Economic value of using African weaver Ants as biological control in fruit production and export in Tanzania

Food consumer demands are increasing for safe crop production systems because of ecological and health risks of pesticides. African weaver ants are alternative to pesticides to promote production and facilitate export. An experiment was conducted to test the weaver ants (with and without feeding) in 2012/13 and 2013/14 seasons and was compared with insecticides and no-pest control. A qualitative survey on export problems was conducted in 2013/14 buying season. The objective was to investigate the economic value of using African weaver ants as biological control agent in both production and export. The methods of analysis were partial budgeting techniques involving Marginal Rate of Return (MRR) and measures of return on investments namely: Net Present Value (NPV), Benefit Cost Ratio (BCR) and Internal Rate of Return (IRR). Export problems were interpreted from the perspective of institutional theory. Results shows that switching from insecticides to African weaver ants in cashew led to positive net change in benefits of 8731 TZS/tree in 2012/13 and 13 903 TZS/tree in 2013/14 seasons. Higher MRR values was obtained when switching from no-pest control to African weaver ants without feeding at 235% in 2012/13 and at 405% in 2013/14 seasons. It ranked first for all decision criteria used (NPV at TZS 66 926 per tree, BCR at 2.5:1 and IRR at 57%). In mango, switching from insecticides to African weaver ant without feeding gave positive net change in benefits by 8957 TZS/tree in 2012/13 and 20 736 TZS/tree in 2013/14 seasons. The MRR were higher at 509% in 2012/13 and at 743% in 2013/14 seasons when switching from no-pest control to African weaver ants without feeding. Conflicting results were noted when ranking feasibility. African weaver ants without feeding was superior for NPV at TZS 66 926 per tree. The use of African weaver ants without feeding in both orchards and was recommended. It facilitates to capture organic markets of cashew and mango products from Tanzania to the target export market in Europe such as meeting export product quality, insufficient volumes of products.Danish International Development Agency (DANIDA)