Witches’ brooms increases arthropod-plant interactions in Ouratea hexasperma (Baill.) (Ochnaceae)

Abstract Ouratea hexasperma (Baill.) (Ochnaceae) trees can be infected by pathogens, which drastically alters branch structure by inducing witches' brooms, a massed proliferation of short and bushy branches, similar to broom. These structures can be used by other organisms, mainly arthropods, as nest refuges and places for prey. In this study, we tested and confirmed the hypothesis that witches' brooms can act as ecosystem engineer for O. hexasperma, promoting significant increases in arthropod/plant interactions. We found arthropods belonging to eleven different orders, associated with O. hexasperma, when plants generated witches' brooms; Psocoptera and Thysanoptera were the most abundant tenants. Plants without witches' brooms were only associated with two arthropod orders (Coleoptera and Araneae). Alternately, we did not find any positive links between the number of witches' brooms in plants, and arthropod abundance and richness within them. This study demonstrates that witches’ brooms are structures that generate better micro-habitats for different organisms, thus maximizing arthropod/plant interactions.