Horizon scanning for invasive insects with potential threats to crop production in South Africa

In many countries, pests, particularly those that are alien and invasive are regarded as one of the main factors contributing to the extinction of species and ecological degradation. The use of horizon scanning has recently gained momentum to help managers assess the preparedness level of governments and relevant agencies to respond to threats by invasive alien species. The purpose of the study was to identify and rank the invasive alien insects that are already present in other parts of Africa and are likely to be introduced to South Africa; and make recommendations on insect pest risk analysis, management strategies, surveillance protocols, regulatory frameworks, and response plans for invasive insects. The highest-scoring pests were Maconellicoccus hirsutus and Thrips palmi. Zygodacus cucurbitae, Bactrocera latifrons, B. zonata, Paracocus marginatus, and Pectinophora gossypiella had the second highest score, indicating a high probability of these economically important pests entering and establishing in the country. Complete pest risk assessments and surveillance for the presence or introduction of pests in the country were the most frequently recommended phytosanitary measures against highly prioritised invasive alien insects with the highest scores.