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"It has long been an axiom of mine that the little things are infinitely the most important" (Sherlock Holmes)

 

 

Identification & Distribution:

Adult Myzaphis bucktoni apterae are pale yellow to pale green with a dark brown head and dark brown dorsal markings. The markings consist of two large brown patches on the pronotum and paired brown stripes extending from the mesothorax to the base of the cauda converging between the siphunculi (see first picture below). Like other Myzaphis species, Myzaphis bucktoni is a small aphid: Their body length varies from 1.0-1.9 mm

 

The median frontal tubercle of Myzaphis bucktoni is rounded (see first micrograph below) and usually bears four hairs as long as, or longer than, the basal diameter of the third antennal segment.

 

Their alates have rather weak abdominal pigmentation which is usually divided intersegmentally in the midline, with large marginal sclerites on abdominal tergites 2-4 (see second picture above). The hairs on the front of the head are conspicuous. Antennae of Myzaphis bucktoni alates have 14-32 secondary rhinaria on the third antennal segment but none on the fourth.

This species mainly occurs on wild roses such as dog rose (Rosa canina) and harsh downy rose (Rosa tomentosa). Myzaphis bucktoni apterae feed dispersed along the mid-ribs of upper sides of the leaves. Sexual forms occur in November. Males are small, dark, wingless and very active. Oviparae are pale dusky olive green and have strongly swollen hind tibiae. Myzaphis bucktoni occurs throughout Europe, Asia and North America.

 

Biology & Ecology:

Most aphids form colonies on the undersides of leaves. Myzaphis bucktoni is relatively unusual for an aphid in that it is a solitary species which lives on the upper sides of leaves. In this it resembles the aphid Monaphis antennata the nymphs of which live scattered on the upper sides of birch leaves. In that species the adults move to the underside, but Myzaphis bucktoni remains on the upperside throughout its life. Both species rely heavily on crypsis to escape natural enemies.

The picture above shows a solitary adult Myzaphis bucktoni sitting on the midrib of a rose leaf. We have only found Myzaphis bucktoni at one site in Britain - on the Dundreggan estate, in Inverness-shire, in Scotland - but it occurs throughout Britain.

One unusual feature of the Myzaphis bucktoni at Dundreggan was the great variability in size of the adult apterae. All the aphids in the picture below are adults, yet even on the same plant they were found to vary in size by a factor of 1.5 times.

This may well result from their solitary lifestyle. Aphids living in a colony create a sink effect when feeding together in a colony, and all individuals will tend to obtain a similar level of nutrients. But solitary aphids will receive a much more variable food supply depending on where they have settled.

Acknowledgements

We especially thank Trees for Life  for their kind assistance, and permission to sample.

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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