February 26, 2018

A sunscreen for biopesticides

Scientists have taken a step forward in their efforts to tackle serious crop pests by reducing the sensitivity of biopesticides to sunlight

Insect pests consume around a third of all the crops we grow, sometimes threatening food security. The main way of controlling these pests is by spraying chemical pesticides but these can be damaging to the environment and so safer alternatives are urgently required including more effective biological pesticides.

Professor Ken Wilson of the Lancaster Environment Centre at Lancaster University and Principal Scientist David Grzywacz of the Natural Resources Institute at the University of Greenwich, both experts in the field of insect viruses, have been working with the lean formulations company, Exosect Ltd, on a two-year biopesticide formulation programme.

The programme was funded by the UK’s Agritech Catalyst fund, administered by Innovate UK, the UK’s innovation agency, and co-funded by the UK’s Biotechnology and Biological Sciences Research Council.

Exosect Ltd has this month (February) announced ‘excellent results’ from this virus formulation programme and have formally begun licensing discussions.

The team developed a sprayable formulation technology based on Exosect’s proprietary formulation platform, Entostat®, which dramatically improves the performance of baculovirus biopesticides for the control of insect crop pests.

Initial development showed that the virus suffered no impairment through the novel formulation process. The formulation protected the virus throughout its journey to the insect gut where the Entostat was successfully broken down by the high pH, releasing the virus. They also tested its ability to withstand sunlight (UV).

Common to all viruses, baculoviruses are highly sensitive to ultraviolet (UV) radiation. Once applied to a crop, UV degradation can reduce efficacy significantly within 4 to 24 hours of application in full temperate sunlight.  Repeated applications are often required in order to control multiple generations of insect pests. Both of the aforementioned factors can increase costs to the grower significantly.

The team set out to improve the commercial viability of virus use in crop protection by developing a formulation that would increase the persistence of the virus on the crop by improving its UV stability – in other words, they produced a sunscreen for the virus.

Results showed that the new Entostat formulation enabled a fifty percent reduction in the amount of virus required to match the treated control. It also greatly increased the longevity of the virus when exposed to UV radiation which will enable growers to significantly extend application intervals.

Professor Ken Wilson said: “Developing robust virus formulations is currently a key area of interest for the crop protection and life sciences sectors as the potential for beneficial uses grows. Together, we have developed a technology that could solve one of the long-recognised issues associated with biological pesticides – their sensitivity to sunlight. This could be a particularly valuable tool for controlling insect pests in the tropics, where UV levels are at their highest.”