California tree nut producers discover new mode of action against navel orangeworm

Efficacious insecticide has 4-hour REI, 0-day PHI, and MRL Exemption

California tree nut producers are discovering the power of SPEAR® LEP, a peptide-based insecticide, in the battle to take back control over navel orangeworm. Being the first insecticide since 2007 with a new neuromuscular mode of action (IRAC Group 32) producers can add SPEAR LEP to their insect management rotation to reduce the overuse of traditional synthetic chemicals. It’s proving especially valuable at pre-harvest with its 4-hour REI, 0-day PHI and MRL exemption.

“Our origin story excites people, because our products are based on peptides modified from the venom of spiders and other venomous animals that have evolved to kill insects,” explains Bill Hume, Senior Director of Strategic Accounts with Vestaron, who brings more than 25 years of experience in sales, business development, and leadership roles in agriculture. “It’s the first novel broad-spectrum nerve and muscular mode of action in 15 years.”

SPEAR LEP targets all lepidopteran pests including Amyelois transitella – or navel orangewormthe most damaging pest in pistachio crops. In 2023, extension experts and advisors reported devastating NOW damage resulting in severe yield and quality reductions, which dramatically impacted growers’ bottom line. Larvae will be destroyed in as little as two days when SPEAR LEP is used in conjunction with a low dose of the widely used insecticide Bacillus thuringiensis (Bt), which disrupts the larvae’s gut. The active substance in the product enters the pest’s bloodstream and attacks its central nervous system. Fully biodegradable and highly specific to the target pest, SPEAR LEP is soft on pollinators and has an excellent human and environmental safety profile, with 0-day pre-harvest interval and no maximum residue limits.  More than 800 field trials with SPEAR LEP show performance that is equivalent to conventional insecticides.

Growing market share

“Our market share in pistachios has grown to double digits, and we see continued growth in almonds as well as other specialty crops,” says Hume. “As California accelerates sustainable pest management (SPM) transitioning away from traditional higher-risk pesticides, SPEAR LEP and future Vestaron technology is well placed to be the right solution at the right time.”

SPEAR LEP has been a beneficial IRAC group rotation in our worm control program. When needed, the short PHI is also a bonus.”
~ Charlie Lowe, Farm Manager, who grows pistachios at RHM Farms in Le Grand, Planada and Madera County.

The 0-day PHI is definitely helpful,” he says, “especially on the pistachio side where you’re going in between shakes.”
~ Jonathan Lehrman, Helena Ag sales representative, says the product’s flexibility is a major value-add.

Hume says customers are seeing very good results integrating SPEAR LEP into their rotation because it’s a new mode of action with no known resistance or cross-resistance. SPEAR LEP also provides growers and PCA’s peace of mind with no MRL concerns, the shortest re-entry time allowable, and a 0-day pre-harvest interval. “That means increased efficiency, and we know that in a tight market, every hour and every dollar counts,” he says.

Hume understands producers are inundated with product information, and understanding how bioinsecticides work can be confusing. “We have highly experienced sale and technical teams based locally so we can ensure prompt service, technology transfer and following up on any questions you may have. Our products have extensive replicated field trials, with proven efficacy and no complaints. With efficacy and cost similar to current grower practices, the additional benefits that SPEAR LEP provides creates an opportunity to be on every acre of pistachios and almonds,” he says.

In almonds, SPEAR LEP gives us a break from overusing the traditional NOW chemicals, and in pistachios, it gives us a tool to use in between shakes because of its 0-day PHI.”
~ B&B Walker Farms

Drivers of
Initial Adoption


  • First novel broad spectrum nerve and muscular mode of action 15 years
  • Efficacy proven through >500 replicated trials to be on par with chemical pesticides
  • Price parity with leading traditional chemical pesticides
  • Drop-in existing farming practices and flexible across cropping systems

Incremental Utility
with Continued Use


  • Can be sprayed while pollinators are in the field
  • 4-hour worker re-entry interval (the shortest EPA allows)
  • 0-day pre-harvest interval (compared to 7-10+ days for traditional chemical pesticides)
  • No regulated residues

Overall Return
on Investment


  • Zero incremental spend
  • Reduced labor and other costs due to operational advantages
  • Reduced risk of resistance-related losses
  • Ability to make sustainability, safety and health claims

MEDIA CONTACTS: 

Ben Cicora, SVP Sales & Marketing • (970) 443.9220 • bcicora@vestaron.com
Steve Betz, Sr Director of Communications • +1.515.707.6096 • sbetz@vestaron.com