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Abstract SUMMARY Al Rabta in the North-West of Libya is a rural area where the cutaneous leishmaniasis (CL) is endemic for long time. Few reports are available on sand flies in this area. Therefore, this study aimed at identifying and updating the sand fly species composition, monthly abundance, effect of weather conditions on fly abundance and P. papatasi density-reported CL cases relationship. Sand flies were biweekly collected by CDC light traps from June to November 2012 and April to November 2013 in two villages, Al Rabta East (RE) and Al Rabta West (RW). The following are the main topics examined in this study: ECOLOGICAL STUDIES ON SAND FLIES A. SPECIES COMPOSITION: Nine sand fly species (6 Phlebotomus and 3 Sergentomyia) were reported in the two study villages: P. papatasi, P. sergenti, P. alexandri, P. chabaudi, P. longicuspis, P. langeroni, S. minuta, S. antennata and S. fallax. B. RELATIVE ABUNDANCE: A total of 5605 and 5446 flies were collected in RE and RW, respectively during the two year period. S. minuta (24.6 and 28.3% in RE and RW, respectively) and P. papatasi (22.6 and 21.6% in RE and RW, respectively) were the abundant species. These were followed in descending order of abundance by: S. fallax, P. longicuspis, P. alexandri, P. sergenti and P. chabaudi. Both P. langeroni (1.7 and 1.5% in RE and RW, respectively) and S. antennata (1.1 and 0.7% in RE and RW, respectively) were rare. C. COMPARISON OF FLY DENSITIES IN THE TWO VILLAGES: In general, densities of all sand fly species (of the two years together) in the two villages were insignificantly different (P˃0.05) although higher density was reported in RE (Mean±SD= 11.49±6.22 fly/ trap) than in RW (Mean±SD= 9.26±6.39 fly/ trap). D. SEX RATIOS: More males were collected than females for all species however, the ratios (males: females) were not deviated from the expected 1:1 for most of the species in the two villages. Summary 81 E. RELATION OF FLY DENSITY TO THE WEATHER CONDITIONS: In both villages, the fly density (fly/trap) was directly related to the temperature and RH (P˂0. 01) while it inversely related to wind velocity (P˃0.05). F. MONTHLY ABUNDANC OF REPORTED SAND FLIES: For all species altogether, in the two villages, flies were active from April to November with increased activity from June to October. Prominent peaks were observed in September and another peak was observed in June of the two years. Such trend was followed by P. papatasi, P. longicuspis, and S. fallax. The other two common species, P. alexandri showed a peak in August 2013 instead of September (51 fly) and S. minuta had peaks in July instead of June of the two years. PHLEBOTOMUS PAPATASI ABUNDANCE IN RELATION TO THE REPORTED CUTANEOUS LEISHMANIASIS CASES The relation of monthly densities (Fly / trap) of P. papatasi, the main vector of CL to the reported CL cases during the fly activity periods in the two villages was examined Cases in RE were reported from August to march (2012) and April (2013) with higher numbers in October (4) and November (2) in both years. Peaks of P. papatasi activity were during September 2012 and 2013. Cases in RW were reported in April and from August to November (2012) with higher numbers (4) in October (2012) while in 2013, no cases were reported due to insecticide application. Peaks of P. papatasi activity were during September 2012 and 2013. This indicates that the period of high abundance of P. papatasi (August – October) coincided with detection of higher numbers of CL cases (August – November). SAND FLY CONTROL Sand fly control using ULV spraying with cypermethrin was evaluated in RW through 3 spraying cycles during April, June and September 2013 and revealed that during the post-spraying periods: (1) Density of the different species and the overall density for all species altogether were significantly reduced, (2) the reduction in densities of different species ranged from 33.33% to 77.52% with 46.69% as an overall reduction for all species altogether and (3) Sex ratios of the most of species deviated from the expected 1:1 ratio in favor of males. Moreover, ULV spraying reduced the reported CL cases from 36 in 2012 to only 4 in 2013 (88.89% reduction). The obtained results indicate the efficiency of ULV spraying in reducing sand fly population and consequently the disease transmission |