Diet of Phylloicus (Trichoptera: Calamoceratidae) caddisfly larvae in forest streams of western Pará, central Brazilian Amazonia

Abstract

Aim The aquatic larvae of the Phylloicus (Trichoptera: Calamoceratidae) caddisflies are typical shredders. However, the trophic classification of Phylloicus has been based on the morphology and behaviour of the larvae. The aim of this study was to investigate the diet of caddisfly larvae Phylloicus in streams. Methods In order to provide a more reliable classification of Phylloicus diet, we analyzed the stomach contents of 185 larvae collected, sampled with D-frame entomological net from 18 streams located in the tropical forests of western Pará, Brazil. We compared the stomach contents between the larval stages, seasons (dry and rainy), and substrates (i.e., sand, leaf litter, roots, clay and mixed substrates). Results We identified the stomach contents as fine particulate organic matter (FPOM), coarse particulate organic matter (CPOM) and plant tissue. The diet of the Phylloicus larvae was composed basically of FPOM, independent of the larval stage (90,4%), was a higher consumption of FPOM in the dry season and there were no significant differences in food resource between substrates. Conclusions These findings indicate that the classification of Phylloicus as a shredder may in fact be based on the processing of leaves for the building of larval cases, rather than the diet, which is in fact detritivorous, enjoying the availability of FPOM in the streams. The great quantity of FPOM consumed by caddisfly larvae Phylloicus highlight the importance of this food resource for macroinvertebrate communities from tropical streams. Therefore, regional studies of feeding habits are needed for accurate classification trophic of Phylloicus.

Diversity and enzymatic capabilities of fungi associated with the digestive tract of larval stages of a shredder insect in Cerrado and Amazon Forest, Brazil

“…It is highly probable that the set of Triplectides larvae collected belonged to a narrower group of species. Studies (Clair, 1994;Pimentel et al, 2020) report both Phylloicus and Triplectides as little selective and the availability of food items is the greatest influence on their diet. Phylloicus are detritivores, being shredders only for breaking down leaves for shelter construction (Pimentel et al, 2020), another explanation for the higher diversity of fungi in DT of this genus as compared to Triplectides.…”

Odonata, Coleoptera, and Heteroptera (OCH) Trait-Based Biomonitoring of Rivers within the Northwestern Rif of Morocco: Exploring the Responses of Traits to Prevailing Environmental Gradients

“…Several taxa showed higher frequencies in specific substrates, which are related to the nature of the occupied substrate, water flow speed, and food resource type. For example, Progomphus (Odonata) has been reported to be associated with sandy substrates, and this genus' nymphs burrow and are adapted to prey on other animals buried in the sandy substrate [84,85], a pattern that has been reported to be linked to the substrate's characteristics and the feeding resource type it contains [86].…”

Do Methodological Differences in Experiments with Stream Shredders Imply Variability in Outputs? A Microcosm Approach

“…ii) Shredders with a case have higher consumption and survival rates because removing the case can cause stress due to impaired thermal regulation and respiration (Houghton et al 2014). However, the oxygen levels will not affect shredder consumption or survival, as these organisms are abundant in pools and backwaters in forested streams with high dissolved oxygen (range to 6.8 mg/L; Martins et al 2015;Pimentel et al 2020;Firmino et al 2021) but can also be found in urban streams with low dissolved oxygen (e.g., 2.6 mg/L; Martins et al 2017b). iii) Shredders have higher consumption and survival rates in microcosms with stream water than bottled water due to the similarity of the water characteristics to their natural environment.…”