The Thysanoptera fauna of Brazil is one of the most diverse on the planet. More than 530 species have been described based on specimens collected in Brazilian territory, and about 700 species are currently listed for this country (this site). This number represents more than 10% of the total of species described in the order. Besides this species richness, the thrips fauna in Brazil is diverse in ecology and life stories. Below you will find information about the main aspects of the Brazilian Thysanoptera fauna.

 

The studies with thrips in Brazil

Most of the descriptions of thrips species from this country were produced by researchers from the Northern hemisphere in the last century. Two North American researchers deserve mention for their taxonomic contributions: James Douglas Hood (Cornell University, New York) and Dudley Moulton (United States Department of Agriculture, California).

 

Hood described more than 320 thrips species from Brazil, especially from material collected by Fritz Plaumann in Nova Teutônia (nowadays the municipality of Seara) in Santa Catarina state. He also made some expeditions to Rio de Janeiro and Pará states in the decade of 1950, from which several thrips species were described. Curiously, Hood never published identification keys that could help in recognizing these species, despite some of them being illustrated in detail. The entire Hood collection of Thysanoptera was bequeathed to the United States National Museum of Natural History, Washington, and is currently housed, together with the USNM collections of Insecta-Sternorrhyncha, in buildings of the United States Department of Agriculture at Beltsville, Maryland.  MY WORDING IS CAREFULLY CONSTRUCTED TO AVOID POLITICAL PROBLEMS – “responsibility” would not be an acceptable word!!!

 

Moulton described dozens of species from Brazil, of which about 45 are considered to be valid. Most of these species were described from material collected in the Southeastern region. Moulton was the first researcher to publish keys that allowed the identification of Brazilian species, such as the keys for Frankliniella (Moulton 1948) and Liothrips (Moulton 1933) species. Despite being important tools a few decades ago, these keys do not allow anymore the precise identification of the species of these groups. The species described by Moulton are deposited in the collection of California Academy of Sciences, Entomology.

 

The number of Thysanoptera studies conducted by Brazilian researchers began to increase starting in the decade of 1990. During this time, research groups were created at ESALQ (Piracicaba), UFRGS (Porto Alegre) and UFU (Uberlândia), through the collaboration of international researchers. Starting with these collaborations, numerous contributions about taxonomic, biological and ecological aspects were published in the country. More recently, research groups in the North (INPA, Manaus) and Northeastern (UFPI, UECE, UESB) regions have been established, producing studies on thrips in this country.

 

 

An underestimated richness

Historically, the fauna from some Brazilian biomes and regions was never properly investigated (Monteiro 2002). Most of the taxonomic and faunistic studies occurred in the Southern and Southeastern regions, and only part of these studies was conducted in natural areas. Studies on Thysanoptera in representative biomes such as Amazonian Forest, Cerrado and Atlantic Forest are scarce.

 

The diversity of Thysanoptera on dead twigs and leaves in the Amazonian region is impressive. In a quick sampling of this microhabitat it is possible to observe a great abundance of fungivorous Tubulifera, especially Idolothripinae (Diceratothrips and Elaphrothrips spp.) and Adraneothrips spp. However, it is hard to access and sample the fauna of phytophagous thrips in the Amazonian forest. The vegetation inside the forest is composed of large trees, and probably the majority of phytophagous thrips live in the canopy.

 

The Cerrado occupies about 25% of the Brazilian territory and seems to be a biome with a great diversity of ecological interactions involving thrips. Observations in this biome suggest a large number of galling thrips species from the genus Holopothrips, mainly in leaves of Myrtaceae and Vochysiaceae species. Thrips of family Heterothripidae are especially rich and abundant in Malpighiaceae flowers in the Cerrado region, and their biology is closely associated with the sequential flowering of these plants (Alves-Silva 2010). The ectoparasitic thrips of genus Aulacothrips are particularly common in Cerrado, where they infest a great diversity of tree-hoppers with mutualistic associations with ants (Cavalleri et al. 2010, Alves-Silva & Del-Claro 2011).

 

The Atlantic Rainforest is remarkable for its great biological diversity and high levels of endemism of several plant and animal groups. The association between Thysanoptera and plants in this biome is also poorly known. Some plant families like Bignoniaceae, Lauraceae, Melastomataceae and Myrtaceae seem to support a large richness of phytophagous thrips. Studies also suggest that thrips are pollinators on several species of Mollinedia (Monimiaceae) and Ocotea porosa (Lauraceae), an endangered species in the Atlantic Rainforest (Danieli-Silva & Varassin 2013; Silveira 2014). Another outstanding characteristic is the large number of galling thrips species, from the genus Holopothrips, in these areas, although several of them still need to be described. Thrips in leaf litter are particularly diverse in the Atlantic Rainforest, especially the fungivorous Phlaeothripidae of “tribe” Glyptothripini. For instance, Hood described more than 30 species of these thrips associated with leaf litter, in a forest area of only 50km² in Santa Catarina state (Mound 1977). Despite such a large species richness, studies indicate that the abundance of these species in the leaf litter is curiously low (Santos 2016).

 

Comparisons of the Brazilian Thysanoptera fauna with neighbouring regions and countries is still limited due to the lack of studies in these areas. In South America, only for Argentina is there a published list of species, with about 120 species recorded (De Bórbon 2008). In the remining countries, only isolated works with specific taxonomic groups (e.g. Frankliniella) have been performed. Overall, about 990 thrips species are informally recorded in South America, 800 of these described from the region. It is not possible to forecast how much of the fauna still awaits to be discovered, but the number of species is surely greatly underestimated.

Published in: 16/11/2016
Posted by: Adriano
Tags: Diversity, species, distribution