Fig. 5 in Identification guide to Nordic aphids associated with mosses, horsetails and ferns (Bryophyta, Equisetophyta, Polypodiophyta) (Insecta, Hemiptera, Aphidoidea)

Fig. 5. Dioecious two-year holocycle in Adelgidae, e.g., Adelges laricis (shoot galls on spruce, Picea; needles of larch, Larix). All females oviparous. The fundatrix (hatched from a fertilized egg) overwinters as a larva, and induces the formation of a pineapple-like gall on the primary host. All her offspring are alate (gallicolae) and migrate to the secondary host, where they lay eggs on the needles. The aphids hatching move to the twigs where they hibernate as young larvae (the 'neosistens' stage). In spring they move back to the needles and become adults (sistentes). Their offspring are either alate sexuparae and migrate to spruce, or apterous 'progredientes'. In autumn the sexuparae fly to spruce and lay eggs which become sexual females and males, which mate. The females then lay eggs out of which new fundatrices hatch.