We present a de novo transcriptome of the mosquito vector Culex pipiens, assembled by sequences of susceptible and insecticide resistant larvae. The high quality of the assembly was confirmed by TransRate and BUSCO. A mapping percentage until 94.8% was obtained by aligning contigs to Nr, SwissProt, and TrEMBL, with 27,281 sequences that simultaneously mapped on the three databases. A total of 14,966 ORFs were also functionally annotated by using the eggNOG database. Among them, we identified ORF sequences of the main gene families involved in insecticide resistance. Therefore, this resource stands as a valuable reference for further studies of differential gene expression as well as to identify genes of interest for genetic-based control tools.

Research on the urban malaria vector Anopheles stephensi has intensified in recent years following its rapid spread throughout the Horn of Africa and beyond. In addition to behavioural and ecological traits which may limit the efficacy of control efforts, insecticide resistance is a notable problem in invasive An. stephensi populations. The most frequently used laboratory reference strain for An. stephensi is SDA500 originally colonized from Pakistan; though considered insecticide susceptible, quantitative demonstration of this crucial assumption is lacking. We characterized the susceptibility status of SDA500 against multiple insecticide classes used for adult and larval control using the standard WHO techniques for larval bioassays and two alternatives for adults: bottle bioassays and glazed tile bioassays. SDA500 showed full susceptibility against all insecticides tested, and via dose-response assays, we provide the first comprehensive LC₅₀ dataset for a strain of An. stephensi, filling a key knowledge gap and providing an important resource for all future studies of resistance in this important malaria vector. Whilst tile and bottle adult bioassays produced broadly comparable results for both SDA500 and additional laboratory strains, differences were found when testing neonicotinoids and butenolides, which require the addition of the compound MERO® for effectiveness. Nevertheless, the glazed tile bioassay represents a much higher throughput and less resource-intensive technique than bottle bioassays for simultaneous screening of multiple insecticides.