Differences Among Scotch Pine Varieties in Susceptibility to European Pine Sawfly
Pinus sylvestris L. seedlots from 108 natural stands in Eurasia were tested in replicated test plantations in southern Michigan. During the fifth to seventh years four such plantations were attacked by European pine sawfly, [Neodiprion sertifer (Geoff.)]. The percentage of trees attacked varied from 0 to 6 for north Eurasian varieties, from 6 to 11 for south European varieties, and from 12 to 26 for central European varieties. The varietal differences were consistent between plantations and between years. In general the tallest varieties were attacked most. The most important exception was var. uralensis which was attacked much less than expected for its height growth. Compared with other varieties, it has wider needles, develops yellow color earlier in autumn, and has lower foliage concentrations of N, P, Na, Mg, Pe, and B. Field observations showed that larvae feeding on the resistant var. uralensis were 1/2 to 1 instar later in development than those on other varieties In an artificial feeding experiment, late-instar larvae showed no preference.
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Document Type: Journal Article
Affiliations: Former Graduate Student, Michigan State University
Publication date: 01 June 1967