Survey study on mosquito (Diptera: Culicidae) in Amant Al-Asimah (Sana’a city)-Yemen

This study was conducted to know the common mosquito species in Amant Al-Asimah (Sana’a city) – Yemen, during the period from August 2018 to April 2019. Larvae mosquito were collected and identified to presence of two species in two genera. Culisetalongiareolata was more prevalence (98.1%) and well distributed in most districts of Amant Al-Asimah, while Culexpipiens was found with less prevalence (1.9%) and distributed in only four districts.Vectors of viruses and nematodes which caused different diseases were recorded in this study. Keyword: Yemen, Mosquito, Culisetalongiareolata, Culexpipiens and Vectors. Introduction Mosquitoes belong to Phylum Arthropoda, Class Insecta, Order Diptera and Family Culicidae, This family has a large and copious cluster that occurs throughout temperate and tropical regions of the world. Mosquitoes are most different and least known in tropical forest environments (1). Mosquitoes are the most medically important group of insects and worldwide distributed in most eco-systems. Some mosquitoes are responsible for the transmission of many important pathogens and parasites, such as viruses, bacteria, protozoans and nematodes which cause serious diseases to human and domestic animals. The most important genera of mosquitoes borne diseases pathogens are Aedes, Anopheles, Culex,Mansonie and Culiceta(11; 12and 13). Worldwide, there are over 4500 known species of mosquitoes belonging to113genera of Anophelinae (3 genera) and Culicinae (110 genera). The important genera are Aedes, Anopheles, Culex, Mansonie, Psorophora, Haemagogus, Sabethesand Culiseta (7; 8;9and19).The environments such as temperatures and high mountain areas, has resulted in altering factors affecting the vector fauna of the state. There are a few studies in Yemen for identifying mosquitos’ species such as Al-Maktariand Bassiouny. (3). Malaria vector, An. arabiensis, has been incriminated in Tihama region of Yemen and in Taiz region (2 and10). An. arabiensis has been identified by PCR as the only member of the An. gambiaecomplex from the collected specimens in Tihama and Taiz region (2 and 12 ). AlAzab et al. (1) recorded six species of mosquitoes that were cx. pipecas, cx. laticincitus, cx. tigripes, cx. mattinglyi, Ae. aegypti and Cs. longiareolata in Sana’a governorate, during 20152016. The aim of this work is to Identify the common mosquito species in Amanat Al-Asimah (Sana’a city) by using the traditional taxonomic key. Survey study on mosquito ...............Ebtehaj H. Al-Ajmi, Abbas Al-Azab,Mohammed Raweh Univ. Aden J. Nat. and Appl. Sc. Vol. 25 No.1 – April 2021 90 Materials and Methods: Study sites This study was carried out in different districts of Amanat Al-Asimah (Sana’a city) Yemen, geographically considered as High Mountains area. Sana'a is the capital city of Yemen, located at 2150 meter above sea level, located 15°70' 16°66' N, 33° 00' – 48° 50' E. The weather is cold in winter and moderate during summer. Mosquitoes larvae were collected from 21 sites belonging to nine districts of Amanat Al-Asimah(Sana’a city), Maeen(1), Al-Tahreer (1), Al-Thawrah (1), Shu'ub (6), Al-Wehdah (2), Al-Sabe'ein(1), old Sana’a (1), Bani Al-Hareth (5) and Al-Safyah (3) that were after rainfall season from August 2018 to April 2019, (Fig: 1 and 2). Preparing larvae for identification: Collected mosquitoes larvae were placed in glass tubes containing 80% ethanol. Mosquitoes larvae were dehydrated in a series of ascending ethanol (80%, 90% and 100%), cleared with xylene and mounted in D.P.X. Mosquitoes are reliably and usually identified as the 4 instar larvae (15and 18). Identification was based on their morphology characters by using different insect keys (5; 6; 14;16 and 17). This work was performed in the Department of Biology, Faculty of Science, Sana'a University. Fig. 1: Yemen Map showing Sana’a city.(Google earth). Survey study on mosquito ...............Ebtehaj H. Al-Ajmi, Abbas Al-Azab,Mohammed Raweh Univ. Aden J. Nat. and Appl. Sc. Vol. 25 No.1 – April 2021 91 Fig2: Districts of Amanat Al-Asimah (Sana’a city).(Yemen Remote Sensing). Result and Discussion The present study was conducted to know the prevalence of mosquitoes species, especially the species Ae. aegypti , in Amanat Al-Asimah (Sana’a city). The mature larvae (4 instar) were collected from different districts of Amanat Al-Asimah, after rainfall season from August 2018 to April 2019. A total of 2857 mosquitoes larvae were collected from 21 sites belonging to nine districts of Amanat Al-Asimah. Two species in two genera were identified, namely Culisetalongiareolata and Culex pipiens. Table (1) summarizes the abundance of mosquito species in different districts of Amanat Al-Asimah. The highest number of mosquito larvae was collected from Al-Sabe'ein district 1088 (38%), followed by Bani Al-Hareth544 (19.1%) and Shu'ub595 (13.8%), while the lowest collection 11 (0.4%) was recorded in Al-Thawrah district, followed by Al-Wahdah53 (1.2%) and Al-Safyah761 (5.8%).The highest collection of mosquito larvae was recorded in Al-Sabe'ein district (1088 larvae). This may be attributed to the presence of water for a long time following rain in Al-Sabe'ein damp which creates favorable and suitable conditions for mosquitoes breeding. On contrast, the total abundance of mosquito species in most districts was poor, this could be attributed to temporary pods in these districts holding water for 2 weeks or less fallowing rains, which make it unfavorable for mosquitoes breeding. Culiseta Longiareolata was more abundant (98.1%) and well distributed in different districts except in Al-Thawrah district, while Cu. pipiens was found with less abundant (1.9%) and was distributed in only four districts : Al-Sabe'ein, Al-Thawrah, Bani Al-Hareth and Old Sana’a. Survey study on mosquito ...............Ebtehaj H. Al-Ajmi, Abbas Al-Azab,Mohammed Raweh Univ. Aden J. Nat. and Appl. Sc. Vol. 25 No.1 – April 2021 92 Data in Table (1) indicate that Al-Sabe'ein district recorded the highest number of Cs. Longiareolata larvae (1077 (37.6%)), followed by Bani Al-Hareth( 533 (18.7%)) and Shu'ub( 395 (13.8%)), while the lowest number was recorded in Al-Wahdah district (53 (1.2%)), (Figure: 3). On the other hand, Cu. pipiens larvae were found with a low number in four districts. Old Sana’a recorded the highest number (21 (0.7%)), while the three rest districts had similar number of larvae (11 (0.4%)). Culex larvae were present in four districts with a fewer numbers sharing the other species Cs. Longiareolata of the same habitats in three districts. This finding is in agreement with the results 1 and4 . It is worth to noticing that occurrence of the two species at the same district was recorded only at three districts: , Al-Sabe'ein, Bani Al-Hareth and Old Sana’a (Figure: 4). Table 1: Abundance and distribution of mosquito species in different districts of Sana’a city after rainfall season from August 2018 to April 2019 No. Districts Number of sites Mosquito Species Culiseta longiareolata Culex pipiens 1 Al-Sabe'ein 1 1077 (37.6%) 11 (0.4%) 2 Al-Safyah 3 167 (5.8%) _ 3 Al-Tahreer 1 234 (8.2%) _ 4 Al-Thawrah 1 _ 11 (0.4%) 5 Al-Wahdah 2 34 (1.2%) _ 6 Bani Al-Hareth 5 533 (18.7%) 11 (0.4%) 7 Maeen 1 70 (2.5%) _ 8 Old Sana’a 1 293 (10.3%) 21 (0.7%) 9 Shu'ub 6 395 (13.8%) _ Total Nine districts 21 sites 2803 (98.1%) 54 (1.9%) Survey study on mosquito ...............Ebtehaj H. Al-Ajmi, Abbas Al-Azab,Mohammed Raweh Univ. Aden J. Nat. and Appl. Sc. Vol. 25 No.1 – April 2021 93 Fig. 3: Culiseta longiareolatalarva (posterior), A: Comb scale, B: Siphon with a single pair of seta and Pecten tooth, and C: head. A B


