Study of population dynamics of Orius laevigatus on green beans and marigold as banker plants in greenhouse strawberry planting

The western flower thrips, Frankliniella occidentalis is one of the strawberry pest which threats the health of strawberry consumers due to the widespread use of pesticides against it. The aim of this study was to evaluate the suitability of the host plant as a substrate for oviposition and growth of stable population of O. laevigatus and thus control of western flower thrips in strawberry greenhouse. O. laevigatus laid more eggs on marigold than strawberry and green bean in both choice and no-choice experiments. The number of eggs laid on the marigold was 19.60 ± 1.16 in choice and 42.20 ± 2.92 in no-choice test, respectively. In addition population density of immature stages and adults of both thrips and predator was measured throughout the growing season of green bean, marigold and strawberry. The results showed that the density of the thrips on green bean was significantly decreased whereas the density of the predator was significantly higher on marigold. Green bean showed a higher potential than marigold as a banker plant to support the population of O. laevigatus on strawberry to reduce the western flower thrips population.