Super Host Research Articles

Insect galls in three species of Copaifera L. (Leguminosae, Caesalpinioideae) occurring sympatrically in a Cerrado area (Bahia, Brazil)

Abstract The aim of this study was to characterize galls of three species of the Copaifera genus (C. sabulicola, C. luetzelburgii and C. depilis), which occur sympatrically in a Cerrado area from Bahia state. A total of 23 gall morphotypes were found, 9 morphotypes on C. sabulicola, 7 on C. luetzelburgii and 7 on C. depilis. Galls predominated on leaves and stems. The most abundant colours found among galls were brown and green. Regarding the period of the year, from 35,511 leaflets analysed, 16,322 were collected in the dry season and 19,189 in the rainy season. In the dry season, 1,635 leaflets having galls were observed, and the highest proportion was observed on C. luetzelburgii (16.31%). In relation to the rainy season, there is statistical difference in the incidence of leaflets with galls between C. sabulicola and C. depilis, these two species are affected differently during the rainy season. In general, most of the gall morphotypes were more abundant in the dry season. The gallers of 18 morphotypes cannot be determined, because the gall samples were collected occupied by parasitoids or without dwellers. Cecidomyiids induced galls in five morphotypes. Associated invertebrates belonging to the orders Hymenoptera, Diptera, Coleoptera and Acari were found among all gall morphotypes. The results obtained here indicate that the three species of Copaifera have an expressive number of galls, but lower than reported in the literature for C. langsdorffii, which is considered a super host.

Subtropical Interactions: Comparing Galling Insect and Host Plant Diversity in Southern Brazil and Florida.

Gall-inducing insects seem to have a diversity pattern distinct from the usual latitudinal decrease in species, with more species occurring in xeric environments instead. Many questions regarding galler diversity over geographical scales remain unanswered: for example, little is known about beta diversity, and the role super host plants play in local/regional richness. Our aim was to compare galling insect and host plant diversity in different biogeographical regions, but under similar environmental conditions. We sampled short stature coastal woodlands on sandy soils of the Atlantic coast in both USA (Florida) and Brazil (Rio Grande do Sul, RS), between 25° and 30° latitude. Little-used 200-m long trails were searched during 90min for galls; there were four trails in USA and five in Brazil. Gall functional traits (galled plant organ, gall shape and colour) proportions were not different between Florida and RS. Local galling and host plant species richness also did not differ, and neither did regional galling diversity. The beta diversity pattern, however, was distinct: sites in Florida have more similar galling faunas than sites in RS. Common diversity patterns indicate common environmental biotic (plant diversity, vegetation structure) and abiotic (climate, soil) factors might be contributing to these similar responses. As Brazilian sites are in the Atlantic forest hotspot, a high galling insect beta diversity might be caused by a higher heterogeneity at larger scales-sample-based rarefaction curves were ascending for Brazil, but not for USA. Myrtaceans were super hosts in Brazil, but not in Florida, where oaks take up this role.

Structure and development of 'witches' broom' galls in reproductive organs of Byrsonima sericea (Malpighiaceae) and their effects on host plants.

Galls are anomalies in plant development of parasitic origin that affect the cellular differentiation or growth and represent a remarkable plant-parasite interaction. Byrsonima sericea DC. (Malpighiaceae) is a super host of several different types of gall in both vegetative and reproductive organs. The existence of galls in reproductive organs and their effects on the host plant are seldom described in the literature. In this paper, we present a novel study of galls in plants of the Neotropical region: the 'witches' broom' galls developed in floral structures of B.sericea. The unaffected inflorescences are characterised by a single indeterminate main axis with spirally arranged flower buds. The flower buds developed five unaffected brownish hairy sepals and five pairs of elliptical yellow elaiophores, five yellow fringed petals, 10 stamens and a pistil with superior tricarpellar and trilocular ovary. The affected inflorescences showed changes in architecture, with branches arising from the main axis and flower buds. The flower buds exhibited several morphological and anatomical changes. The sepals, petals and carpels converted into leaf-like structures after differentiation. Stamens exhibited degeneration of the sporogenous tissue and structures containing hyphae and spores. The gynoecium did not develop, forming a central meristematic region, from which emerges the new inflorescence. In this work, we discuss the several changes in development of reproductive structures caused by witches' broom galls and their effects on reproductive success of the host plants.

