Rhagoletis cerasi

Cherry fruit fly ( Rhagoletis cerasi )

The cherry fruit fly ( Rhagoletis cerasi ) is a fly from the family of fruit flies ( Tephritidae ). It is the most important pest in Süßkirschenanbau because their Made in developed cherries.

Features

The flies are 3.5 to 5 millimeters long. They have a black body with yellow spots on the head and thorax. The tag ( scutellum ) is yellow. Their wings are colored very characteristic transparent and with four black blue napkins. You have green compound eyes.

The larvae reach a length of four to six millimeters and have a whitish colored body.

Way of life

The larvae of the flies develop in the fruits of bird - cherry (Prunus avium), sour cherries (Prunus cerasus), honeysuckle ( Lonicera ), snow berries ( Symphoricarpos ) and the ordinary bird cherry (Prunus ).

The flight time of the cherry fruit fly, depending on the temperature between late May and early July. In sunshine the flies sit on the leaves and fruits of the larval food plants and suck sap exiting. 10 to 15 days after hatching, the females begin to lay eggs in warm weather. Be laid 50 to 80 eggs, which are individually inserted beneath the epidermis of maturing fruits. After 5 to 12 days, hatch the maggots that feed around the core from fruit pulp. Thus, the fruit begins to rot and fall to the ground. The larvae are fully grown after about 30 days and leave the fruit to bury themselves in some centimeters deep in the soil and pupate. If not from the fruit, the animals can be down to a spun yarn. The insects overwinter. The dolls can also use two or three times lie before the imago emerges.

Reduce the time of flight cool temperatures and high rainfall populations of flies. Accordingly, in dry years the cherry trees are particularly affected. Also rather late varieties are attacked by the fruit, as early varieties will mature when the flies have not yet properly developed.

Combat

In order to control the cherry fruit fly in amateur gardening so-called yellow traps are marketed. These will be hung at the beginning of yellowing of the cherries on the south and west sides of the tree and remember the flies on the color of cherries. The fly traps are coated with gum, which the flies stick lay their eggs in the attempt. Some traps are supplied with an attractant which incites the flies to prefer the case as a destination. Per meter tree height two traps should be used. A single fly can lay up to 200 eggs and thereby infect more than one kilogram of cherries. The attachment of yellow traps is insufficient to protect all crops from maggot infestation.

To prevent severe effects in cherry varieties can be planted, the fruits are not sufficiently matured at the time of oviposition or already harvested. Depending on the location air oviposition takes place at different points in time, whereby it is very dependent on the location, which species are less sensitive. Chickens and ducks scratch the dolls out of the ground and eat them. Even the fallen fruit is often eaten by these animals. An insulating ground cover, such as mulching material, delaying the warming of the soil and thus the hatching of flies. The tree is located on a prairie, so it is beneficial will not mow until the cherry harvest.

Organic Farming

In organic farming the cherries are ( for example, a cherry - protective net ) protected by a dense network. Since it is not possible with large trees, this completely einzunetzen the tree is pruned regularly so that it remains small and the network can be extended over the whole tree. In organic farming insects injurious nematodes come ( nematodes ) are used.

Conventional agriculture

In conventional orchards, the requirement that only cherries may reach the market that may be infested with maggots to a maximum of 2% exists. Until a few years ago, this was achieved through the use of the insecticide Lebaycid. This poison was banned in Germany due to negative effects on the environment. As an alternative, dimethoate was admitted to control the cherry fruit fly, which also has a very high efficiency, but results in an infection rate that is very close to the approved limit. Agricultural Institute and the manufacturers of pesticides subsequently conducted by large-scale studies of the effectiveness of other compounds to control the cherry fruit fly. It turned out that even pyrethrum and Neempräparate have some efficacy against the cherry fruit fly and can reduce the infection rate is zero conditions in combination with other insecticides. In addition, since 2005, the active ingredient acetamiprid for pest control in conventional cultivation is authorized EU wide.

Swell

• Peter Galli: cherry fruit fly control by approval status and recent experiments, online: PDF (44 KB)
• Institut national de la recherche agronomique (English)