Karl W. Kleiner

Stability of phenolic and protein measures in excised oak foliage

The stability of protein and phenolic measures in excised foliage from two oak species was measured under conditions that simulated the handling and treatment of foliage during insect rearing trials. Excised foliage kept hydrated under refrigeration or insect-rearing conditions maintained stable levels of protein content, proanthocyanidins, gallotannins, total phenolics, and protein-binding capacity for up to 48 hr following field sampling. Measures of protein content, total phenolics, protein-binding capacity, and proanthocyanidins were significantly greater 48–72 hr after field sampling, followed by declines to near field levels within 120 hr.

The impact of water and nutrient stress on oak leaf quality and gypsy moth performance

It is widely accepted that abiotic stress can increase the suitability of plants to insect herbivores and subsequently improve herbivore performance and increase their abundance (Mattson & Haack, 1987; Larsson, 1989; Jones & Coleman, 1991). In the eastern United States, gypsy moth (Lymantria dispar L.) populations exhibit outbreaks periodically every 8–12 years and are most likely to develop in stands growing on sandy or thin rocky soils. In central Pennsylvania, these forest stands occur on steep upper slopes and ridgetops which have been characterized as having extremely well drained, poor quality soils (Doane & McManus, 1981).