Benthic macroinvertebrate communities of Lake Tanganyika tributaries in pristine, forested, and impacted, deforested, watersheds were examined. Samples were collected using a Surber-sampler, and identified under a dissecting microscope. Family biotic indices (FBI), percent of Ephemeroptera/Plecoptera/Trichoptera (%EPT), relative Chironomid abundance (RCA), and taxa richness of five impacted str...

The present work, based on material from northern, central-western, and northeastern Brazil, contributes to the knowledge of the two-winged Cloeodes Traver (Ephemeroptera: Baetidae) in South America. Two new species, C. maracatu, sp. nov. and C. spaceki, sp. nov., are described, the former based on nymphs and reared adults and the latter only on nymphs; the male and female imago of C. auwe and ...

The kinematics and hydrodynamics of free-swimming mayfly larvae (Chloeon dipterum) were investigated with the aid of a simple wake visualisation technique (tracer dyes) and drag measurements on dead insects. The basic swimming movement consists of a high-amplitude dorso-ventral undulation and, during continuous swimming, this produces a wake of ring vortices shed alternately to the dorsal and v...

Whole body Zn concentrations in individuals (n = 825) from three aquatic insect taxa (mayflies Rhithrogena spp. and Drunella spp. and the caddisfly Arctopsyche grandis) were used to predict effects on populations and communities (n = 149 samples). Both mayflies accumulated significantly more Zn than the caddisfly. The presence/absence of Drunella spp. most reliably distinguished sites with low ...

Ephemeral emergent insects, such as mayflies (Hexagenia spp.), are commonly used as biomonitors of persistent organic pollutants (POPs) and provide a vector for aquatic-terrestrial contaminant transfer. Mayflies bioaccumulate sediment-associated contaminants by bioconcentration and biomagnification during the aquatic stage and concentrate POP residues postemergence due to bioamplification, whic...

The male imago of Cloeodes irvingi Waltz & McCafferty, 1987 is described for the first time based on reared nymphs collected from the state of Pernambuco, northeastern Brazil. It is differentiated from Neotropical congeners, among other characteristics, by the marginal intercalary veins being paired, except between veins ICu1-ICu2 and ICu2-CuP where they are single and between Sc-R1 and CuP-A w...

Despite its wide, almost worldwide distribution, the mayfly genus Cloeon Leach, 1815 (Ephemeroptera: Baetidae) is restricted in the Western hemisphere to North America, where a single species is reported. In the Neotropics, except for some species wrongly attributed to the genus in the past, there are no records of Cloeon. Recently, however, specimens of true Cloeon were collected along the coa...

Analysis of a single kick sample from a 2 order stream in Guilford, NY of known water quality showed slight variation among three 100 fixed-count subsamples in calculating EPT Richness at family and genus level of taxonomic resolution. EPT (Ephemeroptera, Plecoptera and Trichoptera) richness of one subsample varied enough to assign the site to a water quality level below other subsamples when c...

We report new data about mayfly diversity from a 85 km area in East Kalimantan (Borneo, Indonesia). More than 40 mayfly genera have been collected in a lowland Dipterocarpaceae forest. They belong to the following families (by decreasing diversity order): Baetidae (12), Leptophlebiidae (7), Caenidae (6), Heptageniidae (5), Ephemerellidae (2), Potamanthidae (2), Teloganodidae (2), Isonychiidae (...

Most investigations of insect gas exchange patterns and the hypotheses proposed to account for their evolution have been based either on small-scale, manipulative experiments, or comparisons of a few closely related species. Despite their potential utility, no explicit, phylogeny-based, broad-scale comparative studies of the evolution of gas exchange in insects have been undertaken. This may be...