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Cavariella theobaldi

Willow - parsnip aphid

On this page: Identification & Distribution  Other aphids on the same host 

Identification & Distribution:

Adult Cavariella theobaldi apterae are green with the tips of the antennae and apices of the legs dark. The antennae are 0.50 times the length of the body and the terminal process is 2.1-3.5 times the base of the last antennal segment. The siphunculi are more than twice as long as the cauda; they are not swollen, but are cylindrical or tapering from base to tip (cf. Cavariella aegopodi,  Cavariella archangelicae,  Cavariella pastinacae  and Cavariella konoi  all of which have their siphunculi swollen towards the tip). The supracaudal process is more or less four-sided and small, about 0.3-0.7 times the caudal length. The body length of Cavariella theobaldi apterae is 1.8-2.8 mm.

The alate of Cavariella theobaldi has a dark abdominal patch formed by more or less fused cross bands on tergites III-VI. The antennae of the alate are dark and its siphunculi are brownish.

The clarified slide mounts below are of adult viviparous female Cavariella theobaldi : wingless, and winged.

Micrographs of clarified mounts  by permission of Roger Blackman, copyright AWP  all rights reserved.

The willow - parsnip aphid host alternates between willows (Salix species) and some umbellifers mainly wild parsnip (Pastinaca) and hogweed (Heracleum). Cavariella theobaldi is found over most of Europe into west Siberia, and parts of North America.


Other aphids on same host:

Primary hosts

For lists of of aphid species on willows (Salix) see our aphids on willow page. 

Secondary hosts


Our particular thanks to Roger Blackman for images of his clarified slide mounts.

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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