Ethanol, methanol, acetone, and acetaldehyde-chemicals identified in the inner bark of living trees-were used to bait vane traps placed in crowns of oak trees in Connecticut. Ethanol-baited traps caught more cerambycid, scolytid, and clerid beetles than unbaited traps. Buprestidae were not attracted to ethanol. Acetaldehyde and acetone were not attractive to any family. A mixture of ethanol, methanol, and acetaldehyde was no more attractive than ethanol alone. The vane traps were very effective at catching Cerambycidae and Scolytidae, but ineffective compared to sticky panels at catching Buprestidae.

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Sugar maple (Acer saccharum) is a keystone species in the forests of the northeastern and midwestern United States and eastern Canada. Its sustained health is an important issue in both managed and unmanaged forests. While sugar maple generally is healthy throughout its range, decline disease of sugar maple has occurred sporadically during the past four decades; thus, it is important to understand the abiotic and biotic factors contributing to sugar maple health. Soil moisture deficiency or excess, highway deicing salts, and extreme weather events including late spring frosts, midwinter thaw/freeze cycles, glaze damage, and atmospheric deposition are the most important abiotic agents. Defoliating insects, sugar maple borer (Glycobius speciosus), Armillaria root disease, and injury from management activities represent important biotic factors. Studies of sugar maple declines over the past four decades reveal that nutrient deficiencies of magnesium, calcium, and potassium; insect defoliation; drought; and Armillaria were important predisposing, inciting, and contributing factors in sugar maple declines. Forestland managers can contribute to sustained health of sugar maple by choosing appropriate sites for its culture, monitoring stress events, and examining soil nutrition.

Black oak (Quercus velutina Lam.) and gray birch (Betula populifolia Marsh.) trees were defoliated in 0, 1, 2, or 3 successive years. Concentrations of 8 minerals, 4 sugars, and 25 amino acids in the foliage of these trees were measured when gypsy moth, Lymantria dispar (L.), reared on them were in instars I, III, IV, and V. These concentrations were tested for changes among years, and changes due to previous-and current-year defoliations. Most foliar constituents varied in concentration from year to year, though relatively few were affected by current or previous defoliations. In black oak, concentration of total free sugar measured during the fifth instar was reduced by current defoliation and correlated with gypsy moth pupal weight. In gray birch no decrease in sugar concentration due to defoliation was apparent, but pupal weights of gypsy moths reared on these trees were correlated with the ratio of total free sugar to calcium in the foliage measured during the fifth instar. Some implications of these apparent relations for gypsy moth larval growth and population dynamics are discussed.

A study established in 1985 in north-central Pennsylvania to determine effects of lime fertilization on declining sugar maple (Acer saccharum Marsh.) was evaluated in 1993 and showed that liming positively affected growth and crown vitality in sugar maple. This effect of lime on sugar maple offered an opportunity to assess other indicators of tree vitality and their response to lime additions. Foliar polyamines, starch and soluble sugars in root tissues, and cambial electrical resistance (CER) at breast height were evaluated. Foliar putrescine, soluble sugars, and CER decreased, while starch increased in lime-treated trees. Changes in these indicators were correlated with tree growth and crown vitality, which improved in limed plots. However, they were more highly correlated with lime-induced changes in foliar and soil elements and soil pH. Putrescine, soluble sugars, and CER decreased and starch increased, as Ca and Mg and molar ratios of Ca/Al and Mg/Mn increased and as Al and Mn decreased in both soil and foliage, and as soil pH increased. Results showed the beneficial effect of lime on tree vitality that was not reflected in visual assessments of crown vitality and demonstrated the potential utility of these physiological and biochemical measures as indicators of vitality in sugar maple.Résumé : Une étude établie en 1985 dans le centre-nord de la Pennsylvanie pour déterminer les effets du chaulage sur le dépérissement de l'érable à sucre (Acer saccharum Marsh.) a été évaluée en 1993 et a montré que le chaulage avait un effet positif sur la croissance et la vitalité de la cime chez l'érable à sucre. L'effet du chaulage sur l'érable à sucre offrait une opportunité pour évaluer d'autres indicateurs de la vitalité des arbres et de leur réaction à l'addition de chaux. Les polyamines foliaires, l'amidon et les sucres solubles des tissus racinaires ainsi que la résistance électrique cambiale (REC) à hauteur de poitrine ont été évalués. La putrescine foliaire, les sucres solubles et la REC ont diminué tandis que l'amidon a augmenté chez les arbres traités à la chaux. Les changements dans ces indicateurs sont corrélés à la croissance des arbres et à la vitalité de la cime qui se sont améliorées dans les parcelles chaulées. Cependant, ils sont davantage corrélés aux changements dus à l'effet du chaulage sur les éléments minéraux dans les feuilles et le sol et sur le pH du sol. La putrescine, les sucres solubles et la REC ont diminué et l'amidon a augmenté avec l'augmentation du Ca, du Mg et du ratio molaire de Ca/Al et de Mg/Mn, la diminution de Al et de Mn dans le sol et le feuillage et l'augmentation du pH dans le sol. Les résultats montrent que l'effet bénéfique du chaulage sur la vitalité de la cime ne se reflétait pas dans l'évaluation visuelle de la vitalité de la cime. Ils démontrent également l'utilité potentielle de ces mesures physiologiques et biochimiques comme indicateurs de vitalité chez l'érable à sucre.[Traduit par la Rédaction] Wargo et al. 641

Sapling sugar maple (Acersaccharum Marsh.) trees were defoliated artificially at 10-day intervals beginning May 27 and ending August 5, 1981. Refoliation, terminal bud and shoot development, and xylem starch and sap sugar concentration were observed in defoliated and control trees. All defoliated trees refoliated, but decreasingly with later defoliation. Defoliation caused an acceleration in the rate of primordia initiation in terminal shoot apices. After early season defoliations, the developing buds in the axils of the removed leaves abscissed, but axillary and terminal buds on the refoliated terminal shoots survived through winter. In late season defoliation, most buds of refoliated shoots did not survive and the next year's growth depended on axillary buds formed prior to defoliation. Thus, when progressing from early to late defoliations, the next year's shoot growth depended decreasingly on the last-formed and increasingly on the first-formed portions of the previous year's shoot. Early October starch concentration in xylem decreased with later defoliation and was nearly absent in shoots and roots of trees defoliated in late July. There was not, however, a corresponding decrease in sap sugar concentration. Mortality occurred only in late defoliated trees and was associated with starch depletion.

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