Vertical-looking radar as a means to improve forecasting and control of desert locusts

Abstract Outbreaks of desert locusts are believed to start when solitarious phase locusts encounter favourable conditions and breed prolifically. The current method used to obtain the earliest warning of outbreaks is therefore to combine survey information on the distribution and abundance of solitarious phase populations with data on the distribution of concurrently favourable hahitats. This paper introduces the idea that it may now be practicable to routinely supplement conventional survey data with information about the abundance of solitarious phase locusts flying at high altitude, i.e., above 100 m. The objective would be to detect moving solitarious phase populations, and so enhance the accuracy and reliability of outbreak forecasts. Routine aerial monitoring has recently been made possible by the advent of a new technique which uses inexpensive, vertical-looking radar (VLR) to detect the presence of insects flying overhead. The radar runs automatically for long periods, analyses its own data and produces plots of the density, altitude and direction of the insects’ migration, and of their size and hence of their probable identity. VLRs are based on standard marine radar transmitters, which are mass produced, and reliable, and the systems are designed to be run by non-specialist personnel.