The woolly plant louse is a common pest that affects many species of plants, including apple trees. Also known as the woolly apple aphid, this insect can cause significant damage to crops, leading to reduced yields and poor fruit quality. However, there are several synonyms used to refer to this pest, including the woolly aphid, apple woolly aphid, and woolly elm aphid. These names reflect the fact that the insect can infest a variety of tree species, not just apple trees. Regardless of the name, this pest remains a major concern for growers and requires careful management to prevent economic losses.