Insect galls of São Tomé das Letras (MG, Brazil)

Six localities of São Tomé das Letras (MG, Brazil) were investigated from September, 2011 to June, 2012. The local vegetation was examined in search of insect galls. A total of 152 morphotypes of insect galls were found on 94 plant species (74 genera and 37 families). Fabaceae, Melastomataceae, Myrtaceae, and Asteraceae were the plant families with the greatest richness of galls, with 20, 18, 17, and 12 gall morphotypes, respectively. The super host genera were Copaifera L. (Fabaceae), Myrcia DC. ex. Guill. (Myrtaceae), and Miconia Ruiz & Pav. (Melastomataceae), with 10, 10 and 09 gall morphotypes, respectively. The super host species was Copaifera cf.langsdorfii Desf. (Fabaceae), with 10 gall morphotypes. Galls were found on leaves, stems, buds, and aerial roots. Leaves were the most galled plant organ, followed by stems, and buds. The inducers belong to Diptera, Lepidoptera, Hemiptera, Thysanoptera, Coleoptera, and Hymenoptera, being Cecidomyiidae (Diptera) the most frequent and diversified gallers. The associated fauna included parasitoids (Hymenoptera), inquilines (Lepidoptera and Thysanoptera), successors (Formicidae, Hymenoptera), and predators (pseudoscorpion), obtained from 18, 02, 02, and 01 gall morphotype, respectively. Ten galling species are recorded for the first time in São Tomé das Letras (MG). The present study indicates São Tomé das Letras (MG) as an area of great richness of insect galls.

Comparing galling insect richness among Neotropical savannas: effects of plant richness, vegetation structure and super-host presence

Plant species diversity maintains the stability of ecosystems and the diversity of consumer species such as insect herbivores. Considering that gall-inducing insects are highly specialized on their host plants and dependent on the occurrence, abundance and distribution of plants, we evaluated the diversity patterns of gall-inducing insect along Brazilian Neotropical savannas and the potential role of plant species richness, vegetation structure and super-host presence on determining these patterns. We found 1,882 individual plants that belonged to 64 different host plant species grouped in 31 families, associated to 112 galling insect species. The galling richness was positively influenced by plant species richness and the presence of the super-host genus Qualea (Vochysiaceae). Plant species richness explained 48 % of the galling richness and areas with presence of super-hosts had more than twice of galling species than areas where they were absent. On the other hand, we found no evidence that larger plants hosted more species of galling insects. We observed that for the diversity of galling insects in the Brazilian Cerrado, vegetation structure explained almost the same portion as plant richness, because structural variables did not have an effect on residuals of galling richness and plant richness regression. Our findings suggests that plant richness has a more important role on the mitigation of natural enemies and adaptive radiation of galling species, while structural aspects of the vegetation does not seem to have that effect. Furthermore, we show that the super-host taxa provide an increment in local galling richness because they present a great diversity of local number of gall morphospecies (i.e. alpha diversity) and the high turnover of morphospecies among different localities (i.e. beta diversity). Therefore we argue that the quality of resources (richness and super host presence) appears to be a most important factor for the diversity of galling insects in Neotropical systems, than the amount of resources.

Galhas de insetos da Reserva Biológica Estadual da Praia do Sul (Ilha Grande, Angra dos Reis, RJ)

Trinta e seis morfotipos de galhas de insetos foram registrados pela primeira vez para a Reserva Biológica Estadual da Praia do Sul (Ilha Grande, Angra dos Reis, RJ), sendo a maioria foliar (64%). Galhas desenvolvidas no caule e na gema também foram encontradas (25 e 14%, respectivamente). As Myrtaceae representaram a família de planta com maior riqueza de galhas. Mikania sp. (Asteraceae) e Guapira opposita (Nyctaginaceae) foram as espécies vegetais super-hospedeiras. Os Cecidomyiidae (Diptera) destacaram-se como o principal grupo galhador, responsáveis por 75% dos morfotipos. Galhas de Hemiptera e Lepidoptera também foram registradas (11 e 2,8%, respectivamente).