The appearance of Fall Armyworm (FAW) (Spodoptera frugiperda) in Africa has caused much consternation: "The hungry caterpillar threatening a global food crisis", according to a headline in the Guardian newspaper. The UK Department for International Development (DFID) commissioned CABI to compile an evidence note, which was published by CABI in September 2017. This article is a summary of the evidence note, which aimed to assess the potential impact of FAW in Africa if left uncontrolled, and recommend and prioritise control options. The first confirmed reports of FAW were from West Africa in early 2016. Research to date suggests that both strains of FAW that are found in the Americas entered Africa, perhaps as stowaways on commercial aircraft, either in cargo containers or airplane holds, before subsequent widespread dispersal by the wind. The probability is high (>90%) that the introduction to Africa was from the characterised Florida strain of FAW, which is restricted to the eastern seaboard of the USA, and the Caribbean islands. Based on information from literature searches, personal communications and internet mining, as for August 2017 28 countries have confirmed the presence of FAW. A further nine countries suspect its presence, or are awaiting official confirmation of the pest in the country. Two countries (Somalia and Djibouti) have conducted surveys and not found any FAW. Using distribution and climate data collected from South America and in Ghana and Zambia, models were used to investigate the environmental (climatic) factors affecting the distribution of FAW. Results from multiple models have been combined to produce an environmental suitability index for FAW across Africa. Fall Armyworm (FAW) in Africa has the potential to cause maize yield losses in a range from 8.3 to 20.6m tonnes per annum, in the absence of any control methods, in just 12 of Africa's maize-producing countries. This represents a range of 21%–53% of the annual production of maize averaged over a three year period in these countries. The value of these potential losses is estimated at between $2,481m and $6,187m. FAW should be expected to spread throughout suitable habitats in mainland sub-Saharan Africa within the next few cropping seasons. Northern Africa and Madagascar are also at risk. As of August 2017, the pest has been confirmed present in 28 countries in Africa (compared to 12 in April 2017), with suspected presence in a further 9 countries. Control of FAW requires an integrated pest management (IPM) approach. Immediate recommendations include (i) awareness raising campaigns on FAW symptoms, early detection and control, including beneficial agronomic practices; (ii) national preparation and communication of a list of recommended, regulated pesticides and biopesticides and their appropriate application methods. Work should also start immediately to (i) assess preferred crop varieties for resistance or tolerance to FAW; (ii) introduce classical biological control agents from the Americas. A conducive policy environment should promote lower risk pest management approaches.

Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a polyphagous pest indigenous throughout the Americas, which recently appeared in Africa, first reported from São Tomé, Nigeria, Bénin and Togo in 2016, and which we now report from Ghana. This species is recognised to comprise two morphologically identical but genetically distinct strains or species in the Americas, and we found both to be present in Ghana. We discuss possible routes of entry to Africa, of which the likeliest is adults and/or egg masses transported on direct commercial flights between the Americas and West Africa, followed by dispersal by adult flight within Africa. Identification of Lepidoptera is normally based on the markings and morphology of adults, and not on the larvae which actually cause the damage, and therefore larvae have to be reared through to adult for authoritative identification. We confirmed that the use of DNA barcoding allowed unequivocal identification of this new pest from Ghana based on the larvae alone. As authenticated barcodes for vouchered specimens of more pests become available, this approach has the potential to become a valuable in-country tool to support national capability in rapid and reliable pest diagnosis and identification.

Climate change is affecting the biology, distribution and outbreak potential of pests in a vast range of crops and across all land uses and landscapes. Up to 40% of the world’s food supply is already lost to pests; the reduction in pest impact is more important than ever to ensure global food security, reduced application of inputs and decreased greenhouse gas emissions. Climate-smart pest management (CSPM) is a cross-sectoral approach that aims to reduce pest-induced crop losses, enhance ecosystem services, reduce the greenhouse gas emissions intensity per unit of food produced and strengthen the resilience of agricultural systems in the face of climate change. Through the implementation of CSPM, crop production, extension, research and policy act in coordination towards more efficient and resilient food production systems.

Classical biological control (CBC) is the introduction of a natural enemy of exotic origin to control a pest, usually also exotic, aiming at permanent control of the pest. CBC has been carried out widely over a variety of target organisms, but most commonly against insects, using parasitoids and predators and, occasionally, pathogens. Until 2010, 6158 introductions of parasitoids and predators were made against 588 insect pests, leading to the control of 172 pests. About 55% of these introductions were made against pests of woody plants. Establishment rates of natural enemies and success rates were higher in CBC projects targeting pests of woody plants than other pests. This review aims to answer the questions most commonly asked regarding CBC against insect pests, with particular emphasis on tree pests. The topics covered include, among others: variations in rates of successes among different systems, different target insect groups and different agents; temporal trends in CBC practices and successes; economic and environmental benefits; risks and ways to mitigate the risks; CBC against native pests; accidental successes through the adoption of the invasive pests by native natural enemies or accidentally introduced agents; and prospects and constraints for the practice of CBC in the future. Questions are answered based on the analysis of two databases, the BIOCAT2010 database of introductions of insect biological control agents for the CBC of insect pests, and a database of introductions of entomopathogens against insect pests.