Aspects of bio-intensive pea aphid, acyrthospihon pisum (Harris) management on lentil, lens culinaris (Medikus)

[摘要] Damage caused by the Pea aphid, Acyrthosiphon pisum (Harris) is a limiting factor in lentilproduction in Ethiopia. Although application is minimal, losses are combated with theapplication of synthetic pesticides like Primicarb®. However, the continuous application ofsynthetic pesticides may result the development of insect resistance to insecticides, adverseeffect on non-target organisms and environmental pollution. It is therefore necessary toimplement a multi-faceted approach in order to keep A. pisum populations below economicthreshold level.This thesis highlights aspects of an integrated pest management approach to this pest.The components studied were host plant resistance, biological control and chemical controlwith bio-rational pesticides. All the trials were done under glasshouse condition in theUniversity of the Free State, Bloemfontein, South Africa.The host plant resistance study was completed in two phases. The first phase dealtwith the preliminary screening of fifty entries of lentil introduced for such purposes. Oneentry appeared to be resistant while six were moderately resistant to A. pisum. The resistantentry and four of moderately resistant entries selected randomly were chosen for the nextstudy. The second phase thoroughly examined and identified the mechanisms of resistance ofeach entry previously identified as moderately resistant and/or resistant.With in the field of microbial control of agricultural pests, the effect of Beauveriabassiana on population of A. pisum was evaluated. This method appeared to be effective insignificantly reducing the population of A. pisum compared with the control. The lastcomponent investigated the influence of the botanical product Neemolin® and extracts ofWild sering, Burkea africana on the fecundity of A. pisum. A. pisum populations treated withNeemolin® produced significantly fewer offspring than the control and proved to be aneffective control measure. On the other hand, application of extracts of Wild sering, Burkeaafricana did not affect A. pisum population. The result does not indicate the failure of thisextract against the pest rather highlights the need to keep the extract in water for long hoursso that the extract can dissolve and the insecticidal property can be enhanced.The results of this study therefore indicate that the components of an integrated pestmanagement approach included in this study will serve as a base towards effectivemanagement of this pest.

[发布机构] University of the Free State