title: Identity of Schizaphis species (Hemiptera: Aphididae) in the United Kingdom: are they a threat to crops?
abstract: The greenbug, Schizaphis graminum (Rondani), is a major pest of cereals in some parts of the world and is of particular concern because it can be resistant to some insecticides and overcome the resistance of crops. In the UK, it has never been found on crops, but two rather little-known and closely-related species (Schizaphis holci and Schizaphis agrostis) are associated with the wild grasses, Holcus lanatus and Agrostis stolonifera. Since 1987, winged (alate) aphids morphologically resembling the greenbug have been found in increasing numbers in 12.2 m high suction-trap samples of the Rothamsted Insect Survey (RIS); hence, studies were undertaken to establish their identity. Clones (=asexual lineages) established from populations collected from H. lanatus in southern England showed strong preference for Holcus over Agrostis and Hordeum in laboratory tests and produced sexual morphs when transferred to short-day conditions, the males being apterous, as expected for S. holci. Multivariate morphometric comparisons of alatae caught in UK RIS suction traps in 2007 and 2011 with named specimens from museum collections, including S. graminum from many countries, indicated that the suction-trapped alatae were mostly S. agrostis and S. holci. Cytochrome c oxidase subunit I (COI) mtDNA obtained from 62 UK specimens from suction-traps had 95.4-100% sequence identity with US specimens of S. graminum. Two of the UK specimens had identical COI sequence to the US sorghum-adapted form of S. graminum, and these specimens also had 100% identity with a 640 bp fragment of nDNA CytC, indicating that this form of S. graminum may already be present in the UK. Present and future economic implications of these results are discussed.
authors: Department of AgroEcology, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
authors: Amalia
authors: A
authors: Kati
authors: Kevin A
authors: KA
authors: Shufran
authors: Mark S
authors: MS
authors: Taylor
authors: Shalva
authors: S
authors: Barjadze
authors: Victor F
authors: VF
authors: Eastop
authors: Roger L
authors: RL
authors: Blackman
authors: Richard
authors: R
authors: Harrington
mesh_terms: D031703:Agrostis / Q000469:parasitology; D000818:Animals; D001042:Aphids / Q000145:classification* / Q000235:genetics*; D001483:Base Sequence; D001837:Body Weights and Measures; D017931:DNA Primers / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D004739:England; D031752:Holcus / Q000469:parasitology*; D001467:Hordeum / Q000469:parasitology; D008969:Molecular Sequence Data; D015999:Multivariate Analysis; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D017931:DNA Primers; D003576:Electron Transport Complex IV