Bioactive natural compounds for thrips control
Abstract
Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), the western flower thrips, is one of the most destructive pests of greenhouse vegetable crops. In 2003, 102 hectares cucumber (91,1 % of the total Austrian production) and 22 hectares sweet pepper have been cultivated in Viennese greenhouses. Both are preferred host plants of F. occidentalis. Natural secondary plant compounds are part of the chemical defence system of plants against phytophagous insects. They have previously been found to have considerable biological activity such as repellent and/or feeding and oviposition deterrent properties against F. occidentalis. These findings point at natural compounds as promising synergists for various biological or chemical control measures in conventional, integrated or organic farming systems, the more so because they are generally regarded as not toxic to non-target organisms and do not persist in the environment. Up to now research focussed mainly on a possible utilisation of non-toxic effects of natural compounds in the control of F. occidentalis. Yet, any plant compound considered for utilisation as crop protection agent has to be tested for its toxicity to the target pest, particularly when the intended application on crop plants is similar to an insecticide treatment. Therefore, the scientific objective of the proposed study is to determine the direct contact toxicity of selected repellent and/or deterrent natural plant compounds to F. occidentalis and to evaluate their sublethal effects on its development when applied on cucumber and sweet pepper. Furthermore, a comparison of effects on two essential host plants cultivated in Viennese greenhouses will give indications about possible influences of the plant species on the biological activity of the compounds. Fulfilling these objectives, the study will contribute to an evaluation of the factual applicability of natural plant compounds in current and future biological or integrated pest management (IPM) strategies.
keywords Frankliniella occidentalis secondary plant compounds toxicity life history parameters
Publikationen
Project staff
Elisabeth Helene Koschier
Ao.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Elisabeth Helene Koschier
elisabeth.koschier@boku.ac.at
Tel: +43 1 47654-95303
Project Leader
01.01.2006 - 31.12.2006