Flying mammals - bats that play a critical role in controlling the pests are now swarming the apple orchards in Rohru and Jubbal, the areas known for quality fruit production.
Bat raids on orchards across the apple-growing regions have escalated this week with reports of attack on high-return apple varieties.
"The number of fruit bat attacks on the orchards has increased in the past one week. We believe that bats have migrated from other areas where food is scarce for them," says Bishan Lal Negi, a fruit grower of Kanda village, 5 km from Rohru town. Negi, this time, noticed bat attack on his orchards a fortnight ago.
Bats feed on the ripe apples and leave a claw mark on the fruit, which reduces the quality of apple. "This time, we are unable to find any solution to the bat attack," says Negi, who regularly patrols his orchards at night along with his family members. Bats have damaged 20% fruit crops in Negi's orchards.
The bat attack is more common on apple orchards situated in the vicinity of Rohru town. "A villager from Bakherna informed that the number of bats was in thousands. The skies at night echoes with flapping sound of bat wings," says Rajkumar Neetu, president of Rohru municipal council. "We will take up the matter with the civil administration and also with the forest department. Colonies of bats can be noticed on Alnus trees growing along banks of Pabbar river and its tributary, Skhikri Khad. They sleep on trees, hanging upside down and become restless in the evening. They thrive on fruit, causing great damage to orchards as they clear all the fruit from a tree.
Not only the surrounding areas of Rohru town are being raided by bats but the flying mammals have now escalated attacks on fruits in Bral and Jharag villages, which are known for quality apple production.
"Apple orchards in the area have already been hit by hail earlier this year. Now the bat attacks are adding to the woes of fruit growers," says Daulat Chauhan, a resident of Bral village.
"It appears that bats are facing a dearth of food in the area. Food scarcity is the only one main reason that appears to have forced bats to swarm apple orchards," says Vijay Thakur, assistant director at Regional Horticulture Research Station, Mashobra. "We have reports that bats attacks were common on maize crop. There is a strong reason to believe that their population has gone up in the area," he adds. According to Thakur, although bats cause some damage to the fruit, their invisible role in keeping the environment healthy is far greater than the damage they cause.
Zoologists observe that that problem of bat is seasonal. "Bats migrate from one place to another in search of food. Controlling bat attacks on apple orchards is a difficult task," says JN Julka, former director of high-altitude regional centre of Zoological Survey of India, Solan. "These bats can fly up to 15-30 km overnight.
They return back to their colonies before sunset," he said. According to Julka, firing gun shots at night or beating drums is the only solution to stop bats from settling on trees. "Loud noise can scare away bats," says Julka, adding that flashlights are also helpful in keeping bats away. Installing flashlights is a costly affair, one can just fire guns shots," he adds, while he remembered that bat attacks were frequent in fruit growing areas in early 60s. At that time people went for large-scale culling.
Studies conducted by the ZSI show that Himachal Pradesh plays host to 24 species of bats. These include the Great Himalayan horseshoe bat, the intermediate horseshoe bat, the Great Himalayan leaf-nosed bat, the Schreiber's long-fingered bat and the Siliguri. Increased population of bats has also raised fear of disease outbreak amongst the locals since Rohru sub-divisions lies in the sylvatic belt (prone to vector-borne diseases). The area has witnessed occurrence of pneumonic plague thrice in 1945, 1998 and 2002.