BACKGROUND
The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a polyphagous species with a worldwide distribution and a variety of biotypes. North China is a traditional agricultural area with abundant winter and summer hosts of A. gossypii. While the life cycles of A. gossypii on different plants have been well studied, those of the biotypes of North China are still uncle...
