Influence of white pine watering regimes on feeding preferences of spring and fall adults of the white pine weevilPissodes strobi (Peck).
Spring and fall adults of the white pine weevil,Pissodes strobi (Peck), were exposed in no-choice and two-choice tests to bark from water-stressed and non-water-stressed white pine (Pinus strobus L.), which had also been exposed or not exposed to weevil attack. This experiment demonstrated that the weevils could discriminate between bark from water-stressed white pine and preferred bark from the nonstressed plants. The weevils also preferred bark from nonstressed plants that were previously exposed to weevil damage. Spring and fall adults displayed the same feeding preferences. No sex differences were found in feeding preferences. Less nitrogen, phosphorus, and potassium were found in bark from the nonstressed plants, and the potassium level was higher in damaged plants. We expect that the biological performance of the weevil should be favored by vigorously growing plants rather than by stressed plants.
Canadian Forest Service-Quebec Region, 1055 du P.E.P.S., P.O. Box 3800, G1V 4C7, Sainte-Foy, Quebec, Canada.
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Lavallée
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Albert
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Mauffette