Phlebotomine sand flies (Diptera: Psychodidae) in the Greek Aegean Islands: ecological approaches

Emmanouil Dokianakis,Christos Kourouniotis,Bulent Alten,Christoforos Pavlou,Vasiliki Christodoulou,Nikolaos Tsirigotakis,Maria Antoniou

doi:10.1186/s13071-018-2680-4

Abstract

BackgroundBlood-sucking phlebotomine sand flies are the vectors of the protozoan parasites Leishmania spp. Different Phlebotomus species transmit different Leishmania species causing leishmaniases which are neglected diseases emerging/reemerging in new regions. Thirteen sand fly species, ten belonging to the medically important genus Phlebotomus and three belonging to Sergentomyia are known in Greece. An increasing number of human and dog cases are reported each year from all parts of the country including the Aegean Islands. However, no previous study has been conducted on the sand fly fauna on the islands, except for Rhodes and Samos. The aim of this study was to investigate sand fly species in eleven small Aegean islands; to understand species-specific relationships with environmental and climatic factors and to compare sand fly community parameters among islands. A risk analysis was carried out for each species using climatic and environmental variables.ResultsNine sand fly species: Phlebotomus neglectus, P. tobbi, P. similis, P. simici, P. perfiliewi, P. alexandri, P. papatasi, Sergentomyia minuta and S. dentata, were collected from the islands studied. Phlebotomus (Adlerius) sp. and Sergentomyia sp. specimens were also collected but not identified to the species level. There was a positive effect of distance from the sea on the abundance of P. neglectus, S. minuta and S. dentata, and a negative effect on the abundance of P. tobbi, P. simici and P. similis. In general, temperature preferences of sand fly populations were between 21 and 29 °C. Nevertheless, there were significant differences in terms of temperature and relative humidity preference ranges among species. The most important species found, P. neglectus, was indisputably the most adapted species in the study area with a very high reaction norm, favoring even the lower temperature and humidity ranges. Overall, the sand fly fauna in the islands was very rich but there were differences in species diversity, as indicated by the values of the Shannon-Wiener index, along with evenness and richness of the sand fly fauna between the islands and altitude ranges in the islands.ConclusionsThe study indicated that the Greek Aegean Islands, however small, maintain a rich sand fly fauna. This includes important vectors of Leishmania spp. representing a risk for parasite transmission to humans and dogs along with the danger of maintaining new Leishmania spp. if introduced to the area.

Highlights

Blood-sucking phlebotomine sand flies are the vectors of the protozoan parasites Leishmania spp
The main objectives of this work were to investigate the sand fly fauna of eleven small islands scattered in the Aegean Sea between Greece and Turkey; to reveal sand fly relative abundance in positive traps; to compare the species found to those encountered in the two mainlands; to study the relationship of the species found to environmental and climatic factors; and to compare the islands in terms of some community parameters such as species diversity, dominance and species richness
Phlebotomus neglectus and S. minuta were present in all 11 islands and P. similis in out of the islands (Table 3, Fig. 2)

Summary

Introduction

Blood-sucking phlebotomine sand flies are the vectors of the protozoan parasites Leishmania spp. Sand flies are active during the warm months, they spread their activity geographically and for longer periods of time during the year due to favorable climatic changes This allows them, and the pathogens they carry, to reach new hosts and regions. Delicate insects and use sheltered places to rest during the day, being active mostly at dusk and night [6] They have a very strong adaptation capacity and a plastic reaction norm against changing environmental and climatic conditions. Sand flies are mostly found in rural and peri-urban environments and not at high altitudes since they require warm temperatures They were, found in South America living in caves at 2800 m above sea level (masl) transmitting leishmaniasis [8, 9]. It is possible that an increase in genetic variation tracking the environmental (developmental temperature) change may have considerable implications on the distribution and range expansion of sand fly species, especially in warmer environments

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