Search results for "Midge"

The chronic effects of fullereneC 60 -associated sediments in the midge Chironomus riparius – Responses in the first and the second generation

2017

Abstract The life cycle parameters of the benthic invertebrate Chironomus riparius make it a relevant organism for use in multi-generation chronic ecotoxicology tests. Since studies on chronic exposures with fullerene carbon nanoparticles have revealed adverse effects at lower concentration ranges, it is crucial to gain understanding of the consequences in following generations. The aims of this study were to investigate whether sediment-associated fullereneC 60 impacts on C. riparius emergence and breeding, thus affecting the growth of the second generation. Larvae were exposed to fullerene-spiked sediment at concentrations of 0.5, 10 and 40 mg/kg sediment dw. Total emergence and breeding …

Rapid adaptation to high temperatures in Chironomus riparius

2018

AbstractEffects of seasonal or daily temperature variation on fitness and physiology of ectothermic organisms and their ways to cope with such variations have been widely studied. However, the way multivoltines organisms cope with temperature variations from a generation to another is still not well understood and complex to identify. The aim of this study is to investigate whether the multivoltine midgeChironomus ripariusMeigen (1803) responds mainly via acclimation as predicted by current theories, or if rapid genetic adaptation is involved. To investigate this issue, a common garden approach has been applied. A mix of larvae from five European populations was raised in the laboratory at …

Rediscovery and identity of Pumilomyia protrahenda De Stefani (Diptera, Cecidomyiidae) in Sicily with redescription and reassessment of its taxonomic…

2016

Abstract A population of the gall midge Pumilomyia protrahenda De Stefani, 1919 causing galls on Artemisia arborescens (Asteraceae) was discovered near Palermo (Sicily) in 2008. This species had not been found since 1918. Detailed study of morphological characters of adults, larvae and pupae revealed that Pumilomyia protrahenda belongs to the genus Rhopalomyia Rübsaamen, 1892, tribe Rhopalomyiini. The monotypic genus Pumilomyia De Stefani, 1919 is therefore synonymized under Rhopalomyia Rübsaamen, 1892. Rhopalomyia protrahenda comb. n. is redescribed, with important morphological characters illustrated. Adults have one-segmented palpi, antennae with 12–13 short flagellomeres and long legs w…

Vertical sediment migrations of dominant midge species in subtropical lakes with implications for bioassessment

2018

Abstract Propsilocerus akamusi (Diptera: Chironomidae) is a dominant species in numerous eutrophic lakes and they could burrow into deep sediments (>30 cm) during summer months. However, common-used grab samplers are efficient in collecting surface-dwelling species (

Development and localization of microsatellite markers for the sibling species Chironomus riparius and Chironomus piger (Diptera: Chironomidae)

2006

Five variable microsatellite loci are reported for the nonbiting midge species Chironomus riparius and Chironomus piger. All loci show considerable intraspecific variation and species-specific alleles, which allow to discriminate among the two closely related species and their interspecific hybrids, and to estimate genetic diversity within and between populations. Additionally, the loci were localized on C. riparius polytene chromosomes to verify their single copy status and investigate possible chromosomal linkage. The described markers are used in different studies with regard to population and ecological genetics and evolutionary ecotoxicology of Chironomus.

Characterization of two globin genes from the malaria mosquito Anopheles gambiae: Divergent origin of nematoceran haemoglobins

2007

The chironomid midges are the only insects that harbour true haemoglobin in their haemolymph. Here we report the identification of haemoglobin genes in two other nematoceran species. Two paralogous haemoglobin genes (glob1 and glob2) from the malaria mosquito Anopheles gambiae were cloned and sequenced. Furthermore, we identified two orthologous haemoglobin genes in the yellow fever mosquito Aedes aegypti. All four haemoglobins were predicted to be intracellular proteins, with the amino acids required for heme- and oxygen-binding being conserved. In situ-hybridization studies showed that glob1 and glob2 expression in An. gambiae is mainly associated with the tracheal system. This pattern re…

Effects of Activated Carbon on PCB Bioaccumulation and Biological Responses of Chironomus riparius in Full Life Cycle Test

2016

The nonbiting midge Chironomus riparius was used to study the remediation potential and secondary effects of activated carbon (AC, ø 63-200 μm) in PCB contaminated sediments. AC amendments efficiently reduced PCB bioavailability determined by Chironomus riparius bioaccumulation tests and passive samplers. PCBs were shown to transfer from larvae to adults. Lower PCB concentrations were observed in adult midges emerging from AC amended compared to unamended sediments. Increased reproduction, survival, larval growth and gut wall microvilli length were observed with low AC dose (0.5% sediment dw) compared to unamended sediment, indicating an improved success of larvae in the sediment with low o…

Neonicotinoids from coated seeds toxic for honeydew-feeding biological control agents

2021

Seed coating (‘seed treatment’) is the leading delivery method of neonicotinoid insecticides in major crops such as soybean, wheat, cotton and maize. However, this prophylactic use of neonicotinoids is widely discussed from the standpoint of environmental costs. Growing soybean plants from neonicotinoid-coated seeds in field, we demonstrate that soybean aphids (Aphis glycines) survived the treatment, and excreted honeydew containing neonicotinoids. Biochemical analyses demonstrated that honeydew excreted by the soybean aphid contained substantial concentrations of neonicotinoids even one month after sowing of the crop. Consuming this honeydew reduced the longevity of two biological control …

CYNIPIDAE, CURCULIONOIDEA E CECIDOMYIIDAE GALLIGENI IN SICILIA: STATO DELLE CONOSCENZE E NUOVI DATI

Complete Nucleotide Sequence of a Hemoglobin Gene Cluster from the Midge Chironomus thummi piger

1991

The aquatic larvae of non-biting midges (Chironomidae, Diptera) contain a variety of Hb proteins in their hemolymph that enable them to survive in an anoxic environment (1). In Chironomus thummi thummi, 12 different Hb variants have been identified and their amino acid sequences determined (2). Based on these primary structures, the evolutionary relationships between the five monomeric and the s e v e n dimeric Hb proteins have been deduced (2). The two groups are thought to have evolved in two different lineages which separated more than 255 million years ago.