“More is lost by indecision than wrong decision.” – Marcus Tullius Cicero

Rainfall influences the timing of the Lygus migration. Dr. Peter Goodell, the retired extension super-agent in the Central Valley, wrote that the rainfall extended into spring allows for longer wild host growth which resulted in large migrations into the Central Valley. The rain creates green bridges from wild hosts and early season host crops through the early summer months that end with large hordes of Lygus coming into cotton in late summer and early autumn.

A similar process was believed to be at work on the Central Coast, where the Lygus migrate from the hills down to the lowlands like hungry raiders preying on the cities of Babylon. Many growers, PCAs, and scientists I have spoken to have said that once the hills dry down then Lygus populations would grow in April and May.

But lately there are reports of Lygus detected in strawberries from across all three districts. I saw some in a second-year strawberry field and in first year plantings. Detections were being reported in February and currently in early March. I was told by folks that the second-year observations were par for the course. It’s the observation in the first-year strawberries that are cause for concern.

The hills haven’t even bloomed in some areas so what could be driving Lygus so much earlier than expected? One explanation could be climate change as presented by mild winters. Lack of enough cold weather could have let many overwintering Lygus adults survive, which leads to starting the year with a larger than normal population. A second explanation could be back-to-back strawberry plantings with no host-free period. These are easy green bridges for Lygus to pass through. And a third explanation could be poor weed management that allows Lygus to overwinter closer to fields.

Monitoring and spray coverage are more critical than ever with the mandated reduction of the use of some of our systemic insecticide options. But this also an opportunity to stem the tide of Lygus migrations by cultural controls. In a long rainy season, getting ahead of your weed control is critical on the field boundaries, make sure you are using multiple modes of action for your herbicide sprays. Or if you choose non-chemical means, then discing, or mowing to keep weed pressure down when you find Lygus nymphs helps a lot. Put the weeds down and the Lygus out of town!

But weed control is just one small part of this equation and probably the easiest one in our control. The bigger issues are mild winters and lack of a host-free period for strawberry production. These will both require adaptions or the creation of tools to accommodate them. I understand the economic incentive of keeping a second-year field or having back-to-back plantings. As the new guy on the block, I am hesitant to make any bold proclamations on what growers should do in this case. It’s a competitive world, and what may be scientifically sound isn’t necessarily economically viable. I will do my best to work with the system presented to me. Powers beyond our control will force us to adapt. Together we can find the adaptation that serves all growers.