Two new records of flies causing myiasis from Saudi Arabia with a survey of flies parasitizing goats and sheep in Jazan Region.

Despite the medical, veterinary and forensic relevance of myiasis-causing flies, knowledge of their diversity in Saudi Arabia is limited especially in the southern region. Therefore, a survey of myiasis-causing flies in the Jazan region was carried out using Red Top Fly Catcher traps baited with either decomposing beef liver or a lure composed primarily from fishmeal during the period April 2013-March 2014. Twelve known species were identified and recorded in this study, seven species of them belonging to Calliphoridae (Chrysomya, Lucilia, and Hemipyrella) and five species belonging to Sarcophagidae (Sarcophaga). Two of these species were recorded for the first time for Saudi Arabia, namely Hemipyrella pulchra (Wiedemann, 1830) and Sarcophaga (Liosarcophaga) exuberans Pandellé, 1896. Images of the species recorded are also provided for the first time. The results expand the knowledge of geographical distribution, fauna, and habitat of the myiasis-causing flies in Saudi Arabia. Biological information and world-wide geographical distribution of these species are included together with some taxonomic remarks.

Two new records of flies causing myiasis from Saudi Arabia with a survey of flies parasitizing goats and sheep in Jazan Region

@#Despite the medical, veterinary and forensic relevance of myiasis-causing flies, knowledge of their diversity in Saudi Arabia is limited especially in the southern region. Therefore, a survey of myiasis-causing flies in the Jazan region was carried out using Red Top Fly Catcher traps baited with either decomposing beef liver or a lure composed primarily from fishmeal during the period April 2013-March 2014. Twelve known species were identified and recorded in this study, seven species of them belonging to Calliphoridae (Chrysomya, Lucilia, and Hemipyrella) and five species belonging to Sarcophagidae (Sarcophaga). Two of these species were recorded for the first time for Saudi Arabia, namely Hemipyrella pulchra (Wiedemann, 1830) and Sarcophaga (Liosarcophaga) exuberans Pandellé, 1896. Images of the species recorded are also provided for the first time. The results expand the knowledge of geographical distribution, fauna, and habitat of the myiasis-causing flies in Saudi Arabia. Biological information and world-wide geographical distribution of these species are included together with some taxonomic remarks.

Spatial distribution modeling of Stegomyia aegypti and Culex tritaeniorhynchus (Diptera: Culicidae) in Al-bahah Province, Kingdom of Saudi Arabia.

Dengue hemorrhagic fever and Rift Valley fever are the most important mosquitoborne diseases in the Kingdom of Saudi Arabia. The characteristic habitat requirements of Stegomyia aegypti and Culex tritaeniorhynchus, the two mosquito vectors will help in the identification of "high risk" areas in their development. Species distribution modelling was assessed by using MaxEnt software combined with geographical information systems (GIS) to predict suitable larval habitats for these two vectors and develop potential risk maps that can be used for their targeted control. Climate and topographical data layers from Worldclim and larval occurrence records were used to model these two vectors. The results showed that suitable habitats of St. aegypti are widely distributed only in the central region and Cx. tritaeniorhynchus were in the central and southwestern parts of Al-Bahah Province. The highest predictive power was shown by topographical variables in St. aegypti modeling and the minor contributions were shown by precipitation and temperature related variables. The maximum contribution was shown by temperature related variables and minor contribution was shown by topographical and precipitation related variables in Cx. tritaeniorhynchus modeling. Linear regression model indicates non significant correlation between TDS/pH and species abundance of these two mosquitoes.

Spatial distribution modeling of Stegomyia aegypti and Culex tritaeniorhynchus (Diptera: Culicidae) in Al-bahah Province, Kingdom of Saudi Arabia

Dengue hemorrhagic fever and Rift Valley fever are the most important mosquitoborne diseases in the Kingdom of Saudi Arabia. The characteristic habitat requirements of Stegomyia aegypti and Culex tritaeniorhynchus, the two mosquito vectors will help in the identification of “high risk” areas in their development. Species distribution modelling was assessed by using MaxEnt software combined with geographical information systems (GIS) to predict suitable larval habitats for these two vectors and develop potential risk maps that can be used for their targeted control. Climate and topographical data layers from Worldclim and larval occurrence records were used to model these two vectors. The results showed that suitable habitats of St. aegypti are widely distributed only in the central region and Cx. tritaeniorhynchus were in the central and southwestern parts of Al-Bahah Province. The highest predictive power was shown by topographical variables in St. aegypti modeling and the minor contributions were shown by precipitation and temperature related variables. The maximum contribution was shown by temperature related variables and minor contribution was shown by topographical and precipitation related variables in Cx. tritaeniorhynchus modeling. Linear regression model indicates non significant correlation between TDS/pH and species abundance of these two mosquitoes.

Ecology and habitat characterization of mosquitoes in Saudi Arabia.

