5 natural ways to get rid of damaging pests like box hedge caterpillars
Caterpillars of the Box Hedge family are more widespread in East Asia, yet they have become a terrible nuisance on British coasts. Here’s how to deal with them.
Box hedge caterpillars, sometimes known as box tree caterpillars, eat box plants and can quickly devastate a healthy plant. The pests were initially discovered in gardens in the United Kingdom in 2011, and they soon expanded over England, Wales, Scotland, and Northern Ireland.
Caterpillars are frequently discovered by gardeners when webbing and caterpillars are seen on box plants.
Look for pale yellow flattish eggs deposited sheet-like on the underside of box leaves, overlapping one other.
Greenish-yellow caterpillars with black heads emerge from their cocoons.
Caterpillars that are older are greenish-yellow in color with strong black and thin white stripes running the length of their bodies.
With a wingspan of roughly 4cm, the adult moth normally has white wings with a faintly iridescent brown border, but the wings can sometimes be totally brown or clear.
The caterpillars feed on box leaves and weave a web around their dining location.
Plants may also show patches of dieback, which are especially noticeable on pruned plants; however, be careful not to confuse this with dieback caused by the disease box blight.
Caterpillars can also peel bark off a hedge as they take over the entire structure.
According to the Royal Horticultural Society (RHS), there are two approaches for removing pests: with or without pesticides.
In 2017, the insects were rated the top pest in the Royal Horticultural Society’s (RHS) annual top ten plant pests and illnesses rankings, according to Guy Barter, Chief Horticulturist.
“At RHS Garden Wisley, we have cages of caterpillar-infected bushes,” he remarked.
“One method is to use nematodes, which are small worms that kill insects.
“We’re still looking into that, and it’s unclear whether it’ll be possible.
“Unfortunately, in the long run, it will almost certainly be required to replace the box with comparable plants.
“Box bushes that have been stripped of their leaves frequently do not recover. A high level of vigilance is required.
“Picking caterpillars off a large hedge can be a difficult operation, but it is doable on a smaller scale.
“No one wants to use insecticides because they hurt all insects, not just destructive ones, but there is no other option if a severe attack occurs.”