Occurrence and characterization of entomogenic galls in an area of Cerrado sensu stricto and Gallery forest of the state of Bahia, Brazil

Abstract We surveyed insect galls in an area of Cerrado sensu stricto and Gallery forest in the municipality of Caetité (BA) to contribute to current knowledge of the local flora and its associated gall-inducing insects. Monthly collections were made between February/2015 and January/2016, totaling 12 field campaigns (involving two or three people and lasting four hours) that followed an established path through the countryside. A total of 63 gall morphotypes were identified on 47 host plant species belonging to 22 families; 17 morphotypes were found in the Gallery forest and 46 in Cerrado vegetation. The plant families showing the greatest gall richness were Leguminosae (n=15), Myrtaceae (n=9), and Asteraceae (n=7). The species with the greatest number of galls was Mimosa gemmulata Barneby (Leguminosae) (n=3). Most galls were observed on leaves (66%) and stems (24%); they were mostly green (49.3%) or brown (26%), with globoid shapes (39.7%) or marginal roll (17.4%), and were unilocular (87%), glabrous (62%) and isolated (89%). Cecidomyiidae (Diptera) were the principal gall-inducing insects. The associated fauna was principally composed of Hymenoptera. Eight plant taxa were recorded for the first time as hosts of galling fauna.

摘要 本研究对巴西巴伊亚州卡埃蒂特市境内的严格型塞拉多植被（Cerrado sensu stricto）与廊道林（Gallery forest）区域的昆虫虫瘿开展调查，旨在丰富当地植物区系及其伴生致瘿昆虫的现有研究认知。研究于2015年2月至2016年1月期间实施月度采样，累计完成12次野外调查活动，每次由2至3名研究人员参与，耗时4小时，采样沿预设的乡村样带开展。本研究共在隶属于22个科的47种寄主植物上鉴定出63种虫瘿形态型；其中廊道林内发现17种虫瘿形态型，塞拉多植被区域则发现46种。虫瘿丰富度排名前三的植物科依次为豆科（Leguminosae，n=15）、桃金娘科（Myrtaceae，n=9）与菊科（Asteraceae，n=7）。虫瘿数量最多的寄主植物为含羞草属Mimosa gemmulata Barneby（豆科，Leguminosae），其虫瘿数量达3个。多数虫瘿着生于叶片（66%）与茎秆（24%）；虫瘿颜色以绿色（49.3%）或褐色（26%）为主，形态多为球形（39.7%）或叶缘卷曲型（17.4%），且大多为单室（87%）、表面无毛（62%）且单生（89%）。双翅目瘿蚊科（Cecidomyiidae，Diptera）为主要的致瘿昆虫类群，伴生动物类群则以膜翅目（Hymenoptera）昆虫为主。另有8个植物分类单元首次被记录为致瘿动物的寄主。