By Luis Espino, UCCE Rice Farming Systems Advisor
For the last two weeks the number of true armyworm moths has declined, indicating that at this point there should be very little egg laying going on. In a couple of locations on the west and south part of the valley the number of western yellowstriped armyworm moths has increased. In the past, I have not seen western yellowstriped armyworm be a problem, I have only seen a few worms of this species in rice this year. Just in case, I’m providing graphs with total number of moths (the graphs on the left) and separated by species (on the right).
This year the worm infestation seemed to linger longer than before. It might be related to the slightly cooler conditions we experienced the past couple of weeks. There is always a few smaller worms left behind in the field after the big worms cycle out, but this year it seemed the larger worms stayed in the field longer.
More comments and graphs: http://rice.ucanr.edu/Armyworm_traps/