There are several species of weevil (Cionus species) that can cause damage to figworts and other plants in gardens.
Plants affected
Figworts (Scrophularia species), buddleias - particularly Buddleja globosa, Phygelius species and Verbascum species.
Symptoms
Damaged plants have eaten and dried up foliage, particularly at the shoot tips, and there is also damage to the flower buds. The adult beetles (illustrated above) are black and greyish white and are up to 4-5mm long with one or two black circular marks where the wing cases meet. The larvae are up to 6mm long and are slimy, yellowish-brown grubs with black heads. The larvae feed on leaves by grazing the surface of the leaf. The remaining damaged tissues dry up and become brown or white. When fully grown the larvae spin spherical brownish cocoons, in which they pupate, on the plant stems; these cocoons closely resemble the seed pods of figwort.
Biology
Adult weevils overwinter in the soil and leaf litter. They emerge in May and June when they seek out host plants on which they lay eggs. There are two generations during the summer.
Control
The weevils and larvae can be controlled by either hand picking or spraying with an insecticide containing bifenthrin (Doff All-In-One Garden Pest Killer, Scotts Bug Clear Gun or Bayer Sprayday Greenfly Killer Plus). If it is necessary to spray while plants are in flower, do so at dusk in order avoid harming bees.