Australia to approve new active spiromesifen and Interrupt 240 SC Miticide

The APVMA is considering an application for the registration of Bayer CropScience Pty Ltd's product Interrupt 240 SC Miticide, containing 240 g/L spiromesifen, as a suspension concentrate formulation.

Spiromesifen is a member of the spirocyclic tetronic acid group, whose members include spirodiclofen and spirotetramat, which act as broad-spectrum insecticides/acaricides. Spiromesifen is classified as an insect growth regulator that acts through inhibition of acetyl CoA carboxylase in the lipid synthesis and growth regulation pathways (IRAC Group 23). Spiromesifen is considered to be locally systemic in plants, displaying translaminar movement within leaves which allows it to move through the leaf epidermis and mesophyll to control mites not directly exposed to sprayed surfaces. Mites are affected soon after application with the impact on control becoming evident between 4 and 10 days after application. Spiromesifen will offer a miticide with a new mode of action for use in Australia against two-spotted mites infesting pome and stone fruits.

Interrupt 240 SC Miticide is intended for the control of two-spotted mites (Tetranychus urticae) in pome and stone fruit. Proposed application methods are by vertical sprayer, at a rate of 50-60 mL/100 L, applied to the point of run-off to ensure complete coverage of foliage and fruit. No more than one application per season is to be made in each crop, at a maximum rate of 1.6 L/ha per application.

The APVMA chemistry section has evaluated the chemistry and manufacturing aspects of the active constituent spiromesifen and associated product Interrupt 240 SC Miticide – including the identification, physicochemical properties, manufacturing process, quality control procedures, stability, batch analysis results and analytical methods – and found them to be acceptable. The available storage stability data indicate that the formulated product is expected to remain stable for at least 3 years when stored under normal conditions. Based on a review of the chemistry and manufacturing details, the registration of Interrupt 240 SC Miticide, and approval of the active constituent spiromesifen, are supported from a chemistry and manufacturing perspective.

In accordance with section 13 of the Agvet Code, the APVMA invites any person to submit a relevant written submission from 25 June 2024 to 23 July 2024 as to whether Interrupt 240 SC Miticide should be registered. Submissions should relate only to matters that are required by the APVMA to be taken into consideration in determining whether the safety, efficacy or trade criteria have been met. Submissions should state the grounds on which they are based.