The Department of Horticulture here has gone for biological control of black-headed hairy caterpillars in coconut palms as its menace has been increasing in some parts of Mangalore and Bantwal taluks.
The caterpillar is known as Opisinia Arenosella. The caterpillar-infested palms look dry. The yield in a palm hit by the menace has dropped up to 60 per cent in the second year of attack itself, according Yogesh H.R., Deputy Director of Horticulture, Dakshina Kannada.
He told The Hindu that though the affected palm would not die, its yield would be low.
“The caterpillars live under the surface of leaflets inside silken galleries and feed voraciously on the chlorophyll containing functional tissues. This affects the health of palm by reducing photosynthetic area and results in reduction in yield,” he said.
Mr. Yogesh said that chlorophyll in any plant absorbed sunlight directly and prepared food for a plant by absorbing water and nutrients through roots. The process was called photosynthesis.
He said that the department has developed a parasite (which is a kind of insect) called Goniozus Nephantidis in its laboratory at Thumbe. This parasite was widely used by the department in some other prominent coconut growing districts in the State to control the menace.
Mr. Yogesh said that the infestation was severe from February to June, when they multiply, and less in rainy season. But with the drastic reduction in rainfall this year, there are chances of the menace increasing , if the temperature went up.
He said that 10 to 20 parasites are left at the bottom of the palm. As soon they reached the leaflets in search of caterpillars and ate them. If they are not found there, they go to the next palm.
The department has now called bids to develop nine lakh parasites en mass at an estimated cost of Rs. 2.5 lakh at its laboratory in the current financial year.
For freeThe parasites now developed would be given to farmers for free in test tubes. A tube would have about 100 insects. Though the tubes would be charged, the money collected would be refunded when they are returning.
For more information, call 9036893214.