D3414: Assessing the impact of the biological control agent Pseudophilothrips ichini on the flush of Brazilian Peppertree (Schinus terebinthifolia) in the Rio Grande Valley

The Brazilian Peppertree (Schinus terebinthifolia), or BPT, poses a significant ecological threat as a highly aggressive, invasive shrub that forms dense canopies, outcompeting native vegetation and drastically reducing biodiversity. Current control strategies for BPT are costly, amounting to millions of dollars annually in the United States, highlighting the urgent need for effective, sustainable alternatives. One promising solution is the use of Brazilian Peppertree thrips (Pseudophilothrips ichini), a host-specific biocontrol agent from South America that feeds on the BPT’s flushing leaves, stunting its growth. Despite initial releases in the Rio Grande Valley (RGV) of South Texas, where BPT is prevalent, the efficacy of thrips in reducing BPT growth in the region remains unexplored.

This study aims to assess the potential of P. ichini in controlling BPT by evaluating thrips-induced damage on wild BPT flushes. Flushes were first infested with varying densities (10, 30, 40, or 80) of adult thrips enclosed in organza sleeve bags to examine visual damage. Damage was evident on flushes exposed to 10, 20, or 30 adult thrips, and was quantified by measuring dry weight. The results will determine whether thrips can induce significant damage in BPT flushes in South Texas, potentially supporting conventional management methods. Further research and field trials are necessary to validate this strategy and mitigate further ecological and economic harm caused by the Brazilian Peppertree.