Predicting the current potential and future world wide distribution of the onion maggot, Delia antiqua using maximum entropy ecological niche modeling.

Shuoying Ning,Jinian Feng,Jiufeng Wei,Hugo Rebelo

doi:10.1371/journal.pone.0171190

Abstract

Climate change will markedly impact biology, population ecology, and spatial distribution patterns of insect pests because of the influence of future greenhouse effects on insect development and population dynamics. Onion maggot, Delia antiqua, larvae are subterranean pests with limited mobility, that directly feed on bulbs of Allium sp. and render them completely unmarketable. Modeling the spatial distribution of such a widespread and damaging pest is crucial not only to identify current potentially suitable climactic areas but also to predict where the pest is likely to spread in the future so that appropriate monitoring and management programs can be developed. In this study, Maximum Entropy Niche Modeling was used to estimate the current potential distribution of D. antiqua and to predict the future distribution of this species in 2030, 2050, 2070 and 2080 by using emission scenario (A2) with 7 climate variables. The results of this study show that currently highly suitable habitats for D.antiqua occur throughout most of East Asia, some regions of North America, Western Europe, and Western Asian countries near the Caspian sea and Black Sea. In the future, we predict an even broader distribution of this pest spread more extensively throughout Asia, North America and Europe, particularly in most of European countries, Central regions of United States and much of East Asia. Our present day and future predictions can enhance strategic planning of agricultural organizations by identifying regions that will need to develop Integrated Pest Management programs to manage the onion maggot. The distribution forecasts will also help governments to optimize economic investments in management programs for this pest by identifying regions that are or will become less suitable for current and future infestations.

Highlights

Climate is one of the principal factors defining the potential range of insects and climate change directly affects the distribution of species [1,2]
The model performance for this pest was better than random (AUC = 0.94 for training data and areas under the curve (AUC) = 0.923 for test data); the model produced highly effective in predicting the suitable habitat area for this species
The MaxEnt model’s current predictions of the most suitable habitats for the development of the onion maggot generally agreed with available host occurrence records

Summary

Introduction

Climate is one of the principal factors defining the potential range of insects and climate change directly affects the distribution of species [1,2]. The initial occurrence of onion maggot was reported in the USA in some regions of Wisconsin in the early twentieth century [18]. This pest continues to cause serious damage in Asia, in China and Japan, Europe, and North America [19,20,21]. Second- and thirdgeneration larvae cause little damage to the crop relative to the first generation, but feeding injury can distort bulbs and allow entry of pathogens, both of which render crops unmarketable [23,24]

Methods

Results

Conclusion