Effect of essential oils on host plant location of pollen beetles – Olfactometer and field-cage experiments 2013.

Summary

Essential oils can have an impact on pollen beetle (Meligethes spp.) host plant location behaviour. Lavender oil (Lavendula angustifolia) showed the highest repellency value in laboratory studies comparing five different essential oils (Mauchline et al. 2005). However, lavender oil is one of the most expensive essential oils – a fact that could seriously hamper onfarm implementation of this strategy. To find a less expensive essential oil with comparable efficacy to lavender oil, we compared the essential oils of Mentha arvensis, Eucalyptus globulus, Melaleuca alternifolia, Citrus sinensis, Citrus paradisi, Citrus limon, Juniperus mexicana, Abies sibirica, Illicium verum, Gaultheria procumbens, Cymbopogon flexuosus, Syzygium aromaticum, and Litsea cubeba as well as the pine oil product Heliosol using a Ytube- olfactometer. Essential oils were diluted 1:10 in acetone and 40 μl of the dilution were applied on a 3.1 cm2 filter paper. Filter papers were placed in the odour containers of the olfactometer together with a flower cluster of spring oilseed rape (variety Hero) with 5 open flowers and 10-15 buds. Filter papers treated only with acetone were used as a control. Starved pollen beetles were released individually into the olfactometer. The choice of the beetles and the time period until choice were recorded. Flowers and essential oils were changed between replicates. Six replicates with six beetles each were conducted.