Gall-inducing insects of deciduous and semideciduous forests in Rio Grande do Sul State, Brazil

Abstract

Galls are specific changes induced by insects on plant organs mainly through increases in plant cell number and/or size. Gall diversity is easy to recognize in the field because gallers are mostly species-specific, and thus each gall morphotype can be a proxy for a galling species. Insect galls are virtually unknown in Seasonal Deciduous and Semi-Deciduous forests of southern Brazil. Here, galls and host plants were surveyed between 2015 and 2017 in four forest fragments of Rio Grande do Sul State in these two vegetation types, in secondary-growth and areas under restoration. We recorded 89 gall morphotypes, with gallers belonging to Lepidoptera and Diptera, with the latter represented mainly by Cecidomyiidae. Galls were associated to 46 plant species in 27 families. Asteraceae, Piperaceae, Fabaceae, Myrtaceae and Lauraceae were the richest families in terms of galls, whilst Piper aduncum and Mikania glomerata were superhosts. Most galls occurred in leaves and shoots. The most common shapes were fusiform, globoid and lenticular. Forty-eight gall morphotype records are new for both Rio Grande do Sul and Brazil, an expressive number considering only two seasonal forest types sampled and few sampling points, showing how important surveys still are for these little know fauna both in taxonomic and ecological terms.

Distribution of gall-inducing arthropods in areas of deciduous seasonal forest of Parque da Sapucaia (Montes Claros, MG, Brazil): effects of anthropization, vegetation structure and seasonality

“…These differences in floristic composition may also influence the diversity of the gall-inducing fauna (Araújo et al, 2013). Considering the mean number of gall morphotypes per sampled area/fragment, the richness of gall-inducing species recorded in the present study is similar to or greater than that found in other studies (mean of 30, 22 and six morphotypes per area for Coelho et al, 2009, Goetz et al, 2018and Santos et al, 2011.…”

“…morphotypes),Goetz et al (2018; 89 morphotypes) andSantos et al (2011; 64 morphotypes) in other areas of Brazilian dry forest. This difference may have been due to the sampling method used, because the present study evaluated only one fragment of dry forest, whileCoelho et al (2009) sampled three, Goetz et al (2018) sampled four, and Santos et al (2011) sampled 11 areas.…”

“…Gall-inducing arthropods have been studied in several types of ecosystems in Brazil, including humid tropical forests (e.g., Almada & Fernandes, 2011;Araújo & Espírito-Santo Filho, 2012;Fernandes et al, 2009;Julião et al, 2005), Restingas (e.g., Mendonça et al, 2010;Rodrigues et al, 2014) and savannas (e.g., Araújo & Guilherme, 2012;Araújo et al, 2014). On the other hand, relatively little research has been done on gall-inducing arthropods in deciduous seasonal forests in Brazil (e.g., Coelho et al, 2009;Goetz et al, 2018;Santos et al, 2011). Due to the seasonal change of vegetation in these forests, with high deciduousness during the dry season, the composition of the herbivorous insect fauna is quite variable, with their abundance increasing during the rainy season (Filip et al, 1995).…”

Checklist of the gall midges (Diptera, Cecidomyiidae) in the state of Bahia (Northeastern Brazil) / Lista dos Cecidomyiidae (Diptera) no estado da Bahia (Nordeste do Brasil)

“…Refs. :Maia & Couri 1993, Monteiro et al 1994, Maia & Souza 2013, Maia & Carvalho-Fernandes 2016, Maia & Silva 2016, Goetz et al 2018, Maia 2020a. Host plant: Guapira opposita (Vell.)…”

Insect galls of Paraty (State of Rio de Janeiro, Southeastern Brazil) / Galhas de insetos de Paraty (estado do Rio de Janeiro, Sudeste do Brasil)

“…(Asteraceae) was the unique multi-host species, with six gall morphotypes. All other plant species hosted a single morphotype.In Brazil, Fabaceae, Asteraceae and Myrtaceae are families often cited for their great gall richness, being important flora components of the surveyed localities (e.g Coelho et al 2013, Maia & Mascarenhas 2017, Goetz et al 2018…”