Tropentag, October 6 - 8, 2009 in Hamburg "Biophysical and Socio-economic Frame Conditions for the Sustainable Management of Natural Resources"

Interactions Between the Omnivorous Bug Orius laevigatus and the Entomopathogenic Nematode Steinernema feltiae, Natural Enemies of the Western Flower Thrips, Frankliniella occidentalis

¹Leibniz Universität Hannover, Plant Disease and Plant Protection, Germany
²Hebrew University of Jerusalem, Entomology, Israel

Abstract

Studies were carried out to explore the possible interaction between predatory bug Orius laevigatus and entomopathogenic nematode Steinernema feltiae, natural enemies of western flower thrips, (predation, parasitism and synergisms) in both laboratory and field condition in Israel. Starved adult females Orius and fifth instars were placed in petridishes with filter paper socked with nematode suspension (5000 ml^-1 water) and filter paper socked only with water served as a control treatment. Significantly shorter survival time of Orius laevigatus was observed in nematode treatments as compare to control. About 80% of the Orius laevigatus were observed infected with nematode. In the study the new food preference of Orius in the presence and absence of nematodes, negative response of predator towards the nematode recorded; the predator clearly avoided the nematode–infected arenas. In the experiments, ability of Orius to differentiate nematode infected thrips and healthy one; it was found that Orius was unable to preferentially feed on healthy thrips. In the study about impact of the nematodes on western flower thrips population, no significant differences were found in WFT populations in control and nematode treatments. Similarly, there was no significant different in the population of Orius in control and nematode treatments. Orius and nematode were found to be incompatible to each other in laboratory condition. It seems less possibility of combine use of these natural enemies to control western flower thrips population. No significant impact of the nematode was found to control western flower in the presence of naturally occurring Orius in Arava valley, Israel.

Keywords: Predator, Orius, Parasitoid, Steinernema, Western flower thrips

Contact Address: Bishnu Kumari Bhandari, Leibniz Universität Hannover, Plant Disease and Plant Protection, Dorotheen Straße - 7- 556, 30419 Hannover, Germany, e-mail: bhandari.bishnugmail.com