Sajjad Manzoor*, Hafiz Muhammad Arslan Abid, Muhammad Nasir, Muhmmad Tayyab (University of Agriculture, Faisalabad)
*Corresponding author: [email protected]
Fruit fly is a serious pest of fruits and vegetables in Pakistan. It causes intensive fruit losses from 50 to 90 % (Fig: 1). Mango, guava, citrus, ber, melon and cucurbits are mainly effected by it. Quality of fruits, financial losses, health problems and quarantine risk are caused by its attack. Prominent species found in Pakistan are Bactrocera zonata, B. dorsalis, B. cucurbitae, Dacus ciliates and Carpomya vesuviana.
Fig 1: Fruit fly damaged fruit fallen on ground in Citrus field (Fruit Losses)
Life Cycle: Due to short life cycle, its population increase enormously. Life cycle consist of 4 stages (Fig: 2) and its duration depends upon temperature. Mostly it completes in 21-37 days. Its adult are smaller than house fly. Female lays eggs under the 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 fallen on the ground and mature larvae pupate into the soil. Adult flies emerge in 8-10 days from the pupae and infest again the fruit.
Fig: 2 Life Cycle of Fruit Fly
Mode of Damage:
Fruit fly damages the fruits by oviposition inside the fruit. After oviposition, eggs hatch and maggots feed on the fleshy part of the fruits. Larval feeding causes the most damage. Eventually, fruit drops from the tree and decomposition take place due to secondary microorganisms (Fig: 3). Larval tunnel provides entry for bacteria and fungi and rotting occur. Maggots also attack the seedlings, succulent tap roots and buds of the host plant. Due to such damage, it effects the production, quality and export barrier.
Fig 3: Citrus fruit infested by fruit fly.
Different methods are used for 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 very effective modern technique in which 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 the field, feed on the surface larvae. Other predators include ants, earwigs and nematodes also reduce the population. Parasites like wasp also control the fruit fly population.