Warmer Temperatures This Spring May Mean Increased Insect Activity
April 30, 2014 As temperatures in the San Joaquin Valley climb into the 90s this week, growers might want to keep an especially close eye on their orchards.
“The Almond Doctor,” aka University of California Cooperative Extension (UCCE) Farm Advisor David Doll, reports in his blog that, based on data shared April 10, we have accumulated 33% more degree days in most areas of the San Joaquin Valley than in 2013, and nearly 50% more than in 2012.
High egg-laying navel orangeworm (NOW) activity has been reported and experienced where Doll is based in Merced County, which is about a month earlier than a “normal” year. “Poorly sanitized, or orchards located next to poorly sanitized almonds, pistachios, or walnuts will have higher-than-normal NOW pressure in 2014,” he reports. “Hopefully, an earlier than normal harvest occurs, which will help reduce damage.”
Peach twig borer and codling moth bio-fixes have also been reported earlier than normal, according to Doll. Trap catches were thrown off a bit by the week of rain, but now seems that traps are active again. Spray timings for these pests will be earlier than “normal.”
Interestingly, Doll notes that there are potential benefits from an earlier bloom/development and warmer than normal temperatures, such as earlier shell hardening, which would reduce the risk of leaf-footed plant bug damage. Also, later infections of bacterial spot may not cause as much crop loss since the fruit size will be larger, more mature. Finally, an earlier than normal harvest would help if the predictions for an El Niño year come true.
However, it’s best to stay on guard, as Doll says we are entering “uncharted territory.”
A similar situation can be found in Northern California, reports Dani M. Lightle, the new UCCE Farm Advisor for Glenn, Butte, and Tehama counties, in the UC’s Sacramento Valley Almond Newsletter. The warmer than average temperatures so far this year have led to early insect activity.
She compared the bio-fix dates for five orchard insect pests trapped in Tehama County – codling moth, Oriental fruit moth, peach twig borer, San Jose Scale and NOW — compared to the previous five years. The bio-fix for all five pests is earlier this year than in prior years.
In fact, the average bio-fix date for the five pests was 12 days earlier this year than last, and an average of 25 days earlier than in 2012.
Subscribe Today For
