Aphid damage on Rosaceae (fruit trees, strawberry, raspberry)

On peach and apricot, the green peach aphid (Myzus persicae), the most frequent, causes direct damage by deforming the foliage and indirect damage by transmitting viral diseases like plum pox virus (Sharka).

Watching for Myzus persicae must start straight away from January, when buds are swelling (stage A), when the first individuals hatch from the winter eggs. Damage from aphids varies depending on the fruit variety. They can be seen from April, when the calyx is shed. Inspections should be made of two branches per tree before the corolla becomes visible (stage D): an intervention is necessary when 7% of the trees are found to be carrying Myzus persicae.

On plum, colonies of the leafcurl plum aphid (Brachycaudus helichrysi) and of the mealy plum aphid (Hyalopterus pruni) lead to strong early crinkling of foliage and formation of sooty mould on leaves and fruit. The various kinds of damage due to aphids are caused by individuals present from flower-bud opening, at the time winter eggs are hatching, until the petals fall. The green peach aphid (Myzus persicae) can also occur on plum. These three species can transmit the plum pox virus.

Cherry leaves can be host to black cherry aphid (Myzus cerasi). This induces strong crinkling in the foliage, contortion of growing branches and more especially their necrosis followed by sooty mould development. A watch must be organized over the populations of black cherry aphids, starting when the flower buds begin to develop and continuing until alates appear in May and June.

On pear, the mauve pear-bedstraw aphid (Dysaphis pyri) brings about leaf rolling and formation of sooty mould. Aphids more dependent on apple like the apple-grass aphid (Rhopalosiphum insertum) and the green apple aphid (Aphis pomi) can also cause leaf deformation. The pear phylloxera or pear bark aphid (Aphanostigma piri) attacks the fruit. A watch over these aphids must be kept from the time the first sepals fall, particularly if the trees have already had infestations the previous year.

The apple tree is colonized by several aphid species: the grey rosy apple aphid (Dysaphis plantaginea), the green apple aphid (Aphis pomi) and the apple-grass aphid (Rhopalosiphum insertum). Their presence causes severe leaf rolling, crinkling and yellowing or reddening of leaves. The appearance of the first aphid larvae can be detected from the time of bud swelling. The first foci of the rosy apple aphid (Dysaphis plantaginea) must be watched over before flowering, from stage D, from either April in the South of France or three weeks later in the Val de Loire. Subsequently, from July to harvest time, more than 50% occupation of shoots by the green apple aphid (Aphis pomi) will result in loss of fruit quality. The presence of the woolly apple  aphid (Eriosoma lanigerum) must be detected between the fall of the first petals and harvest time.

On strawberry, the strawberry aphid (Chaetosiphon fragaefolii) is the most frequent. This anholocyclic species sustains itself in mild winters on very young leaves. In spring, it colonizes the whole plant, particularly the underside of leaves which blacken and dry out. When strong outbreaks occur, growth of shoots can be slowed down or even stopped which is detrimental to fruit formation. Abundant honeydew is excreted on which the sooty mould develops. Moreover, this aphid is an important vector of several viral diseases: strawberry yellow edge virus (SYEV), strawberry crinkle virus (SCV), strawberry mottle virus (SMV).

Other species are encountered on strawberries. In order of frequency, can be seen the pelargonium aphid (Acyrthosiphon malvae), the strawberry root aphid (Aphis forbesi) and the yellow rose aphid (Rhodobium porosum). Also found, but to a lesser extent, are the species Aulacorthum solani, Macrosiphum euphorbiae, Myzus ascalonicus, M. ornatus and M. persicae.

Aphis forbesi is holocyclic and spends winter as eggs. It lays these on leaf petioles or on the collar. The stem mothers hatch in March and engender colonies that spread over the collar, petiole and base of leaves. The alates appear at the end of spring and colonize other strawberries. Aphis forbesi produces abundant honeydew which ants come to fetch.
Acyrthosiphon malvae, Myzus ornatus, M. ascalonicus, and Aulacorthum solani can transmit viral diseases to strawberry.

The control strategy against these aphids is based on the release of auxiliary organisms as the use of chemical plant protection products is becoming increasingly restrictive.
Some firms have developed biological products adapted to strawberry cultivation. These are prepared for deploying more generalist predators (Chrysoperla carnea, C. lucasina, Aphidoletes aphidimyza, Adalia bipunctata, Coccinella septempunctata) or for letting go single-species parasitoids or mixtures (2- 6 species) (Aphidius ervi, A. colemani, A. matricariae, Aphelinus abdominalis, Ephedrus plagiator, Praon volucre).

                      Parasitism (observed in crops) on principal aphids of strawberry

XX Certain parasitism, X Uncertain parasitism
      
Two species frequently colonize raspberries: the small raspberry aphid (Aphis idaei) and the large raspberriy aphid (Amphorophora idaei).
In spring these two species cause foliage deformation and fading. They can also transmit viral diseases. Aphis idaei is very often visited by ants.