Anholocycle

Anholocycle

Certain aphids have totally or partially lost the possibility for reproducing sexually. They proliferate by parthenogenesis throughout the year and are said to be anholocyclic.

An apterous virginopara can give birth to between 40 and 60 larvae depending on the particular climate or weather conditions.

The anholocyclic strategy can be a complete one. It can affect an entire species (currently no sexual form has been identified for Myzus ascalonicus) or just some clones (Metopolophium festucae). Or such a cycle can be partial. In such cases it only affects part of the population. In certain species for example, the rarity of the primary host in some regions or mild winter conditions leads locally to the almost complete disappearance of the sexual phase. This is the case for Rhopalosiphum padi which, in Western Europe, can be present throughout the year on different grasses. Certain species can also overwinter in the parthenogenetic form in sheltered settings like greenhouses, or in tunnels where crops are growing under protective cover.

Rhopalosiphum padi: parthenogenetic reproduction (viviparous female)

Larviposition in Acyrthosiphon pisum

Modification date : 07 February 2023 | Publication date : 25 November 2010 | Redactor : Evelyne Turpeau, Maurice Hullé, Bernard Chaubet