There are several options available for controlling fruit flies in your orchard. Physical barriers such as mosquito nets that cover the entire tree can keep them out. These can be fixed to the trunk, bags, or sleeves. However, it is important to leave a space between the netting and fruit. The female flies are able to penetrate the netting. Moreover, the use of deterrent sprays is not sufficient. You must also use attractants or baits that prevent fruit flies from entering the trees.
Bait and deterrent sprays
While bait and deterrent sprays are effective methods of controlling fruit fly populations in orchards, there are other options. The bait application method is the most widely used among cherry growers in Washington. The bait GF-120 has proven to be effective, and it is widely used by Washington’s cherry industry. Washington inspectors found no larvae in fruit packed in north central Washington packing houses last season.
These treatments can also be combined. Some bait sprays contain a protein laced with a toxin that kills adult fruit flies. Protein is necessary for the female fruit fly to mature eggs and maintain egg production, so baits can suppress the entire population. Bait and deterrent sprays are most effective when applied early and consistently over the entire orchard. Bait applications begin weekly when fruit is half-sized and weekly spraying is most effective.
The foliar and bait application methods were not equally effective. In the same trial, a group of four people applied GF-120 to papaya trees. The spray was applied to the PLMs and foliage of each tree. In each plot, 10 half-ripe and quarter-ripe fruits were harvested. The ripeness of each fruit was characterized using qualitative descriptions. Then, each sampled fruit was placed into a 4-liter bucket with a substrate of sand.
Traps
Traps are an important part of effective fruit fly management. These pesticides can be used to control adult fruit fly populations, or to prevent their reproduction in orchards. Fruit fly management should begin when the first fruit sets. Traps should be checked periodically for adults. After trapping the adult fruit fly, producers should pick up rotten or damaged fruit. Fruit fly management may include a combination of cover spray, bait application, and orchard hygiene. If fruit fly populations are high, the pesticide application may be combined with bait.
In addition to reducing insecticide use and labor costs, bait stations also minimize the effects of traps on nontarget organisms. The INIFAP trap is as effective as ground sprays in rainy conditions. Fruit fly management is important in tropical climate regions. Traps may be more effective in areas with higher fruit production than in other regions. Although the effectiveness of bait stations depends on the pesticide being used, this method is effective when used with a mass trapping strategy.
Bait spray applications are another effective tool for controlling fruit fly populations in orchards. For effective trap applications, bait applications should be done in late June or early July, depending on where you grow your fruit. In the Central Valley, spinosad bait treatments should start as soon as fruit hardens or reaches 10 mm in diameter, which is when the flies begin stinging them and developing. The bait sprays should be applied according to label directions, one every other tree row and biweekly.
Attractants
The use of attractants is a proven strategy for control of fruit flies. These insects are attracted to sugary and proteinaceous substances present in fruit. These chemicals can increase fruit set and size, as well as promote vigor in the orchards. Several attractants are available on the market, including insecticidal sprays and natural traps. But which is the best fruit fly attractant?
One method of controlling these flies is mass trapping. Researchers have successfully used attractants to control Ceratitis capitata, the Mediterranean fruit fly. These attractants lure insects to a coated surface, thereby killing them. The other method, mass trapping, reduces fruit damage by the same amount but does not reduce population numbers. These attractants also reduce damage to fruit by reducing non-target insect populations.
In this method, the attractant is mixed with a food protein and placed on the host tree or on other locations around the garden. The attractant is sprayed on the trunk of the fruit tree or other plants, and the adult flies are attracted by the bait droplets. The insecticide kills the adult flies. This method is not only effective, but it is also very safe for people and the environment.
Bait spray applications are another effective method of controlling fruit fly populations. The application of bait sprays starts when trap captures increase, which should be at the beginning of June or early July in the Central Valley. For orchards with a history of damage, bait treatments should begin at the beginning of pit hardening, i.e., when fruit starts to reach 10 mm in thickness. The adults are enticed to feed on small droplets of sticky bait. This method of controlling fruit fly population can be effective in low populations, but it is not rain-fast. You must apply it every 7 days to maintain effective control.
Codling moth larvae
Keeping your orchards clean can reduce the number of insect pests that can cause major crop damage. One way to do that is by controlling the codling moth larvae. These insects are attracted to protected entry sites, such as in thinning the fruit. Thinning also allows you to better apply insecticide to the entire fruit. Also, stripping fruit will help eliminate the outside sources of codling moth larvae.
Using pheromone traps, you can monitor the population of codling moths by visually observing the infested fruit. In orchards with more than a few acres, one trap is needed per five acres. Set the traps at the outer edge of the orchard, while the center section of the orchard should be monitored separately. Spring trap checks should be conducted every one to two days until the moths begin to biofix. Biofix marks the start of consistent moth flight, and a single captured moth should be enough to indicate the presence of codling larvae.
In late July and early August, codling moth larvae emerge and overwinter as mature larvae. They feed on the seeds in apples and excrete their waste in golden brown frass. During their life cycle, codling moth larvae lay their eggs on leaves and fruit. The larvae exit the apple after feeding. However, it is difficult to spot the eggs in commercial orchards.
Spinosad
Spinosad is an insecticide that is effective against a variety of insects. This herbicide will cause a temporary paralysis in the insect, preventing it from feeding on the plant. The insecticide is effective for a few days and should not be used more than six times during the growing season. In some cases, the pesticide will prevent fruit fly infestations by up to two days.
The research involved spraying Spinosad in four different orchards. The spray was applied to the lower part of each tree’s trunk, which is known to receive less sunlight after noon and is therefore an important roosting site for adult fruit flies. The Spinosad compound was found to be effective against the fruit fly population and proved to be a safe and efficient alternative to Malathion.
A second important reason to consider Spinosad for orchard use is its relatively low environmental impact. Its low toxicity makes it suitable for organic farming. In Lindsey, California, Spinosad was first used to treat olive orchards. Olive fruit flies were damaging the olive industry. Olive fruit flies lay their eggs on olives and hatched within a couple days. These flies bore through the fruit and destroyed the olives. Spinosad also proved to be a highly effective herbicide at a very low rate.
While using Spinosad for orchard pest management is effective, it has a low tolerance. The best time to use it is in early summer and late June, when trap captures begin to increase. In orchards with a history of damage, bait treatments should be applied when the fruit reaches 10 mm in diameter, or when the flies begin to sting the fruit. The spray should be applied every other tree row and biweekly.
Environmentally friendly management
In South Africa, the subtropical industry has made a transition away from the heavy use of chemical insecticides to eco-friendly management practices. Nevertheless, chemical insecticides are still registered for subtropical crops. However, other methods have emerged as environmentally-friendly management options, including the use of nucleopolyhedrovirus against the African bollworm and entomopathogenic fungi and the release of egg parasitoids. A sterile insect technique is also being used to suppress the false codling moth.
Ecologically friendly management of fruit fly orchard pests requires a diversified approach that takes into account all the factors that influence fruit fly populations in orchards. The introduction of predatory wasps and parasitoids has also helped to combat fruit fly pests. Other beneficial species include ants, ground beetles, spiders, dragonflies, and robber flies, and lizards. Birds and beetles also eat fruit fly maggots.
Ecologically-friendly methods for controlling fruit fly include a variety of biological and organic techniques. The most effective method, known as exclusion, involves covering an individual fruit or a cluster of fruits, or even an entire tree. Commercial exclusion bags are available in waxed paper, polypropylene, and cloth, while the simplest method is using newspaper glued to a frame. During the early stages of the season, fruit should be covered with netting.