Impact of Modified Caneberry Trellis Systems on Microclimate and Habitat Suitability for Drosophila suzukii (Diptera: Drosophilidae)

The Economic Analyses of the Drosophila suzukii's Invasions: A Mini-review

The objective of this paper is to bring to the fore the type of economic analyses that have been carried out on the invasion of the Drosophila suzukii Matsumura (Diptera: Drosophilidae) and what has been learned. The analysis is limited to the original research articles published in peer-reviewed journals and book chapters. A total of 20 relevant studies are identified. The studies are analysed based on their main purpose, which is either economic impact assessment or economic evaluation of management programmes. The analysis also considers the key methodological points highlighted in recent reviews of the economic literature on alien invasive species. Over time, the focus of these studies has gradually shifted from raising awareness of the magnitude of the impact, particularly on agricultural production, to supporting the decision-making process concerning effective pest management. Most studies have been conducted from a private perspective, measuring private costs and providing guidance to the industry. However, some papers include, or focus on, the societal costs caused by the invasions of D. suzukii. This review has found few impact studies in the recently invaded areas and no economic evaluation of management programmes. There are not only geographical areas, but also themes that need more attention and analysis in the economic studies on D. suzukii. Assessing the economic effectiveness of integrated pest management programmes in specific settings, included the Latin American countries, is crucial.

Mapping the global distribution of invasive pest Drosophila suzukii and parasitoid Leptopilina japonica: implications for biological control

Insect pest invasions cause significant damage to crop yields, and the resultant economic losses are truly alarming. Climate change and trade liberalization have opened new ways of pest invasions. Given the consumer preference towards organic agricultural products and environment-friendly nature of natural pest control strategies, biological control is considered to be one of the potential options for managing invasive insect pests. Drosophila suzukii (Drosophilidae) is an extremely damaging fruit pest, demanding development of effective and sustainable biological control strategies. In this study, we assessed the potential of the parasitoid Leptopilina japonica (Figitidae) as a biocontrol agent for D. suzukii using ecological niche modeling approaches. We developed global-scale models for both pest and parasitoid to identify four components necessary to derive a niche based, target oriented prioritization approach to plan biological control programs for D. suzukii: (i) potential distribution of pest D. suzukii, (ii) potential distribution of parasitoid L. japonica, (iii) the degree of overlap in potential distributions of pest and parasitoid, and (iv) biocontrol potential of this system for each country. Overlapping suitable areas of pest and parasitoid were identified at two different thresholds and at the most desirable threshold (E = 5%), potential for L. japonica mediated biocontrol management existed in 125 countries covering 1.87 × 10⁷ km², and at the maximum permitted threshold (E = 10%), land coverage was reduced to 1.44 × 10⁷ km² in 121 countries. Fly pest distributional information as a predictor variable was not found to be improving parasitoid model performance, and globally, only in half of the countries, >50% biocontrol coverage was estimated. We therefore suggest that niche specificities of both pest and parasitoid must be included in site-specific release planning of L. japonica for effective biocontrol management aimed at D. suzukii. This study can be extended to design cost-effective pre-assessment strategies for implementing any biological control management program.