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Genus Pineus

Woolly pine aphids

Species Overview: Pineus Pineus pini

Genus Pineus [Adelgidae]

Distinguished by having only four distinct pairs of abdominal spiracles. Wingless adults on secondary hosts are pear-shaped or globular and have a fused and pigmented head and prothoracic shield. They generally secrete white wax-wool.

There are about 23 species through Europe, Asia and North America. The primary host of species with a sexual stage in their life cycle species is spruce (Picea), and the secondary host is pine ( Pinus). The galls on spruce are usually on the shoot tips and are less compact than those of Adelges. Several species have lost sexual reproduction and host alternation, and instead live all year on spruce or pine.

 

Pineus pini (Pine woolly aphid, Scots pine adelgid))

The apterous female (the 'sistens') is dark brown to dark red, almost spherical and covered in white wax wool. The head and prothorax are heavily chitinized. The antennae are 3-segmented. The abdomen has four distinct pairs of spiracles and an ovipositor. The body length of the wingless form is 1.0-1.2 mm. The winged female is mainly reddish grey with 5-segmented antennae. The forewings are hyaline and the veins are tinged with red. The body length of the winged form is 1.0 -1.2 mm.

The pine woolly aphid has lost host alternation and sexual reproduction and remains all year on pine (Pinus sylvestris and Pinus mugo). There is an overwintering generation on the twigs and two or more overlapping generations attacking the current year's shoots. Eggs are laid in abundant wax-wool. The second of the summer generations in May-June includes winged forms which disperse to other pine trees. Young seedling pines are commonly infected by first instar crawlers dispersed by wind.

 

Acknowledgements

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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