Insecticide resistance is a major threat challenging the control of harmful insect species. The study of resistant phenotypes is, therefore, pivotal to understand molecular mechanisms underpinning insecticide resistance and plan effective control and resistance management strategies. Here, we further analysed the diflubenzuron (DFB)-resistant phenotype due to the point-mutation I1043M in the chitin-synthase 1 gene (chs1) in the mosquito Culex pipiens. By comparing susceptible and resistant strains of Cx. pipiens through DFB bioassays, molecular analyses and scanning electron microscopy, we showed that the I1043M-resistant mosquitoes have: (i) a striking level of DFB resistance (i.e., resistance ratio: 9006); (ii) a constitutive 11-fold over-expression of the chs1 gene; (iii) enhanced cuticle thickness and cuticular chitin content. Culex pipiens is one of the most important vector species in Europe and the rapid spread of DFB resistance can threaten its control. Our results, by adding new data about the DFB-resistant phenotype, provide important information for the control and management of insecticide resistance.

Microbial activity has been documented in various lacustrine environments, suggesting its fundamental role in mineral precipitation and, therefore, in the formation of organo-deposits such as microbialites. Many studies are currently focused on documenting how the association of microbes and extracellular polymeric substances (EPSs) may influence the authigenesis of Mg-rich clay minerals and the subsequent carbonate precipitation in growing microbialites in lacustrine environments. In this study, we investigate the present-day microbialites of the alkaline Bagno dell’Acqua lake (Pantelleria Island, Italy) using X-ray diffraction (XRD) scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Our results reveal the intimate association of Mg-smectite/carbonate minerals with the EPS and microbes, and, for the first time, we selected microbes belonging to phylum Firmicutes (Bacillus sp.), from natural microbialites, to carry out laboratory experiments that testify their direct role in the precipitation of clay and carbonate minerals.

Here, we report the discovery of silica- and sulfur-enriched deposits forming on the seafloor off Zannone Island (western Mediterranean Sea), where hydrothermal activity is ongoing. Our multidisciplinary investigation reveals that these deposits form through the interplay between hydrothermal processes and microbial activity. The deposits result from a dynamic equilibrium involving microbial mediation, sedimentation, and episodic lithification, driven primarily by two mineralization pathways: silica and sulfur precipitation. This study provides new insights into the bio-sedimentary processes shaping authigenic crusts in shallow submarine hydrothermal settings, contributing to a broader understanding of mineralization in marine environments influenced by both geological and biological factors.