Insect galls and their host plants in gallery forest in Bahia State, Brazil

Inventories of insect galls in gallery forests in Northeastern Brazil have been quite infrequent, and the richness of gall-inducing insects in that vegetation type has been little unknown. To contribute to our knowledge of galls, galling insects, and their host plants from gallery forest habitats in Northeastern Brazil, we documented and characterized the macroscopic aspects of the galls, identified the plant hosts and their endemism level and surveyed the associated fauna in an area of gallery forest in Caetité, Bahia State. We found 30 different gall morphotypes on 20 host plant species belonging to 17 genera and 13 families. The main host families of galls were Leguminosae and Myrtaceae with ten and four morphotypes, respectively. Most galls occurred on leaves and were globoid, green, glabrous, and grouped. Most of the gall-inducing insect species found belonged to Diptera (Cecidomyiidae) and Coleoptera, while the associated fauna was represented by Hemiptera, Hymenoptera, Collembola, and Thysanoptera. We recorded galls the first time on six plant species. These results reinforce the importance of gall inventories in gallery forest areas not yet examined to better understand gall richness, galling insects, and their host plants in that vegetation type.