Environmental, manpower and financial analysis of locust control in South Africa

English: The brown locust, Locustana pardalina (Walker), has regularly recurring outbreaks in the region Karoo region of South Africa. The endemic region comprises an area of approximately 40 million hectares. The locusts in the gregaria phase cause considerable damage to natural pastures and is in direct competition with stock farming. The National Department of Agriculture administers locust control campaigns. Trained volunteers (supervisors and assistants) in the locust districts conduct locust control campaigns and are remunerate for their efforts. Any sustainable agricultural setup and pest control should adhere to the following three criteria: environment, manpower and financial resources. This study was aimed at analyzing the 1996/97 locust control campaign, with the emphasis on the De Aar, Hanover, Hay and Postmasburg locust districts, based on these three criteria. The project was divided into two main parts: a component analysis for managerial purposes and a spatial analysis (in ArcView-GIS) for operational purposes. The component analysis was done on supervisor level within the districts and the spatial analysis was done on both farm and district levels. Great variation existed between the supervisors and districts analysed in all three criteria. The highest number of bands and swarms was controlled in the Hanover district (5392), followed by Hay (1 961) De Aar (1 519) and Postmasburg (859). The supervisors in the De Aar district controlled a higher percentage of hopper versus adult locusts (87 vs. 13 %). The opposite was encountered in Hanover (28 vs. 72 %), Hay (32 vs. 68 %) and Postmasburg (45 vs. 55 %). The highest total area (Ha) bands and swarms was sprayed in the De Aar district (Il 410), followed by Hanover (9 493), Hay (5 054) and Postmasburg (2 816). Locusts had the highest impact on grazing in the Hanover district. Effective control operations resulted in small areas of each district being sprayed: De Aar (2,13 %), Hanover (2,63 %), Hay (0,40 %) and Postmasburg (0,16 %). An early warning system to facilitate locust control is possible with the incorporation of reliable biotic and abiotic data. Dissimilarities in manpower utilisation were evident through the area (Ha) and amount of pesticide sprayed per assistant per day in the various districts. The highest numbers of supervisor (800) and assistant (2 039) days were recorded in the Hanover district and the lowest numbers (172 vs. 129) were recorded in the Postmasburg district. A geographic information system enables visual monitoring of job creation and socio-economic implications of locust control. The pesticide and travelling expenditure accounted for most of the expenses. The expenses per hectare (RlHa) were the highest in the Hay district (70,07) and the lowest in Postmasburg (23,17). The actual financial damage caused by the locusts was much lower than the potential financial loss. Investment return factors (IRF's) of more than one hundred were achieved in all the districts. The integrated operational and management information system enables visual access to extensive locust control data. This information system eases management by facilitating proper planning within and among campaigns.