Insecta, Homoptera, Aphididae .
Description, Biology, Life Cycle, Damage, Common Names, Images
- Hatching of winter eggs laid on Rhamnus cathartica or the alder buckthorn (Fragula alnus) (primary host plants) takes place at the beginning of April. The fundatrix produces, some three weeks later, nymphs which in turn, produce virginiparous and viviparous females, mostly winged. The latter leave the primary host and establish new colonies on various secondary hosts (weeds, potatoes and others).
The aphid extracts sap from these plants, by inserting its stylet in the phloem.
- On account of its feeding method (piercing-sucking) the buckthorn aphid acts as a vector for strains of the Y virus (potato virus Y, including that regarded as causing necrosis of the veins of tobacco leaves), A virus (rough mosaic), yellow spot virus, and also, M and S viruses. Opinions differ on transmission of the leaf curl virus.
- During the summer, several virginiparous generations follow on from each other, partly composed of winged individuals and partly of apterous forms. The winged forms attack new summer host plants and can be disseminated over a great distance by the wind. Especially warms springs and summers, following-on from large-scale migration from the primary host are particularly conducive to swarming.
- Once summer development is complete, the aphid in the form of gynoparous females and males returns in September to the primary host, where mating occurs and where the females lay their fertilized eggs at the base of buds and in cracks in the buckthorn bark, where they will spend the winter.
- Mandatorily heteroecious, holocyclic.
- Winter eggs remain on buckthorn from autumn to April.
- The aphid reproduces on secondary hosts during the remainder of the year.
- Direct damage, caused by piercing/sucking of sap is rarely seen, solely in the event of a large-scale attack on well-grown potato plants, the growth of which is then hindered. The aphid does not cause deformation.
- Transmission of virus causes serious indirect damage, in particular, on seed potatoes, since the buckthorn aphid can also appear in huge numbers on crops where the green peach aphid (Myzus persicae) is relatively rare.
This pest is common throughout Central Europe on potatoes; its incidence increases from west to east, contrary to the green peach aphid (unfavourable weather conditions for the winter host, peach) and is highly dependent on the presence of buckthorn, which prefers limestone-rich soils.
DE: Kreuzdornblattlaus ES: Pulgón del cambrón FR: Puceron du nerprun IT: Afide del ramno PT: Piolho do catapereiro GB: Buckthorn aphid
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.