The Kingdom of Saudi Arabia (KSA) contains many of the world's mosquito vectors of parasitic and arboviral diseases. However, few studies addressed their geographic distribution and larval habitat characteristics. We carried out a 14-months mosquito survey in three KSA regions: Makkah and Al-Baha (western) and Jezan (south-western). Larvae were collected by dipping from various water habitats and adults by CDC light and BG sentinel traps. Climatic conditions and physicochemical characteristics of collection sites were recorded. We collected a total of 3331 mosquitoes {larvae (n= 2766, 83%) and adults (n= 565, 17%)} of 21 species from six genera (8 Anopheles, 8 Culex, 1 Aedes and 3 others). Larval water habitats included streams, rocky pits, seepage, leakage and containers (plastic and concrete). Of the total larvae collected, 52% (n= 1439) were Anopheles, 44.3% (n= 1226) were Culex, 0.51% (n= 14) were Aedes aegypti and 3.1% (n= 87) were from four other species. The most abundant species were Culex tritaeniorhynchus (n=1008, ~36.3%) and Anopheles dthali (n= 976, ~35.3%). The medically-important species were Anopheles arabiensis (n= 128) and Anopheles sergenti (n= 58), vectors of malaria and Culex tritaeniorhynchus, Culex quinquefasciatus (n= 53) and Ae. aegypti (n= 14), vectors of arboviral diseases. Three species are new records in KSA and all from Jezan: Anopheles superpictus (n= 3), Culex duttoni (n= 1) and Culex mimeticus (n= 1), however the numbers were very low, which requires further investigations. Only two species were collected in the adult stage, Cx. quinquefasciatus (n= 561: 551 females and 10 males) from Makkah and Culex theileri (n= 4, all females) from Al-Baha. Only 3.8% (n= 21) of Cx. quinquefasciatus females were blood-fed. This study provides new information on the bionomics of 21 mosquito species in KSA including six dominant vector species and thus adds to the scarce data available on them. This information is essential to better understand mosquito population dynamics in relation to disease transmission and control.

Breeding habitats characterization of Anopheles mosquito (Diptera: Culicidae) in Najran Province, Saudi Arabia.

An ecological study on mosquito larval breeding habitats was conducted in Najran Region, Saudi Arabia during 2005-2006 to study the breeding habitats determinants for Anopheles mosquito in two ecological types (cities and villages). The increased rate of developmental activities promotes man-made mosquito breeding habitats, which regulate Anopheles mosquito abundance or absence. The linear regression analysis revealed that An. gambiae s.l. abundance or absence is regulated by the presence of natural water habitats, which has the highest rate (79%) in villages. Other ecological, biological and physiochemical predictors for Anopheles mosquito larvae abundance or absence in the two ecological types were discussed.

Distribution and seasonal activity of mosquitoes in al Madinah Al Munwwrah, Saudi Arabia.

In this study, 2654 adults and mosquito larvae, which belong to 18 species and 4 genera, were collected: Aedes (2 spp.), Anopheles (7 spp.), Culex (8 spp.) and Culiseta (1 sp.). They were Aedes caspius, Ae. aegypti, Anopheles. azaniae, An. d'thali, An. multicolor, An. rhodesiensis, An. stephensi, An. Sub-pictus, An. turkhudi, Culex laticinctus, Cx. perexiguus, Cx. pipiens, Cx. quin-quefasciatus, Cx. simpsoni, Cx. theileri, Cx. tritaeniorhynchus, Cx. univittatus and Culiseta longiareolata. A total of 2270 mosquito larvae were collected, and Culex spp. were the most abundant, where 1629 (71.76%) larvae were collected, followed by 499 (21.98%) Anopheles spp., 94 (4.14%) Aedes spp. and 48 (2.12%) Culiseta longiareolata. Of, 384 adult mosquitoes collected Culex spp. were the most abundant and 328 (85.42%) were collected, followed by 22 (5.73%) Aedes spp., 19 (4.94%) Anopheles spp. and 15 (3.91%) Culiseta longiareolata. The physical properties of the water in the breeding sites of mosquito larvae showed that pH of water varied between 6.9 & 9.9, the total dissolved salts (TDS) varied between 378-9504 ppm and water temperature varied between 8.7 degrees C in winter to 29.9 degrees C in summer. There was no correlation between pH & TDS of water in breeding site and distribution of larvae. The population density started to increase in March, with a peak in August when temperature was 36 degress C. The activity started to decrease in October, and minimum activity was in January, when temperature was below 5 degrees C. The seasonal abundance of adult mosquitoes was not affected by rainfall. A. aegypti, vector of Dengue fever virus, Cx. tritaeniorhynchus, vector of Rift Valley fever and Cx. univittatus, vector of sindbis virus were reported for the first time in Al Madinah Al Munawwrah Region. These vectors constituted a major health problem, and every effort should be made for feasible control.

Mosquito fauna (Diptera: Culicidae) and seasonal activity in Makka Al Mukarramah Region, Saudi Arabia.

