title: Identification of Aphis gossypii Glover (Hemiptera: Aphididae) Biotypes from Different Host Plants in North China.
abstract: 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 unclear.
  
  
  RESULTS
  Host transfer experiments showed that A. gossypii from North China has two host-specialized biotypes: cotton and cucumber. Based on complete mitochondrial sequences, we identified a molecular marker with five single-nucleotide polymorphisms to distinguish the biotypes. Using this marker, a large-scale study of biotypes on primary winter and summer hosts was conducted. All A. gossypii collected from three primary hosts-hibiscus, pomegranate, and Chinese prickly ash-were cotton biotypes, with more cotton-melon aphids found on hibiscus than the other two species. In May, alate cotton and cucumber biotypes coexisted on cotton and cucumber seedlings, but each preferred its natal host. Both biotypes existed on zucchini, although the cucumber biotype was more numerous. Aphids on muskmelon were all cucumber biotypes, whereas most aphids on kidney bean were cotton biotypes. Aphids on seedlings of potato and cowpea belong to other species. In August, aphids on cotton and cucumber were the respective biotypes, with zucchini still hosting both biotypes as before. Thus, the biotypes had different fitnesses on different host plants.
  
  
  CONCLUSIONS
  Two host-specialized biotypes (cotton and cucumber) are present in North China. Hibiscus, pomegranate, and Chinese prickly ash can serve as winter hosts for the cotton biotype but not the cucumber biotype in North China. The fitnesses of the two host-specialized biotypes differ on various summer hosts. When alate aphids migrate to summer hosts, they cannot accurately land on the corresponding plant.
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Xiang-Zhen
authors.initials: XZ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Li
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.
authors.forename: Jin-Jie
authors.initials: JJ
authors.lastname: Cui
mesh_terms: D000818:Animals; D001042:Aphids / Q000235:genetics*; D001483:Base Sequence; D002681:China; D018553:Cucumis sativus / Q000469:parasitology; D004272:DNA, Mitochondrial / Q000235:genetics; D017344:Genes, Insect; D003368:Gossypium / Q000469:parasitology; D058507:Host Specificity; D006790:Host-Parasite Interactions; D008969:Molecular Sequence Data; D058889:Molecular Typing; D010935:Plant Diseases / Q000469:parasitology*; D018515:Plant Leaves / Q000469:parasitology; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial