Potential global distribution of Aleurocanthus woglumi considering climate change and irrigation

Abstract

Citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), is an important agricultural quarantine pest, causing substantial economic losses to citrus and many other cultivated crops. Aleurocanthus woglumi is found in tropical and subtropical regions but is presently unknown in Europe and the Mediterranean Basin. We used CLIMEX to model the potential distribution of A. woglumi under an historical climate scenario (centred on 1995), including a spatially explicit irrigation scenario. We found that A. woglumi could potentially invade the Mediterranean Basin, and south-east Asia, including Australia. There is potential for it to invade most of sub-Saharan Africa. Irrigation is revealed as an important habitat factor affecting the potential distribution of A. woglumi, increasing its potential range by 53% in Asia. Under a future climate scenario for 2050, its potential distribution increased across all continents except Africa, where potential range expansion due to relaxation of cold stresses was limited, and was offset by range decrease due to lethal heat or dry stress. As global climates warm, Europe is likely to face a substantial increase in the area at risk of establishment by A. woglumi (almost doubling under the 2050 irrigation scenario). The biosecurity threat from A. woglumi is significant in current citrus production areas and poses a challenge to biosecurity managers and risk analysts.

Modelling tools for including climate change in pest risk assessments

“…They also vary in the extent to which they can infer information from distribution and phenological observations versus relying on laboratory observations. When used to explore climate change scenarios, each of these models tends to perform well, or at least in a way that is consistent with theoretical expectations, revealing potential range expansions at the poleward and altitudinal limits and, in some cases, potential range reductions at the warm, dry range limits (Akrivou et al, 2021;Gutierrez et al, 2021). Notably, some models do not produce results that conform to these expectations.…”

“…In addition to modelling the potential area of establishment for a pest, risk managers are now also paying attention to areas where the species can be present for only part of the year and complete at least one generation (e.g., Figure 1; Akrivou et al., 2021; Weinberg et al., 2022). This additional information allows pest risk managers to factor in the risks of likely disruption to market access and the cost of expensive incursion responses if there is a detection in this ephemeral habitat zone.…”

“…Climate suitability for Aleurocanthus woglumi modelled using CLIMEX (Akrivou et al., 2021) (a) under current climate (1995). The yellow to red shading is the ecolimatic index, showing the modelled climatic potential for pest establishment.…”

Risk assessment of Citripestis sagittiferella for the EU

“…Irrigation has been pointed out as a climate-modifying factor that may favour the establishment of some pests (Akrivou et al, 2021). Practically all the commercial citrus orchards existing in the EU are irrigated nowadays (Carr, 2012).…”