Insect galls on Myrtaceae: richness and distribution in brazilian restingas

Abstract: Inventories in Brazilian restingas have been indicating that Myrtaceae are the plant family with the greatest richness of insect galls. A compilation of published data plus new records was elaborated with the aim of stablishing the number of gall morphotypes on this family in this physiognomy of the Atlantic Forest, producing a list of galled species, pointing out the predominant gall features, evaluating the taxonomical knowledge of the gallers, listing the associated fauna, and based on host plant endemisms and monophagy proposing the endemism of some galling species. Myrtaceae harbor 111 morphotypes of insect gall (about 75% induced by Cecidomyiidae, Diptera) on 25 host plant species, 15 endemic. Eugenia L. highlights as the plant genus with the highest number of galled species and gall richness. Leaves are the most galled organ. There is a predominance of globoid and fusiform shapes, green color, glabrous surface and a single internal chamber. The taxonomical data on gallers is deficient as many records have been presented at supraspecific levels. The associated fauna is rich and includes parasitoids, inquilines and predators. Twelve species of Cecidomyiidae, a single species of Curculionidae (Coleoptera) and one species of Eriococcidae (Hemiptera) have been associated exclusively with endemic hosts and then are proposed in the present study as endemic too. The geographical distribution of many galls and respective gallers are restricted to the State of Rio de Janeiro, where most inventories have been carried out. For the first time, Eugeniamyia dispar, previously known from a rural area of Rio Grande do Sul and restinga areas of São Paulo, is recorded in the State of Rio de Janeiro.

摘要：巴西滨海沙生植被（restinga）相关调查显示，桃金娘科（Myrtaceae）是虫瘿物种丰富度最高的植物科。本研究整合已发表数据与新记录，旨在明确该大西洋森林植被型中桃金娘科植物的虫瘿形态型数量，编制受瘿寄主物种名录，阐明主要虫瘿特征，评估造瘿昆虫的分类学研究现状，梳理其伴生动物类群，并基于寄主植物特有性与单食性特征，推测部分造瘿昆虫的特有性。桃金娘科共有25种寄主植物，其上记录有111种虫瘿形态型（其中约75%由双翅目（Diptera）瘿蚊科（Cecidomyiidae）诱导形成），其中15种寄主为特有物种。番樱桃属（Eugenia L.）是受瘿物种数与虫瘿丰富度最高的植物属。叶片是最易被造瘿昆虫侵害的器官。虫瘿以球形、纺锤形为主，颜色多为绿色，表面无毛，内部具单个空腔。由于多数造瘿昆虫的记录仅达到超种阶元，造瘿昆虫的分类学数据仍较为匮乏。伴生动物类群丰富，涵盖寄生性天敌、客居昆虫与捕食性天敌。本研究发现，12种瘿蚊科昆虫、1种鞘翅目（Coleoptera）象甲科（Curculionidae）昆虫以及1种半翅目（Hemiptera）绒蚧科（Eriococcidae）昆虫仅与特有寄主植物相关联，因此推测这些昆虫也为特有物种。多数虫瘿及其造瘿昆虫的地理分布仅局限于里约热内卢州，该州也是本研究开展多数调查工作的区域。本研究首次在里约热内卢州记录到Eugeniamyia dispar（此前仅见于南里奥格兰德州的乡村区域与圣保罗州的滨海沙生植被区域）。