Insects/Mites
Fruit fly
Damage
Adults and larvae-maggots cause fruit damage. Egg-laying females puncture the fruits leaving scars and holes on the fruit surface. Larval feeding causes premature fruit drop and destroys the pulps of the fruit. The fruit eventually rots making it unsuitable for harvesting and human consumption.
Description
Eggs of fruits flies are small, white, and slender. These are laid, or inserted into fruit in groups of up to 37 eggs. They hatch within 2-4 days.
Larvae are cylindrical, elongate, narrowed, and somewhat curved downward with their mouth hooks at the head. The larvae live and tunnel through the fruit, feed on the pulp, and continue feeding inside the fruit. They jump rather than crawl. When the larvae are ready to pupate, they emerge from the fruit and drop to the ground.
Pupae occur in the soil beneath the host plant. The pupal stage lasts for about 10 days.
Adult fruit flies are very small insects which lay their eggs in various plant tissues. Wide heads, black or steely green or blue bodies, bright greenish to bluish eyes, and wings that are usually mottled brown or black, characterize the Tephritidae. The Drosophilidae are yellowish and in the wild are largely found around decaying vegetation. The larvae living in fruit feed on the yeasts growing in the fruit. A female adult lays eggs in groups within the fruit and may lay as many as 1,200 eggs in her lifetime. The average life span of the adult is about 30 days. The life cycle of the fruit fly ranges from 12-28 days depending on the climatic condition. In countries with high temperatures, its life cycle is 12 days and longer in areas with cool weather. Important fruit fly species
Oriental fruit fly. The adult Oriental fruit fly is somewhat larger than a housefly, about 8 mm in length. The body color is generally bright-yellow with a dark T-shaped marking on the abdomen. The wings are ransparent. The female has a pointed slender ovipositor use to deposit eggs under the skin of host fruit. Eggs are minute cylinders laid in batches.
Medfly. The adult Medfly is slightly smaller than a common housefly and is very colorful. It has darkblue eyes, a shiny-black back, and a yellowish abdomen with silvery cross bands. Its wings, normally drooping, display a blotchy pattern with yellow, brown, and black spots and bands. This adult Medfly attacks all fruits and it is the most widespread and destructive.
Melon fly. The adult Melon fly is 6-8 mm in length. Distinctive characteristics of the adult are the wing patterns and long third antennal segment. The back of the thorax is reddish-yellow with light-yellow
markings and without black markings. Its head is yellowish with black spots. Soon after emergence,
the Melon fly begins looking for food. The adults are capable of very long flights and can fly as far as 30-
60 km. The melon fly is rated as one of the world's most serious pests and the most important pest of vegetables especially melons and squashes.
Control measures
Cultural practices
1. Remove fruits with dimples and oozing clear sap. This method is more effective although laborious than picking rotten fruits from the ground as the maggots may have left the fruits to pupate.
2. Harvest crops early when mature green. This is the stage of maturity when crops are not
susceptible to fruit fly attack.
3. Pick overripe fruits. These are good breeding sites for fruit flies.
4. Practice crop and field sanitation. Collect and destroy fallen and damaged ripe fruits. Do not put collected damaged fruits in compost heaps, instead feed to pigs or poultry, or bury to eliminate all sources of possible breeding sites. Field Guide to Non-chemical Pest Management in Mango Production
Physical control
1. Bagging the fruits
To make your own bags, cut old newspapers measuring 15 x 22 cm or 12.5 x 27.5 cm. Double
the layers, as single layer breaks apart easily. Fold and sew or staple the sides and bottom of the
sheets to make a rectangular bag.
To bag a fruit, blow in the bag to inflate it. Remove some of the fruits, leaving 1 on each
cluster. Insert one fruit per bag then close the bag using coconut midrib or firmly tie top end of bag with
string or wire. Push the bottom of the bag upwards to prevent fruit from touching the bag. Use a ladder
to reach as much fruits as possible. Secure the ladder firmly on the ground and for bigger and
higher fruits trees, secure or tie the ladder firmly on big branches. Start bagging the mango fruit 55-60
days from flower bloom or when the fruits are about the size of a chicken egg.
When using plastic bags, open the bottom or cut a few small holes to allow moisture to dry up.
Moisture trapped in the plastic bags damage and/or promotes fungal and bacterial growth that caused
diseased-fruits. Plastic also overheats the fruit. Bags made of dried plant leaves are good
alternatives to plastic.
Remove the bags during harvest and dispose them properly.
2. Fruit fly trap
To make your traps, you need 1-liter used plastic bottles. Heat an iron rod to make holes on
the neck. Also make a hole on the lid, big enough for the string or wire to pass through. Insert a string
or wire at the lid's hole. Place the bait inside the bottle. Hung traps in a shady part of the tree just
above the lower leaves. Replace the bait at least 2 times in a week. Fresh bait is often attractive to the flies.
Fruit fly baits
· Ripe banana peel cut into small pieces and mixed with sugar, flour, and water
· Mixture of 1 tsp vanilla essence, 2 tbsp ammonia, ½ cup sugar, and 2 liters of water
· Mixture of 1 cup vinegar, 2 cups water, and 1 tbsp of honey.
· Mixture of sugar, soya sauce, and ammonia.
3. Yellow sticky traps
baited with vials containing a ratio of 1 part ammonia and 1 part of water
Plant extracts
Basil leaf extract
Neem seeds extract
Basil leaf extract Method of preparation Grind leaves 50 g of basil leaves Soak overnight in 2-3 liters of water Strain Add 8-12 ml soap Stir well Pests controlled Caterpillars Fruit flies Red spider mites Red scales Spotted leaf beetles Fungal diseases Nematodes |
Neem seeds extract Method of preparation Pound gently 3-5 kg of de-shelled neem seeds. Place pounded seeds in a clay pot. Add 10 liters of water. Cover the mouth of the pot securely with the cloth and leave it as such for 3 days. Strain to get clear extract. Dilute 1 liter of neem seed extract with 9 liters of water. Add 100 ml of soap. Stir well. Pests controlled Most agricultural pests |
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