Research commissioned on behalf of multi-national companies and involving laboratory bioassays and screening of chemicals by means of field trials is conducted on an ongoing basis. Control efficiency is evaluated in open-topped field enclosures and by caging samples of sprayed locusts immediately after treatment. Rates of knock-down and mortality are continuously recorded at fixed time intervals up to 72h post application. All relevant meteorological data is recorded both at the time of application and throughout the post application period.

Current preventative control methods for locusts rely exclusively on applying broad-spectrum insecticides. Standard application practice is to deliver the insecticide by means of ultra-low-volume (ULV) sprays. However, such spraying of pesticide is now being viewed with increasing concern by landholders and conservationists because of possible environmental damage. Considerable efforts are being made worldwide to find safer alternatives.


Baits offer a practical and ecological attractive alternative method of controlling small to medium-sized locust outbreaks and probably also for direct crop protection by farmers. South Africa pioneered the use of insecticide baits for locust control. Baiting offers one method of presenting a toxic dose to a pest at the same time limiting the numbers of non-target organisms coming in contact with the pesticide. In the search for more environmentally acceptable alternatives the role of baits in brown locust control are being re-examined. Broadcasting moistened bran bait by hand in a ±1m wide barrier around the roost in the early morning, has proved a most effective manner of baiting. When applied in a manner that ensured direct interaction with the target, such as by exploiting the basking and aggregation behaviour of locusts coming off their roost in the morning, effective control has consistently resulted. Furthermore, because only a relatively small strip is treated with bait, with no fall-out of spray in the adjacent downwind area, environmental contamination is greatly reduced.

Although labour intensive, baiting by control brigades hired on a temporary basis could involve rural communities and thereby create jobs and strengthen the economies of these areas. Small scale band control by means of such baiting technology could complement the mainstream ULV ground spray operations and thus be successfully integrated into the present locust control strategy. The ease of bait preparation and simple low cost application which does not require specialised equipment makes baiting an attractive method of locust control in resource poor communities.


The technique of spraying persistent organochlorine insecticides, such as dieldrin, on to narrow strips of vegetation as a barrier against hopper bands was extensively used in Central and North Africa in the past against the Red Locust and the Desert Locust, but was never used against the Brown Locust. However, a new generation of insecticides, with good persistence on vegetation but without the bio-accumulation problems associated with the organochlorines, is now available. The efficacy of barrier treatments against the fast-marching Brown Locust hopper bands in the Karoo, with its sparse vegetation cover is being evaluated.

Contact: ​Roger Price,