Invasive alien species have environmental, economic and social impacts, disproportionally threatening livelihood and food security of smallholder farmers in low- and medium-income countries. Fall armyworm (FAW) (Spodoptera frugiperda), an invasive insect pest from the Americas, causes considerable losses on maize to smallholder farmers in Africa since 2016. The increased use of pesticides to control FAW in Africa raises concerns for health and environmental risks resulting in a growing interest in research on biological control options for smallholder farmers. In order to evaluate the occurrence of local natural enemies attacking FAW, we collected on a weekly basis FAW eggs and larvae during a maize crop cycle in the rainy season of 2018–2019 at four locations in the Lusaka and Central provinces in Zambia. A total of 4373 larvae and 162 egg masses were collected. For each location and date of collection, crop stage, the number of plants checked and amount of damage were recorded to analyse which factors best explain the occurrence of the natural enemy species on maize. Overall parasitism rates from local natural enemies at each location varied between 8.45% and 33.11%. We identified 12 different egg-larval, larval and larval-pupal parasitoid species. Location, maize growth stage, pest density and larval stage significantly affected parasitoid species occurrence. Our findings indicate that there is potential for increasing local populations of natural enemies of FAW through conservation biological control programmes and develop safe and practical control methods for smallholder farmers.

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), has become one of the main invasive species on earth since it was first found outside its native range in Africa in 2016. Integrated pest management (IPM) is a comprehensive tool that can help farmers managing pests while reducing the need of synthetic pesticides. Within an IPM strategy, proper time of planting is a critical management decision for farmers as planting too early or too late can lead to complete loss of the crop. Commonly, planting early to avoid peak infestation of FAW is recommended to farmers, however, no empirical data in Africa is available to sustain the advice. We studied the effects of planting dates of maize as well of maize growth stages on FAW density and on its local parasitoids in a field study. Three plots were setup (early, intermediate and late planting) and data was collected weekly in each plot. Plots were 20 m × 20 m to avoid small-plot effects, but the relatively large size of the plots was resource intensive and prevented replication. As such, this paper presents preliminary results due to the lack of true replicates across locations and years. Generalized Linear Models were used to model FAW density and parasitoids abundance and diversity. Our results showed an increase of egg masses over time from early to late planting. Additionally, parasitism probabilities were lower in the early planting treatment than for the intermediate and late plantings and decreased with increased maize maturity. Results on biodiversity of parasitoids show a less even trend for early and late whorl stages which are dominated by one or two species while maize reproductive stages show a more even distribution of species. Our preliminary research is the first to provide empirical evidence that planting early helps to avoid the peak activities of FAW moths. These findings provide important information for the sustainable management of FAW in Zambia with the aim to reduce chemical inputs and increase farmers’ incomes and livelihood.

Smallholder farmers are the mainstay of the agricultural economies of sub-Saharan Africa (SSA), where they produce several crops, predominantly centered on maize. Smallholder productivity remains limited resulting from a range of confounding factors, but a primary cause is loss from pests and diseases, particularly insects. To improve productivity, recommendations for the mitigation of crop loss globally include early-warning and management systems for in-season indigenous pests. There are many early-warning systems in temperate regions; however, such systems are poorly established in Africa. This is in part due to the need for a combination of pest modeling, data handling and dissemination infrastructure, capacity, and resource provision. While each of these components is progressing in Africa, the means to successfully deploy such systems remain limited. To bridge this, the development of the Pest Risk Information Service (PRISE) began in 2017 for farmers in SSA. Implemented in Kenya, Ghana, Malawi, and Zambia, PRISE developed temperature-driven phenology models for major maize, bean, and tomato pests. Using downscaled and processed Earth Observation data to drive the models, PRISE partnered with African national agencies to communicate pre- and in-season pest alerts that forecast the time to act against key insect pests. Alerts were designed to be integrated into country-specific Good Agricultural Practice (GAP) recommendations to provide a complementary package to agricultural stakeholders. End line studies with farmers showed that those who received information about the target crops including PRISE pest forecasts, generally reported better outcomes in terms of reduced losses and increased incomes compared with farmers who did not.

Background: Fall armyworm, Spodoptera frugiperda, an alien invasive pest from the Americas, was detected in Zambia late 2016 and since has caused significant losses on maize threatening livelihood and food security. Individually, farmers continue to rely on synthetic pesticides, a reactive measure to manage new invasive insect pests, posing risks to human health, the environment and biodiversity. Biological control has been proven to be an efficient, cost effective and safe method for pest and disease management, and when adopted collectively, its effectiveness can increase. In addition, collective action has been acknowledged to be a critical component for invasive species management, but is still poorly studied in low- and middle-income countries (LMIC) where the national plant health system, in-place to prevent and manage biological invasions, is limited. Methods: To study the feasibility of creating a collective action to promote biological control for fall armyworm among smallholder farmers in rural Zambia and the social and institutional conditions needed for it to be successful and sustainable, we conducted focus group discussions and in-depth interviews in two districts with maize smallholder farmers. Our model to assess the results applies both Ostrom’s 8 Design Principles for a community-based management of common-pool resources and criteria of an agricultural innovation that meet the community’s requirements, and also pays attention to the exchange and brokering processes needed to match the two. Results: Our results showed that some conditions are already in place to support a collective action to manage fall armyworm such as matching rules to local conditions, collective-choice arrangement, conflict-resolution mechanism and minimal recognition of rights to organize which are supported by traditional leadership of the communities. However other conditions would need to be strengthened for the collective pest management to be sustainable. The most important criteria for a pest management innovation selected by participants from both districts, in no specific order, were price, efficacy, recommended by agrodealer/extension officer and immediate action. Conclusions: This study fills a gap in understanding social and institutional conditions in LMIC needed to sustain a collective action that aim at controlling a highly mobile and invasive pest. Our study emphasizes the need to redefine technologies and dissemination in terms of supporting the processes of co-designing innovation based on social and ecological conditions.