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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Diversidade e distribui??o da termitofauna no ec?tone cerrado/caatinga no sul do Piau? frente ? expans?o agr?cola. 2010. / Diversity and distribution of the termitofauna in cerrado/caatinga ecotone in southern of Piau? against agricultural expansion. 2010.

N??ez, Brenda Nury da Costa 19 August 2010 (has links)
Made available in DSpace on 2016-04-28T14:57:33Z (GMT). No. of bitstreams: 1 Brenda Nury da Costa Nunez.pdf: 4336690 bytes, checksum: 046530796e88eee7c7743614a28a287a (MD5) Previous issue date: 2010-08-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The southern region of Piaui state is inserted in a region that since 90s, is considered one of the last agricultural frontiers of Brazil, this process has intensified through the implementation of large projects to the production of grains, with the flagship soybeans, export-oriented. In general, monocultures are always related to pests, because they increase the supply of food, benefiting some groups of organisms. The termites are considered a pest of major problem in urban, suburban and rural areas, but this status can only be used for a few species. They occur in tropical and temperate areas, and worldwide there are about 2.800 described species, and about 300 of them are distributed in Brazil in four families: Kalotermitidae, Rhinotermitidae, Termitidae and Serritermitidae. In this context, this study aimed to determine the distribution and diversity of termites in the ecotone cerrado/caatinga of the southern region of the Piaui state, Brazil, in areas of natural vegetation and areas modified by agriculture. The termites were collected actively from November, 2009 to February, 2010, throughout the transects of an area of a hectare in preserved vegetation and soybean monocultures, evaluating the architecture of epigean nests, distribution, volume, food groups, associated fauna, dominance, association with the vegetation and edaphic profile of sampled areas. In the caatting of the south of Piaui, all termites collected in the preserved vegetation area, belong to a single family (Termitidae), and 10 species were identified: Armitermes sp., Constrictotermes cyphergaster Silvestri, Inquilinitermes fur (Silvestri), Inquilinitermes microcerus (Silvestri), Labiotermes longilabius (Silvestri), Nasutitermes sp1., Nasutitemes sp2., Spinitermes sp., Syntermes wheeleri Emerson and Syntermes molestus Burmeister. C. cyphergaster (42%), Nasutitermes sp1. (30%), S. wheeleri (25%) were classified as eudominants based on the total number of nests sampled (n = 57). In the nests of S. wheeleri, it was verified the presence of five orders of arthropods (Araneae, Scorpions, Coleoptera, Orthoptera and Isoptera) associated. Nasutitermes sp1. presented nesting only in the arboreous plants: canela-de-velho (Cenostigma macrophyllum, Caesapinioideae). In the cerrado of the south of Piaui, only two termite species were found in the soybean monoculture areas: Coptotermes sp. and Cornitermes silvestrii Emerson. Coptotermes sp. was found attacking trees of Eucalyptus sp. and C. silvestrii in soybean areas. The present study demonstrates that the termite fauna in this ecotone runs risk of being reduced due to the destruction of its natural habitat after the implementation of monocultures, or of selecting more able species to become pests because of the decrease of its natural enemies and of the introduction of botanical species suitable for their establishment. Key words: Isoptera, termites, monoculture, hypoxerophytic caatinga / O sul do estado o Piau? est? inserido em uma regi?o que desde a d?cada de 1990, ? considerada uma das ?ltimas fronteiras agr?colas do Brasil, esse processo intensificou-se por meio de implementa??o de grandes projetos para a produ??o de gr?os, tendo como carro chefe a soja, voltada para a exporta??o. De um modo geral, as monoculturas est?o sempre relacionadas a pragas, pois aumentam a oferta de alimento, beneficiando alguns grupos de organismos. Os t?rmitas ou cupins s?o considerados uma das pragas de maior problema em ?reas urbanas, suburbanas e rurais, contudo este status s? pode ser empregado a poucas esp?cies. Eles ocorrem nas ?reas tropicais e temperadas, e em todo o mundo existem cerca de 2.800 esp?cies descritas, sendo destas aproximadamente 300 est?o distribu?das no Brasil em quatro fam?lias: Kalotermitidae, Rhinotermitidae, Serritermitidae e Termitidae. Dentro deste contexto, o presente estudo teve como objetivo de determinar a distribui??o e a diversidade de t?rmitas no ec?tone cerrado/caatinga na regi?o sul do estado do Piau? em ?rea de vegeta??o natural e em ?reas modificadas pela agricultura. Foi realizada no per?odo de novembro de 2009 a fevereiro de 2010, a coleta ativa de cupins em transectos de ?rea de um hectare, em ?rea de vegeta??o preservada e monoculturas de soja, avaliando-se tamb?m a arquitetura dos ninhos ep?geos, distribui??o, volume, grupos alimentares, fauna associada, domin?ncia, associa??o com a vegeta??o e o perfil ed?fico das ?reas de coleta. Na caatinga do sul do Piau?, observou-se que todos os cupins coletados na ?rea de vegeta??o preservada pertenceram a uma ?nica fam?lia (Termitidae), sendo 10 esp?cies identificadas: Armitermes sp., Constrictotermes cyphergaster Silvestri, Inquilinitermes fur (Silvestri), Inquilinitermes microcerus (Silvestri), Labiotermes longilabius (Silvestri), Nasutitermes sp1., Nasutitemes sp2., Spinitermes sp., Syntermes wheeleri Emerson e Syntermes molestus Burmeister. C. cyphergaster (42%), Nasutitermes sp1. (30%) e S. wheeleri (25%) foram classificadas como eudominantes, com base no n?mero total de ninhos amostrados (n = 57). Nos ninhos de S. wheeleri, verificou-se a presen?a de cinco ordens de artr?podes (Aranae, Escorpiones, Coleoptera, Orthoptera e Isoptera) associadas. Nasutitermes sp1. apresentou nidifica??o somente em plantas arb?reas, ou seja, na canela-de-velho (Cenostigma macrophyllum, Caesapinioideae). No cerrado do sul do Piau?, apenas duas esp?cies de cupins foram encontradas ?rea de monocultura de soja: Coptotermes sp. e Cornitermes silvestrii Emerson. Coptotermes sp. foi encontrada atacando ?rvores de Eucalyptus sp. e C. silvestrii em ?rea de plantio de soja. O presente estudo demonstra que a fauna de t?rmitas neste ec?tone corre risco de ser reduzida devido ? destrui??o de seu habitat natural decorrente da implementa??o de monoculturas, ou, de selecionar esp?cies mais aptas a ser tornarem pragas diante da diminui??o de seus inimigos naturais e da introdu??o de esp?cies bot?nicas ideais para seu estabelecimento.

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