The Aphididae are a very large insect family in the aphid superfamily (Aphidoidea), of the order Hemiptera. Several thousand species are placed in this family, many of which are well known for being serious plant pests. They are also the family of insects containing most plant virus vectors (around 200 known) with the green peach aphid (Myzus persicae) being one of the most prevalent and indiscriminate carriers.