Physical Habitat characterization of black flies was performed in the Tafna Basin of Algeria, based primarily on stream size, substrate, and aquatic and riparian vegetation. A total of 143 samples were taken between April and October 2009 at 11 sampling sites in the Tafna catchment. Dams exerted an effect through a slowdown of flow and sedimentation of fine particles, eliminating coarse microhabitats favorable for black flies. Stream and substrate characteristics are key parameters that determined the microhabitats of the species. Of 10 species considered, four were widely present with significant plasticity for the stream and substrate. Four other species were more closely associated with faster streams and eroded substrate. A greater rheophilic tendency was found for Simulium bezzii (Corti), Simulium sergenti Edwards, Simulium quadrifila Grenier, Faure and Laurent and Simulium galloprovinciale Giudicelli, which represents a new record for Algeria.

Twelve species of the genus Hydropsyche (Trichoptera) are reported from the Maghreb; six in Tunisia, eight in Morocco, and eleven in Algeria. These three North African countries are inhabited by common species, except that H. siltalai has been reported only from Algeria and H. pandiel only from Morocco. A list of Hydropsyche species known from the Maghreb is presented and a key for identification of described larvae of Maghreb Hydropsyche species is provided.

The main purpose of our paper is to document genus Hydropsyche (Trichoptera: Hydropsychidae) in northwestern Algeria and to provide the larval descriptions of the species set. Larvae, pupae, and imagines were collected from 14 sampling sites over a five-year period (2014–2019). Eight Hydropsyche species have been identified, with Hydropsyche siltalai being a new record for Algeria and North Africa, and Hydropsyche pellucidula a new record for Algeria. A comparison of our checklist with those of the Moroccan Rif and Europe is provided, as well as the geographical distribution of each species. This Algerian Hydropsyche species revision provides precise and reliable taxonomic characters for distinguishing larvae of the species, and a taxonomic key is proposed for their identification. In addition, information regarding their distribution is included.

The caddisfly fauna of Algeria is far from complete. In this study, we present data from Trichoptera sampling in northwestern Algeria (Tafna and Ghazouana River basins) during 2014–2019, enhancing knowledge of this group in the country. We were able to identify 30 species and 17 genera in the study area. Among the listed taxa, five species (Hydroptila fortunata, Ecnomus deceptor, Tinodes waeneri, Limnephilus lunatus, Setodes argentipunctellus,) are new records for Algeria. An updated species checklist of Algerian Trichoptera includes 63 species. We also provide an update of the Maghreb checklist with comments on species distributions. The Maghrebian caddisfly checklist, which includes 44 Maghrebian endemic species, is still very poor in relation to that of neighboring Mediterranean geographical areas and countries, such as the Iberian Peninsula (Spain and Portugal), France, or Italy.

In the cities of Algeria, Culex pipiens L. (Diptera: Culicidae) is the mosquito which presents most interest because of its wide geographical distribution and of its abundance which engender a strong nuisance. Besides, its role of vector of the virus West Nile arouses a particular interest in the Mediterranean Basin. These insects are generally controlled by conventional insecticides for the greater part, chemicals which cause in the long term side effects (effects on the not aimed bodies and the resistance of the aimed species). A research for the effect of the bioinsecticide Bacillus thuringiensis (granulated commercial shape in 200 IUT 1 /mg) was realized on préimaginales populations of the artificial deposits sites (taken directly of them natural the deposits sites) and cleansed populations (stemming from a breeding) having never been handled previously, taking into account local weather and physico-chemical conditions. Analyses of variance, allowed to determine the combined effect of the factor measure and of the factor time which by increasing, increase the efficiency of the product. The results of the rates of mortalities registered after treatment allowed to loosen the DL50 and the DL90 for every embryonic stage. From the results, we estimated the degree of sensibility of the larva populations of Culex pipiens which have proved heterogeneous in partial tolerance in Bacillus thuringiensis for the populations of the sensitive artificial and homogeneous the deposits sites for those stemming from the breeding.