Application strategies for entomopathogenic nematodes in the control of oilseed rape pests

摘要

Biological control strategies include (i) conservation, (ii) inundation, (iii) inoculation, and (iv) classical introduction of natural enemies for the control of pests (Eilenberg et al., 2001). Conservation biological control implies keeping alive andenhancing the effectiveness of those natural enemies that are already present in the target ecosystem, and is the main method which can rapidly be applied over large areas in open-field agricultural systems. Inundation implies adding natural enemies tothe system in large numbers, repeatedly, when (under natural conditions) they are present in too low numbers to be effective. Our earlier survey showed that entompathogenic nematodes (EPNs) occur in European rapeseed fields only at a very low density (Zec-Vojinovic et al., 2006). Therefore, only the inundative strategy, or inundation/inoculation followed by conservation biological control, is possible if effective use of EPNs for the management of oilseed rape (OSR) pests is desired. The arm of this study was to investigate the potential of EPNs in controlling OSR pests, in particular the pollen beetle (Meligethes aeneus) as the model target pest. As the timing and method of EPN application appeared to play a crucial role along with the EPN dose applied, this study focused on determining the effect of these factors on pollen beetle mortality. Effects on cabbage flea beetle (Phyllotreta spp.) were also assessed.