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Capitophorus similis

Buckthorn-Butterbur aphid

On this page: Identification & Distribution  Biology & Ecology 

Identification & Distribution:

On the primary host both the fundatrix and viviparous females of Capitophorus similis are pale greenish, frequently a little reddish, and with longitudinal rows of green spots. The siphunculi are about 3.5 times the length of the cauda (they are a little shorter on the fundatrix) . On the secondary host, the apterous viviparous female Capitophorus similis is whitish to yellowish white (see upper aphid in first picture below). The antennal terminal process is 6.1-7.5 times the length of the base of that segment. The siphunculi are thin, slightly curved towards their inner sides, with the apices curved outwards, and 3.7-5.0 times as long as the tongue-shaped cauda.

The alate female Capitophorus similis (see second picture above) has a greenish-white abdomen, with rather large, dark marginal sclerite and postsiphuncular sclerites, a black quadrangular dorsal patch on tergites 3-6, and small sclerites on the posterior tergites.

The buckthorn-butterbur aphid host alternates between the primary host, buckthorn (Hippophae) and the secondary host, coltsfoot (Tussilago) or butterbur (Petasites). Males and winged females are produced in autumn. Capitophorus similis is distributed throughout Europe into the eastern Himalayas in Asia.

 

Biology & Ecology:

One of the primary hosts of Capitophorus similis is sea buckthorn (Hippophae rhamnoides) - a thorny shrub which grows in coastal areas (see images below). The other primary host is oleaster (Elaeagnus) (not shown).

 

Two species of Capitophorus overwinter on sea buckthorn and oleaster, Capitophorus similis and Capitophorus hippophaes.  The picture below shows immature Capitophorus (species undetermined) on oleaster (Elaeagnus angustifolia).

The secondary hosts of Capitophorus similis are butterbur (Petasites) (see first picture below) and coltsfoot (Tussilago) (see second picture below).

 

We have found large colonies of Capitophorus similis on butterbur leaves, with aphids fairly widely spaced out over the underside of leaves.

 

The capitate hairs characteristic of aphids of this genus are clearly visible in the picture of the apterous adult below.

Several likely predators were present on the leaves including midge larvae (see first picture below) and anthocorid bugs (see second picture below). However, the anthocorid bugs may not have been predating the aphids, instead either feeding on plant liquids or on the aphid honeydew.

 

Acknowledgements

We especially thank Rye Harbour Nature Reserve  for their kind assistance, and permission to sample. Also, Alan Outen Bedfordshire Invertebrate Group,  for identifying the butterbur leaves shown above.

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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