Figure 1. DALL-E generated image from the author’s text input of a Lygus bug pondering his existence while thinking about a strawberry.

The Lygus Question is one that has dogged me in my whole career as an entomologist. When I first started working on bush beans, there was Lygus. When I moved to the south, I found more Lygus. And now that I work on strawberries, even . . . more. . . Lygus!

Everyone understands that regular monitoring, removing weed hosts, and having excellent spray coverage are key to success. But the common response I have heard is that “we NEED new chemistries.”

I agree we need more diverse modes of action on the market available to the strawberry industry. The reliance on chemistries, however, makes the industry vulnerable to the mercurial advances of scientific discovery. It takes 10-15 years and upwards of 200 million dollars to discover, test, receive government blessings, and market a new pest control product. And if you’re unlucky, they’ll pull the rug out from under you as was done with clothianidin in Germany in 2008, only 3 years after the chemical was approved for the market in 2005.

Lygus management needs a whole new class of tactics to strengthen the overall strategy. One of these new developments is the Lygus sex pheromone. Since the early 2000s there have been researchers examining the pheromones in various Lygus species. The California Strawberry Commission funded research in 2014-2015, with researchers from Greenwich University, UC Riverside, UCCE, and UC Berkeley, who found a two-component blend that attracted Lygus hesperus. Research by George et al. from the USDA at Stoneville, MS zeroed in on an exact ratio of a three-component blend for Lygus lineolaris.

This summer I will test two product formulations from an insect monitoring and mating disruption company, to test their attractiveness for L. hesperus. At the very least they can function as a monitoring tool, but the holy grail would be a pheromone disruption technique for Lygus in strawberry and other crops. Given the plethora of research, it is only a matter of time and tenacity before we see it in the IPM toolkit.

Figure 2. DALL-E generated image from the author’s text input: hemipteran insect attracted to a sticky trap using an odor attractant with strawberries in the background.

Combine this development with the expected new chemistries for the market, Avaunt Evo, Sefina, and Plinazolin. Avaunt Evo is an indoxacarb which is a voltage dependent sodium channel blocker. Sefina is a pyropene which modulates sensors in insect stretching organs that aid in balance and maintain sense of direction and movement. Plinazolin is an isoxazoline, which binds to the GABA receptor. In layman’s terms Sefina gives the insects vertigo, Avaunt Evo gives them spastic diarrhea, and Plinazolin lights them up like a Christmas tree.

But new chemistries will not always be there when we need them. This is truly a serendipitous moment in time.

Figure 3. DALL-E generated image from the author’s text input: A young bottle of insecticide waiting in agony to receive his federal EPA registration number so he can begin trials for registration in California.

Looking forward a combination of pheromone disruption, proper chemical rotations with many modes of action, weed management, cultivar tolerance, and if we are lucky, the use of biocontrol agents that target 1st and 2nd instar nymphs would relegate Lygus from a first-tier pest to a fourth-tier nuisance. A true IPM model with an emphasis on the integration of various techniques that work in tandem is the key for having a leg up against Lygus. If the worst excesses of the arcadian agriculture movement cannot be put in check, then our only hope will be viable economical alternatives to stay in business.

Now come here little Lygus bug and prepare to be bruised and confused!

Featured image obtained from UC IPM web site: https://ipm.ucanr.edu/agriculture/strawberry/lygus-bug