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Leaf nest-conifer root aphidsOn this page: Prociphilus Prociphilus bumeliae and Prociphilus fraxini Prociphilus pini
The Prociphilus genus contains about 50 species which are fairly evenly distributed through the northern hemisphere. Prociphilus have lost their evolutionary constraint to Populus and transferred their sexual generation in relatively recent times to live in pseudogalls on various more advanced "primary" hosts, e.g. in Rosaceae, Caprifoliaceae and Oleaceae. However, as in the related genus Pachypappa, the parthenogenetic generations have retained an association with the roots of conifers.
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, usually ash (Fraxinus species). The first image below shows a mature colony. 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 5-segmented antennae are about a third of the length of the body. There are no siphunculi.
Guest images copyright Dr László Érsek, all rights reserved.
Alates (see second picture above) 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.
Prociphilus bumeliae and Prociphilus fraxini can only be distinguished at the alate stage produced in the leaf nest.
Both these Prociphilus species host alternate from ash (Fraxinus) to fir (Abies). Prociphilus bumeliae sometimes also uses privet (Ligustrum vulgare) or Common lilac (Syringa vulgaris) as a primary host. The fundatrices colonize the base of the primary host. 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. In October sexuparae develop on fir, and migrate back to hawthorn where the sexual forms are produced.
Prociphilus pini (Hawthorn-pine root aphid)
Overwintering eggs on hawthorn hatch in spring to give fundatrices which , together with their progeny, curl and yellow hawthorn (Crataegus) leaves. The progeny all develop to alates, which have a light green to greyish green abdomen. These migrate to the secondary host, the roots of Scots Pine (Pinus sylvestris) and related Pinus species.
Guest images copyright Alan Watson Featherstone all rights reserved.
The adult apterae of Prociphilus pini on the secondary host are cream or pale pinkish and are covered with dense wax wool. In October winged sexuparae (see pictures above) develop on the pine roots and migrate back to hawthorn. The head has paired wax gland plates showing as clear areas between antennae and/or on the posterior part of head. The number of secondary rhinaria on the antennae is diagnostic - segment III: 15-32, IV: 5-12; V: 2-11; VI: 0. The body length of the sexupara is 1.6-2.3 mm.
Sexuparae are produced on pine roots in October, but British populations seem to mainly persist throughout the winter on pine, and it is less commonly found on its primary hosts, hawthorn. Prociphilus pini occurs in the British Isles, and in north-west and central Europe.