Citizen science reveals the current distribution of the new plant pest Aphis nerii in Slovakia.

This paper presents the first record of the oleander aphid (Aphis nerii Boyer de Fonscolombe, 1841; Hemiptera: Aphididae) in Slovakia, and also one of the most northern record of this natural pest on the invasive common milkweed (Asclepias syriaca Linnaeus.; Apocynaceae) in Central Europe. Modern social media crowdsourcing has achieved comprehensive distribution data in the horticultural community, and a total of 35 new distribution sites were discovered in 28 Slovak settlements, one new site in Austria, and one in the Czech Republic. It was further established that the oleander aphid could survive in anthropogenic refuges during the winter months. [ABSTRACT FROM AUTHOR]