Controlling raspberry beetles
The raspberry beetle lays its eggs in the raspberry blossom. They hatch out into the familiar fruit-infesting grubs, which eventually drop to the ground, bore down and become chrysalids which, in their turn, change in late spring into adults that repeat the process.
Spraying to make sure of killing the beetles may also destroy hundreds of pollinating insects, such as bees, that throng the blossom, so it is much safer to use the organic method. Spread lawn-mowings between the rows, keeping them from actual contact with the canes, partly to suppress, but also partly to give the grubs an easy passage so that they will not burrow so far into the .
Then, in mid-autumn, dig between the rows (shallowly, to avoid root damage), and do this again in early winter. You will soon spot one or more robins pecking busily where you have been digging. Robins are naturally quick to spot insects, chrysalids, eggs and larvae in the soil, and will soon solve your raspberry beetle problem, devouring many other pests at the same time.
Digging during winter is also a good policy if you have had trouble with carrot fly orroot fly, because the robins will eat these pests just as readily.