Introduction
Mosquitoes belong to Phylum Arthropoda, Class Insecta, Order Diptera and Family Culicidae, This family has a large and copious cluster that occurs throughout temperate and tropical regions of the world. Mosquitoes are most different and least known in tropical forest environments (1). Mosquitoes are the most medically important group of insects and worldwide distributed in most eco-systems. Some mosquitoes are responsible for the transmission of many important pathogens and parasites, such as viruses, bacteria, protozoans and nematodes which cause serious diseases to human and domestic animals. The most important genera of mosquitoes borne diseases pathogens are Aedes, Anopheles, Culex,Mansonie and Culiceta (11; 12and 13). Worldwide, there are over 4500 known species of mosquitoes belonging to113genera of Anophelinae (3 genera) and Culicinae (110 genera). The important genera are Aedes, Anopheles, Culex, Mansonie, Psorophora, Haemagogus, Sabethesand Culiseta (7; 8;9and19).The environments such as temperatures and high mountain areas, has resulted in altering factors affecting the vector fauna of the state.
There are a few studies in Yemen for identifying mosquitos' species such as Al-Maktariand Bassiouny. (3). Malaria vector, An. arabiensis, has been incriminated in Tihama region of Yemen and in Taiz region (2 and10). An. arabiensis has been identified by PCR as the only member of the An. gambiaecomplex from the collected specimens in Tihama and Taiz region (2 and 12 ). Al-Azab et al. (1) recorded six species of mosquitoes that were cx. pipecas, cx. laticincitus, cx. tigripes, cx. mattinglyi, Ae. aegypti and Cs. longiareolata in Sana'a governorate, during 2015-2016.
The aim of this work is to Identify the common mosquito species in Amanat Al-Asimah (Sana'a city) by using the traditional taxonomic key.

