Repellent tricks insects' feet

A cheap, durable, non-toxic and environmentally safe insect repellent coating 'tricks' the feet of insects feet by making them self-lubricate.

The coating, developed by scientists at Cambridge University, could be used against termites, cockroaches and other pests such as ants and locusts, which are responsible for billions of pounds worth of damage to homes, crops and people’s health across the globe each year.

Insects are capable of clinging to almost any natural and artificial substrate by using an emulsion with properties similar to custard or ketchup. They secrete this fluid from pads located on the bottom of their feet.

When studying insect pads in detail, the Cambridge researchers discovered that the special surface coating changes the properties of this fluid. As a consequence, the adhesive secretion turns into a lubricant and the insects start slipping.

Jan-Henning Dirks, who studied insect adhesion for his PhD, said: ‘We first came across these surface properties quite by accident, but soon we realised that this could actually be something really useful.’

The research team demonstrated in lab tests that insects were able to climb with ease a glass rod coated with non-stick PTFE. However, insects trying to reach an apple slice at the top of the glass rod coated with the new material slipped. On the new material, the insects' feet reached, on average, only about 40 per cent of the friction forces they showed on PTFE.

The research team believes its surface coating has the potential to restrict the movement of many insects and, despite its effectiveness and durability, leave the insects unharmed.

‘We are very excited by the potential of this completely new approach to pest control that has arisen from a basic research project into insect adhesion,’ said Gillian Davis, technology manager at Cambridge Enterprise, the university's commercialisation arm.

‘We have patented the technology and are now seeking a commercial partner to work with the inventors to develop the technology.'

She added: ‘Surfaces at risk of infestation both inside and outside the home may benefit from the insect repellent coatings. From crop protection to pest-proof ventilation pipes, furniture and Wellingtons, as well as insect-repellent food containers and baby bottles, the practical applications for use are endless and hugely exciting.’