THIRUVANANTHAPURAM: Just a couple of weeks more and it should be time for the cool summer showers. But the first heavy rain in the hot summer will bring in an army of ‘moopli’ beetles that invade your homes, in the dark of the night, especially in areas near rubber plantations.
But scientists at Devagiri College have now found that these beetles may soon move on to other trees if rubber is not available.
These litter-dwelling beetles are called ‘Moopli vandu’ as they were first found in the Moopli Rubber Plantations. Also called ‘Ola prani,’ ‘Ola chathan’ and ‘Otteruma’ in North Kerala, these dark brown to black beetles come in swarms of thousands.
What attracts these rubber leaf-eating beetles (scientifically called Luprops tristis) to our homes is definitely the lights at night. They crawl up the walls, fall off the ceilings, into our beds and even food. Mothers run around looking for cotton to plug their sleeping babies’ ears, to prevent these bugs from crawling in there.
Until now, these nuisance pests were confined just to rubber-growing areas. A study conducted by a team of scientists at St Joseph’s College, Devagiri, in Kozhikode, has found that these ‘Ola chathans’ have now learned to appreciate the taste of jackfruit leaves and to a much lesser extent, cocoa leaves as well.
The Devagiri team led by Sabu K Thomas and comprising Greeshma Mohandas and P Aswathi plucked out leaves of various ages of seven trees such as cashew, mango, sapota, wild jack and cassia, apart from jackfruit and cocoa, and offered them to the beetles to find a pattern of preference.
Rubber leaves were the most preferred, with the tender leaves being more yummy to the beetle palate than the older leaves. The scientists reason that the preference for young leaves should be because of the high nutritional value.
If neither young nor old rubber leaves are available, the beetles munch on jackfruit and cocoa leaves and very reluctantly on sapota. This also means that in case of need, these beetles of the night can survive on jackfruit and cocoa leaf litter. However, in the case of cocoa, equal preference was shown for both tender as well as mature leaves.
So, if you are near a rubber or cocoa plantation, or even have jackfruit trees at home, be on your guard. Once inside your homes, these bugs stay on for another two weeks, without any particular reason to do so. Sometimes, they would aggregate and go into a deep dreamless sleep.
These beetles do not sting or bite, but don’t ever try to pick them up. They squirt out a stinking spray that might cause something like a burn on certain skin types. Maybe why even lizards keep away from ‘beetle meals.’
Sabu K Thomas, who has published the study on feeding patterns of the beetle in the latest issue of the entomology journal ‘Psyche,’ had earlier worked out the life cycle of the beetle
along with Vinod K V and Joby M C.