title: Holopothrips molzi sp.n. (Thysanoptera, Phlaeothripidae): natural history and interactions in Myrtaceae galls.
abstract: Holopothrips molzi sp. n. (Thysanoptera: Phlaeothripidae) is described from southern Brazil inducing leaf galls on Myrcia guianensis (Myrtaceae). Field observations revealed that the numbers of this thrips were highly variable within galls, and two other insect species were recorded living in these galls: Myrciathrips variabilis Cavalleri et al. (Phlaeothripidae) and an eulophid wasp (Hymenoptera). We investigated here if morphological traits of leaf and gall and abundance of the invader thrips were correlated with the gall inducer's abundance. In order to determine the feeding habit and behaviour of M. variabilis and its interactions with the gall inducer we performed observations ad libitum and attack simulation tests on both thrips species to observe their response to possible invaders. Our results showed that leaf size is not related to H. molzi abundance, and gall size is relevant only when total numbers of both thrips species are considered. Myrciathrips variabilis was observed feeding on gall tissues, and no direct antagonistic interactions between the two thrips were recorded. The results of the behavioural tests simulating attacks were remarkably different in the two thrips species, indicating different strategies when threatened or disturbed. The interaction between the two thrips species is probably a case of inquilinism.
authors.affiliation: Departamento de Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970, Porto Alegre, Brazil; Email: mflindner@hotmail.com.
authors.forename: Mariana Flores
authors.initials: MF
authors.lastname: Lindner
authors.affiliation: Departamento de Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970, Porto Alegre, Brazil; Email: unknown.
authors.forename: Milton De Souza Jr
authors.initials: Mde S
authors.lastname: Mendonça
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rua Mal. Floriano Peixoto, 2236, São Lourenço do Sul, RS, Brazil.; Email: cavalleri_adriano@yahoo.com.br.
authors.forename: Adriano
authors.initials: A
authors.lastname: Cavalleri
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D001938:Brazil; D017753:Ecosystem; D005260:Female; D008297:Male; D027822:Myrtaceae / Q000469:parasitology*; D009929:Organ Size; D018515:Plant Leaves / Q000469:parasitology; D010941:Plant Tumors / Q000469:parasitology*; D061149:Thysanoptera / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development