The role of aphids in wood formation. II. The effect of the Lime aphid, Eucallipterus tiliae L. (Aphididae), on the growth of Lime, Tilia X vulgaris Hayne.
In one year, saplings of T. X vulgaris [T. X europaea] increased very little in weight when a population of E. tiliae was allowed to develop on them. However, growth above ground, as indicated by girth, height increment, and leaf number and size, was normal, and the reduction in total weight increase of the infested saplings was due to poor root growth. In the year following aphid infestation, the size of the annual ring was the same in both infested and uninfested saplings; the infested saplings had only half the leaf area of the controls, but their leaves were heavier, contained more N and fixed more energy per unit time. Infested saplings shed their leaves earlier than controls, and the onset of leaf-fall was related to the time of aphid infestation. Results are compared with those obtained in similar studies on Acer pseudoplatanus [cf. FA 32 No. 6394]; the drain on annual net production and stemwood production in Tilia and the ecological effects of heavy aphid infestation are discussed.
Hemiptera \ insect pests \ effects \ increment \ insect pests \ host relations \ Therioaphis tiliae \ Tilia X europaea