The researchers tested the insects with all ambient air, with ambient air and ozone, with ambient air and volatile organic compounds, and with ambient air and a mix of ozone and volatile organic compounds. When presented with an ambient air or volatile organic compound airstream, the beetles chose the volatile organic compound tube 80 percent of the time.
"However, as the ozone levels increased, they chose the path to the flower less frequently," said Fuentes. "By the time the mix contained 80 parts per billion ozone, the beetles showed no preference for either tube."
The researchers also tested the beetles with volatile organic compounds and a mix of volatile organic compounds and ozone. At low ozone levels, the insects showed no preference, but as ozone levels increased, the insects increasingly preferred the ozone-free path. At 80 parts per billion, the beetles chose the volatile organic compounds without ozone significantly more often than the ozonized mixture.
While one might think that higher ozone levels in the lower atmosphere would improve crops because predator insects would be unable to find their hosts, the additional ozone would also interfere with mutualistic insect plant responses such as pollination.
|Contact: A'ndrea Elyse Messer|