Performance of pine sawflies under elevated tropospheric ozone
Silva Fennica 30(23): 179184
Concentration of the phytotoxic air pollutant, ozone (O3) is continually increasing in the lower layer of the troposphere. The purpose of this study was to compare performance of pine sawflies on Scots pine seedlings in ambient and future levels of ozone. Scots pine seedlings were grown in field fumigation system where the ozone doses in fumigated plots were 1.5–1.6 times the ambient level. Larvae of the European pine sawfly (Neodiprion sertifer) and Gilpinia pallida were reared on the foliage of Scots pine. The levels of resin acids and monoterpenes in foliage were analysed. There were no significant effects of ozone fumigation on sawfly performance or levels of defence compounds in pine foliage. The results suggest that the elevated ozone concentrations do not strongly affect the needle quality of young Scots pine and the importance of these two diprionid sawfly species as forest pests.
Received 22 September 1995 Accepted 12 June 1996