Biodiversity Assessment of Chironomids (Diptera: Chironomidae) in Rajsamand Lake (Rajsamand, Rajasthan, India)

Present study was performed for taxonomic identification, assemblage, richness, spatial distribution and abundance analysis of chironomid larvae in the benthic and lentic shoreline habitat of Rajsamand Lake, India. Chironomids play an important role in shallow water aquatic ecosystems, so this study will give an idea about ecology of this area. Topographical and environmental factors are strongly correlated with the composition of chironomid communities. No information is available regarding these organisms in this defined area, so this study would provide data for comparison with chironomid community present in nearby and other ar ea, where study on chironomids is already done or will be done. This study on chironomids was conducted for the first time in Rajsamand Lake, India. Specimens were collected at seven sampling sites along shoreline of the Lake. A total of four genera (viz. Chironomus, Cryptochironomus, Einfeldia and Polypedilum) were reported. Polypedilum was the most dominant genus reported followed by Chironomus, Einfeldia and Cryptochironomus. Genus Cryptochironomus was reported for the first time in Rajasthan.

Corrigendum: Using DNA metabarcoding for assessing chironomid diversity and community change in mosquito controlled temporary wet-lands. MBMG 2: e21060. https://doi.org/10.3897/mbmg.2.21060

Chironomids have been proposed as important indicators for monitoring freshwater ecosystems, however, morphological determination is very challenging. In this study, we investigated the effectiveness of metabarcoding for chironomid diversity assessment and tested the retrieved chironomid operational taxonomic units (OTUs) for possible changes in relative abundance and species diversity in relation to mosquito control actions in four temporary wetlands. The biocide Bacillus thuringiensis var. israelensis (Bti) is widely applied for mosquito control in temporary wetlands of the German Upper Rhine Valley. Even though Bti is considered environmentally friendly, several studies have shown non-target effects on chironomids, a key food resource in wetland ecosystems Three of the studied wetlands were, for the first year after 20 years of Bti treatment, partly left Bti-untreated in a split field design, and one wetland has never been treated with Bti. Our metabarcoding approach detected 54 chironomid OTUs across all study sites, of which 70% could be identified to species level comparisons against the BOLD database. We showed that metabarcoding increased chironomid species determination by 70%. However, we found only minor significant effects of Bti on the chironomid community composition. Subsequent studies will have to address if and how the chironomid community composition might change in the now Bti-untreated temporary wetlands to assess effects of Bti.

Discovering a Resilient and Hyperdiverse Midge Fly Fauna in a Singaporean Swamp Forest.

Researchers uncover a highly unique and diverse chironomid community in a Singaporean swamp forest highlighting the importance of these ecosystems and the power of Next-Generation Sequencing for biomonitoring efforts.

Response of Chironomidae to environmental disturbances in a high mountain lake in Patagonia during the last millennium

Through the last millennium, Patagonia has been affected by changing climate conditions and successive volcanic eruptions. Lake Tonček is a high-altitude lake in the Southern Volcanic Zone in the northern Patagonian Andes. We documented the responses of the subfossil chironomid community to the effects of successive volcanic and different conditions in a sedimentary sequence from this lake comprising the last 900 years. The community composition and structure (abundance, diversity, and richness) and the development of morphological anomalies in the chironomid mouthparts were evaluated throughout the core. Both climatic conditions and volcanism affected the chironomid community differentially. The chironomid community changed following short-term climate change patterns, being affecting not only by temperature changes but also by variations in the regional precipitation regime. Decreases in abundance and diversity were only observed in coarse volcanic layers. In these samples, we recorded a high percentage of damaged chironomid mouthparts caused by mechanical wear, breakage or abrasion, possibly due to the increase of mineral particles. Our results represent important baseline data about the responses of chironomid communities to environmental disturbances in high-altitude lakes over long time frames.

Effects of Three Selected Pesticides on the Non-Biting Midges (Diptera: Chironomidae) in Rice Agro-Ecosystem of an area of West Bengal; India

Deformities of non biting midge larvae’s mouthparts are considered as indicators of environmental degradation that caused by water pollutants like pesticides, heavy metals, organic contaminants etc. The present investigation was aimed to assess the effects of 3 pesticides, viz. Cartap Hydrochloride, Carbofuran and Fipronil on deformities of chironomid larvae of the Rice fields of Village Dhunui; Memari Block-II of Burdwan district in West Bengal. The study area is dominated by the species of the genus Chironomus of chironomid community. Concurrently six (6) species were considered. The average percentage of mouthpart deformities was 14% in all chironomid larvae. Highest degree of malformation was noticed in Chironomus circumdatus in which more than 18.90% of all specimens were affected. However, further investigative efforts are essential to investigate the actual explanation in support of the occurrence of high degree of deformities in chironomid.