Dont panic over flea beetle
FLEA beetle damage to backward sugar beet is fairly widespread, but spraying to tackle the pests is inadvisable on crops already treated with Gaucho (imidacloprid), says Brooms Barn.
Researcher Alan Dewar advises growers not to not panic. "Consider the causes before splashing expensive and hazardous chemicals about." Untreated crops could merit treatment, though there are no advisory thresholds and the pests can be hard to see in dull weather, he points out.
To get a lethal dose of seed treatment the shiny black beetles must take a bite or two, so some shot-holing or notching is inevitable, Dr Dewar explains. Spraying will not cure such damage and the insects may already have been killed, he notes.
Ninety-nine % of a gamma-HCH spray on to small cotyledons will fall on bare ground killing beneficial insects, and safer pyrethroids offer only limited protection, he adds. *