Cinara cedri
Cinara cedri
The Cedar aphid (Cinara cedri Mimeur, 1936) is a homopteran rincote belonging to the Aphididae family.
Systematics –
From a systematic point of view, it belongs to the Eukaryota Domain, Animalia Kingdom, Subgenus Eumetazoa, Superphylum Protostomia, Phylum Arthropoda, Subphylum Hexapoda, Class Insecta, Subclass Pterygota, Exopterygota Cohort, Subcoorte Neoptera, Superorder Paraneoptera, Rhynchotoidea Section, Rhynchota Order, Suborder Homoptera, Section Sternorrhyncha, Aphidoidea superfamily, Aphididae family and therefore to the genus Cinara and to the C. cedri species.
Geographical Distribution and Habitat –
The cedar aphid is an insect that lives on the Pinaceae and in particular on Cedrus atlantica, C. deodara and C. libani. Their area of diffusion corresponds mainly to that of diffusion of these three tree species.
Morphology –
Cinara cedri is an aphid 3-4 mm in size, with dark bronze or reddish brown coloring with darker segmental signs and the presence of a slight dorsolateral and ventral cerosity.
They live in large and dense colonies on the bark of branches 1-5 cm thick, along the axis of the shoot, and can also cover the woody organs inside the foliage as a sleeve.
Their presence is evident also for the abundant honeydew emitted and for the establishment on this of abundant fumaggini.
Attitude and biological cycle –
The Cinara cedar winters like an egg, on the persistent leaves; then resumes its activity in the spring with the maximum infestations in the months of May-June; generations follow one another even in summer until the unfavorable season arrives.
Ecological Role –
The presence of the cedar aphid, in addition to its morphological and external aspects, in the case of strong infestations, can also partially defoliate. Massively infested trees do not produce cones and stunted growth is reduced.
The damage is caused by nutrition bites on the shoots that produce more or less extensive necrosis, with consequent reddening and desiccation of the leaves.
Usually the attacks occur in conjunction with the heat, in spring and especially in summer.
The Cinara cedar can attack even larger woody organs, causing the same damage. Furthermore, the abundant production of honeydew smears the vegetation, accentuates the necrosis, causes asphyxia and favors the establishment of the fumaggini; finally the honeydew causes discomfort in the use of the sub-flavors, especially in the park areas and in the gardens.
The affected plants, apart from the damage of an aesthetic nature, are subject to progressive deterioration, especially if the attacks are massive and repeated over the years, becoming more receptive to infections of secondary pathogens or to the aggression of secondary pests.
Furthermore the needles redden and fall, the branches have reduced vegetation, limited to the distal part. The severely affected individuals perish and can even die within a few years. In the wild these Aphids are controlled by natural enemies and, sometimes, their presence is sufficient to keep the phytophagous population under control; furthermore some useful species (Api, Diptera Sirfidi) feed on honeydew. Especially in ecosystems with good biodiversity the balance between the various populations of insects and predators allows a normal distribution and density of the populations that always remain below the damage threshold.
In conditions of low biodiversity of tree and shrub species and, above all in parks and gardens designed without these criteria, the populations of these insects can increase dramatically.
Their presence can then occur particularly high even in nurseries.
In order to avoid the presence of Aphids on the Cedar, it is advisable to periodically check the state of health of the plant and encourage the presence of harmless insects, natural antagonists of Aphids such as Coccinelle and Diptera Sirfidi.
If we are in the presence of mild infestation, we can proceed by manually eliminating the aphids and honeydew through jet washing with water and copper based solutions. This is a non-invasive method that allows you to keep the situation under control without using pesticides and safeguarding useful entomofauna and fauna.
For the containment of the population of this aphid it is necessary to intervene only in case of real danger for the safety of the plants or in the parks and gardens in case of real inconvenience to the use of these green spaces. In nurseries the need may be greater and the intervention, in case of necessity and of massive and prolonged infestation, must be operated with aficidi, evaluating however and always the period, the dynamics of populations of the useful entomofauna and, above all in the natural areas , also the fauna present. In these latter cases it is always advisable to intervene with low toxicity products. In any case, it is always better to intervene, considering all these conditions, when the first colonies appear.
Guido Bissanti
Sources
– Wikipedia, the free encyclopedia.- Russo G., 1976. Agrarian Entomology. Special Part. Liguori Editore, Naples.- Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.