Forum communautaire francophone des insectes et autres arthropodes
Animateurs : lauzette, guillaume
=> trop tôt pour A. tardus ?ananas gall, strongly resembling the gall of A. laricis, but the gall ripens much later, in August-October. Contrary to laricis the galls occur in groups, mixed with galls from preceding years. The alatae are blackish, with much wool.
The gall has has a creamy colour, 1-1.5 cm diameter, a globular shape and a waxy texture.
HOST PLANTS
Pinaceae, monophagous
Picea abies, alcoquiana, glauca, glehnii, koraiensis, mariana, orientalis, pungens, sitchensis.
Concernant la dernière possibilité, il est précisé:1a On above-ground part => 2
2b On vegetative parts => 3
3a On buds or young shoots => 7
7a Galls on young shoots => 8
8a Galls ± locally. Originate on young shoots, may partially persist on lignified ends of twigs after inducers have left; caused by animals => 9
9a Galls develop with predominant involvement of needles => 10
10a Conspicuous, egg-shaped to elongate cylindrical galls originating from swelling of basal needle parts; caused by aphids => 11
11a Gall compact, usually less than 20 mm => 14
14a Galls mainly terminally and on all-sides, strawberry- or pineapple-like; scales glabrous on outside, needles not- or only slightly protruding. Top of gall with or without tuft => 16
16a Galls on P. abies and related species => 18
18a Many galls ± egg-shaped, up to hazelnut size, pale green or whitish; scales partially provided with stub-shaped, distinctly recognisable needle stumps. Usually on top of shaded lanky lateral shoots, only exceptionally surmounted by a tuft of needles or a short atrophied shoot => 19
19a Aphid holocyclic, migrating to Larix decidua. Galls mature in June. Picea spp.: Adelges laricis
19b Galls similar, but mature in late-summer, August-October. Aphid especially biologically distinct from the previous one, anholocyclic, not alternating. P. abies, glauca, pungens, sitchensis: Adelges tardus
19c In similar galls, P. abies, live the following closely related species: Adelges tardoides and/ or, P. abies, glauca, jezoensis, mariana, pungens, sitchensis: Adelges lapponicus
Messimilar to the gall of the related A. tardus. Generally many galls together, mixed with galls from the previous years; they open in June, July. The aphids are dark red.
