Predicting Suitable Habitats for the Brazilian Peppertree Biological Control Agent Pseudophilothrips Ichini (Thysanoptera: Phlaeothripidae) in Florida

Authors: LEFALCHIER, EMILY - University Of Florida; CAMPBELL, L. P. - University Of Florida; Halbritter, Dale; Wheeler, Gregory; Leidi, Jorge; WILLIAMS, DEAN - Texas Christian University; PANDEY, MANOJ - Florida Department Of Agriculture And Consumer Services; KIKER, G. A. - University Of Florida; MINTEER, CAREY - University Of Florida

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2025
Publication Date: 1/13/2023
Citation: Lefalchier, E.J., Campbell, L., Halbritter, D.A., Wheeler, G.S., Leidi, J.G., Williams, D.A., Pandey, M., Kiker, G., Minteer, C.R. 2023. Predicting Suitable Habitats for the Brazilian Peppertree Biological Control Agent Pseudophilothrips Ichini (Thysanoptera: Phlaeothripidae) in Florida. Biocontrol Science and Technology. https://doi.org/10.1080/09583157.2025.2452878.
DOI: https://doi.org/10.1080/09583157.2025.2452878

Interpretive Summary: Classical biological control agents can be used to target invasive plants and reduce their aggressive growth and damage to novel, invaded environments. Scientists select agents from the native environment of the plant that only feed on the invasive target plant. It is also important to pick an agent species that would be best adapted to survive in the novel, invaded environment. Occasionally, the problem arises to where agents do not survive in all or parts of the new environment. Brazilian peppertree (BP) is a highly aggressive invasive shrub in Florida, Hawaii, Texas, and California and is considered one of the worst invasive species in FL. A species of thrips (Pseudophilothrips ichini) was an agent approved for release in Florida in 2019, with over 6 million thrips released to date. However, the survival and establishment of these thrips in FL have been inconsistent, and little research has been conducted to understand why. To help solve this problem, we collected data on where thrips and BP exist in the native environment, where thrips and BP now exist in the novel, invaded environment, and historical climate data from both areas. These data were used in computer models to predict where the thrips and BP would be most likely to survive and establish in FL. The model correctly predicted where BP occurs, but thrips have been found in areas in FL that have BP but where the model predicted would be less suitable for thrips survival. This work contributes to our understanding of the limitation of purely climate-based models and emphasizes the need for more research to include other factors from the environment to make more accurate models. With this knowledge, we can ensure we release the agents we spend time and resources on in environments in which they are most likely to be successful.

Technical Abstract: Invasive plants are rapidly infiltrating new ecosystems due to globalization, increased trade, and frequent disturbances of natural habitats. Schinus terebinthifolia Raddi, known as the Brazilian peppertree, is a particularly aggressive invasive shrub in Florida, Hawaii, Texas, and California. Due to its aggressive growth and the damage it can cause to ecological systems, it is considered one of the worst upland invasive species in the state of Florida which has prompted extensive biological control efforts. The classical biological control agent, Pseudophilothrips ichini, was approved for release in Florida in 2019, with over 6 million thrips released to date. However, the establishment and persistence of these thrips have been inconsistent, and little research has been conducted to understand these patterns. Here, we employ ecological niche modeling as a tool to predict suitable habitats for both species. Ecological niche models were calibrated using location data of Brazilian peppertree and P. ichini from their native ranges and bioclimatic data from WorldClim. These models accurately predicted the potential distribution of both organisms. The projections indicated that most of Florida is climatically suitable for the Brazilian peppertree, aligning with its known distribution. However, discrepancies were observed between the projected and actual distribution of P. ichini, suggesting that additional environmental or biotic factors might be influencing their establishment. Further research is necessary to refine these models and enhance the integration of P. ichini into pest management programs to better conserve time, resources, and funds.