Since the garden appears to be suffering an onslaught of pests and diseases at the moment I thought it may be useful to share some of my problems. So today’s little horror is tortrix moth or, more specifically, the larvae of them. The adults are not seem that often and they vary in shape and colour since there are many species, but the most common are rusty brown and upside-down shield shaped and about slightly more than 1cm long. There are 400 species in the UK but the only common ones are the apple moth (which affects apples) and the carnation tortrix moth which is not so fussy about what it attacks and although most common as a pest in summer it can breed all year round in greenhouses. What is characteristic is the way the moths lay the eggs singly and as soon as the caterpillars hatch out the ‘stitch’ two leaves together and feed within a little tent, munching away at the leaf tissue. So you do not often see the grubs themselves but should be suspicious if you see two leaves stuck together at odd angles. I pulled apart these hibiscus leaves and there was the little grub.
Because the grubs are hidden, there is little point in spraying with a contact insecticide. You could use a systemic insecticide but there is no point really and if you want to control them you can simply squash them in their little homes. Or you could pull their tents apart and reveal the pests for the birds.
Here is a buddleia that was attacked.