Richness of insect galls in Caatinga sites with different degrees of anthropogenic impact, Bahia State, Brazil

ABSTRACT The current knowledge of insect galls in Caatinga vegetation is still only fragmentary, with most scientific efforts concentrated in only a few areas in the states of Pernambuco and Bahia. In the present study, we characterized morphologically insect galls in areas of Caatinga vegetation showing different degrees of anthropogenic impact in Ibiassucê, state of Bahia. Three sites were selected based on their levels of human disturbance, and four random plots (10 m2 each), separated from each other by 10 m, were then established in each area, for a total of 12 plots. Twenty gall morphotypes were found on nine plant species belonging to eight families. The greatest gall diversity was found in sites showing intermediate levels of anthropogenic impacts (n=8), followed by heavily impacted areas (n=7), and preserved areas (n=5). Globoid galls, brown, with only a single chamber, glabrous, and separately disseminated were the most frequent. Lepidoptera, Coleoptera and Diptera (Cecidomyiidae) were the gall-forming insect orders. The results presented here show the importance of this kind of research and the need of inventories of galls in neglected Caatinga areas.

摘要 当前对卡廷加（Caatinga）植被中虫瘿的认知仍较为零散，绝大多数科研工作仅集中在伯南布哥州和巴伊亚州的少数区域。本研究针对巴伊亚州比亚苏塞（Ibiassucê）不同人为干扰程度的卡廷加植被区域内的虫瘿开展形态学表征。研究依据人为干扰等级选取3处样地，每处样地内设置4个彼此间距10米的随机样方（单样方面积10 m²），总计12个样方。研究共在隶属于8个科的9种植物上发现20种虫瘿形态型。虫瘿多样性最高的区域为中度人为干扰样地（n=8），其次为重度干扰样地（n=7），原生保护样地则位列第三（n=5）。最常见的虫瘿类型为球形、褐色、单室、无毛且可独立传播的虫瘿。造瘿昆虫类群涵盖鳞翅目（Lepidoptera）、鞘翅目（Coleoptera）以及双翅目（Diptera）瘿蚊科（Cecidomyiidae）。本研究结果彰显了此类研究的重要价值，同时表明亟需对尚未得到充分关注的卡廷加植被区域开展虫瘿资源调查。