It’s Time to Stomp Out Almond Pests Before They Flourish

Oh my, time sure does fly by.

It’s hard to believe growers will start harvesting almonds next month.  It’s even harder to believe that summer arrives in a couple weeks. Time sure does fly by.

As we prepare for hulls to start splitting open, growers are busy doing their prep work while  monitoring their orchards for pests.

Field scout Jenna Mayfield says growers have been busy working the ground between and around the rows of trees. “The winter rains really made the weeds grow this year. Everyone has been doing ground work. The first harvesting starts in six weeks for many growers.”

As weeding wraps up, growers need to keep an eye out for ants on the ground, Jenna says. “You want to get rid of the ants way before harvest.”

Indeed, farm advisers point out a large ant population can consume 1 to 2 percent of a crop in only four days. June is prime time to monitor for ants.

Red color identifies fire ants.

If ant problems exist, growers need to put out baitone month before harvest to maximize effectiveness on crop-damaging pavement and fire ants. Bait shouldn’t be used within 24 hours after irrigation or 48 hours before irrigation with sprinklers. Usually, you’ll find ants a problem around drip- or sprinkler-irrigated orchards.  Experts point out conventional insect sprays aren’t generally effective this time of year.

Pavement ants.

Here’s a cautionary note before going out to treat for ants. It’s important to understand there are good ants and bad ants and distinguish between the two types. A nifty trick is to put out potato chips or a hot dog – any brand will do – near the ant mound. If ants gobble up the tasty fare, it’s a safe bet the pests will feast on almond kernels as well.

If you don’t want to waste good food, try another trick: Stomp near the ant mound to rouse the ants out of their underground home. When they swarm out, check to see if the pests are red in color with a black rear end and if they bite. If they do, then it’s a sure sign they are fire ants.

Monitor for Navel orangeworm.

With summer around the corner, growers also need to monitor for early signs of hull split. It’s important to protect the crop from the second generation of navel orangeworm  (NOW) laying eggs. The first NOW treatment should be done before 1 percent hull split.

Now also is time to keep an eye for webspinning spider mites. This pest overwinters in the bark or under trash on the ground, In the spring they will migrate into the lower part of the almond trees. As the weather heats up, spider mite populations can explode during the summer months.

This is a web created by webspinning spider mites.

Spider mites will suck on the tree leaves. Webs will appear around the leaves and spurs. Eventually, the leaves will drop. A major mite infestation can lead to crop loss and reduced vegetative growth the following season.

Check out UC IPM for more information about managing spider mites and ants in almonds.


“It’s important to get pest problems under control before harvest,” Jenna says.