15 Jul Phytosanitary Pest Focus: Fruit Flies
The production of citrus, deciduous and subtropical fruits are usually constrained by local fruit fly pests which either cause direct damage resulting in crop losses or restrict market access as they are classified as a phytosanitary pest. Due to this, it is considered vital to control fruit fly pests before they get out of hand.
Multiple generations of fruit flies can occur within a year, and environmental factors like temperature affect their development. Fruit flies cause damage to fruit by stinging the fruit to deposit their eggs (Fig. 1) underneath the fruit rind, which hatch into larvae (Fig. 2). The larvae then feed on the fruit pulp leading to decay and secondary infections. Larval development usually lasts for 10-25 days, after which the larvae leave the fruit to pupate in the soil and emerge as an adult fruit fly.
The production of citrus, deciduous and subtropical fruits are usually constrained by local fruit fly pests which either cause direct damage resulting in crop losses or restrict market access as they are classified as a phytosanitary pest. Due to this, it is considered vital to control fruit fly pests before they get out of hand.
Multiple generations of fruit flies can occur within a year, and environmental factors like temperature affect their development. Fruit flies cause damage to fruit by stinging the fruit to deposit their eggs (Fig. 1) underneath the fruit rind, which hatch into larvae (Fig. 2). The larvae then feed on the fruit pulp leading to decay and secondary infections. Larval development usually lasts for 10-25 days, after which the larvae leave the fruit to pupate in the soil and emerge as an adult fruit fly.
The puncture caused during ovipositing can cause secondary bacterial infections, both of which cause fruit rot. Export markets have all fruit fly species listed as phytosanitary pests and a single larva could lead to an entire consignment being rejected, which could also affect market access.
The puncture caused during ovipositing can cause secondary bacterial infections, both of which cause fruit rot. Export markets have all fruit fly species listed as phytosanitary pests and a single larva could lead to an entire consignment being rejected, which could also affect market access.
Monitoring
Some precautionary practices have been found to be very effective. Monitoring for fruit fly is important to establish the pest pressure within the orchard, which will help guide the control practices that need to be applied. Monitoring products like the Invader Lure (Fig.3) using the Lynfield Trap to monitor for Bactrocera Dorsalis (Oriental Fruit Fly) or the Capi & Quest Lure (Fig. 4) to monitor for Ceratitis Capitata (Mediterranean Fruit Fly) is useful to measure pest pressure. Fruit flies can be found within the canopy of the crop, on ripe fruit, or on decaying fallen fruit.
Through monitoring efforts, growers can effectively protect their crops and establish the need for corrective action. With this, good sanitation practices can also assist with lower pest pressure. Removing rotten/fallen fruit, deadwood, and invasive weeds can lower the chances of population growth and infestations.
Control Measures
With several control measures available for fruit fly, not all are environmentally friendly and can leave harmful MRL’s behind. This needs to be considered when planning your season spray programme. River Bioscience remains committed to providing growers with sustainable solutions for phytosanitary pests and providing the necessary monitoring tools as mentioned above.
Fruit fly control products available from River Bioscience that comply with integrated pest management programmes that are safe to use for both the consumer and the environment are:
Invader-B-Lok™
Invader-B-Lok™ is a fibre block impregnated with methyl eugenol and mercaptothion (Fig. 5). The methyl eugenol component of the Invader-B-Lok™ is highly attractive to males of several Bactrocera species. Male fruit flies which are attracted to the methyl eugenol mixture die upon contact with the mercaptothion. The application of Invader-B-Lok™ follows the principle of the male annihilation technique (MAT), targeting high levels of male mortality for species that respond to methyl eugenol. Eradicating males significantly reduces the amount of mating in the fruit fly population, thereby suppressing the population and lowering fruit infestation.
The efficacy of male annihilation is largely improved when combined with protein baiting, either through sprays or the use of protein bait stations, such as the M3™ which targets females.
Invader-B-Lok™
Invader-B-Lok™ is a fibre block impregnated with methyl eugenol and mercaptothion (Fig. 5). The methyl eugenol component of the Invader-B-Lok™ is highly attractive to males of several Bactrocera species. Male fruit flies which are attracted to the methyl eugenol mixture die upon contact with the mercaptothion. The application of Invader-B-Lok™ follows the principle of the male annihilation technique (MAT), targeting high levels of male mortality for species that respond to methyl eugenol. Eradicating males significantly reduces the amount of mating in the fruit fly population, thereby suppressing the population and lowering fruit infestation.
The efficacy of male annihilation is largely improved when combined with protein baiting, either through sprays or the use of protein bait stations, such as the M3™ which targets females.
M3™ BAIT STATIONS
The use of M3™ Bait Stations (Fig. 7) has proven to be an effective tool in controlling fruit fly populations in fruit orchards due to its attract-and-kill properties. The M3™ Bait Station contains protein hydrolysate & plant extract with alpha-cypermethrin which attracts female fruit flies and kills them upon contact.