When It Comes to Bugs in the Orchard, Some Like It Hot

 Put on the hat and slap on the sunscreen. Hot, hot  weather has arrived in the Valley.

 While summer is still some three weeks away, weather forecasters say we’re in for more triple-digit temperatures and plenty of 90-degree days. For almond growers, this late-spring mini-heat wave could trigger a population explosion of web spinning spider mites.

Now is the time for the spider mite population to increase.
- UC IPM photo

Almond field scout Jenna Horine says she is bracing for these pests this week and will be keeping a close eye for them as she makes her rounds scouting almond orchards across the Valley. What a difference a week makes when temperatures were in the 80s and pests were in check.

Here’s what University of California Integrated Pest Management has to say about webspinning spider mites: “The mites reproduce rapidly during warm weather between June and September. During favorable conditions, mites develop within seven days, with eight to 10 generations per season.”

Spider mite damage will  impact crops the following year.
- UC IPM photo

On damage: “Mites damage foliage by sucking cell contents from leaves. The damage begins with leaf stippling. Leaves can turn yellow and drop off. High populations cover tree terminals with webbing. Crop reduction and reduced vegetative tree growth shows up the year after damage occurs.”

Jenna says most growers added a miticide in their May spray. We’ll keep you updated to see how effective the treatment was and what Mother Nature cooks up during this hot spell.

Meanwhile, cotton field scout Carlos Silva says cotton plants are developing nicely and should thrive in this hot weather. Growth is good with the advanced plants having two to three fruiting branches and eight to 10 main stem nodes.

- University of Florida agriculture extension diagram

Growers are wrapping up the first irrigation of the growing season.

During his field visits, he’s been finding a beneficials in his sweep net – bigeyed bugs, minute pirate bugs and lady bugs. That’s good.

In alfalfa fields, Carlos has caught some weevils but it’s nothing to worry about for the moment. 

Growers should be starting the third cutting in a couple weeks. He expects to see growers leaving strips of uncut alfalfa to keep pests from migrating to nearby fields, especially cotton.

Speaking of cotton, don’t forget this Wednesday’s Cotton Field Day from 10 a.m. to noon at the McCurdy Farm along Highway 33 in Fresno County. Go to the Sustainable Cotton Project website for directions. 

Headlining this impressive line-up of UC experts are: Dr. Pete Goodell, who will offer 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 Race 4 fusarium.  See you there.