 A group of scientists from Germany and Wageningen University have discovered a connection between the behavior of insects and isoprene secretions of some trees.
Isoprene (2-methyl-1,3-butadiene) is formed naturally in some plants with the levels of the gas secretions increasing as temperatures increase.
When plants are attacked by insects, they emit specific odours that act as an emergency signals and attract predatory parasitic wasps to the location which then act to control the population of pests.
However it has been noted that trees such as Oak (Quercus), Willow (Salix), and Poplar (Populus) emit such a quantity of isoprene that these emergency signals are completely overwhelmed and the parasitic wasps are unable or unwilling to rescue any plants located near these trees from the predations of the plant eating insects.
The observations were verified when the gene which controls the manufacture of isoprene was inserted into Sandrocket plants (Diplotaxis tenuifolia) which do not naturally produce isoprene. Entomologists noted that the plant-eating insects were not perturbed by the presence of the isoprene, even thought the ‘emergency signals’ were produced and emitted as would be expected. However predatory wasps bypassed the plant that was emitting the signal, indicating that it was somehow now undetectable.
The implicationsThis finding has interesting implications for nurseries and landscape designers for consideration of which plants to grow in close proximity with each other, especially if biological controls are being used or contemplated. In addition it should be noted that as isoprene production increases with temperature it is likely that this phenomenon will become more prevalent as climate change increases.
The scientists are the first to establish a connection between the behavior of insects and isoprene secretions. They recently published their findings in the online edition of the proceedings of the National Academy of Sciences.
source: De Boomkwekerij |
