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Hawthorn-buttercup mealy gall aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution:
The curled-leaf gall (see first picture below) of Dysaphis ranunculi on hawthorn (Crataegus monogyna) its primary host is pale yellowish-green, often suffused with rosy pink (our gall was yellowish green but had no pink colour). There is no sharp demarcation between the pink of the gall and the green of the leaf lamina (cf. Dysaphis crataegi where such a demarcation is present). The Dysaphis ranunculi fundatrices are deep blue-grey with a wax bloom, and the immature offspring of the fundatrix are usually brownish grey to grey. The immature offspring in the gall shown below second were light green with wax markings - hence the identification of this gall as resulting from Dysaphis ranunculi, based on gall-appearance, may not be correct.
Winged forms arise in the second generation and the alates migrate to the basal parts of buttercups (Ranunculus spp.). On Ranunculus the adult Dysaphis ranunculi apterae are mottled grey-green, brownish around the bases of the siphunculi, wax dusted and with variable dark sclerotization. There are usually 9 or more secondary rhinaria on the fifth antennal segment (cf. Dysaphis crataegi where there are usually 0-1).
The images below show confirmed Dysaphis ranunculi immatures living on the roots of the secondary host, Ranunculus (no other Dysaphis species live on Ranunculus.)
Other aphids on same host:
Dysaphis ranunculi has been recorded from 6 Crataegus species (Crataegus altaica, Crataegus laevigata, Crataegus ×lambertiana, Crataegus monogyna, Crataegus sanguinea, Crataegus submollis).
Blackman & Eastop list 16 species of aphid as feeding on common hawthorn (Crataegus monogyna) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 15 as occurring in Britain (Show British list).