone-flies, and abundant may-flies had stable populations. Variable populations included fine particle feeders and caddis flies with net spinning larvae or light cases, Site scores (based on species abundance) in indirect gradient analysis were best associated with groups defined by the discharge pattern in the year before emergence. Years with permanent good flow, winter and spring spates, or low flow were ordered along the horizontal axis; years with unpredictable (non-seasonal) flow were shifted along the vertical axis. Direct gradient analysis found water temperature, precipitation and discharge in the winter before emergence, and discharge in the summer of the respective year, and of the year before to influence the EPT emergence. High or low abundance of many species was associated with one of the discharge patterns. Community diversity was highest in years with winter and spring floods, and lowest in years with random floods. Differing discharge patterns forced the community into different community states.

New Contributions to the Knowledge of Mediterranean Stoneflies (Plecoptera)

The first description of the ♀ of Leuctra balearica Pardo & Zwick, 1993 from Majorca (Spain) is provided. Protonemura androsiana sp. n. is described for males and females from Andros and Naxos (Greece), and Protonemura lagrecai (Aubert, 1954) and Protonemura macrura (Aubert, 1953), respectively, are for the first time recorded from Greece and Sicily, respectively.

Deforestation alters the resource base and biomass of endemic stream insects in eastern Madagascar

Summary1. Rainforest streams in eastern Madagascar have species‐rich and diverse endemic insect communities, while streams in deforested areas have relatively depauperate assemblages dominated by collector‐gatherer taxa. We sampled a suite of benthic insects and their food resources in three primary rainforest streams within Ranomafana National Park in eastern Madagascar and three agriculture streams in the park's deforested peripheral zone. We analysed gut contents and combined biomass and stable isotope data to examine stream community responses to deforestation in the region, which is a threatened and globally important hotspot for freshwater biodiversity.2. Gut analyses showed that most taxa depended largely on amorphous detritus, obtained either from biofilms (collector‐gatherers) or from seston (microfilterers). Despite different resource availability in forest versus agriculture streams, diets of each taxon did not differ between stream types, suggesting inflexible feeding modes. Carbon sources for forest stream insects were difficult to discern using δ13C. However, in agriculture streams dependence on terrestrial carbon sources was low relative to algal sources. Most insect taxa with δ13C similar to terrestrial carbon sources (e.g. the stonefly Madenemura, the caddisfly Chimarra sp. and Simulium blackflies) were absent or present at lower biomass in agriculture streams relative to forest streams. Conversely, collector‐gatherers (Afroptilum mayflies) relied on algal carbon sources and had much higher biomass in agriculture streams.3. Our analyses indicate that a few collector‐gatherer species (mostly Ephemeroptera) can take advantage of increased primary production in biofilms and consequently dominate biomass in streams affected by deforestation. In contrast, many forest stream insects (especially those in the orders Plecoptera, Trichoptera and Diptera) depend on terrestrial carbon sources (i.e. seston and leaf litter), are unable to track resource availability and consequently decline in streams draining deforested landscapes. These forest‐specialists are often micro‐endemic and particularly vulnerable to deforestation.4. The use of consumer biomass data in stable isotope research can help detect population‐level responses to shifts in basal resources caused by anthropogenic change. We also suggest that restoration of vegetated riparian zones in eastern Madagascar and elsewhere could mitigate the deleterious effects of deforestation on sensitive, endemic stream taxa that are dependent on terrestrial carbon sources.

New records and clarifications of the pennsylvania stonefly (Plecoptera) fauna, with an annotated list of the stoneflies of Pennsylvania, U.S.A

Five species, Nemoura trispinosa Claassen, Strophopteryx appalachia Ricker and Ross, Alloperla biserrata Nelson and Kondratieff, Neoperla robisoni Poulton and Stewart, and Neoperla choctaw Stark and Baumann, are added to the Pennsylvania fauna. Five species, Allocapnia wrayi Ross, Leuctra carolinensis Claassen, Tallaperla anna (Needham and Smith), Tallaperla elisa Stark, and Malirekus hastatus (Banks) are deleted. An annotated list of the 133 described Pennsylvania stonefly species is presented.

Notes On The Distribution Of Leuctra Carolinensis And L. Variabilis Records

The distributions of Leuctra carolinensis and L. variabilis in Maryland are clarified. The former is a late spring emerging species and known from the Appalachian Plateaus and Blue Ridge portions of the state while the latter species emerges during late autumn and recorded only from the Piedmont and Coastal Plain Physiographic Provinces. The status of Yugus bulbosus in Maryland is reevaluated and new state records are reported for five additional species of stoneflies: Pteronarcys dorsata, Acroneuria frisoni, Agnetina capitata, Neoperla stewarti, and Isoperla dicala. A total of 103 species are now known to occur in Maryland.

Molecular phylogenetic analysis of evolutionary trends in stonefly wing structure and locomotor behavior.