Preparing larvae for identification:
Collected mosquitoes larvae were placed in glass tubes containing 80% ethanol. Mosquitoes larvae were dehydrated in a series of ascending ethanol (80%, 90% and 100%), cleared with xylene and mounted in D.P.X. Mosquitoes are reliably and usually identified as the 4 th instar larvae (15and 18). Identification was based on their morphology characters by using different insect keys (5; 6; 14;16 and 17). This work was performed in the Department of Biology, Faculty of Science, Sana'a University.

Result and Discussion
The present study was conducted to know the prevalence of mosquitoes species, especially the species Ae. aegypti , in Amanat Al-Asimah (Sana'a city). The mature larvae (4 th instar) were collected from different districts of Amanat Al-Asimah, after rainfall season from August 2018 to April 2019. A total of 2857 mosquitoes larvae were collected from 21 sites belonging to nine districts of Amanat Al-Asimah. Two species in two genera were identified, namely Culisetalongiareolata and Culex pipiens. Table (1) summarizes the abundance of mosquito species in different districts of Amanat Al-Asimah. The highest number of mosquito larvae was collected from Al-Sabe'ein district 1088 (38%), followed by Bani Al-Hareth544 (19.1%) and Shu'ub595 (13.8%), while the lowest collection 11 (0.4%) was recorded in Al-Thawrah district, followed by Al-Wahdah53 (1.2%) and Al-Safyah761 (5.8%).The highest collection of mosquito larvae was recorded in Al-Sabe'ein district (1088 larvae). This may be attributed to the presence of water for a long time following rain in Al-Sabe'ein damp which creates favorable and suitable conditions for mosquitoes breeding. On contrast, the total abundance of mosquito species in most districts was poor, this could be attributed to temporary pods in these districts holding water for 2 weeks or less fallowing rains, which make it unfavorable for mosquitoes breeding. Culiseta Longiareolata was more abundant (98.1%) and well distributed in different districts except in Al-Thawrah district, while Cu. pipiens was found with less abundant (1.9%) and was distributed in only four districts : Al-Sabe'ein, Al-Thawrah, Bani Al-Hareth and Old Sana'a. Table (1) indicate that Al-Sabe'ein district recorded the highest number of Cs. Longiareolata larvae (1077 (37.6%)), followed by Bani Al-Hareth( 533 (18.7%)) and Shu'ub( 395 (13.8%)), while the lowest number was recorded in Al-Wahdah district (53 (1.2%)), (Figure: 3). On the other hand, Cu. pipiens larvae were found with a low number in four districts. Old Sana'a recorded the highest number (21 (0.7%)), while the three rest districts had similar number of larvae (11 (0.4%)). Culex larvae were present in four districts with a fewer numbers sharing the other species Cs. Longiareolata of the same habitats in three districts. This finding is in agreement with the results 1 and4 .

Data in
It is worth to noticing that occurrence of the two species at the same district was recorded only at three districts: , Al-Sabe'ein, Bani Al-Hareth and Old Sana'a ( Figure: 4).