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Crypturaphis grassi

Italian alder aphid

Identification & Distribution  Other aphids on the same host 

Identification & Distribution:

Crypturaphis grassi apterae are brownish and dorso-ventrally flattened. The body length of apterae is 2.3-3.2 mm. Winged forms have a black head and thoracic lobes, a paler prothorax, and an ill-defined and variably developed brown patch across abdominal tergites 5-6. The body length of Crypturaphis grassi alates is 2.2-3.0 mm. Immature stages are green.

Shown below are an immature, and a winged adult.

 

The three images below show an apterous adult dorsal & ventral, and an immature Crypturaphis grassi, all in alcohol.

   

Italian alder aphids live dispersed along veins on both upper and lower leaf surfaces of Italian alder (Alnus cordata), and are apparently specific to this host. Oviparae and males occur in October-November, but aphids may overwinter viviparously. Crypturaphis grassi is native to southern Italy and Corsica, but was first recorded in the UK in 1998, and has since spread widely in southern England and Wales.

 

Other aphids on same host:

Blackman & Eastop list 2 species of aphid  as feeding on Italian alder (Alnus cordata) worldwide, and provide formal identification keys. Baker (2015)  lists both aphid species as occurring in Britain: Crypturaphis grassii and Pterocallis alni. 

Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994)  and Blackman & Eastop (2006)  supplemented with Blackman (1974) , Stroyan (1977) , Stroyan (1984) , Blackman & Eastop (1984) , Heie (1980-1995) , Dixon & Thieme (2007)  and Blackman (2010) . We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure  provided by Blackman & Eastop (2006).

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