Insects in the order Plecoptera (stoneflies) use a form of two-dimensional aerodynamic locomotion called surface skimming to move across water surfaces. Because their weight is supported by water, skimmers can achieve effective aerodynamic locomotion even with small wings and weak flight muscles. These mechanical features stimulated the hypothesis that surface skimming may have been an intermediate stage in the evolution of insect flight, which has perhaps been retained in certain modern stoneflies. Here we present a phylogeny of Plecoptera based on nucleotide sequence data from the small subunit rRNA (18S) gene. By mapping locomotor behavior and wing structural data onto the phylogeny, we distinguish between the competing hypotheses that skimming is a retained ancestral trait or, alternatively, a relatively recent loss of flight. Our results show that basal stoneflies are surface skimmers, and that various forms of surface skimming are distributed widely across the plecopteran phylogeny. Stonefly wings show evolutionary trends in the number of cross veins and the thickness of the cuticle of the longitudinal veins that are consistent with elaboration and diversification of flight-related traits. These data support the hypothesis that the first stoneflies were surface skimmers, and that wing structures important for aerial flight have become elaborated and more diverse during the radiation of modern stoneflies.

A New Apterous Leuctra (Plecoptera) Species from Turkey

Leuctra boluensis sp.n., which is the only apterous stonefly from Turkey, is described and illustrated. The ecology is also given.

A revision of Acroperia (Plecoptera: Zelandoperlinae) and removal of species to Taraperia new genus

Acroperia (Plecoptera: Zelandoperlinae) is revised and a new diagnosis given. A. samueli, A. spiniger, and A. trivacuata are redescribed and A. christinae new species is described. A.flavescens is transferred from Nesoperla and redescribed. A diagnosis for Taraperia new genus is given and A. ancilis and A. howesi are removed from Acroperia to Taraperia and redescribed; T. pseudocyrene new species is added.

Oogenesis of stone flies. Development of the follicular epithelium and formation of the eggshell in ovaries of Perla marginata (Panzer) and Perla pallida Guérin (Plecoptera: Perlidae)

Development of the follicular epithelium in panoistic ovaries of stone flies Perla marginata (Panzer) and Perla pallida (Plecoptera: Perlidae) has been described. The major function of the follicular epithelium in Perla sp. is the secretion of eggshells. In this contribution some other functions of the epithelium are postulated as well. The follicular epithelium passes through several distinct stages of oogenesis. Particularly, during the period of middle vitellogenesis, the follicular epithelium could serve as a cellular pathway of egzogenous yolk precursors into the oocyte. The intercellular spaces (patency) are engaged in the vitellogenin's transport only during late vitellogenesis. The process of choriogenesis and a diversification of follicular cells into subpopulations responsible for formation of specialized elements (main body chorion, chorionic collar, attachment structure) of the chorion are also discussed.

Trypanosome transmission by Corethrella wirthi (Diptera: Chaoboridae) to the green treefrog, Hyla cinerea (Anura: Hylidae).

Seventy-two percent of 215 male green tree frog, Hyla cinerea (Schneider), captured in Alachua and Levy counties, FL, between April and mid-September 1978 and 1979 were infected with an undescribed Trypanosoma sp. None of the 31 female frogs captured concurrently was infected. Periodic sampling of the peripheral blood from the infected male frogs showed that the trypanosomes were present in high numbers only at night. Conspecific trypanosomes also were found in the mid and hind guts of female Corethrella wirthi Stone flies collected on or near male frogs in the field. Transmission of the parasite to uninfected frogs was demonstrated by exposure of male and female frogs to naturally infected flies and to parasites injected subdermally. This is the first report of parasite transmission by a species of Corethrella.

Drumming of Four North American Euholognathan Stonefly Species, and a New Complex Signal Pattern in Nemoura spiniloba Jewett (Plecoptera: Nemouridae)

Drumming is described for the first time in North American species of Bolshecapnia and Capnia (Capniidae), Oemopteryx (Taeniopterygidae), and Nemoura (Nemouridae). Bolshecapnia maculata (Jewett) and Capnia quadrituberosa Hitchcock males call with simple 3-5-beat monophasic signals that conform to the ancestral pattern previously found in the Capniidae. Adults occur at the same time in some streams, yet calls of some B. maculata populations closely approximate those of C. quadrituberosa. C. quadrituberosa females answer the male with 4-beat, monophasic signals. Oemopteryx vanduzeea (Claassen) males call with an ancestral 11- or 12-beat signal having even, 13-ms intervals. Drumming exchanges of Nemoura spiniloba (Jewett) are the most complex yet discovered in the Euholognatha and in the order Plecoptera. The male call is composed of an 11-27-beat first phase and a grouped, 3-5-beat second phase. Females answer with about 6 groups of 4-beat bursts, followed by the male response signal averaging 14 burst groups, each composed of an average of 3 beats. Females sometimes complete a four-way exchange by answering the male response with four 3-beat bursts. The implications of these data to the developing theory of drumming evolution in Plecoptera are discussed.

