Besides providing food and shelter to natural enemies of crop pests, plants used in conservation biological control interventions potentially provide additional ecosystem services including providing botanical insecticides. Here we concurrently tested the strength of these two services from six non-crop plants in managing cabbage pests in Ghana over three successive field seasons. Crop margin plantings of Ageratum conyzoides, Tridax procumbens, Crotalaria juncea, Cymbopogon citratus, Lantana camara and Talinum triangulare were compared with a bare earth control in a three-way split plot design such that the crop in each plot was sprayed with either a 10% (w/v) aqueous extract from the border plant species, a negative control (water) and a positive control (emamectin benzoate 'Attack' insecticide). Pests were significantly less numerous in all unsprayed treatments with non-crop plant margins and in corresponding sprayed treatments (with botanical or synthetic insecticide positive control) while treatments with bare earth margin or sprayed with water (negative controls) had the highest pest densities. Numbers of predators were significantly depressed by synthetic insecticide but higher in other treatments whether unsprayed or sprayed with botanical insecticide. We conclude that some plant species have utility in both conservation biological control and as source of botanical insecticides that are relatively benign to natural enemies. In this crop system, however, the additional cost associated with using botanical insecticides was not justified by greater levels of pest suppression than achieved from border plants alone. Insect pest attack causes huge crop losses 1 affecting the potential availability of food for over one billion people 2 , and threatening global food security 3. Effective pest management is critical to meeting global food demands 4-6 and synthetic insecticides have been the principal tool in the past six decades 7,8. Even with the introduction of newer and relatively safer insecticides 8 and increased application per unit area and time 9 , crop loss resulting from insect damage has doubled in the past four decades 1,10,11. Indiscriminate and excessive application has led to the elimination of important organisms in the agroecosystem that support crop production 12,13. This is especially prevalent in developing countries including Ghana where farmers and the environment are exposed to high levels of synthetic insecticides, including active ingredients that have been banned in developed nations due to high toxicity and persistence 14. Inadequate provision of important ecosystem services including natural enemy-mediated pest control reinforces reliance on hazardous inputs such as insecticides and threatens agricultural sustainability 15,16. Conservation biological control based on habitat manipulation has been proposed as a sustainable alternative to synthetic insecticides 17. Habitat manipulation involves intentionally establishing plant species at the farm scale or landscape scale to provide conduc...