EFFECT OF EL NIÑO PHENOMENON ON THE SEASONALITY OF Pulicidae (Siphonaptera) IN DOGS IN A RURAL AREA OF SOUTHERN BRAZIL

The aim of this study was to investigate the effect of El Niño phenomenon on the seasonality of flea species present on dogs from a rural area in Southern Brazil, and on the relationship between the frequency of these species and the climatic conditions in that micro-region. Over three years (2013-2016) 8,974 fleas were collected from 20 dogs. Ctenocephalides felis was the most frequent species (70.14%), followed by Pulex irritans (28.82%) and Ctenocephalides canis (1.05%). The number of C. felis and C. canis individuals varied significantly with the year and with the season of the year, whereas the number of P. irritans was only influenced by the season. C. felis was more prevalent than all the other species in all seasons studied. There was a significant difference in the number of specimens collected during 2015, under the influence of El Niño, compared to 2013 but not to 2014. There was a higher incidence of P. irritans during the cooler periods. C. canis population increased during colder seasons whereas no individuals were collected in years with lower average temperatures. The present study expanded the current knowledge about the seasonal variations in the Siphonapteran populations parasiting dogs, especially in the years under influence of El Niño.