Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Identification & Distribution:Apterae of Cinara kochiana are greyish-brown to lead grey or greyish-green, and are slightly wax powdered. The dorsum shows a distinct dark flecked patterning of scleroites and there is often a spinal stripe. The siphuncular cones are small and black. The legs are hairy and the hind tibiae are uniformly brown/black. The body length of Cinara kochiana is 4.7-6.1 mm.
The fourth rostral segment (R IV) is 0.29-0.42 mm long and bears 21-34 hairs arranged in 4 longitudinal rows. The long fourth rostral segment and the four rows of hairs distinguish Cinara kochiana from Cinara cuneomaculata in which R IV is 0.15-0.25 mm long and bears 5-11 hairs arranged in 2 longitudinal rows.
Cinara kochiana is found on various larch species, including Larix decidua. Most reports state it occurs in ant attended colonies in bark crevices on the lower part of the trunk or bases of older branches, or in midsummer on exposed roots. Oviparae and winged or wingless males occur in October-November and eggs laid in bark crevices. Durak (2014) notes that Cinara kochiana is one of only five out of about 200 Cinara species to have both winged and wingless males.
Cinara kochiana has been reported from most parts of Europe except the Spain and Portugal, but is considered rather rare. It occurs as a subspecies in Korea.
Biology & Ecology:
There have been rather few recent observations on this aphid, and as far as we know no detailed studies on the ecology of the giant larch aphid. Borowiak & Wilkaniec (2010) recorded the species in the latter part of October in Cytadela Park in Poland. We have only found this species once, in July 2014, in a mixed forest in East Sussex, UK. Contrary to most other reports, we found colonies on the older lower side branches (about 2 cm diameter) of a rather young partially fallen tree.
They occurred where the bark was shaded by other vegetation. None was found on the trunk or exposed roots of the tree.
The colonies were attended by large numbers of southern wood ants (Formica rufa).
Pontin (1960) found a heavily parasitized population on larch roots. Our observations also suggest that the presence of attending ants does not provide as good protection to the giant larch aphid from parasites and predators as for example in the case of Cinara piceicola. The picture below shows a parasitized aphid in the colony we found.
Predators were also present, in particular syrphid larva (see below).
Graham Rotheray commented on this larva "This is an early stage larva that hasn't developed all the features I need to be certain of its identity. Only three genera have the upright projections along the body shown in the image, Didea, Eriozona and Megasyrphus. But which of these genera the larva belongs to I can't really tell. ..... simply on the grounds of abundance, it is most likely to be a Didea". (18 Aug 2014)
Damage and control
Rozhkov & Mikhailova (1993) note that Cinara kochiana has been recorded as one of the aphid species damaging larch trees in coniferous forests polluted with fluorides in Eastern Siberia. However, its presence probably resulted from the already damaged state of the trees resulting from the fluoride pollution. Cinara kochiana is a rare species and should probably be given protected status.