Do Flower-Rich Windbreak Margins Enhance Predator Communities in Citrus Orchards?

Conservation biological control is central to sustainable pest management; however, its effectiveness depends on providing natural enemies with adequate floral resources and habitat structure. In Florida citrus, living windbreaks offer potential for improvement through floral resource provisioning. We evaluated whether flower-enriched windbreaks increase predator abundance and group richness in citrus orchards in north and central Florida over two years and assessed the role of wildflowers in supporting predator communities. In central Florida, treatment groves supported higher predator abundance and group richness across both sampling methods (vacuum and sticky trap) and both study years, particularly spiders, ants, minute pirate bugs, long-legged flies, and wasps. In north Florida, floral plantings did not significantly increase overall predator abundance or group richness, although some treatment effects emerged in the second year, suggesting delayed benefits related to plant establishment. Predator–plant interactions were region-specific: blanket flower attracted the highest proportion of predator visitors in both regions, accounting for 66% of visits by ants in central Florida and 62% of visits by syrphid flies in north Florida. Predator abundance was generally higher near windbreak edges in both regions. In central Florida, wasp abundance was significantly negatively associated with Asian citrus psyllid abundance, with each one-unit increase in wasp density associated with an approximately 2.7% decrease in expected psyllid abundance, whereas spider and ant associations were not statistically significant. Floral enhancements can strengthen predator communities, but outcomes vary across regions and years and depend on regional conditions, plant establishment, predator functional traits, and ecological interactions. Therefore, conservation biological control in citrus requires region-specific plant selection and consideration of ecological context beyond abundance alone.