Publications des agents du Cirad


Visitantes florais em espécies cultivadas e nao cultivadas de algodoeiro (Gossypium spp.), em diferentes regioes do Brasil

Pires C., Da Silveira F., Cardoso C.F., De Oliveira G.M., Pereira F.F.O., De Souza V., Nakasu E.Y.T., De O. Paes J.S., Teles E., Silvie P., et al.. 2006. Brasilia : EMBRAPA, 40 p.. (Boletim de pesquisa e desenvolvimento : Embrapa-Recursos Genéticos e Biotecnologia, 148).

The gene flow from commercial varieties of cotton to wild species have been studied under the context of environmental risk analysis of GM cotton. Due the role of the bees in the pollen transportation among cotton plants and the possible impacts of the Bt toxin on these species, it was conducted an inventory of flower visitors in different species and different production regions of Brazil during 2003, 2004 and 2005. Information about diversity and abundance of bees on flowers of cultivated species, Gossypium hirsutum and three different wild species of cotton was obtained. In all studied area it was used the large sampling plots method, methodology previously developed and tested in 2003 in the Federal District in a commercial farm cultivated with Gossypium hirsutum (var. Delta Opal). In 2003, the sampling was conducted in Campina Grande, PB on the wild species G. barbadense, G. mustelinum e G. hirsutum var. marie-galante and in Barbalha (CE) on G. hirsutum latifolium. In 2004 the sampling were repeated in the Federal District. The inventory on G. hirsutum latifolium were developed in 2005 in the states of Bahia (Barreiras), Mato Grosso (Primavera do Leste and Rondonópolis), Goiás (Santa Helena de Goiás, and Jussara) and São Paulo (Jaboticabal), and also extended to different areas in the Federal District. Also, in 2005, the studies on the wild species of cotton were conducted in the region of District Federal and northwest of Minas Gerais state. The studies on G. hirsutum latifolium were conducted on commercial farm with and without insecticide applications and also in the Embrapa experimental fields. The bees were the main flower visitors on cotton plants. Taking in account all studied areas, from 153 insect species collected on flowers, 47.40% (72 species) are from four families of bees and 49.78% (1,630) of the total number of individuals collected (3,274) are bees. One species of the genus Exomalopsis is a new species, undescribed in the literature. How was predicted, were collected more species in areas without insecticide and nearby natural vegetation. Apis mellifera, an introduced bee for commercial use, was the most abundant species on cultivated cotton in all sampling areas, however, with low abundance on the wild species and not collected on flowers of G. mustelinum. In G. hirsutum, were collected 41 species of bees in the Federal District (DF) 19 in Bahia (BA), 29 in Mato Grosso (MT), nine in Goiás (GO), five in São Paulo (SP) and only Apis mellifera in Ceará (CE). The most abundant wild species on flowers of G. hirsutum were: Geotrigona mombuca (BA), Melissoptila cnecomala (DF), Paratrigona lineata (DF, MT), Partamona mulata (MT), Trigona spinipes (DF, BA), Tetragonisca angustula (SP), Scaptotrigona depuis (GO) and Xylocopa hirsutissima (GO). In the wild species of Gossypium, were collected 23 species in the state of Paraíba, 10 in Federal Disctrict and three species in the northwest of Minas Gerais. In the state of Paraíba, Ceratina sp.3 and C. chloris, were the most abundant species, followed by Melitoma segmentaria, Lithurgus huberi, Ptilothrix plumata, T. spinipes and Augochlora sp.2. Others insects were collected in lower abundance. The groups more frequent, in terms of species and abundance of individuals, are from the orders Coleoptera, Diptera, Hemiptera and Hymenoptera (considering only ants). In a preliminary analysis it was identified Coleoptera predators of the family Coccinelidae, one species from Dermaptera and at several nectar feeding species of Diptera. Four important pest species were collected in a large number inside the flowers: Anthonomus grandis (Coleoptera: Curculionidae), two species of Diabrotica (Coleoptera: Chrysomelidae) e tree species of Astylus (Coleoptera: Melyridae) e one species of the genus Dysdercus (Hemiptera: Pyrrocoridae). All four species are pollen feeders during the adult phase. Life history and ecology information of the bees are been used for species prioritisation f...

Agents Cirad, auteurs de cette publication :