Number and success of classical biological control (CBC) introductions. Upper two panels A number of introductions of CBC agents per decade introduced in Europe, North Africa, and the Middle East against pests on (full line) all plants, (dashed line) woody plants, and (dotted line) herbaceous plants B total number of introductions for all target host plants, woody plants, and herbaceous plants (black bars) including repeated introductions of agents against the same target and (grey bars) for unique agent-target combinations. Note that some targets feed on both woody and herbaceous plants. Lower six panels: Percentage of successful biological control introductions (left side) per decade and (right side) overall, against pests on C, D all plants E, F woody plants, and G, H herbaceous plants. Success was measured in terms of (blue line) agent establishment, (purple line) partial to complete control of the target (i.e., impact), and (red line) substantial to complete control (i.e., control). Repeated introductions within specific agent-target combinations are included in the calculation of the percentages per decade and in full-coloured bars. Light-coloured bars indicate percentages based on unique agent-target combinations.