Uso do caulim no controle do pulgão preto do feijoeiro Aphis craccivora Koch (Hemiptera:Aphididae)

Abstract

The present work had as objective to evaluate the effect of kaolin on the aphid Aphis craccivora black control Koch of the bean. The experiment was conducted in the experimental area of the academic unit of Serra Talhada, Universidade Federal Rural de Pernambuco in the municipality of Serra Talhada-PE. Evaluated the effect of kaolin on prevention of aphid infestation black and your effect on mortality of aphid in screenhouse nursery. As it was decided to split the methodology experiment in two steps, in both was used the variety of cowpea "Paulistinha", in the first step to evaluate the efficiency of kaolin as preventive agent was conducted in random blocks design where the treatments consisted of weekly sprays (i) kaolin and scatter adhesive, (ii) only scatter adhesive and (iii) witness (water), enough to cover the whole aerial part of plants, in the second stage in order to evaluate the effect of kaolin on the black aphid mortality the experiment was carried out in completely randomized design, being made manually infestation plants 20 days after your emergency and after the establishment of the colony of aphids the treatments consisted of a single spraying with: (i) kaolin and scatter adhesive and (ii) water, and made scores of individuals living and dead every 24 hours until the fifth day after application. The black aphid a. craccivora presented high infestation in the field, all blocks and treatments with greater than 90% infestation, not showing differences between blocks and treatments. The percentage of infestation per week of black aphid bean cowpea plants showed that in every week (1-5) with larger infestations in the first two weeks with decreasing values ranging of 88.21% 93.91%, respectively. The kaolin presented toxic effect on the black bean aphid with mortality of approximately 20% a day after application. It is concluded that the application of the kaolin as preventive agent in the emergence of the black bean aphid showed no significant effects, not showed your effect on the occurrence and population growth of the aphid, the reduction of the infestation occurred in all treatments. On the other hand, the kaolin caused mortality of black aphid, under controlled conditions, on the first day after application, so applications with kaolin, every two days, will promote a black aphid control in Cowpea bean culture.