Weevil Damage on Young Trees
In Spring 2012 I came across a severe infestation of Phyllobius weevils on a newly planted woodland site. The weevil is 3 or 4 mm long and is blue-green in colour. It feeds on the leaves of young trees cutting notches in the leaf and, when present in large numbers, totally defoliating it.
I found the infestation on an old grassland site during herbicide spraying operations in the middle of May. When I returned at the end of the month the number of weevils was much lower and the trees were beginning to show fresh re-growth. It appears that, although an infestation of Phyllobius weevils can look very damaging at the time, the effects are generally short-lived and most young trees recover fully. The following year the infestation is rarely so heavy, the trees are better established and have many more leaves. There is no pesticide approved for the control of the weevil but I found that a sharp whack with a bamboo cane dislodged most of the blighters. OK, they could easily climb back up the tree, but it made me feel better at the time.