Ultrastructural and histochemical studies of the egg capsules of Perla marginata (Panzer, 1799) and Dinocras cephalotes (Curtis, 1827) (Plecoptera : Perlidae)

Eggshells of stone flies P. marginata and D. cephalotes (Plecoptera : Perlidae), inhabiting mountain streams, were examined using scanning and transmission electron microscopes, a phase-contrast light microscope and histochemical methods to detect proteins, lipids and polysaccharides. The eggshells of the species investigated consist of a vitelline envelope, chorion and gelatinous sheet decorated on its outer surface with mushroom-like structures. An anchoring structure (attachment disc) is situated on the posterior pole of the egg. The structure and function of the attachment disc, as well as the possible taxonomic applications, are discussed. The morphology and histochemical composition of all these elements of the shell clearly demonstrate good adaptation to land and aquatic habitats; the chorion consists of 2 layers, the internal layer being finely perforated by numerous aeropyles. The external layer, with fewer, regularly placed aeropyles, protects the egg interior against dehydration in the land habitat. The gelatinous sheet seems to provide additional protection. Mushroom-like structures, situated on its surface, correspond with the positions of aeropylar openings. These and other interrelations between chorion structure and function are discussed.

Review: Mayflies and Stoneflies - Life Histories and Biology

Campbell, I. C. (ed.), Mayflies and Stoneflies: Life Histories and Biology. - Series Entomologica 44: 1-366. ISBN 0-7923-0289-3.

The First Record of Stoneflies from the Malvinas/Falkland Islands

This is the first record of Plecoptera from the Malvinas/Falkland Islands. The nymphs of 2 species of Gripopterygidae are described.

Oocytes develop from interconnected cystocytes in the panoistic ovary of Nemoura sp. (Pictet) (Plecoptera : Nemouridae)

The 2 ovaries of Nemoura sp. (Plecoptera : Nemouridae) are comb-like and house about 60–70 ovarioles each. By ultrathin serial sections through a whole ovariole of a last-larval instar, we gathered information on its ultrastructure and 3-dimensional architecture. The germarial region contains several clusters of interconnected oogonia or oocytes. The intercellular bridges (ring canals) are filled with fusomes. Most of the fusomes assemble to polyfusomes and some of the intercellular bridges move together and their cells assemble to rosettes. Results indicate that existence of polyfusomes is not sufficient for rosette formation. The oogonia or oocytes of each cluster develop synchronously. Oocytes detach from clusters next to intercellular bridges. A transdetermination of oogonia to nurse cells does not occur. Thus, the stone flies remain true panoists.

Genetic variation and biochemical systematics of british nemouridae

An electrophoretic survey of 16 enzyme loci in nine of the eleven British Nemouridae (order Plecoptera) was carried out in order to assess their systematic relationships and to determine the level of genetic variation in these primitive insects. The species screened were: Nemoura cinerea, N. cambrica, N. dubitans, N. avicularis, Nemurella picteti, Protonemura meyeri, P. praecox, Amphinemura sulcicollis and A. standfussi. The Nei genetic distances between all the species are large, ranging from 0.53 to 2.07, and consistent with a proposed ancient origin for these insects. The derived genetic relationships between the species are in agreement with the taxonomic classification of this family based on morphological characteristics. The amount of variation within each species is small, with an overall mean expected heterozygosity per locus of 0.047, mean proportion of polymorphic loci of 0.146 and mean number of alleles per locus of 1.25. A reasonable explanation for these low levels of variability is that variation has been lost during periodic population bottle-necks. The usefulness of allozymic analysis in species identification is also discussed.

The incidence of predation on lake‐dwelling leeches

SUMMARY. 1. Erpobdella octoculata (L.), Glossiphonia complanata (L.) and Helobdella stagnate (L.) were eaten readily by larval and adult dytiscid beetles, larval caddisflies and Sialis, nymphal odonatans and various fish in laboratory experiments.2. A serological technique showed that very few lake‐collected specimens of these predatory taxa, plus triclads, leeches and stone fly nymphs, had been feeding on leeches.3. A literature survey of lake studies on fish diet indicated that usually less than 6% of individuals with gut contents had eaten leeches. Few detailed records of waterfowl feeding on leeches have been documented.4. It is concluded that predation pressure on lake‐dwelling leeches is light, and is more severe from fish than invertebrates, less on populations inhabiting stony shores than in vegetation, and greater on the erpobdellid than the two glossiphoniid species.

Blue, red, and yellow insects

Notes are given on yellow, blue, and red examples of 7 species of normally green insects in New Zealand. These records include the orders: Mantodea, Plecoptera, Orthoptera, Hemiptera, and Lepidoptera. Results of a breeding experiment with a yellow praying mantis, Orthodera ministralis (Fabricius), are discussed.

Distribution and ecology of the stoneflies (Plecoptera) in Catalonian rivers (NE-Spain)

On a commence en 1978 un programme extensif pour connaitre les macro-invertebres des bassins de Catalogne (Nord-Est de l'Espagne). Cette etude porte sur les bassins des rivieres Tordera, Llobregat, Bresos, Ter, Foix et Segre (y compris les rivieres d'Andorre). On a recolte 51 especes de plecopteres entre 100 et 2250 m d'altitude. Certaines de ces especes sont des stenothermes de haute altitude, d'autres habitent des ruisseaux temporaires des Pyrenees ou du littoral mediterraneen. Quelques especes de Leuctridae, Capniidae et Chloroperlidae vivent en milieu interstitiel a certains stades de leur cycle