Interactions of the invasive Lasius neglectus (Hymenoptera: Formicidae) with aphids (Hemiptera: Sternorrhyncha: Aphididae)

Summary Since the invasive garden ant Lasius neglectus Van Loon, Boomsma & Andrásfalvy, 1990 was first detected in 1998 in Seva (Barcelona), and despite the number of amateurs and professionals dedicated to the study of ants in Spain, this species had only been located outside Catalonia in Tenerife, Vizcaya and Valencia. Here we present a detailed study of its presence in the city of León (north-western Spain) and its trophic relationships with aphids. In the city we found two clearly separated supercolonies of L. neglectus attending 32 species of aphids living on 31 plant taxa. Lasius neglectus seems to avoid landscaped areas with high humidity and mainly attends aphids that live on shrubs and trees. The study is complemented with all the aphid–ant interactions known for this species.