In June and July the female beetle lays its eggs on the stamen and other parts of the … Adult Japanese Beetles also feed on raspberry … It is 1 / 2 to 5 / 8 inch long. The grubs sometimes attack vegetables and other garden plants, such as lettuce, raspberry, strawberry and young ornamental trees. White grubs (larvae) of various insects such as Japanese beetle or Rose Chafer live in the soil for much of the year and will feed on newly planted strawberry, blueberry and raspberry roots, especially following sod or on lighter soils causing gradual decline in plant vigor.. Japanese beetle grub found attacking berry roots. Quick facts Common name Raspberry beetle. Scientific name … The raspberry beetle is a common pest of raspberry plants but can also attack loganberries and other hybrid berries. The grubs can be found immediately below the surface, usually lying in a characteristic comma-like position. The grubs of raspberry beetle damage the fruits of raspberry, blackberry and other cane fruits and is the most serious pest of these plants. The grubs of raspberry beetle damage the fruits of raspberry, blackberry and other cane fruits and is the most serious pest of these plants. The thorax is yellow to orange and has two conspicuous spots. Chafer grubs feed below ground for 3–4 years before changing into adult beetles… The raspberry cane borer, Oberea bimaculata, is a small, slender, black or very dark beetle with long antennae. …