The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and projected future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit the spread of FAW to North and South Africa. Future projections suggest that FAW invasive range will retract from both northern and southern regions towards the equator. However, a large area in eastern and central Africa is projected to have an optimal climate for FAW persistence. These areas will serve as FAW ‘hotspots’ from where it may migrate to the north and south during favorable seasons and then pose an economic threat. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa.

This chapter describes the application of ILCYM (Insect Life Cycle Modelling) software, which supports the development of process-oriented temperature-driven and age-stage structured insect phenology/population models. ILCYM interactively leads the user through the steps for developing insect phenology models, for conducting simulations, and for producing potential population distribution and risk mapping under current or future temperature (climate change) scenarios. The phenology model developed for the potato tuber moth Phthorimaea operculella (Lepidoptera: Gelechiidae) is used to demonstrate the resulting modelling outputs.

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Tephritid fruit flies are considered one of the world’s most notorious pests of horticultural crops, causing extensive direct and indirect damage. Over the past two decades, a comprehensive, integrated pest management (IPM) package for the management of a plethora of fruit fly pests, including Bactrocera dorsalis, B. latifrons, B. zonata, Ceratitis cosyra, C. rosa, C. fasciventris, C. quilici, C. capitata, Dacus spp. and Zeugodacus cucurbitae, has been developed, disseminated and promoted among horticultural growers in Africa. To estimate the numbers of beneficiaries reached by the fruit fly IPM technology and the barriers to technology uptake, we interviewed 290 experts in 30 African countries covering five regions of the continent, and the responses collected were represented as follows: Southern Africa (39.1%), Eastern Africa (31.6%), Western Africa (18.0%), Central Africa (9.0%) and Northern Africa (2.0%). Our results revealed that the use of fruit fly IPM technologies varied across the regions, with Eastern Africa and Western Africa the leading regions, with the highest IPM technology penetration. Field sanitation remains the most common practice for managing fruit flies, followed by protein bait spray, use of biopesticides, male annihilation technique and parasitoid releases. According to the survey, over 101 million people have benefited from the fruit fly IPM interventions in the countries surveyed representing only 19.1% of the estimated beneficiaries. The region that benefitted the most was Eastern Africa (50.2 million), followed by Central and Western Africa (11.7 to 17.7 million), and Southern and Northern Africa had the fewest beneficiaries (10.4 to 11.0 million). The limitations to the IPM technologies uptake varied among the regions, but the common ones include a lack of awareness of the IPM technologies, a lack of access to the IPM products, insufficient training, a low involvement of private sectors and a lack of policies for the regulation of IPM technologies. Although significant strides have been made in promoting the fruit fly IPM technologies over the past two decades, our study reveals that the demand surpasses the current supply. Our study recommends a comprehensive strategy for the dissemination and promotion of the technologies through a multi-institutional alliance that enhances public and private partnerships, digital platforms and youth engagement to consolidate previous gains at the regional and continental levels.

Insect Life Cycle Modelling (ILCYM) software is an open-source computer-aided tool built on R and Java codes and linked to the uDig platform, which is a basic geographic information system (GIS). The software package consists of three modules: (i) the 'model builder'; (ii) the 'validation and simulations'; and (iii) the 'potential population distribution and risk mapping' module. ILCYM's model builder contains a library of several empirical linear and non-linear models, including the derivations of biophysical models, which have been proposed to define critical temperature effects in insects' development. Several statistical measures are incorporated in this module for estimation of parameters and comparison of models. The validation and simulations module demonstrates the application of the phenology models for estimating and simulating insect population abundance under constant and fluctuating temperatures. Outputs of the simulations are demographic parameters that include: (i) net reproduction rate; (ii) mean generation time; (iii) intrinsic rate of increase; (iv) finite rate of increase; and (v) the doubling time. Through these analyses, the biology and temperature requirements of insects are defined, and the effects of different diets or host plants in insects' demographic are assessed. The ILCYM-GIS component estimates three indices (the establishment risk index (EI), the generation index (GI) and the activity index (AI)) that guide in assessing the potential population distribution and abundance of a particular species. Several functionalities for vector (dbf to shape, raster to points, raster to polygons, extract by points) and raster analysis (merge, cut, mask, aggregate/disaggregate, re-class, describe, raster calculator) are part of the ILCYM-GIS component. Such features improve the manipulation of large datasets and help ILCYM's users in analysing and visualizing the risk assessment maps. The phenology model developed for the potato tuber moth Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) a worldwide pest of potato (Solanum tuberosum L.) is used to demonstrate resulting modelling outputs.

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