Fruit fly is a serious pest of fruits and vegetables in Pakistan. It causes intensive fruit losses from 50 to 90%. Mango, guava, citrus, melon, and cucurbits are seriously affected. The quality of fruits, financial losses, health problems and quarantine risk is caused by its attack. Prominent species found in Pakistan are Bactrocera zonata, B. dorsalis, B. cucurbitae, Dacus ciliates and Carpomya vesuviana.
Due to a short life cycle, its population increases enormously. Lifecycle consists of 4 stages and its duration is dependent on temperature. Mostly it completes in 21-37 days. Its adult is smaller than a house fly. Female lays eggs under surface of fruit in groups. Eggs hatch within a few (1-2) days. Larvae feed on fruit pulp and develop within 7-8 days. Infested fruits fell on the ground and mature larvae pupate into the soil. Adult flies emerge in 8-10 days from pupae and infest again fruit.
Mode of Damage:
Fruit fly damages fruits by oviposition inside the fruit. After oviposition, eggs hatch and maggots feed on fleshy part of fruits. Larval feeding causes the most damage. Eventually, fruit drops from tree and decomposition take place owing to secondary microorganisms. Larval tunnel offers entry for bacteria and fungi and rotting occurs. Maggots also attack seedlings, succulent tap the roots, and buds of the host plant. Due to such damage, it affects production, quality, and export barrier.
Different methods are used to fruit fly management.
Field sanitation: Infested fruits must be removed from the field and buried deep 3 feet inside the soil.
Bait spray: Different proteins with insecticide are used as bait. After feeding on bait, fruit flies are killed.
Sterile Insect Technique (SIT): This is a very effective modern technique in which the male is sterilized and become unable to fertilize the female. It uses against small scale population.
Insecticide: Different insecticides like Deltamethrine, Diptrex, Confidor, and Diazinon etc. are being used for fruit fly management. Sometimes different mixtures are also used for effective control.
Traps: Pheromone traps having methyl eugenol, Liquid trap with food bait and mass trapping are used for fruit fly monitoring and management.
Biological control: Hens in field feed on surface larvae. Other predators include ants, earwigs and nematodes also reduce the population. Parasites like wasp also control fruit fly population.
The above article is jointly authored by Sajjad Manzoor, Hafiz Muhammad Arslan Abid, Muhammad Nasir, and Muhammad Tayyab.