[Culicidae Larvae and Their Seasonal Dynamics in the Region of Fez-Meknes, Morocco]

Objective

As part of the prevention of vector-borne diseases in central Morocco, a study of the seasonal fluctuation of Culicidian biodiversity was conducted from November 2015 to November 2016 on four breeding sites located in the city of Fez in central Morocco (Jnan El Alami, Lgaâda dam, Awinat Elhajaj, Douwar Lhandiya Source). The study aimed to improve the knowledge of seasonal dynamics and activity period of Culicidian mosquitoes, in order to target the period of control.

Methods

Larvae were collected by dipping method at a 15-day interval at least once a month. Statistical analyses were performed using version 3.6.1 of the statistical processing software.

Results

During this study, nine species were found with high monthly and seasonal variations in numbers of each species and from site to site. Predominant species are vectors of disease: Culex pipiens, Cx. perexiguus, Cx. theileri, known vectors of West Nile virus, followed by Anopheles maculipennis s. l. and An. sergentii that are the main vectors of malaria in Morocco. Cx. pipiens and Cx. perexiguus reached the highest density in September, while Cx. theileri was found in large numbers in February and can therefore emerge in late winter and mid-spring. The lowest number of An. sergentii was collected in November, but increased in September, October and December. An. maculipennis s. l. occurred in June, with recurrences in March and July. Culiseta longiareolata was found in spring and summer and in abundance in June. However, Uranotaenia unguiculata was only present in September and October. Both An. cinereus and Cx. hortensis were present in November and February.

Conclusion

The results obtained will be an important tool for management and monitoring Culicidae proliferation and can be used to improve the efficiency of control management.

Quantitative Inventory of Mosquito Larvae (Diptera: Culicidae) and Physicochemical Analysis of Aquatic Habitats in the Region of Fez, Morocco

Mosquitoes occupy a major health problem, as a potential vector for the transmission of many pathogens, the most important of which in Morocco are Plasmodium parasites and West Nile fever virus. Acquiring knowledge about the biotypology of these mosquitoes is an essential step in any control strategy. Thus, the objective of this study is to draw up an inventory of the culicidian fauna in the Fez region (North-central part of Morocco) and to determine the physicochemical parameters influencing the production of mosquito larvae of aquatic habitats in this area. Mosquito larvae of the extant biotopes were sampled every two months between November 2015 and December 2016, by means of the "dipping" method. The physicochemical parameters of the various larval biotopes were collected six times during the year of follow-up. Mosquito species were identified using morphological criteria. The results were analyzed using ecological indices and the generalized linear model (Poisson model) on R software. The identification of the 1,122 mosquito larvae collected from the various studied breeding areas revealed the presence of 11 species belonging to two subfamilies (Culicinae and Anophelinae) and five genera (Anopheles, Culex, Culiseta, Aedes, and Uranotaenia). Anopheles were observed in small numbers in permanent, stagnant, and shallow habitats. The larvae of An. maculipennis s. l. (major vector of malaria in Morocco) were collected. Culex larvae, especially Cx. pipiens (the main vector of WNV in Morocco), were collected in the majority of the larval habitats and on the different types of environments. Two other species of Culex, which plays a significant role in the transmission of WNV, were also collected, particularly, Cx. perexiguus and Cx. theileri. The results found, via this first study of its kind at the regional level, also made it possible to update the list of Culicidae species reported in the Fez region. Four new species have been recorded: Aedes flavescens, Uranotaenia unguiculata, Culiseta longiareolata, and Culex perexiguus. The results of this study will contribute to the provision of information for entomological surveillance and to better plan and guide vector control activities at local and national levels.