Global risk of invasion by Bactrocera zonata: Implications on horticultural crop production under changing climatic conditions

PLoS One. 2020 Dec 23;15(12):e0243047. doi: 10.1371/journal.pone.0243047. eCollection 2020.


The peach fruit fly Bactrocera zonata (Saunders) (Diptera: Tephritidae) is an important invasive species causing substantial losses to the horticulture industry worldwide. Despite the severe economic impact caused by this pest in its native and invaded range, information on its potential range expansion under changing climate remains largely unknown. In this study, we employed maximum entropy (MaxEnt) modeling approach to predict the global potential climatic suitability of B. zonata under current climate and four Representative Concentration Pathways (RCPs) for the year 2050. Outputs from MaxEnt were merged with Spatial Production Allocation Model. A natural dispersal model using Gaussian dispersal kernel was developed. The Areas Under Curves generated by MaxEnt were greater than 0.92 for both current and future climate change scenarios, indicating satisfactory performances of the models. Mean temperature of the coldest quarter, precipitation of driest month and temperature seasonality significantly influenced the potential establishment of B. zonata. The models indicated high climatic suitability in tropical and subtropical areas in Asia and Africa, where the species has already been recorded. Suitable areas were predicted in West, East and Central Africa and to a lesser extent in Central and South America. Future climatic scenarios models, RCP 4.5 and 8.5 show significant potential range expansion of B. zonata in Western Sahara, while RCP 4.5 highlighted expansion in Southern Africa. Contrarily, RCP 2.6 showed considerable decrease in B. zonata range expansion in Central, East and West Africa. There was increased climatic suitability of B. zonata in Egypt and Middle East under RCP 6.0. The dispersal model revealed that B. zonata could spread widely within its vicinity with decreasing infestation rates away from the source points. Our findings can help to guide biosecurity agencies in decision-making and serve as an early warning tool to safeguard against the pest invasion into unaffected areas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Climate Change
  • Crops, Agricultural / parasitology*
  • Egypt
  • Entropy
  • Horticulture
  • Introduced Species
  • Models, Theoretical
  • Rain
  • Tephritidae / physiology*

Grant support

The senior author K. M. Z was supported through the Dissertation Research Internship Programme (DRIP), In-Region Postgraduate Scholarship at the International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya. We gratefully acknowledge the financial support for this research by the following organizations and agencies; Norwegian Agency for Development Cooperation, the Section for research, innovation, and higher education grant number RAF-3058 KEN-18/0005; European Union Funded Integrated Biological Control Applied Research Program (IBCARP)-Fruit Fly Component (Grant Contract No. DCI-FOOD/2014/346-739) and Biovision Foundation Switzerland [BV PH-07/2016-2018 and DPP_005 (01/2019-12/2021) and International Atomic Energy Agency (IAEA), through the CRP on “Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade through icipe. We also gratefully acknowledge the support of icipe core funding provided by United Kingdom’s Foreign, Commonwealth and Development Office (FCDO); the Swedish International Development Cooperation Agency (Sida); the Swiss Agency for Development and Cooperation (SDC); the Federal Democratic Republic of Ethiopia; and the Government of the Republic of Kenya. The Agricultural Research Corporation also provided support in the form of salaries to one of the co-authors [MEEM]. However, all the funders did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Therefore, the views expressed herein do not necessarily reflect the official opinion of the donors. The specific roles of these authors are articulated in the ‘author contributions’ section.