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Aphidinae : Macrosiphini : Dysaphis ranunculi
 

 

Dysaphis ranunculi

Hawthorn-buttercup mealy gall aphid

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

Identification & Distribution

The curled-leaf gall (see first picture below) of Dysaphis ranunculi on its primary host hawthorn (Crataegus monogyna) 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 aphids found in this gall (see second picture below) were light green with wax markings and may well have been inquilines - aphids of another species using the gall after it had been vacated by its original inhabitants.

Winged forms arise in the second generation and the alate adults migrate to the basal parts of buttercups (Ranunculus spp.). On Ranunculus the adult Dysaphis ranunculi apterae (see first picture below) 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). Immatures (see second and third pictures below) are yellowish green when young, darker green as they mature, and with conspicuous orange-red patches around the siphunculi.

The clarified slide mounts below are of adult viviparous female Dysaphis ranunculi : fundatrix (from primary host), lightly sclerotized wingless from secondary host, and winged spring migrant.

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

Dysaphis ranunculi host alternate from hawthorn (Crataegus) to the roots of buttercups (Ranunculus). There is a return migration to hawthorn in September. On the roots of buttercups they are often attended by ants, and the colonies we have found have been ant-tented. The hawthorn-buttercup aphid is found throughout Europe and in central Asia.

 

Other aphids on same host:

Primary 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).

Secondary hosts

Dysaphis ranunculi has been recorded from 8 Ranunculus species (Ranunculus acris, Ranunculus arvensis, Ranunculus bulbosus, Ranunculus muricatus, Ranunculus polyanthemos, Ranunculus repens, Ranunculus sardous, Ranunculus serpens ssp. nemorosus).

Blackman & Eastop list about 14 species of aphid which feed on Ranunculus acris worldwide (Show World list). Of those aphid species, Baker (2015) lists all 14 as occurring in Britain (Show British list).

Blackman & Eastop list about 10 species of aphid which feed on Ranunculus repens worldwide (Show World list). Of those aphid species, Baker (2015) lists all 10 as occurring in Britain (Show British list).

Acknowledgements

We especially thank Trees for Life for their kind assistance. We also thank 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).

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