Currant bluster aphid is a sap-sucking insect belonging to the order that holds the true bugs. Aphids have complex life cycles where they alternate between two host plants. As suggested by their name, these insects target black, red and whitecurrants; whereas, during mid-summer, aphids will migrate to Stachys sylvatica before returning in the autumn to lay overwintering eggs.
Aphids can have several overlapping generations each year so that they can become abundant very quickly. These aphids cause blistering on the currant plants foliage, which appears like red-green and yellow bulges which are unsightly. This is directly a result of aphid feeding, who inject toxic saliva into the plant as they suck the sap, causing plant cells to distort.