What are figwort weevils?

Figwort weevils are several closely related Cionus and Cleopus species of beetles. Both the adult weevils and the larval stage eat the foliage and flowers of Figworts, buddleias, Cape fuchsia and Verbascum 

Symptoms

Plants most commonly fed upon by figwort weevils include Phygelius, Buddleja globosa, Scrophularia and Verbascum. 

• Several species of weevil (Cionus and Cleopus species) partly eat leaves which can lead to foliage drying up, particularly at the shoot tips. There is also likely to be damage to flower buds
• The adult beetles are black and greyish white and are up to 4-5mm (about 1/8in) long, with one or two black circular marks where the wing cases meet
• The larvae are up to 6mm (about ¼in) long and yellowish-brown grubs with black heads
• The larvae feed on leaves by grazing the surface of the leaf. The remaining tissues can dry up and become brown or white
• Fully grown larvae spin spherical brownish cocoons on the plant stems in which they pupate, these can appear seed like

Control

Check susceptible plants frequently from spring onwards so action can be taken before a damaging population has developed. When choosing control options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section. If this is not sufficient to reduce the damage to acceptable levels then you may choose to use pesticides. Within this group the shorter persistence pesticides (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action.

Non-pesticide control

• Where possible tolerate the presence of these weevils. Damage to plants is often minor and they rarely cause long term damage to the host plants
• Where feasible the weevils and larvae can be removed by hand picking
• Encourage wildlife in the garden, such as birds, frogs and predatory ground beetles who will eat the larvae and sometimes the adult beetles

Pesticide control

• Pesticides are likely to be more effective on larvae than adults
• Organic contact insecticides containing natural pyrethrins (e.g. Bug Clear Gun for Fruit & Veg, Neudorff Bug Free Bug and Larvae Killer). Several applications of these short persistence products may be necessary to give good control
• More persistent contact insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer) and cypermethrin (e.g. Py Bug Killer)
• The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available

Download

Pesticide for amateurs (Adobe Acrobat pdf document outlining pesticides available to gardeners)

Biology

• Adult weevils overwinter in soil, leaf litter and other sheltered places
• They emerge in May and June when they seek out host plants on which they lay eggs
• There are two generations during summer between May and late August
• When fully grown, the larvae spin spherical brownish cocoons on the plant stems in which they pupate
• These cocoons closely resemble the seed pods of figwort