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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #385109

Research Project: Development and Implementation of Biological Control Programs for Natural Area Weeds in the Southeastern United States

Location: Invasive Plant Research Laboratory

Title: Ecological host range of Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae), a biological control agent of Brazilian peppertree

item BOWERS, KRISTEN - University Of Florida
item Hight, Stephen
item Wheeler, Gregory
item MINTEER-KILLIAN, CAREY - University Of Florence

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2022
Publication Date: 6/27/2022
Citation: Bowers, K., Hight, S.D., Wheeler, G.S., Minteer-Killian, C. 2022. Ecological host range of Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae), a biological control agent of Brazilian peppertree. Biological Control. 172.

Interpretive Summary: The safety of weed biological control depends the examination of the host range of the potential agent overseas and in quarantine. To confirm those laboratory results, additional tests are conducted under field conditions to determine the agents ecological host range. The results presented here, with the Brazilian peppertree biological control agent, Pseudophilothrips ichini, confirm the quarantine tests. Further they show that the ecological host range of this agent was narrower than the fundamental host range determined from laboratory testing. Thus this biological control agent will be safe to release both in Florida and Hawaii for control of the invasive weed, Brazilian peppertree.

Technical Abstract: Ecological host range testing complements pre-release fundamental host range testing by offering a more realistic picture of insect host plant use in the field, including spillover risk. The biological control program targeting Schinus terebinthifolia Raddi (Anacardiaceae) released the flush feeding thrips Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae) in Florida beginning in 2019. Pre-release testing indicated that P. ichini could oviposit and develop on ten host plant species, two of which are culturally and ecologically important in Hawaii, where S. terebinthifolia is also a serious weed. We performed two open field trials to determine if P. ichini would spillover onto and damage non-target plants under natural conditions. In the first trial, P. ichini did not move onto non-targets when we removed S. terebinthifolia from the experimental blocks. In the second experiment, P. ichini produced no larvae on non-target plants, nor did they damage the non-target apical meristems. Based on the These results of these experiments, we conclude suggest that P. ichini would pose minimal risk to non-target plants if released in Hawaii.