Pest pressure in desert produce has begun to subside, but don’t become complacent.  The local weather forecast calls for above average temperatures for the next 10 days and accordingly, could extend pest activity, particularly in crops near harvest.  Below are some thoughts on the status of local pest pressure based on field sampling, trap counts and PCA reports.
Beet armyworm            
Populations have been down for a couple of weeks, and spray intervals have lengthened. This isn’t surprising given the cooler tempers we experienced in early October and the intensive spraying during September that provided areawide suppression. But they are still out there. 
Cabbage looper             
Loopers were by far the most abundant Lepidopterous pest I saw this fall, but their numbers have noticeably dropped in the past 2 weeks. Be cautious though. With warm weather forecast for next week they could surprise you, especially on produce approaching harvest.  Similarly, don’t relax with Corn earworms. Although trap captures have been down the last few weeks and no recent reports of larvae in head lettuce, it only takes a couple of these dudes at harvest to ruin your day.  (See Corn Earworm on Desert Produce for more information)                       
Diamondback moth      
Trap counts have been below average this season, but we’re seeing an abundance of larvae on the Ag Center and have had numerous reports from PCAs treating for larvae in both direct-seeded broccoli and transplanted cabbage and cauliflower.  Highest trap catches have been in traps adjacent to newly established seed crops and organic transplants (see Areawide DBM Trap Network).  It is advisable to closely examine your earliest plantings a little more closely for the next few weeks, looking for feeding signs in terminal leaves. Remember, larvae hatch on outer leaves but quickly migrate to the growing point. They also do better than other worms in cooler weather (see 2021 Guidelines for DBM Management in Desert Cole Crops for more information).
Thrips              
Western flower thrips populations have slowly been building on romaine at YAC, and areawide traps indicate adult movement has slowly increased in the past week. Because of the potential for INSV to move into the desert on coastal transplants, it is advised that PCAs keep thrips populations suppressed as much as possible in early fields (particularly transplanted lettuce originating from Salinas). It might be worth making an extra spray just to prevent secondary spread to adjacent fields. Also, stress to your growers to disc under recently harvested lettuce/spinach field ASAP. Remember the key to thrips control is to maintain larval populations at low levels. The cryptic or thigmotactic behavior of thrips often makes them difficult to find on lettuce plants. So, when scouting if you find a few, there are probably a lot more that you don’t see within the plant.
Aphids              
Reports of aphids colonizing brassica transplants are starting to come in. They likely hitched a ride on the transplants and may soon be spreading to adjacent fields. As anticipated, we’re beginning to pick up green peach aphids on our sticky traps and have numerous reports by PCAs of winged (alate) aphids beginning to show up on plants. Remember, aphids on produce are cool season pests and do best when temps dip below ~ 70° F.  Stay vigilant, proper ID is important for the selection of the most cost-effective insecticide. Like thrips, it’s best to “nip aphid colonization in the bud”.