Back to nature: Searching for novel sources of host-plant resistance against spotted-wing drosophila

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Commodities

• Fruits: berries (blueberries)

Practices

• Crop Production: crop improvement and selection
• Education and Training: extension
• Pest Management: cultivation, cultural control, integrated pest management
• Production Systems: agroecosystems

The invasion of spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), into the United States in 2008 has inflicted significant damage to soft-skinned fruits such as blueberries, blackberries, raspberries, strawberries, and cherries, resulting in annual losses exceeding $500 million. Presently, Integrated Pest Management (IPM) strategies for SWD heavily rely on chemical control tactics, which are neither economically nor environmentally sustainable in the long term. Thus, it is imperative to develop alternative, more sustainable IPM tactics for better management of this pest species. One such underutilized IPM tactic is host-plant resistance. Host-plant resistance is a key IPM component that leverages the inherent adaptations of many plants to avoid or tolerate insect or disease pests and can be harnessed through modern breeding efforts to develop resistant cultivars. Wild relatives of many domesticated plants represent an untapped potential source of host-plant resistance, as studies have shown that they often exhibit greater resistance to insect pests. However, there has been limited exploration of wild plants as a potential source of resistance to SWD. Therefore, the objective of this research is to identify novel sources of host-plant resistance against SWD by examining various wild and domesticated blueberry populations. This endeavor aims to further the development of host-plant resistance to SWD as a more sustainable IPM tactic. Ultimately, this research will contribute to the advancement of host-plant resistance as a viable and eco-friendly strategy for managing SWD. This proposal aligns with Northeast SARE's Outcome Statement by focusing on the development of sustainable management practices for an invasive pest.

Objective 1. Identify novel sources of host-plant resistance to spotted-wing drosophila (SWD).

I will conduct studies to examine the preference and performance of SWD on blueberry fruits collected from various wild and domesticated populations. Based on prior research, I anticipate that SWD will exhibit a preference for volatiles emitted by wild blueberry fruits but will show better oviposition and performance on domesticated fruits. In addition, I expect the strength of these preference-performance relationships to vary among different wild and domesticated blueberry populations.

Objective 2. Identify the mechanisms of resistance.

I will conduct studies to evaluate various physical and chemical fruit traits that may contribute to antibiosis (reduced performance) and antixenosis (non-preference) resistance across different wild and domesticated populations. I predict that fruit size, firmness, sugar and phenolic content, and volatile emissions will vary among these populations, potentially correlating with SWD performance and preference.

Objective 3. Provide extension resources to growers.

I will disseminate information on pest management and host-plant resistance against SWD through presentations at growers' meetings, articles in newsletters, and the creation of a factsheet. Additionally, I will establish a timeline for these extension activities to ensure timely delivery of information to growers and offer additional support such as training sessions or expert consultations as needed.