As California growers prepare for increasing Lepidopteran pest pressure, biological insecticides remain important tools in both conventional and organic production systems. Allison Walston, Senior Product Development Manager for Insecticides with Valent U.S.A., recently explained how DiPel® DF Biological Insecticide Dry Flowable and XenTari® Biological Insecticide Dry Flowable Bt products help growers manage caterpillar pests while supporting long-term resistance management programs.
Different Cry-proteins Target Different Lepidopteran Pests
Both DiPel and XenTari are based on Bacillus thuringiensis (Bt), a naturally occurring soil bacterium used to control caterpillar pests. However, Walston explained that the two products differ in the specific Cry-protein active ingredients they contain.
DiPel contains four Cry-proteins that target a broad range of caterpillar pests, while XenTari also contains four Cry-proteins, including two unique proteins specifically effective on tough pests such as diamondback moth and armyworms.
Because the products use different Cry-proteins, growers can rotate between DiPel and XenTari as part of resistance management programs, especially in crops where pests like cabbage loopers and imported cabbage worms are common.
Quality and Formulation Matter
Walston noted that Bt labels differ from conventional insecticides because active ingredient percentages do not directly indicate field performance. Instead, Valent focuses heavily on quality control by testing every lot of DiPel and XenTari against live caterpillars to ensure consistent efficacy.
The products are produced through microbial fermentation, and formulation quality plays a major role in performance. Walston explained that Valent invests heavily in making sure the dry flowable products dissolve quickly and mix easily in spray tanks to improve application efficiency.
Early Applications Are Key
For best performance, Walston recommends targeting very young larvae before they become established. Thorough spray coverage is critical because caterpillars must ingest the product for it to work effectively.
Monitoring adult moth activity and preparing for egg hatch can help growers maximize control while reducing pressure on other insecticide groups.
For more information, visit Valent.com/Bts.
Always read and follow label directions.