New insect repellent is harmless to environment

Felicity Davies - News Reporter 22 October 2009

The Cambridge University Department of Zoology has developed a new, environmentally friendly insect repellent which works by lubricating the insect’s feet and causing them to the slide off the plant. The new repellent, developed by Jan-Henning Dirks, Christofer Clemente and Walter Federle, could provide an alternative to pesticides in agriculture.

Jan-Henning Dirks, who studied insect adhesion during his PhD, told The Cambridge Student (TCS): “We first came across these surface properties quite by accident, but soon we realised that this could actually be something really useful.”

Insects are able to climb almost any natural or artificial surface using an adhesive fluid secreted by pads located on the bottom of their feet. Through careful study of the insect pads, the zoologists discovered that the special surface coating they have developed changes the properties of this fluid. As a result, the otherwise adhesive fluid turns into a lubricant and the insects start slipping.

If applied to crops, insects would just slip from the plants. The new coating selectively absorbs parts of the adhesive emulsion leaving only an oily substance, which alone is very slippery. Scientists are therefore able to “trick” the insects into lubricating their own feet, making them unable to climb walls and plants.

This substance differs from existing insect repellents, which can be toxic, or wear off over time. Sticky “fly-paper” becomes less sticky and powder-repellents, which contaminate the feet of insects, erode and become less effective. Pesticides and similar substances are often harmful to the environment and are potentially dangerous for humans and animals. The new technology does not rely on pesticides and has been found to be more durable than other products already in use. Dr Dirks told TCS: “It’s like a selectively absorbing sponge which you can apply to almost any kind or surface to make it slippery for insects. We are currently looking for an industrial partner to develop and commercialise our technology and make it available for everyone.”

The surface coating could restrict the movement of many insects, including ants, cockroaches, termites and locusts, providing an effective and affordable technique to reduce the devastation, health problems and economic loss associated with pests, potentially worldwide. Most surprisingly, despite its effectiveness and durability, the new surface coating leaves insects entirely unharmed.

The University is now seeking a commercial partner to work with the Cambridge team to develop the patented technology for general use. This may be some way off, but access to this technology could have a great impact on the future of farming.

Gillian Davis, Technology Manager at Cambridge Enterprise, the University’s commercialisation arm, has said that “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.”

Felicity Davies – News Reporter