Author
Philip T Clark
pclark.91@ufl.edu
University of Florida
Clermont
Presenting author – Melissa C Smith
Coauthors
Carey R Minteer, University of Florida, Fort Pierce, United States
Melissa C Smith, United States Department of Agriculture (USDA), Fort Lauderdale, United States
Abstract
Earleaf acacia (Acacia auriculiformis) is an invasive tree that threatens Florida’s delicate ecosystems. Classical biocontrol offers a sustainable solution, but success depends on how introduced agents interact with both the environment and each other. Pre-release studies were conducted to examine two underexplored factors in biocontrol efficacy: biotic resistance and priority effects. An observational survey documented predatory arthropods on earleaf acacia, revealing high diversity and site variation. Natural enemies such as predatory ants and tachinid flies may affect agent establishment and performance. A controlled experiment then tested interactions between two candidate agents, a chrysomelid beetle, Calomela intemerata, and a bud-galling chalcid wasp, Trichilogaster sp. nov. Results showed that release sequence influenced oviposition, larval survival, gall formation, and plant responses. Facilitation occurred when defoliation promoted galling, but antagonism arose when early galling reduced beetle success. These findings highlight that agent outcomes are shaped by release timing and plant-mediated effects, and that co-release may not yield additive impacts. Together, this research underscores the importance of considering native enemies, agent release order, and inter-agent dynamics in pre-release planning, offering a more predictive framework for effective biocontrol.
Keywords
Biotic resistance
Priority effects
Multi-agent compatibility
Highlights
Natural enemies recovered from surveys may affect agent establishment and performance
Multi-agent releases may not always result in additive impacts on invasive weeds
Agent release sequence can influence agent development, survival, and plant responses