Fruit growers are being warned of the potential invasion of a pest that has devastated crops in America and is now moving closer to the UK from southern Europe.
The non-native brown marmorated stink bug (Halyomorpha halys) "has yet to come to England, as far as we know, but it has a devastating affect on fruit", said East Malling Research research leader Dr Jerry Cross. "It's an absolutely dreadful pest."
Accidentally introduced into eastern Pennsylvania in 1996 from Asia, the bug has caused millions of dollars' worth of damage to apples across mid American states, wiping out more than one-fifth of the value of the crop. It has since been found in Italy, Greece, France, Hungary and Switzerland.
"It has spread all over the States, can live in all sorts of host plants and trees and can move unrestricted in any environment," Cross told the recent British Independent Fruit Growers' Association technical day (28 January).
"It's also a public nuisance because it invades homes and it will probably arrive in Great Britain before very long," added Cross.
He suggested that pheromone traps may help, while applications of Tracer have helped to fight the native stink bug. But he warned that strict rules on importing predatory insects could stymie biological control.
Bug - Disfigured fruit
The stink bugs feed on a range of fruits and other foods by piercing the outer surface and sucking out juices while injecting saliva. Besides disfiguring fruit, rendering it unsaleable, this can also transmit pathogens.
In the USA it has been found on a range of crops including peaches, apples, green beans, soybeans, cherries, raspberries, and pears. The bugs emit a pungent smell, which has been likened to coriander, as a defence mechanism.
A parasitoid wasp and a fungus are being researched as possible biological controls.
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