Location: Application Technology Research
Project Number: 5082-30500-001-090-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2026
End Date: Aug 31, 2027
Objective:
1) To determine efficacy of nursery container incorporation treatments used under a typical commercial nursery production cycle
2) To determine efficacy of cyantraniliprole and cyclaniliprole as field-grown pre-harvest band spray treatments with earlier May
applications
3) To evaluate nursery container incorporation treatments in large container sizes (15- to 30-gallon size)
Approach:
Nursery plants with roots and soil attached have the potential to transport larval Japanese beetle (Popillia japonica Newman) (JB). The Domestic JB Harmonization Plan (JBHP) specifies methods and insecticides to certify nursery plants destined for Category 1 states (i.e., full quarantine pest; mostly west of the Rocky Mountains) or Category 2 states (non-quarantine pest; mostly the mid-western U.S.). The JBHP has 3 options for containers, including: 1) drenching (imidacloprid, thiamethoxam, or bifenthrin), 2) media incorporation (bifenthrin), or 3) dipping (bifenthrin or chlorpyrifos). There are no treatment options for containers >12-inch diameter for Category 1 or 2 states, except plants up to 32-inch diameter can be dipped for Category 2 states. The JBHP also allows imidacloprid, thiamethoxam, or chlorantraniliprole as pre-harvest band spray treatments for field-grown nursery plants. The JBHP container size restriction is a serious barrier for nurseries shipping to Category 1 or 2 states. Since nurseries transfer smaller plants to larger containers as the plants grow, the original smaller plant core must remain toxic to JB for up to 3-years, which has been the primary issue for certifying larger-sized containers (JBHP Revision Committee communications).
Preliminary testing determined some insecticides like diamides and meta diamides can provide 3-years of JB control with a single media incorporation, and the treatments were not affected by container size. During meetings with the JBHP Treatment Review Committee and the 2026 Western Region Japanese Beetle Cooperators Meeting, regulatory and scientist personnel stated the need to test insecticide incorporations through the entire container plant production process and to obtain additional efficacy data for containers >15-gal size.
Thus, for objective 1, we will work with a commercial nursery to media incorporate container plants before and during transfers to larger container sizes for a 3-year period. For each year of the 3-year period, a portion of containers will be infested by attracting ovipositing adult JB and then examined for surviving larvae in the fall. For objective 2, we will select the optimal insecticides and rates from current JB tests and use those as media incorporations in 30-gal containers. Containers also will be infested in the summer and evaluated for adult survival in the fall. We will repeat a test with 15-gal containers to obtain additional support data at 3-year post-treatment. For objective 3, a suitable field-grown nursery site will be located and SPRING applications applied. Trees will be infested with JB during the summer, machine-harvested in the fall, and the soil sifted to determine larval survival. The test will determine if an earlier May application improves control sufficiently for use as a JBHP Pre-Harvest protocol.