Cavariella aegopodiiapterae are small and greenish or reddish. The tips of their antennae and apices of the legs are brownish. The antennae are about 0.4 times the body length, with the terminal process about 0.85-1.3 times the basal part of segment VI (cf. Cavariella archangelicae,Cavariella konoi,Cavariella pastinacae and Cavariella theobaldi which all have the terminal process more than 1.3 times the length of the basal part of segment VI). Cavariella aegopodiisiphunculi are swollen and about twice as long as the cauda. The supracaudal process is 0.75-1.05 times the cauda, broadest at the base and oblong triangular to conical. The body length of Cavariella aegopodii apterae is 1.5-2.8 mm.
The alate of Cavariella aegopodi has a central black patch on the abdominal dorsum, and a dark cauda and siphunculi. As with the aptera, it is best distinguished from the other common Cavariella species by its short terminal antennal process which is less than 1.5 times longer than the base of antennal segment VI.
Micrographs of clarified mounts by permission of Roger Blackman, copyright AWP all rights reserved.
The willow-carrot aphid host alternates from willows (Salix spp) to umbellifers (Apiaceae). The preferred primary hosts are crack willow (Salix fragilis) and white willow Salix alba, although some Willow species seem only to be colonized in spring, by winged forms from populations which have overwintered parthenogenetically. Preferred secondary hosts are cultivated umbellifers such as carrots (Daucus carota) and fennel (Foeniculum vulgare) and several wild umbellifers. Cavariella aegopodii is widespread throughout temperate and warm temperate parts of the world.
Other aphids on same host:
Blackman & Eastop list over 120 species of aphids as feeding on willows worldwide, and provides formal identification keys for aphids on Salix.
Our particular thanks to Roger Blackman for images of his clarified slide mounts.
Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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).