How to get rid of guava fruit fly

Guava trees produce sweet smelling fruits with an edible rind, with a creamy white, yellow or pink flesh. When ripe, guavas release a sharp, musky odour that draws fruit flies. Fruit flies are among the world’s most serious pests of different horticultural crops due to their direct impact on economy. They are among the most destructive pests. They cause enormous threat to the production of fruits and vegetables throughout the tropical and sub-tropical areas and causes both quantitative and qualitative losses. Fruit flies lay their eggs inside the fruit and the maggots feed on the flesh. As a result fruits rot and infestation often spread quickly.

Most of the damage is caused by the larvae that nourishes inside the fruit during its growth and development. It attack fruits at different stages of maturity but the harm is more noticeable at harvesting stage. The adult female fruit fly place eggs in the flesh of fruits and vegetables. After emerging the larvae feed on the pulp which looks normal from outside. Fruits finally drops down and is not suitable for sale, therefore reduces orchard productivity. During winter the larvae pupate in soil 5-10 cm deep and flies start developing during April onwards, with extreme population during May to July which overlaps with fruit maturity.

Prevention and Control:

Fallen and infested rotten fruits should be removed, as they are capable of spreading further infestation. These should be picked up and destroyed by dumping in a 40-60 cm deep pit and must be covered with soil to eradicate all sources of possible breeding sites. Fruits should be harvested early when they are mature green. Harvesting guavas before they ripen fully is a good practise for preventing infestation. As fruit flies only attack matured fruits, so early harvesting prevents infestation. As this stage of fruit maturity, crops are not susceptible to attack.

Overripe fruits should be also picked as these are ideal breeding sites for fruit flies. Ploughing the topsoil 5-10 cm deep is good for its control. Due to deep ploughing pupae are exposed to predators, parasites, and direct sunlight. Crop and field sanitation is also essential for the control of this pest. Guavas should be avoided to extreme and sudden changes in temperature, moisture, fertilizer or soil pH, as unexpected changes may stress plants and draw fruit flies and other pests.

Pheromone traps such as methyl eugenol capture male flies. Set up methyl eugenol trap in the orchard at the rate of 5 per acre. Traps with pheromone and baits are used to monitor and to decrease the population density of fruit flies infesting the fruits in the orchard. Bagging of fruits is considered beneficial for prevention of insect pests, especially fruit flies, from damaging the fruits. The bag provides physical protection from mechanical injuries and act as barrier against pests.

Fruit fly infestations often spread quickly, but if preventive measures are taken, then the loss can be overcome and its population can be greatly decreased. Almost every guava producers in Pakistan are facing problem of fruit flies attack and their yields are greatly affected. Jazz Bakhabar Kissan service is helping farmers to overcome the losses due to fruit fly attack. Creating awareness among the farmers is very important as mostly farmers are uneducated and they are unaware about the efficient methods to overcome losses. Through the Jazz Bakhabar Kissan Call Centre farmers are able to avail free guidance from the agriculturists and share their problems related to crops and get information about latest technologies and always keep themselves updated.

By Jann Seal Updated June 21, 2021

The taste of guava (Psidium guajava), whether from a bite of the actual fruit or in a jam that sweetens layers of a cake, has a flowery aroma, a bold flavor and can be either sweet or tart. What you don’t want to bite into is the notorious guava insect, known as the guava fruit fly (​Bactrocera correcta)​ and the maggots it produces once it penetrates the fruit. More often found in home-grown varieties of guava, fruit fly infestation can be controlled, but it takes intense dedication to eradicate the pests.

The pesky fruit fly came to America most likely on a cargo ship bringing fruit from Mexico, Central and South America. The fly found the California fruit crops ideal for propagating and stayed. It most likely originated in Southern Asia, from Pakistan through to Thailand before migrating across the ocean, again via foodstuffs being transported. These insects are drawn to orchards with trees that have thin-skinned fruit, and consumers transport them from the market to their kitchens, where the damage occurs.

The female lays its eggs just under the skin of a guava and in about two days, tiny maggots emerge. They tunnel through the flesh of the guava, shedding their skin twice before they emerge out of the other side of the fruit. The entire trip takes about eight to 17 days, depending on the temperature, according to the California Department of Food and Agriculture.

Once the maggots drop from the guava and land on the ground, they burrow into the soil and transform from the immature to mature stage before emerging as fruit flies. The mature females need up to 38 days to develop their egg-laying ability. The cycle continues endlessly unless control measures are put into place.

