Seasonal dynamics of Phlebotomus neglectus (Diptera: Psychodidae) in cave microhabitats in Romania and the rediscovery of Sergentomyia minuta (Rondani, 1843) after 50 years

Background In a countrywide study aiming to update the knowledge on diversity of sand fly species in Romania, a sand fly population was observed in an isolated system of cave microhabitats. The caves are located in the protected area of Canaraua Fetii, Dobrogea region, southeastern Romania. The highest sand fly diversity was recorded in this area between 1968 and 1970. This work presents a study conducted to estimate the seasonal variation of the sand fly species in correlation with the particular environmental factors of the isolated system of cave microhabitats. Methods Sand flies were collected between May and October 2020 from one trapping site of interest in Canaraua Fetii. The trapping site consisted of a cave entrance. CDC miniature light traps and sticky traps were used to collect insects from the exterior walls of the cave entrance. Species identification of collected sand flies was done using morphological keys. Statistical analysis of the trapping and climatic data was performed. Results From all collected sand flies, 99.7% (818/822) were Phlebotomus neglectus, 0.1% (1/822) Ph. balcanicus and 0.2% (2/822) Sergentomyia minuta. Sand fly activity was first observed on 2 July and last on 24 September. A monomodal abundance trend was present, with the peak activity between 16 and 17 July. The analysis of the climatic data showed correlations between the total number of captured sand flies and both average temperature and average relative humidity. The total number of collected specimens was statistically higher when CDC miniature light traps were used compared to sticky traps. The number of females on the sticky traps was significantly higher than the number of males on the same trap type. Compared with the sticky traps, significantly more males were collected by CDC miniature light traps. This is the first record of Se. minuta in Romania after 50 years of no records (despite the trapping effort of the last 5 years in the country). Also, Ph. sergenti, previously present in this location, was not found. Conclusions In the investigated natural habitat, the diversity of the sand fly species appears to have changed, with the predominance of Ph. neglectus instead of Ph. balcanicus and Se. minuta (recorded as the two predominant species in 1968–1970). A monomodal abundance trend was observed as in other regions of the country. The sand fly activity in this particular cave microhabitat appears to be longer than in other regions in Romania. Longer sand fly activity increases the zoonotic risk of various pathogenic species’ transmission, with an impact on public health, as sand flies are important insect vectors. Graphical abstract

Seasonality of Sand Flies (Diptera: Psychodidae) in Cave Microhabitats and The Rediscovery of Sergentomyia Minuta (Rondani, 1843) After Fifty Years

Background: In a countrywide study with the aim to update the knowledge on diversity of sand fly species in Romania, a sand fly population was observed in an isolated system of cave microhabitats. The caves are located in the protected area of Canaraua Fetii, Dobrogea region, southeastern Romania. The highest sand fly diversity was recorded at the above-mentioned area between 1968 and 1970. This work presents an abundance study, which was conducted in order to estimate the seasonal variation of the sand fly species in correlation with the particular environmental factors of the isolated system of cave microhabitats.Methods: Sand flies were collected between May and October 2020 from one trapping site of interest, from Canaraua Fetii. The trapping site consisted of a system of cave entrances. CDC miniature light traps, and sticky traps were used to collect insects from the exterior walls of the cave entrances. Species identification of collected sand flies was done using morphological keys. Statistical analysis of the trapping and climatic data was performed.Results: From all collected sand flies, 99.63% (818/821) were Phlebotomus neglectus, 0.12% (1/821) Ph. balcanicus, and 0.25% (2/821) Sergentomyia minuta. Sand fly activity was firstly observed in 2nd of July and lastly in 24th of September. A monomodal abundance trend was present, with the peak activity between 16th and 17th of July. The analysis of the climatic data showed correlations between the total number of captured sand flies and both, average temperature and average relative humidity. The total number of collected specimens was statistically higher when CDC miniature light traps were used compared to sticky traps. The number of females on the sticky traps was significantly higher than the number of males on the same trap type. When compared with the sticky traps, a significantly higher number of males were collected by CDC miniature light traps. This is the first record of Se. minuta in Romania after 50 years of no records (despite the trapping effort of the last five years in the country). Also, Ph. sergenti, previously present in this location, was not found.Conclusions: In the investigated natural habitat, the diversity of the sand fly species appears to have changed, with the predominance of Ph. neglectus instead of Ph. balcanicus and Se. minuta (recorded as the two predominant species in 1968-1970). A monomodal abundance trend was observed as in other regions of the country. The sand fly activity in this particular cave microhabitat appears to be longer than in other regions in Romania. A longer sand fly activity increases the zoonotic risk of various pathogenic species’ transmission, with an impact in the public health, as sand flies are important insect vectors.

Modeling Spatial Distribution of Sergentomyia minuta (Diptera: Psychodidae) and its Potential Implication in Leishmaniasis Transmission in Morocco

Background: Leishmaniases are parasitic diseases caused by Leishmania species and transmitted by the bite of sand flies. The genus Lutzomyia and Phlebotomus of sand flies are known to be the responsible vector for transmitting almost all Leishmania species to humans. The detection of Leishmania DNA in species of the genus Sergentomyia, in different regions, suggests their likely role in Leishmania transmission. Methods: Our objective was to determine the potential geographical distribution of Sergentomyia minuta, the most dominant Sergentomyia species in Morocco, using ecological niche modeling. Results: The results showed the widespread geographical distribution of S. minuta in Morocco, specifically in northern and central Morocco where visceral and cutaneous leishmaniasis foci occur. There were six abiotic factors affecting the distribution of S. minuta whose annual precipitation, precipitation seasonality and precipitation of driest month as the most important ecological variables of the model. Conclusion: A positive statistical correlation between human leishmaniasis cases and S. minuta abundance was noted suggesting the potential involvement of S. minuta in local Leishmania transmission cycles.

Diversity and Dynamics of Sand Flies (Diptera: Psychodidae) of Two Cutaneous Leishmaniasis Foci in the Fes-Boulemane Region of Northern Morocco

Cutaneous leishmaniasis (CL) is an infectious disease caused by various species ofLeishmaniaand transmitted by several species of sand flies (Diptera: Psychodidae). In order to evaluate the risk of leishmaniasis transmission in Fes-Boulemane, an investigation was carried out in two localities, Aichoun and Bouasseme, during 2011. From January to December, 1120 specimens were collected in Aichoun comprising six species belonging to two genera:Phlebotomus sergenti(76.07%),Phlebotomus longicuspis(9.01%),Phlebotomus perniciosus(8.48%),Phlebotomus papatasi(4.82%),Sergentomyia minuta,andSergentomyia fallax. For Bouasseme, seven species were identified withPhlebotomus sergenti(60.39%) dominating, followed byPhlebotomus perniciosus(20%) andPhlebotomus longicuspis(12.15%). The remaining species,Phlebotomus papatasi,Phlebotomus ariasi,Sergentomyia minuta,andSergentomyia fallax,were less prevalent. The activity of sand flies in both localities is marked by the dominance ofPh. sergentiwith two peaks occurring in June and September. In order to obtain a better understanding of sand fly diversity among their species, results were analyzed by the ecological indices determinant: specific richness, the relative abundance, and Shannon-Weiner index (H′). Further studies of sand fly diversity should employ statistical tests and molecular analyses. This study can be useful in the implementation of appropriate future control measures.