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Stoneflies (Plecoptera) have complex mating behaviour, but little is known about the species Capnia atra, which is considered rare in both Britain and Ireland given its optimal range in the circumpolar region. Observations of post mating behaviour in non-receptive females, which only mate once, and their conspecific males, was found to differ between British and Irish populations. In the British population non- receptive females were able to communicate effectively with the male, ensuring secondary mating did not occur. In contrast, Irish male C. atra actively attempted to mate with the non-receptive female resulting in a 'rolling ball' as the female manoeuvred her abdomen constantly to avoid copulation. Phenological and ecological variation, previously noted for the species, has likely enabled it to survive well outside its optimal circumpolar range. [ABSTRACT FROM AUTHOR]

A population of the caddisfly Setodes argentipunctellus McLachlan, 1877 (Trichoptera: Leptoceridae) is reported from the West of Ireland at Ross Lake, Co. Galway. The species was previously known only from two lakes in the Killarney district in the south-west of the island. [ABSTRACT FROM AUTHOR]

We report the presence of the North American Crangonyx floridanus co-occurring with C. pseudogracilis in two Irish rivers, following surveys in three rivers, eleven lake sites and an ornamental pond in 2020. This is the first record of C. floridanus in Ireland which was previously recorded in Britain in 2017. We predict that this species is likely to expand its range through the river and canal connections in Ireland as well as from inadvertent anthropogenic transmission. The taxonomic criteria are cryptic and for this reason, we used genetic methods to distinguish the two species in this study. The results highlight the need to investigate the distribution and impact of these two species in freshwater habitats in Ireland. [ABSTRACT FROM AUTHOR]

The article discusses brachyptery in stoneflies has well known, with adults having slightly shortened wings and occasionally very shortened or vestigial wings. Topics include the wings of emerging adult stoneflies inflate, expand, dry and strengthen, irrespective of size or polymorphism; and adults of species have been observed with severe wing crumpling, un-associated with normal observed polymorphism.

The Water Framework Directive requires all EU Member States to improve, sustainably manage and protect water quality in all surface waterbodies. To achieve this goal the ecological status of all our streams, rivers and lakes must be assessed against type-specific reference conditions. A number of distinctive or rare river types were not adequately represented in the development of the existing national river typology in 2005, and so it is not known whether they are sufficiently characterised by the current 12-type river typology or represent distinct types. ‘Rare’ in this context refers to systems with a naturally variable or unusual combination of environmental conditions (e.g. naturally low pH) rather than a limited distribution. The rare or distinctive river types highlighted were: (1) groundwater-dominated rivers; (2) highly calcareous rivers with calcium precipitation; (3) low conductivity, naturally acidic rivers; and (4) rivers strongly influenced by lakes (lake outlets). Whether or not these river types host distinct biological communities has yet to be established. While there is a large body of research on the macroinvertebrate communities, research on other biological quality elements such as diatoms is limited. This paper summarises the literature available on the biological characteristics of these rare or distinctive river types. [ABSTRACT FROM AUTHOR]