As the guava matures and its scent becomes more pronounced, fruit flies find homes for their eggs. Only mature guavas are attacked, so it’s recommended that you pick them before they become fully ripe. If you have several guava trees, it may mean harvesting several times a week. Also, check the ground for guavas that have dropped, as they attract the flies and other varmints, suggests Agriculture News, a Pakistani-based agricultural research organization. In addition, try wrapping young guavas in a paper bag, preventing the fruit fly from accessing the ripening fruit.

A limited number of insecticides have been approved for use on guava, according to the University of Florida, which battles the Caribbean Fruit Fly in its guava orchards. Be aware, however, that some are not approved for use when the actual fruit is present. A type of wasp, known as a parasitoid wasp, was introduced to guava orchards to control fruit flies in 1972. They lay their eggs inside the fruit fly larvae, effectively decreasing the fruit fly population.

Thiodan and carbaryl are two insecticides approved for guavas, reports Agrifarming, but their use is limited. Each one needs to be sprayed twice, once before the fruit matures and another at maturity. Do not spray at the stage when the fruit is ripe. It is also recommended that no harvesting be done during the rainy season.

An easy solution to ridding your kitchen of fruit flies, according to the Farmers’ Almanac, is to pour 1/4 cup of apple cider vinegar into a jar. Cover it with plastic wrap, then poke a hole in the wrap. Secure the plastic wrap with a rubber band. The flies will fly in, but they won’t be able to figure out how to get out. The flies also like beer and wine!

Another option is to put a pot of basil on a kitchen shelf near the fruit. The flies don’t like the smell of basil and stay away. Take a few of the leaves and put them at the bottom of your fruit bowl. Or put some apple cider vinegar into the top of a jar, add some dish soap and leave it on the counter. The flies will go for a swim and drown.

References

Tips

• Practice crop rotation. Plant guava trees and other potential fruit-fly host crops in different places each year.

Warnings

• Avoid subjecting guavas to extreme and sudden changes in temperature, moisture, fertilizer or soil pH. Sudden changes may stress plants and attract fruit flies and other pests.
• Protein bait spray and some pesticides, such as dimethoate, may cause leaf burn in guava and other tropical trees. This most commonly happens when the pesticide is not mixed according to the product label instructions.

Writer Bio

A versatile writer, Jann enjoys research as well as doing the actual writing. A career in television writing, as a magazine editor and celebrity interviewer, Jann adapts to her environment, having traveled the world, living overseas and packing and unpacking her treasures for a new location over 30 times.

Guava Fruit Fly (Bactrocera correcta) is an exotic pest that is not established in the continental United States. The California Department of Food and Agriculture (CDFA) conducts eradication projects when evidence of an infestation is found within the State. The purpose of an eradication project is to prevent the environmental and economic damage that would be caused by the establishment of this pest. Establishment of this fly would cause direct economic losses via damaged fruit, increased pesticide use statewide by commercial and residential growers in efforts to lessen this damage, loss of revenue due to export restrictions on fruit both domestically and internationally, and adverse impacts on native plants through the destruction of their fruit. Yearly economic losses would be in the hundreds of millions of dollars.

The eradication treatment, known as the male attractant technique (MAT), is conducted in an area defined by a 1.5 mile radius from each fly find site, for a minimum of 9 square miles. Approximately 600 small gel-like "bait stations" per square mile are applied to the sides of individual utility poles and street trees on public right-of-ways. These bait stations contain a powerful male attractant (methyl eugenol) that is mixed with a small amount of the pesticide spinosad. The bait station will attract and kill male fruit flies before they can breed. In the absence of males, the females go unmated and no offspring are produced, effectively causing the extinction of the population within two life cycles. The attractant is very specific for this group of flies, so much so that other insects such as bees or butterflies will not be harmed because they are not attracted to the lure.

The bait stations are applied to utility poles and street trees by trained CDFA staff in specially modified pick-up trucks. The stations are applied at least 6 feet above ground, well above the reach of children or pets. Bait stations are not applied on school grounds. Applications are repeated every two weeks for up to two life cycles. The fly’s development is dependent on temperature, and it is sped up during warmer temperatures and slowed during cooler periods. Most treatment programs are complete after a 2-3 month period, but those beginning in the fall may extend into the following spring because of the cooler winter temperatures. Following two life cycles of treatment, supplemental fruit fly traps are monitored for an additional life cycle. If no additional guava fruit flies are trapped, the infestation is declared eradicated.