8 research outputs found
Répartition de la végétation dans la savane pré-forestière
The vegetation of the Lamto area has been studied along transects linking the gallery forest to the savanna plateau. The counting strips, 20 metres wide and 200 to 460 metres long, were subdivided into a succession of quadrats 20x20 m. In each of these quadrats trees and shrubs were counted and the grass layer sampled. Results are shown on folding pages 1 to 5. Within the study area four different types of savanna are found, grass savanna, shrub savanna, tree savanna and savanna woodland. The shrub savanna in predominant. The relationships between these vegetation types, topography and soils are discussed
Diversidade de afĂdeos na cultura do algodoeiro no municĂpio de Campo Verde (MT) Aphids diversity on cotton field in Campo Verde, Mato Grosso State
O objetivo deste trabalho foi verificar a diversidade de afĂdeos (Hemiptera: Aphididae) na cultura do algodoeiro (Gossypium hirsutum L.) no municĂpio de Campo Verde (MT). Os afĂdeos foram amostrados diretamente nas plantas e atravĂ©s de armadilhas tipo Moericke. As amostragens foram realizadas a cada dois dias, atĂ© 60 dias apĂłs a germinação das plantas. A espĂ©cie Aphis gossypii Glover prevaleceu nas amostragens realizadas sobre as plantas. Formas aladas, de ocorrĂŞncia acidental na cultura, tais como Aphis spiraecola Patch e Rhopalosiphum padi (Linnaeus) tambĂ©m foram observadas. Com as armadilhas tipo Moericke foram capturados 2280 afĂdeos alados, pertencentes a 13 espĂ©cies: R. padi (52,6% do total), A. spiraecola (26,4%), A. gossypii (8,9%), Rhopalosiphum maidis (Fitch) (5,3%), Geopemphigus floccosus (Moreira) (3,1%), Uroleucon ambrosiae (Thomas) (1,5%), Rhopalosiphum rufiabdominalis (Sasaki) (1,3%), Myzus persicae (Sulzer) (0,4%), Sipha flava (Forbes) (0,3%), Pentalonia nigronervosa Coquerel, Tetraneura nigriabdominalis (Sasaki), Lizerius melanocallis (Quednau) e Toxoptera citricidus (Kirkaldy) (0,1% cada uma). Nas amostragens diretamente sobre as plantas foram observados ápteros e alados de A. gossypii e alados de A. spiraecola e R. padi. Nas armadilhas tipo Moericke, as principais espĂ©cies capturadas foram R. padi, A. spiraecola, A. gossypii e R. maidis.<br>This work was carried out in Campo Verde, Mato Grosso State, Brasil, and its objective was to determine the occurrence of aphid species (Hemiptera: Aphididae) on cotton field (Gossypium hirsutum L.). The aphids were sampled both directly on plants and with Moericke's traps. The samplings were accomplished every other day during 60 days. Aphis gossypii Glover prevailed on cotton plants. Winged forms accidental as Aphis spiraecola Patch and Rhopalosiphum padi (Linnaeus) also occurred. In the water-pan traps 2280 winged aphids were trapped, which are from 13 species: R. padi (52.6% of total), A. spiraecola (26.4%), A. gossypii (8.9%), Rhopalosiphum maidis (Fitch) (5.3%), Geopemphigus floccosus (Moreira) (3.1%), Uroleucon ambrosiae (Thomas) (1.5%), Rhopalosiphum rufiabdominalis (Sasaki) (1.3%), Myzus persicae (Sulzer) (0.4%), Sipha flava (Forbes) (0.3%), Pentalonia nigronervosa Coquerel (0.1%), Tetraneura nigriabdominalis (Sasaki) (0.1%), Lizerius melanocallis (Quednau) (0.1%) and Toxoptera citricidus (Kirkaldy) (0.1%). In the direct samplings on cotton plants were present both wingless and winged forms of the A. gossypii and winged forms of the A. spiraecola and R. padi. In the Moericke's traps, the main captured species are R. padi, A. spiraecola, A. gossypii and R. maidis