Brachycaudus divaricatae – was described by Shaposhnikov in the Middle East as a heteroecious aphid species migrating between Prunus divaricata and Melandrium album. The research conducted in Poland proved that this species can be described as holocyclic and monoecious. A significantly shortened development cycle with a summer-winter diapause characterizes this species in Poland. The aim of our studies was a detailed research of the species biology conducted to explain this phenomenon. Elements of the biology and ecology of the new fauna species Brachycaudus divaricatae Shap., were studied in Poland during the 2008–2010 time period. The term of spring hatching, number of generations per season, development length of particular generations, lifespan of specimen, and fecundity of particular generations were all defined. The three-year study proved that 6 to 8 aphid generations can develop on P. cerasifera in Poland. The emergence of sexuales (amphigonic females and males) of B. divaricatae occurred very early in the season: in mid-May, and the first eggs were laid in June.