Perennially cited as one of the most prevalent of garden insect pests, Vine Weevil (Otiorhynchus sulcatus) is also one of the most dangerous as its larvae feed on plant roots with potentially fatal consequences – the adults nibble at the leaf margins of many herbaceous plants, causing only minor (and mainly aesthetic) damage…
Plants growing in pots and containers are most at risk, so it is rare for an established, ground-planted hedge to succumb. Hedge plants that are often cited as being prone to attack (Euonymus fortunei ‘Emerald ‘n’ Gold’, Cherry Laurel, Photinia Red Robin or Yew) are really only susceptible when they are young and/or growing in containers.
Adult weevils (Pictured Top);
▫ Active from spring to late summer
▫ These dull-black, pear-shaped beetles are c.9mm long. Nocturnal (they hide during daylight), slow-moving and flightless, they are adept climbers
▫ The characteristic serrated nibbling on leaves is the most obvious sign that you have an infestation
▫ The eggs are brown and small – less than 1mm across – and laid in their hundreds. Many a gardener has mistaken slow-release fertiliser pellets for weevils!
▫ Other favoured plants and shrubs include Bergenia, Epimedium, Hydrangea, Primula, Rhododendron, and Strawberry
Larvae (Pictured Bottom):
▫ Active from summer to spring. Plants are most at risk from September to March when the larvae are approaching full-size.
▫ These c.10mm grubs live in the soil and are white, plump, legless with a pale-brown head
▫ They can attack a wide range of plants indoors and out – a few hedges as mentioned but also Begonia, cacti and succulents, Cyclamen, Heuchera, Polyanthus, Primulas, Sedum And Strawberries
In our next post, we’ll look at Prevention, Control and Treatment….