Fruit borers are a group of insects that infest fruits and cause significant damage to crops. They lay eggs on the surface of fruits or flowers, and the resulting larvae bore into the fruit and feed on its flesh and seeds, often making the fruit inedible or reducing its quality. The pomegranate butterfly, or Deudorix isocrates, is a common example of a fruit borer pest that infests pomegranate and guava crops in North India.
Management of Fruit Borer in Guava
The Life Cycle of Fruit Borer
The life cycle of fruit borers generally consists of four stages: egg, larva, pupa, and adult. The female fruit borer lays eggs singly on tender leaves, stalks, or flower buds of the host plant. After a few days, the eggs hatch into larvae. The larvae are dark brown, short and stout, and covered with short hairs. They bore into the fruit or flower buds and feed on the flesh and seeds, causing significant damage. The larval period lasts 18-47 days, depending on temperature and other environmental factors.
Once the larvae have completed their feeding, they enter the pupal stage. The pupa develops either inside the damaged fruit or on the stalk holding it. The pupal period lasts 7-34 days, depending on temperature and other environmental factors. Finally, the adult fruit borer emerges from the pupa as a bluish-brown butterfly. The female butterfly has a V-shaped patch on its forewing, which can aid in identifying the species. The adult fruit borer mates and lays eggs, completing the life cycle, which can take anywhere from 1 to 2 months, depending on environmental conditions
Identification of Fruit Borer in Guava
Identifying fruit borers in a guava field can be important for implementing appropriate management strategies. The larvae of fruit borers are typically dark brown, short, stout, and covered with short hairs. They can be found inside the fruit or flower buds, feeding on the flesh and seeds. If you cut open a damaged fruit, you may be able to spot the larvae inside.
The adult fruit borer is a bluish-brown butterfly. A V-shaped patch on its forewing can identify the female butterfly. Observing the adult butterflies in the field can confirm the presence of fruit borers and their species. Monitoring for the presence of eggs, larvae, and damage to the fruit can also aid in identification.
Damage Symptoms of Fruit Borer in Guava
- Caterpillar/larva boring: The caterpillar or larva of the fruit borer bores into the young fruits and feeds on the internal contents, including the pulp and seeds, making the fruit hollow from the inside.
- Hollow fruits: As the fruit borer larvae continue to feed on the internal contents of the fruit, the fruits become hollow and lose their quality, nutritional value, and commercial value.
- Fruit rotting: The damage caused by the fruit borer provides entry points for other pathogens to enter and infect the fruit, causing it to rot and drop from the tree.