JNTBGRI researchers unravel the mystery behind the ‘shooting’ droplets from Theepacha

A recent study suggests the source of the droplets is not the liana as is commonly believed, but the Aloka depressa, a leafhopper that feeds on sap from the kidney-shaped leaves of its host.

Researchers at the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) may have figured out the secret behind the water droplets that keep drizzling from the Diploclisia glaucescens, a liana or woody vine known locally as the ‘Theepacha.’

Call it the curious case of the leafhopper, the liana, and, well, insect ‘pee.’

The source of the droplets, it appears, is not the liana as is commonly believed, but the Aloka depressa (tribe Phlogisini), a leafhopper that feeds on sap from the kidney-shaped leaves of its host. The tiny insect sucks nutrients from the sap, and, using a springy stylus on its tail-end, flicks away the waste fluid in the form of teeny-weeny droplets.

The fascinating relationship between the Diploclisia glaucescens and the Aloka depressa and the mystery of the ‘shooting’ droplets are the subject of an upcoming research paper in the journal Plant Biology (the paper has been published online). This is the first time that the phenomenon, dubbed ‘sharpshooting’ by researchers, is being reported from India, JNTBGRI said.

Field observations and related studies were led by B. Sabulal of JNTBGRI. Team members included S. Ajikumaran Nair, Anil John J., T. Sabu and Gokul B. S. of JNTBGRI, and H. M. Yeshwanth of the National Centre for Biological Sciences, Bengaluru.

As the droplets appear to drizzle down from the liana, the latter gained the moniker ‘rain showering plant.’ But in reality, it is the insect that causes the droplets to fall. The phenomenon has not been reported elsewhere in India. Only a single type specimen of the leafhopper, Aloka depressa, was previously reported from Karnataka, according to the researchers.

In size, these leafhoppers are tiny. The males are about 6.25 mm in length. A recent study found that the stylus on its rear end serves as a catapult, a sort of insect-realm ‘super propulsion’ tech which helps it fling away the droplet excreta.