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Prociphilus bumeliae & Prociphilus fraxini

Ash leaf-nest aphids

Identification & Distribution  Biology & Ecology  Other species on the same host 

Identification & Distribution:

In spring the fundatrices of Prociphilus bumeliae and Prociphilus fraxini are brown, covered with white wax wool, and form loose leaf-nests on their primary host ash (Fraxinus species). The first image below shows a mature colony. Prociphilus bumeliae sometimes also uses privet (Ligustrum vulgare) or Common lilac (Syringa vulgaris) as a primary host. Both of these aphids may also form colonies on the bark of the stem or branches (see second picture below). Prociphilus bumeliae and Prociphilus fraxini both have distinct wax glands on the head and thorax, as well as large, albeit indistinct wax glands on the abdomen (the white patches of wax in the second picture below mark the positions of the wax glands). The 5-segmented antennae are about a third of the length of the body. There are no siphunculi.

Images copyright Dr László Érsek, all rights reserved.

Alates (see second picture below) have a blackish-brown head and thorax, and a light brown or yellowish red abdomen, more or less covered with white wax wool. The 6-segmented antennae are about half the length of the body.

Images copyright Dr László Érsek, all rights reserved.

The two species we deal with on this page can only be distinguished at the alate stage produced in the leaf nest.

  • In the Prociphilus bumeliae alate the third antennal segment is more than five times longer than the second antennal segment. Also the head has only a pair of posterior dorsal wax pore plates which are conspicuous as clearly defined pale areas much larger than the ocelli.

  • In the Prociphilus fraxini alate the third antennal segment is usually less than five times longer than the second antennal segment. The posterior wax pore plates on the head are ill-defined, but there is usually a pair of small clear anterior wax pore plates.

Both these Prociphilus species host alternate from ash (Fraxinus) to fir (Abies). The fundatrices colonize the base of ash. Their offspring feed on the young shoots and petioles inducing the formation of leaf nests often high in the trees. These develop into alatae, which migrate to the roots of fir.

 

Biology & Ecology:

Prociphilus fraxini and Prociphilus bumeliae are usually densely covered with wax, and wax protected aphids are seldom ant-attended. However, these two Prociphilus are sometimes ant attended - and when they are, the ants have been reported to remove the wax (Way, 1963 ) - a surprising observation given wax is repellent to most insects. If the ants really do remove it, then we have to ask why they should do so. Perhaps the wax has some nutritional value for the ants, or possibly wax may diminish the aphid honeydew responses to tending by the ant. The picture below shows ant attended Prociphilus, with much of the colony still densely coated in wax.

Images copyright Dr László Érsek, all rights reserved.

The picture below shows another part of the colony which has rather little wax, presumably removed by the ants.

Images copyright Dr László Érsek, all rights reserved.

 

Other species on the same host

Blackman & Eastop list only 9 species of aphids  as feeding on the primary host, ash, worldwide, and provide formal identification keys for aphids on Fraxinus. Of the 5 species on European Ash (Fraxinus excelsior), Baker (2015)  lists two species, Prociphilus fraxini & Prociphilus bumeliae, as occurring in Britain, both of which are dealt with on this page.

Acknowledgements

We especially thank Dr László Érsek for the images 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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