Global Habitat Suitability of Spodoptera frugiperda (JE Smith) (Lepidoptera, Noctuidae): Key Parasitoids Considered for Its Biological Control.

Ghislain T Tepa-Yotto,Komi K M Fiaboe,Manuele Tamò,Georg Goergen,Daniel Flø,Samira A Mohamed,Sevgan Subramanian,Emily Kimathi,Saliou Niassy,Karl H Thunes,Henri E Z Tonnang,Sunday Ekesi,Anani Bruce,May-Guri Sæthre,Elfatih M Abdel-Rahman

doi:10.3390/insects12040273

Abstract

Simple SummaryThe fall armyworm (FAW), Spodoptera frugiperda has now become a pest of global importance. Its introduction and detection in Africa in 2016, and subsequent introduction and spread into Asia and Australia, has put several millions of food producers and maize farmers at risk. Not all pest management strategies are sustainable. Biological control with the use of parasitoid wasps is one of the durable and environmentally sound options. The present study was initiated to predict the habitats of high establishment potential of key parasitoids of FAW in South America, which might prove to be effective as classical biological control agents of FAW in regions where it is an invasive species under current and future climate scenarios. The prospective parasitoids are the following: Chelonus insularis, Cotesia marginiventris, Eiphosoma laphygmae, Telenomus remus and Trichogramma pretiosum. The results demonstrate overlapping habitat suitability areas of the pest and the parasitoids, suggesting promises for biological control options for the management of FAW under current and future climate scenarios.The present study is the first modeling effort at a global scale to predict habitat suitability of fall armyworm (FAW), Spodoptera frugiperda and its key parasitoids, namely Chelonus insularis, Cotesia marginiventris, Eiphosoma laphygmae, Telenomus remus and Trichogramma pretiosum, to be considered for biological control. An adjusted procedure of a machine-learning algorithm, the maximum entropy (Maxent), was applied for the modeling experiments. Model predictions showed particularly high establishment potential of the five hymenopteran parasitoids in areas that are heavily affected by FAW (like the coastal belt of West Africa from Côte d’Ivoire (Ivory Coast) to Nigeria, the Congo basin to Eastern Africa, Eastern, Southern and Southeastern Asia and some portions of Eastern Australia) and those of potential invasion risks (western & southern Europe). These habitats can be priority sites for scaling FAW biocontrol efforts. In the context of global warming and the event of accidental FAW introduction, warmer parts of Europe are at high risk. The effect of winter on the survival and life cycle of the pest in Europe and other temperate regions of the world are discussed in this paper. Overall, the models provide pioneering information to guide decision making for biological-based medium and long-term management of FAW across the globe.

Highlights

Invasive species and climate change increasingly threaten the economy worldwide [1]
We examined through the maximum entropy (Maxent) algorithm, known for its high performance compared with other ecological niche models [24,25,26], how likely a decision of deploying the five parasitoid species mentioned above would cope with current and future climate scenarios in major world agroecologies or regions already threatened by, or with potential risk, of fall armyworm (FAW) invasion
The Maxent model outputs for both FAW and its parasitoids provided tight goodness of fit with an area under curve (AUC) value range of 0.802–0.971, which demonstrates that the models showed good predictive performance (Tables 2 and 3)

Summary

Introduction

The continuing spread of fall armyworm (FAW), Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae) to new ecological niches raises regional and global concerns. An updated literature review and surveys recently indicated a total of 353 FAW larval host plant records belonging to 76 plant families, Poaceae (106), Asteraceae (31) and Fabaceae (31) [2]. The most preferred host of the pest is maize. FAW is native to tropical and subtropical regions of the Americas. The pest is known to have high dispersal capabilities. After the first report on its outbreak in Africa [3], farm areas of nearly 25 million hectares of its main host plant (maize) production have been severely compromised within only two years post detection of this pest on the continent

Methods

Results

Conclusion