Adelges (Sacciphantes) abietis (Linnaeus, 1758)

Albrecht, Anders Christian, 2017, Illustrated identification guide to the Nordic aphids feeding on Conifers (Pinophyta) (Insecta, Hemiptera, Sternorhyncha, Aphidomorpha), European Journal of Taxonomy 338, pp. 1-160 : 11-12

Adelges (Sacciphantes) abietis (Linnaeus, 1758)

Figs 17–21

Diagnosis

First instar pseudofundatrix about 0.5 mm, greyish brown; prothoracic pleurospinal sclerites longer than broad; dorsal sclerites with groups of 2–7 ring-like wax pores. Second instar nymphs in winter about 0.6–0.8 mm. Wax filaments of overwintering nymphs numerous, long, glossy grey, stiff, curled in all directions. Adult pseudofundatrix greyish or yellowish brown, exuding abundant fine, white wax wool. Al. gallicola 1.8–2.3 mm, brown to brownish black with thin greyish wax dusting and transverse white wax markings; abdomen yellowish brown; wax wool production fairly weak. Wax glands on head and prothorax absent or indistinct, without clear facets; rhinaria on antennal segments III–V oval to circular. Eggs brownish yellow. Anholocyclic on Picea , occurring in many habitats, usually 1–2 m above ground. In open positions such as forest margins, clearings and solitary trees, the scale margins of the galls become bright red or purple, whereas galls in shaded positions are less strikingly coloured.

The pseudofundatrices hibernate at bud bases and in bud axils, in contrast to A. tardus which prefers the surface of the buds (my own records from Finland). Second instar pseudofundatrices can be found from late autumn onwards, but first instar nymphs may occur as late as in February (according to my own records from S. Finland). Galls 15–35 mm, usually gregarious, pineapple-shaped with needle-bearing shoot apically, bright green with purple, red, pink or brownish (rarely green) scale margins. Scales pubescent, particularly along margins. They often occur along with galls from preceding years and with galls of Adelges tardus ; opening in August–early September. Gall chambers completely closed: no nymphs occur on outer surface.

Recorded hosts

Pinaceae : Picea abies *, engelmannii , glauca , jezoensis , orientalis , pungens , sitchensis , spp.

Distribution

D F N S.

Figures

Fig. 17. Adelges (Sacciphantes) abietis (Linnaeus, 1758), galls on Picea abies. A–B. Almost full-grown. C. Half-grown. Colouration typical for galls growing in open sites. Scale bars: 10 mm.

Fig. 18. Adelges (Sacciphantes) abietis (Linnaeus, 1758), galls on Picea abies. A–D. Galls from different sites showing variation in colouration. A. From a semi-open site. B. In semi-shade. C–D. In deep shade. E–F. Newly opened galls with exuviae and alate gallicolae around. G–H. Galls from previous summer. Note the colony of Cinara pilicornis (Hartig, 1841) on the stem in A. Scale bars: 10 mm.

Fig. 19. Adelges (Sacciphantes) abietis (Linnaeus, 1758) on Picea abies. The gallicolae fly only a very short distance from their mother gall (A–B), where they lay their eggs (C–E). A majority of the eggs remain on the mother’s dorsum, sheltered by her wings. Newly hatched alatae are red-brown (F–G), head and thorax darkening with age (I).

Fig. 20. Adelges (Sacciphantes) abietis (Linnaeus, 1758) on Picea abies in winter. A. First instar exuvium and second instar nymphs. B. First instar exuvium. C–D. Second instar nymphs, in D with wax filaments worn off.

Fig. 21. Adelges (Sacciphantes) abietis (Linnaeus, 1758). A. Adult pseudofundatrix. B. Antenna of alate gallicola. (After Börner 1908, redrawn and modified.)