Let’s Talk Ants, Almonds and Colonization in the Orchard

You remember last week when Jenna mentioned spotting lots of ants parading around some almond orchard floors during her scouting rounds in the Valley.

Now is the time to monitor for ants in the almond orchard.

Well, this is the prime time for growers to head into their orchards, put on their census bureau hats and start taking count of this pest. This is the optimum time to detect ant damage, says veteran entomologist and almond expert Walt Bentley, UC IPM emeritus. You certainly don’t want ants colonizing your orchards come summertime.

This is the damage caused by ants.

Sometimes, growers don’t even know they have an ant problem because nests could be hidden by a cover crop or other things. There are many reasons for ants to build up. Some include the trend toward drip irrigation and microsprinklers as well as drought conditions and warm winters. Ants like to live around moist conditions.

The major concern is at harvest time when almonds are shaken off the trees to dry. Ants can get into an open shell and eat at the kernel. Soft shell varieties such as Nonpareils and Fritz are the most vulnerable.

Take care of ants before tree shaking occurs.

How do you tell if you have an ant problem?

You should be looking at a 1,000 square foot area in the orchard, Walt says. “If you start getting eight or nine colonies in that 1,000 square feet then you probably need to manage the ants, particularly if you have soft shell varieties,” he tells us. The Almond Doctor – UC extension advisor David Doll of Merced County – has made available a handy UC IPM ant colony monitoring form for growers to use.

Use ant bait to control the ant populations.

Ideally, the best time to control ants is in late winter or early spring when ant nests are shallow. As the weather gets warmer, ants will burrow deeper into the ground. Ant bait is considered the preferred method to control the pests. You want to take care of the pest before harvest. Check the http://www.ipm.ucdavis.edu/PMG/r3300411.html for more information about dealing with ants.

In other observations, Walt points out some almond growers may have been lax in orchard sanitation this past year. Walt’s a vocal advocate for getting rid of mummy nuts during the winter to avoid problems with navel orangeworm.  “We had a couple of good years where the navel orangeworm was very low.  Because of that, you can get a little complacent.” The result, Walt says, is “you may see a bit of an uptick in navel orangeworm this season.”

Field Day Alert: An impressive line-up of UC experts are lined up for a Cotton Field Day on Wednesday, June 5 from 10 a.m. to noon at the McCurdy Farm on Highway 33 in Firebaugh. Go to the Sustainable Cotton Project website for directions. The speakers are: Dr. Pete Goodell for a cotton pest management update; Steve Wright of UCCE in Tulare on herbicide resistance; Dan Munk of UCCE Fresno on cotton production risks in low water years; and UC cotton extension specialist Dr. Bob Hutmacher. Tell a friend and neighbor.