General
The large raspberry aphid, Amphorophora idaei, is the most important aphid species found on raspberries in Europe. It only feeds on raspberry.
Life cycle and appearance of Large raspberry aphid
Aphids have a complex life cycle, with both winged and wingless forms of adults and a great variety in colour. In greenhouses, reproduction takes place by parthenogenesis, with unfertilized viviparous females continuing to produce new generations of females. Aphids moult four times before reaching adulthood. With each moult they shed white skin, betraying their presence in the crop.
Wingless females of the large raspberry aphid are 2.6-4.1 mm long, pale to yellowish green with long antennae, legs and siphunculi. The cauda is short and triangular.
Overwintering eggs of the large raspberry aphid are laid near the base of vegetative canes and hatch in spring. After emerging in spring, the aphids mainly feed on the underside of leaves and start to reproduce parthenogenetically. They are very mobile and drop from the plant when they are disturbed. Winged aphids usually appear in June and July and migrate to new canes or host plants where they produce wingless aphids again. In October to December winged aphids appear again. These lay the winter eggs.
Damage symptoms
Large raspberry aphids rarely reach populations that are high enough to reduce yield by direct feeding damage. The major problem is the spreading of various raspberry viruses by the aphids.