Macrosiphum rosae

Macrosiphum rosae

The Aphid of the rose or large aphid or pink lice (Macrosiphum rosae L.) is a small insect belonging to the Aphididae family.

Systematic –
From a systematic point of view it belongs to the Eukaryota Domain, Animalia Kingdom, Eumetazoa Submarine, Bilateral Branch, Phylum Arthropoda, Subphylum Tracheata, Superclass Hexapoda, Classe Insecta, Order Hemiptera, Family Aphididae and then to Genus Macrosiphum and Specie M.roseae.

Geographic Distribution and Habitat –
Macrosiphum rosae is an aphid with distribution all over the world where the rose is cultivated, as the name suggests, the aphid is found on various types of roses and colonizes mainly soft flower buds, young shoots and the lower surface of the young leaves. It is the typical “louse” of the Rose present everywhere, both in intensive cultivation and in gardens and parks.

Morphology –
The Aphid of the rose is a small insect of some mm, of greenish or pinkish color depending on the forms; that can be attired or winged. For the subdivision one should take into account that, normally, he lives in colonies, especially on young shoots and still closed flower buds.

Attitude and biological cycle –
Macrosiphum rosae winters as an egg, even if in certain environments or in vintages with particularly mild winters, adult plants can also be found on the plants, even in winter (parthenogenetic females) that continue the autumn cycle. However, massive infestations have occurred since the beginning of late spring, especially in very humid years, and continue throughout the year, with the overlapping of generations until autumn; sometimes the cycle continues until the following year.
The containment of this aphid has often been carried out with chemical treatments. The interventions are carried out at the appearance of infestations, but this technique has significant flaws and contraindications. In fact, the presence of the numerous natural enemies of Macrosiphum rosae can be drastically reduced with such treatments to create an ecological boomerang that is difficult to restore. It is therefore advisable, before carrying out the intervention, to evaluate the actual consistency of the pests and populations of predators or parasites, among which we remember:
– Ditherteri Sirfidi and Cecidomidi, Coccinellid Coleoptera, Chrysopid Neuroptera, Mites Trombididae and Hymididae Hymenoptera.
For the fight against this aphid, like other similar ones, we recommend some precautions:
– Drastic decrease or elimination of synthetic nitric fertilizers;
– Predispositions of hedges with species that can accommodate the aphid and predators;
– Greater aeration of the rose pruning system;
– Use of Marseille soap, mixed with quassia preparations, and ash;
– Launch of ladybugs;
– Use of insecticides of natural extraction, such as Pyrethroids or natural Pyrethrines, in order to safeguard more useful entomofauna and pronubi.
Furthermore, the use of microbiological preparations based on the Verticillium lecanii fungus, which demonstrates a certain activity on this and on other aphids, is being tested.

Ecological role –
The pink aphid usually winters like egg rose bushes, although in the mild winters some adults can continue to reproduce parthenogenetically. In spring there is the first colonization of the new buds of the rose and there are a large number of winged forms. In this state the aphid of the rose migrates mainly to their secondary hosts, which are essentially plants of the Dipsacaceae family (such as the Dipsacus ferox) and plants of the Valerianaceae family (such as Centranthus, Nardostachys grandiflora, Valeriana and Valerianella). However, the colonies, if they do not have secondary guests, can be found all summer long on the rose or other vegetables.
Moreover, their infestation is facilitated by the ants that “breeds” them and carries them because of the sugary secretion (honeydew) that produces that smears the leaves and the stems, with subsequent production of smokes (saprophytic mushrooms) that pollute and further depreciate the crops .
The damage is determined by the nutrition bites that cause:
– deformation of the shoots, with arrest of their development;
– deformation of the flower buds that do not open, or bloom irregularly
Moreover this Afide produces abundant honeydew that smears the vegetation, causing both indirect consequences (burns, asphyxiation, establishment of fumigations) and a disfigurement of plants and flowers, with consequent aesthetic, functional and economic damages.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– Russo G., 1976. Agricultural Entomology. Special Part. Liguori Editore, Naples.
– Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.