BENGALURU: A tiny, yet an important insect that plays a silent but significant role in improving soil quality and keeping greenhouse gas (GHG) emission undercheck -- dung beetles -- now face the threat of extinction.
“Their population is declining because of increasing concretisation, changing landscape and lack of availability and poor quality of dung,” said Priyadarsanan Dharma Rajan, Senior Fellow, Ashoka Trust for Research in Ecology and Environment (ATREE).
Researchers from ATREE said the world has over 5,000 dung beetle species, of which 500 are in India and 130 in Bengaluru.
Rajan said dung beetles need soil for burying the dung, but availability of such spaces has now become limited. Also the quality of dung is decreasing with cattle feeding on some dangerous items in urban areas, he added.
On an average, a cow produces 30 kg of dung daily and over 10 tonnes per year. As India has the world’s largest livestock population, exceeding 535 million heads, the amount of excrement produced is substantial and plays a crucial role in nutrient cycling.
A significant portion of this dung is processed and decomposed by dung beetles, which belong to the family Scarabaeidae. These beetles feed, breed, and nest in the dung, either burying it or breeding directly within the dung pats.
“Cattle dung is a major source of greenhouse gases. But by burying the dung, beetles help reduce these emissions. These beetles enhance nutrient cycling, improve soil aeration, aid in secondary seed dispersal and help control parasites,” said Dr Seena Karimbumkara, ATREE entomologist and author of - Study on the genus Onitis (Coleoptera: Scarabaeidae: Scarabaeinae) of the Indian Subcontinent.
One new species of dung beetle in B’luru
A team of ATREE researchers in the paper -- Study on the genus Onitis (Coleoptera: Scarabaeidae: Scarabaeinae) of the Indian Subcontinent -- has noted the presence of three new species of dung beetles in the country.
They found Onitis visthara in Hesaraghatta grasslands, which not only support a diverse array of species, but also serve as an important grazing ground for the livestock of local communities.
The team found Onitis kethai in Biligiri Rangaswamy Temple Tiger Reserve and Onitis bhomorensis in Tezpur, Assam. They said that finding Onitis visthara in Hessarghatta further emphasises the need to conserve the grassland ecosystem, which faces threat of urbanisation from realtors and politicians.
In the report, they noted that the species found in Hessarghatta is relatively broad compared to other Onitis species. That is the reason it has been named visthara, meaning breadth in Kannada. O. kethai is named after field assistant late Ketha Gouda and Onitis bhomorensis is named after the bridge Kolia Bhomora across Brahmaputra.