Impact of Pine Leaf Aphid, Pineus pinifoliae (Chermidae) on its Secondary Host, Eastern White Pine

Abstract

Pine leaf aphid infestation produces not only a general reduction in radial growth of white pine but also a modification of the normal pattern of annual radial increment along the length of the stem. The greatest growth reduction occurs in the lower stem with proportionately less in the midcrown area and least in the top. This appears to reflect the distribution of branch mortality which is greatest in the mid- and lower crown. Several defoliators studied by other workers produce the greatest effect on radial growth and on foliage survival in the tops of the tree.Stem elongation reduction occurs only after crown damage and aphid infestation becomes extreme. Lighter infestations are reflected, however, in reduced needle length in the year of attack followed by reduced branch elongation in the year following attack. The combination of stunted and normal needles alternating with stunted and normal branch internodes is probably a unique characteristic of pine leaf aphid damage.

Effects of sap-feeding insect herbivores on growth and reproduction of woody plants: a meta-analysis of experimental studies

“…The individual eVect is signiWcant if the 95% conWdence interval does not include zero; asterisks denote signiWcant (***P < 0.001, **P < 0.01) between-class heterogeneity severely aVects long-term growth (Smith and Schowalter 2001). A series of successive attacks can result in plant weakening or even death (DeBoo et al 1964;Furuno and Nakai 1987). Therefore, we expected to locate several hundred relevant publications; however, our extensive search for literature on the responses of woody plants to sap-feeders resulted in only 52 publications suitable for meta-analysis.…”

Biology and Evolution of Adelgidae

“…This causes reduction in new growth the following year, forcing the adelgids to feed on less nutritious old growth and causing the population to crash (102). Populations of the holocyclic species P. pinifoliae are remarkably synchronized such that populations are almost entirely on either Picea or Pinus in alternate years (38,39,95). Pinus branches with alternating long and short internodes testify to the impact of adelgids in alternate years when radial growth is inhibited by heavy infestations (38).…”

Defoliation and growth loss in young Sitka spruce following repeated attack by the green spruce aphid, Elatobium abietinum (Walker)

“…Several of these aphids are serious pests of commercial forest plantations, and the damage and loss of foliage that they cause has been related to reductions in shoot and height growth (DeBoo et al, 1964;Thompson, 1977;Madoff and Austarå, 1990;Straw et al, 1998), smaller radial and volume increments (Zwolinski, 1990;Day and McClean, 1991;Thomas and Miller, 1994;Straw et al, 2000), and decreases in stand productivity (May and Carlyle, 2003).…”