2016 journal article
Physico-Chemical Responses of Fraser Fir Induced by Balsam Woolly Adelgid (Homoptera: Adelgidae) Infestation
JOURNAL OF ENTOMOLOGICAL SCIENCE, 51(1), 94β97.
The balsam woolly adelgid, Adelges piceae (Ratzeburg) (Homoptera: Adelgidae), is a major pest in Fraser fir, Abies fraseri (Pursh) Poir, Christmas tree plantations in the southern Appalachian Mountains. Shortly after eclosion, A. piceae larvae insert their stylets into intercellular bark tissue to ensure a constant feeding source from cortical parenchyma cells (Balch 1952, Can. Dept. Agric. Publ. No. 867, 76 pp.). Thereafter, the developing adelgid is attached at that site for the remainder of its life (Balch and Carroll 1956, Can. Dept. Agric. Publ. No. 977, 7 pp.). Insects that use a piercing-sucking mode of feeding, such as adelgids, elicit a response similar to that of fungal and bacterial plant pathogens (Walling 2000, J. Plant Growth Regul. 19: 195β216; Bernards and Spohr 2008, Pp. 189β211, In Schaller, A. (ed.), Induced Plant Resistance to Herbivory, Springer Science, Stuttgart, Germany). The synthesis of new compounds or structural barriers after herbivore-induced damage occurs, including the accumulation of proteins and secondary metabolites, are characteristics of induced defenses (Bernards and Spohr 2008). For example, the formation of cell wall modifications can be induced by wounding and herbivory (Ginzberg 2008, Pp. 131β146, In Schaller, A. (ed.), Induced Plant Resistance to Herbivory, Springer Science, Stuttgart, Germany). Host resistance mechanisms include rapid accumulation of monoterpene and juvabione-related compounds, the production of secondary periderm (Mullick 1975, Can. J. Bot. 53: 2443β2457; Hain et al. 1991, Pp. 271β287, In Baranchikov, Y.N., Mattson, W.J., Hain, F.P., Payne, T.L. (eds.), Forest Insect Guilds: Patterns of