From an eco-epidemiological point of view, the province of El Hajeb constitutes a very interesting field of study because of its geographical proximity to the epidemic foci of cutaneous leishmaniasis in the provinces of Sefrou , Moulay Yacoub  and Fes-Boulomane . Similarly, no entomological study has been carried out to determine the composition of the existing phlebotomine fauna despite the presence of indigenous cases of leishmaniasis in this region .
It is within this framework that the present study was carried out to identify the species of sandflies circulating in the province and those vectors of leishmaniasis. Thus, our results offer for the first time the inventory of the sand fly fauna in the region and give information on its biodiversity and its periods of activity during the year. These data are necessary to guide the actions and periods of vector control.
In Morocco, 24 species of sandflies have been described, five of which are known to transmit leishmaniasis, a public health problem . These are P. papatasi, the vector of cutaneous leishmaniasis caused by L. major in the South and South-East of the country [3, 26, 27]. The P. sergenti is responsible for the transmission of cutaneous leishmaniasis to L. tropica where most of the recorded cases are notified in the center of the kingdom [27, 28]. The three species are P. perniciosus, P. ariasi and P. longicuspis which have been proven to be vectors of severe forms of the disease including visceral leishmaniasis with L. infantum where most cases have been reported in the north [3, 29].
In our study, 12 species were identified which represents 50% of the Moroccan sand fly species. Indeed, the five vector species of the disease were found in this study, they represent 91.6% of the sandflies identified in 83% of the sites surveyed (5/6). Also, the analysis of the results obtained showed that there is cohabitation between 3 species: P. papatasi, P. sergenti and P. longicuspis. Although the province of El Hajeb is located in the center of Morocco, this coexistence was also found by Ouanaimi and colleagues  in their study conducted in the south and north of the country.
In terms of individuals collected, the abundance of sandflies was very high compared to the low incidence of leishmaniasis recorded in the said province . This finding has been revealed by other studies in other regions of Morocco [30, 31, 32, 33]. This can be explained by the words of Ouanaimi et al,  who state that leishmaniasis in Morocco is determined by the ecology of the parasite rather than the distribution of the vector.
Concerning the species identified, they belong to two genera: Phlebotomus and Sergentomyia. The species of the first genus belong to three subgenera: Phlebotomus (P. papatasi and P. bergeroti), Paraphlebotmus (P. sergenti and P. alexandri) and Larroussius (P. longicuspis, P. ariasi and P. perniciosus). While the species of the second genus belong to two sub-genus: Sergentomyia (S. minuta, S. schwetzi, S. fallax and S. antennata) and Grassomyia (S. dreyfusi).
For species of the genus Phlebotomus, 79.7% of the identified sand flies were P. longicuspis, this species was the most abundant in our area, it was collected during the whole period and in the six localities studied with a pattern of three peaks, the first in July, the second in September and the third in November. On the other hand, the long period of activity and high abundance of this confirmed VL vector species is threatening and indicates the potential risk of transmission of the visceral form in the said province. These results corroborate with the study of Al-Koleeby et al, (2021)  and Guernaoui et al, (2005)  in one part where the most important peak is located in September and diverges in the other part where this species can show a pattern of a single peak as the case of Chichaoua (35) or with a pattern of two peaks as the case of Zagora province . And even, it can show a pattern of three peaks as in our study. This difference can be explained by the ability of P. longicuspis to adapt to the environmental conditions of each region. In addition, 53% of this species were captured in the locality of Aït Oufella whose altitude is 581 m. In this context, Guernaoui et al (2006)  showed that this species is very abundant between the altitudes of 600 m and 799 m.
The species P. sergenti was encountered in all stations and its period of activity extends from April to November with a bimodal pattern, the first in June-July and the other in September. Our results confirm those found in the province of Fez  which revealed that the seasonal activity of this species is bimodal. This can be explained by the climatic and geographical conditions of the province of El Hajeb which are similar to its neighbor Fez.
Concerning P. perniciosus, it should be noted that the majority of specimens identified were found in their typical form. This species was captured from April to November and its seasonal trend reflects a bimodal pattern with two peaks. This corroborates with the results of Talbi in Sefrou .
As for the species P. Papatasi as a proven vector of L. major especially in southern Morocco and which has long been considered adapted to the arid climate , also proves to be adapted to the temperate climate that prevails in the center of the country since our results show its presence from April to November with two peaks and in the majority of the stations (5/6). This result was also revealed by studies carried out in the neighboring provinces of our study site of El Hajeb where it was also collected from April to November .
From another perspective, sandflies of the genus Sergentomyia prefer, according to Boussaa et al, , altitudes between 800 m and 1000 m. Similarly, Guernaoui et al, (2006)  state that only the species S. minuta persists at altitudes of 1200 m to 2000 m. This was confirmed in our study, particularly in the station of Aït Naaman which is located at an altitude of 1150 m and whose inventory of sand flies captured in this station revealed that the most abundant species belonging to the genus Sergentomyia notably S. minuta which represents 65.9%. Its period of activity extends from April to November with a bimodal pattern in two peaks, the most important in August. In this framework, it is very useful to point out that the selection of the station of Aït Naaman was carried out to compare the fauna of this station where no case of leishmaniasis was declared with the other stations. These results confirm, therefore, the words of experts who argue that the species of the genus Sergentomyia are not yet proven to be involved in the transmission of leishmaniasis [1, 3, 6]. Nevertheless, the absence of leishmaniasis cases should not eliminate the potential risk of transmission since the vector species of L. infantum (P. longicuspis and P. sergenti) were also found.
In summary, this entomological survey around the sand fly carried out in the province of El Hajeb in central Morocco has provided both information on the circulating sand fly fauna in the region and an opportunity to enrich the Moroccan inventory. The sandfly is popularly known by the name "Chniwla" [11, 38]. However, despite the abundance of this insect on the national territory and the recrudescence of cutaneous and visceral leishmaniasis cases declared each year, sand flies are poorly known and their vectorial capacities to transmit these diseases are underestimated by citizens and even health professionals . Vector control strategies must be implemented with emphasis on improving the knowledge of the population and health professionals on sand flies and the means of protection and prevention of health risks.