The biggest pests of cherries are the European cherry fruit flies (Rhagoletes cherry) and the American cherry fruit flies (Rhagoletis girdled). For practical purposes, the two species can be considered together because their life cycle and control are essentially identical, although the European cherry fruit fly emerges 10 to 14 days earlier (from mid-May) than the American one. If these pests are not adequately controlled, serious crop losses can occur because fruit fly larvae (maggots) are found in the cherries during harvest. Find out more here about how to combat the cherry fruit fly and how you can successfully protect your cherry trees from pests.
Fight cherry fruit fly in the soil - the maggots
Cherry fruit flies spend about 10 months of the year as pupae in the ground under the cherry trees and, depending on the species and soil temperatures, emerge as adults from mid-May to July. The adults (around 5 – 6 mm in size) eat and mate, but only lay eggs after around 10 days. After the 10-day feeding and mating period, the flies begin to lay their eggs directly under the skin of the fruit. A female can lay 50 to 250 eggs. The eggs hatch after 5 to 7 days and the maggots feed on the pulp of the cherry. When fully grown, the larvae leave the fruit, fall to the ground and begin their 10-month pupation period in the soil.
Symptoms of an infestation
The larvae feed on the pulp inside the fruit and make the fruit unsaleable. There is no evidence of infestation on the outside of a fruit until the larvae emerge from the exit holes. Large populations can attack a high percentage of the fruit on a tree. You can see suspicious cherries under the tree, but if you see oneinfected cherrypicking, it is easier to identify the pest.
A small portion of the cherry will begin to turn brown and shrivel. Tiny pinholes can be seen along the cherry's skin, from which juice squirts out when squeezed. The fruits rot from the inside and the cherry maggot hatched from the laid eggs appears. Late-fruiting varieties are often more severely affected than early-fruiting varieties.
Remedies against cherry fruit fly
Yellow boards – cherry fly control
Panels are useful for determining the first appearance of the cherry fruit fly, particularly on a regional basis. Trap results should not be relied upon to determine whether control sprays are necessary. Yellow panels are not very efficient for detecting fruit flies, especially when the number of flies is low. Hang the boards in an area where the flies are most likely to be caught. More important than the number of yellow boards is putting them up where you know there is onehigh fruit fly populationis present.
Use commercially available yellow panels that increase the appeal with a fabric. Hang the traps at eye level in exposed, sunny areas of the trees until mid-May. To prevent waste from accumulating in the trap, remove all leaves and twigs within 40 cm of each trap. Check the panels daily until the first flies are caught.
Uncontrolled outdoor sources are a common threat to most growers, so it is important to monitor the nearest boundaries. This ensures that flies that invade your garden are detected early and that agents are applied in a timely manner to prevent them from settlingto prevent spread.
Protect cherry trees from pests with mulch
Ground covers and mulch around the base of trees can prevent the larvae from burrowing into the ground to complete their development to the pupal stage. Successful plant covers are grasses and other plants with extensive, dense root systems that physically impede fruit fly larvae. Garden fleeces and films can prevent the larvae from burrowing and the adults from hatching from the pupae in the ground. Mulch made from other dense materials can also disrupt their life cycle.
Fight cherry fruit fly: net for the cherry tree
A fine net can prevent fruit flies from landing on ripening cherries in your garden. You should stretch the netting over the smaller trees to cover them and secure it with tape. For larger trees, you can wrap individual branches with the net.
Remove fruit from the ground
Maintaining a “clean” orchard where the fruit fly population is kept at low levels from one year to the next is important because high populations are more difficult to control, even with insecticides. In years when there is no harvest or all fruit is not removed from the trees, fruit fly populations may increase and the following yeargreater pest pressurecause. Therefore, it is important to remove fallen fruit from the ground as it may contain larvae. Additionally, remove any abandoned or wild cherry trees nearby.
Fight cherry fruit fly – organically
Birds and rodents take a greater toll on fruit fly larvae, but they also generally consume the fruit and are therefore not considered useful. Chickens and other poultry have been shown to eat fruit fly larvae and pupae in the soil and may provide some benefit.
Cherry tree spray against worms
Insecticide sprays that target the adults are the main tactic for controlling this pest. But try these pests firstcombat it with natural means. Get good advice from your garden center if you decide to use sprays.
Fruit fly larvae develop inside the fruit, where they are protected from most insecticides. Studies of insecticide penetration into fruit have shown that some of the insecticides can penetrate the skin and kill insect eggs and larvae in the fruit. The main goal of control remains to prevent females from laying eggs in the fruit.