From March 2004 to February 2006, a mosquito survey was conducted in Makka Al Mukarrama Region, in the western part of Saudi Arabia, and 19 species which belong to 4 genera, were collected: Aedes (2 species), Anopheles (8 species), Culex (8 species) and Culiseta (1 species). The mosquitoes were Aedes caspius, Ae. aegypti, Anopheles d'thali, An. gambiae, An. multicolor, An. rhodesiensis, An. sergenti, An. stephensi, An. subpictus, An. turkhudi, Culex arbieeni, Cx. laticinctus, Cx. pipiens, Cx. quinquefasciatus, Cx. sinaiticus, Cx. tigripes, Cx. tritaeniorhynchus, Cx. univittatus and Culiseta longiareolata. Cx. arbieeni was reported for the first time in Saudi Arabia from Al Taif District. The physical properties of water of mosquito's larval breeding sites showed the total dissolved salts (TDS) varied between 70-15552 ppm, pH ranged between 5.4-11.2 and water temperature varied between 15 degrees C in winter to 40.7 degrees C in summer. There was no correlation between these physical properties and the distribution of mosquito larvae. Light traps collected 1858 mosquitoes, and adult Culex were the most prevalent as 1658 (89.24%) were collected, followed by 121 (6.51%) Aedes, 68 (3.66%) Anopheles and 11 (0.59%) Culiseta. The effects of temperature and rainfall on seasonal abundance of mosquitoes in the study area are discussed.

The 2000 epidemic of Rift Valley fever in Saudi Arabia: mosquito vector studies.

In mid-September 2000, Rift Valley fever (RVF) virus was diagnosed as the cause of infection in humans and livestock in Jizan Region, Saudi Arabia. This is the first time that this arbovirus has been found outside Africa and Madagascar. Collections of mosquitoes (Diptera: Culicidae) were therefore undertaken (from 25 September to 10 October) at eight sites during the epidemic to obtain mosquitoes for attempted RVF virus isolation. Among 23 699 mosquito females tested, six isolations of RVF virus were made from 15 428 Culex (Culex) tritaeniorhynchus Giles and seven from 8091 Aedes (Aedimorphus) vexans arabiensis Patton [corrected]. Minimum mosquito infection rates per 1000 at sites with infected mosquitoes were 0.3-13.8 Cx. tritaeniorhynchus and 1.94-9.03 Ae. v. arabiensis. Viral activity moved northwards as collecting was in progress and collectors 'caught up' with the virus at the two most northerly sites on the last two trapping evenings. Other species occurred in small numbers and were identified but not tested. Both Cx. tritaeniorhynchus and Ae. v. arabiensis were susceptible to RVF virus and transmitted between hamsters, and an additional quantitative test with Cx. tritaeniorhynchus showed that 71-73% of mosquitoes became infected after ingesting 6.9-7.9 log10 FFU/mL of virus; transmission rates were 10% (post-infection day 14) and 26% (post-infection day 20). It was concluded that both species were vectors on grounds of abundance, distribution, preference for humans and sheep, the virus isolations and vector competence tests.

Rodents and their ectoparasites in Wadi Hanifah, Riyadh City, Saudi Arabia.

A survey was conducted on commercial and wild rodents from different locations in Wadi Hanifah in Riyadh. Six species of rodents were collected with wire net traps baited with fresh cucumber or fatty cheese. The trapped rodents in descending order of numbers were Rattus rattus rattus, Acomys dimidiatus, Meriones libycus, R. r. frugivorus, R. r. alexandrinus and Mus musculus. The ectoparasites were a flea, Xenopsyllus sp. on R. r. frugivorus and a tick, Rhipicephalus turanicus on each of A. dimidiatus and R. r. alexandrinus. In general, rodents and ectoparasites were low in Wadi Hanifah, probably due to the severe hot and very dry weather mainly in the summer season.

Efficacy of flumethrin and coumaphos against the camel tick Hyalomma dromedarii L. (Acari: Ixodidae).

The efficacy of Flumethrin pour on and Coumaphos 50% WP was tested against different stages of Hyalomma dromedarii. With contact method, LC50 values for larvae and adults were 0.04, 0.03 ug/cm2 and 0.05, 1.06 ug/cm2 respectively. The LC50 for coumaphos against the larvae, adults and eggs using dipping method were 44, 63, and 62 ppm respectively. Flumethrin caused significant reduction in oviposition and hatchability in female ticks that survived sublethal concentrations, while sublethal doses of coumaphos had no effect on the reproductive potential of the tick. The results showed that flumethrin was 8 times more toxic than coumaphos.

Seasonal infestation of Oestrus ovis larvae in sheep heads in central region of Saudi Arabia.

During a period of 12 months, 544 sheep heads were examined for infestation with Oestrus ovis larvae in Riyadh abattoir, Central Region of Saudi Arabia. The tested animals were males, less than one year old. The prevalence of infestation was 5.9%. The peak of infestation reached 23.3% in March 2000. The highest mean number of larva per infested sheep head in first, second and third instars larvae were 5, 7, and 5.3 respectively in spring months. A total for all instars being 4.3 larva per sheep head. All three stages disappeared in summer and winter months probably due to the very hot and dry weather.