Studies on the Genus Annitella Klapálek (Trichoptera: Limnephilidae: Chaetopterygini) in the Iberian Peninsula

Three new Annitella species (Trichoptera, Limnephilidae, Chaetopterygini) from the Iberian Peninsula, Annitella amelia sp.n. (Portugal), A. cabeza sp.n. (Spain) and A. lalomba sp.n. (Spain) are described. Psilopteryx (Acropsilopteryx) esparraguera Schmid, 1952 and Psilopteryx sanabriensis Gonzales and Otero, 1985 are transferred to the genus Annitella. Brief decriptions and illustrations of these species and of the related species A. pyrenaea (Navás, 1930) are given. A sketch map of the distribution of the Annitella species in the Iberian Peninsula is included.     

Notes on the genus Agnetina (= Phasganophora) (Plecoptera: Perlidae)

Genus Agnetina Klapálek, 1907 is removed from synonymy with Dinocras Klapálek, 1907 and synonymy between Agnetina and Phasganophora Klapálek, 1914 is established. A list of presently recognised nominal species of Agnetina is provided. For all west palaearctic species, i.e., A. elegantula (Klapálek), A. senilis Klapálek, A. werneri (Kempny), comb, n., lectotypes are designated. Distinctive characters of these three species are described, external male genitalia and eggs are illustrated. Asian A. brevipennis (Navás), comb, n., is briefly compared. A. dubia nom. n. is proposed to replace A. brevipennis Klapálek, 1921 (not Navás, 1912), a doubtful Asian species. A. pedata (Koponen, 1949) and A. undaata (Klapálek, 1921) are considered possible synonyms of A. senilis. which is for the first time recorded from Central Asia (Baikal area).     

Living Apart Together: On the Biology of two Sympatric Leuctra Species (Plecoptera,Leuctridae) in an Apenninic Stream,Italy

Leuctridae is the richest stonefly family on the European continent, with many species of Leuctra often coexisting in sympatry in the same lotic environment. In this work we studied the life cycle and feeding habits of two species, Leuctra fusca and L. hippopus, coexisting in a small Italian Apennine stream. The life cycles of the two species are non‐overlapping, i.e., periods of nymphal growth and adult emergence are separated. Nymphs of both species feed mainly on detritus, but quantities of coarse particulate organic matter (CPOM) and diatoms are also ingested. Larger nymphs of both species ingest more CPOM and fewer diatoms. This suggests a similar trophic behaviour through their development. For example, they act as collector‐gatherers in their earlier instars and as collector‐gatherers or as shredders in their later instars (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Scaling population responses to spatial environmental variability in advection-dominated systems

We model the spatial dynamics of an open population of organisms that disperse solely through advection in order to understand responses to multiscale environmental variability. We show that the distance over which a population responds to a localized perturbation, called the response length, can be characterized as an organisms average lifetime dispersal distance, unless there is strong density‐dependence in demographic or dispersal rates. Continuous spatial fluctuations in demographic rates at scales smaller than the response length will be largely averaged in the population distribution, whereas those in per capita emigration rates will be strongly tracked. We illustrate these results using a parameterized example to show how responses to environmental variability may differ in streams with different average current velocities. Our model suggests an approach to linking local dynamics dominated by dispersal processes to larger‐scale dynamics dominated by births and deaths.     

Adaptations to life in a hypersaline water‐body: Adaptations at the egg and early embryonic stage of Tanytarsus barbitarsis freeman (Diptera,chironomidae)

Oviposition, egg sinking rates, ion excretion in eggs and early embryos, and egg permeability and resistance to desiccation were studied in Tanytarsus barbitarsis a chironomid inhabiting highly saline waters in southern Australia. The aim was to investigate the nature of adaptations displayed by eggs and early embryonic stages of this species to life in hypersaline waters.

Adaptations appear to be of two major sorts: one sort relates to the physiological stress of life in a hypersaline medium, the other to the need to minimize fish predation. The importance of selective forces other than salinity in determining the fauna of salt lakes is highlighted.     

The effect of dispersal ability in winter and summer stoneflies on their genetic differentiation

Abstract.  1. Plecopteran species disperse less than most other aquatic insects. Within stoneflies, members of different families vary in the degree of wing morphology and season of adult emergence.
2. Dispersal limitations were tested to determine if there were increased differences among the nearby, Chagrin and Grand River populations in north-eastern Ohio, by comparing genetic variation within the 16s rRNA region of mitochondrial DNA in two stoneflies. Allocapnia recta emerges in winter and often has rudimentary wings, and Leuctra tenuis emerges in summer with fully developed wings.
3. There was significant genetic variability between the samples of A. recta from two adjacent rivers (FST = 0.20), but not between samples of L. tenuis (FST = 0.07).
4. Distinct clades in A. recta were found to occur within the minimum spanning tree specific to the Chagrin River, which contributed to a significant difference in gene diversity between the two rivers. Haplotypes in L. tenuis appeared randomly distributed between the two rivers; however, nucleotide diversity was significantly less in samples from the Grand River.
5. Shared haplotypes of both species illustrate the inter-connectedness of the Chagrin and Grand River populations, and the lower genetic variability of L. tenuis between the two rivers is indicative of its greater dispersal capability.     

Ecology of <Emphasis Type="Italic">Leuctra geniculata</Emphasis> (Plecoptera: Leuctridae), an atlantomediterranean species on the north-eastern border of its area

The first records of Leuctra geniculata Stephens, 1836 in the north-eastern border of its area (the Czech Republic) are presented and an overview of references, synonyms and distribution of the species is given. The ecological preferences of the species, supported by chemical and hydromorphological parameters, are defined. Probable dissemination paths into the Czech Republic and the supposed life cycle of the species are discussed. Photographs of morphological characters, SEM photos of eggs, associated macroinvertebrate assemblages (EPT taxa) and maps of distribution are included.