ABSTRACT
The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.
Subject(s)
Environmental Monitoring , Larva , Mining , Animals , Larva/growth & development , Insecta , Brazil , Water Pollutants, ChemicalABSTRACT
We describe here ten new species of Ochrotrichiinae from southern Peru in genera Metrichia (7 new species), Ochrotrichia (1 new species), and Rhyacopsyche (2 new species). In addition to describing and illustrating male genitalia of the new species, we also highlight diagnostic features from antennae, head setal warts, and wing venation. These structures have received little attention in taxonomic studies of Hydroptilidae, and we think they may be useful in future morphological studies involving the family. We also record O. puyana for the first time from Peru, which was previously known only from Ecuador. Comments on the distribution of the Peruvian Ochrotrichiinae are also provided, along with a distributional map and an updated checklist of the species recorded in the country. This work revealed a total of 56 species of Ochrotrichiinae from Peru.
Subject(s)
Holometabola , Insecta , Male , Animals , Peru , Animal DistributionABSTRACT
The adult male of a new species of the genus Polyplectropus Ulmer 1905a is described and illustrated based on specimens collected in Parque Nacional da Serra da Canastra, southeastern Brazil. Polyplectropus canastra sp. nov. can be distinguished from other Polyplectropus species by the shape of sternum IX, by the thumb-like mesolateral process of each preanal appendage, by the rectangular ventral branch of each inferior appendage in ventral view, and by the curved claw-like spines of the endothecal membrane. Among all species in the P. annulicornis Group, P. canastra is the only one with a bifid dorsolateral process of each preanal appendage and bearing spinules on the distal half of the rod-like lateral branch.
Subject(s)
Insecta/anatomy & histology , Insecta/classification , Animals , Brazil , Ecosystem , MaleABSTRACT
Three new species of Smicridea McLachlan 1871 are described and illustrated based on specimens collected in Parque Nacional da Serra da Canastra and its surrounding area, Minas Gerais state, southeastern Brazil. Smicridea (Rhyacophylax) necator sp. nov. possibly belongs to the S. (R.) dispar Group, but its placement in this group is weakly supported; S. (Smicridea) franciscana sp. nov. belongs to the S. (S.) nigripennis Group based on morphology of the phallus; S. (S.) sepala sp. nov. is a member of the S. (S.) fasciatella Group, also based on the morphology of the phallus. A new record of S. (S.) sattleri Denning & Sykora 1968 is provided for Minas Gerais state, Brazil.
