Leaffooted plant bug pressure seems to be relatively light thus far for many San Joaquin Valley almond growers; it has surfaced mostly in scattered areas of the southern end of the valley.
Much of the activity was in the east side, says Vern Crawford, PCA with Wilber-Ellis, Shafter, Calif., who works with growers in Kern, Kings and Tulare counties.
He has received reports of almonds being treated around Earlimart in Tulare County and several areas of Kern County, where growers typically see the pest or evidence of its feeding activity each season.
“More fields were sprayed in the Delano areas,” he says. “One PCA had found a few leaffooted plant bugs on the borders of orchards and sprayed them.”
PCA Tony Touma, Bio Ag Consulting, Bakersfield, had been on the outlook for the insect when he spotted one in a customer’s almond orchard near Rosedale. It was in an area where he has seen the pest in the last four or five seasons.
“I saw the bug about 6 feet up in the tree,” he says. “But, they can be anywhere in the tree. Sometimes, one is all you need to see — even very low numbers can do a lot of damage. Usually, there’s no in-between with this insect; either you have a really bad problem or no problem at all.”
In this case, he continued watching the orchard closely, but saw no need to treat. In the first week of May, he found a few more leaffooted plant bugs in the edges of several other fields near Rosedale. Often, the insect enters an orchard in these border areas. Two days later he sprayed those trees to prevent the insect from spreading farther into the orchards.
“You don’t want to wait to treat for this pest,” Touma says,
“because it can create quite bit of damage in just three or four days.”
Farther north in Fresno County, Walt Bentley, University of California entomologist at the Kearney Agricultural Center, saw leaffooted plant bugs for the first time this season during the first week of April. Four or five were in his yard under an oak tree. They are part of small population that overwinters each year at this site, which he uses each to gauge when the weather has warmed enough for the insects to begin emerging. That’s his signal that growers should be able to begin finding the pest if they’re watching for it.
By early May, however, he had not observed any of the insects in orchards he had checked up to that point.
“Leaffooted plant bug numbers appear to be pretty low this year,” he says. “I haven’t found any evidence in the almond orchards I’ve checked, and I’ve heard of no sightings.”
Jim Wagner, PCA with Wilbur-Ellis, Hughson, Calif., works with almond growers in Merced and Stanislaus Counties, and had not seen any leaffooted plant bugs through early May.
He stays alert for signs or news of the bug each spring. “It’s just such an inconsistent critter around here,” he says. “It’s not a pest for us each year, and there’s no timetable for its appearance. If there’s a single sighting or a report, they’re usually in the area somewhere — and when it shows up, it’s usually a problem for growers.”
Another PCA in this area of the Valley took action to control the pest during the second week of May. Donald Thomas, one of the owners of Advanced Agricultural Services, Hanford, Calif., began spraying for the pest.
“We found our first leaffooted plant bug strike May 8 in a small block of almonds in the Fresno area,” he says. “So, they’re starting to fly.”
Agri-Valley Consulting, Merced, Calif., has also been spraying some almond orchards to control the pest. The company works with growers in Fresno, Madera and Merced Counties.
“Through the first week of May, we’ve treated less than 7 percent of our almonds for big bugs this year,” says Chris Morgner, PCA/CCA. “I haven’t seen any, but a couple of my field staff have found them. So far, it doesn’t look like these big bugs are a widespread problem.”
At the same time, David Doll, University of California Cooperative Extension Farm Advisor in Merced County, had not seen or received any reports of leaffooted plant bugs.
That’s very unusual and in marked contrast to 2011, he says. “Last year was a bad one in the county. So far, this seems to be a mild year for the bug. By the first week of May a year ago, I had received more calls about leaffooted plant bug than in any other season, and had found damage in almonds fields. This year, I’ve yet to receive one call.”
But, he says, that doesn’t necessarily mean the bug is absent from the county this year. “It can pop up in an almond orchard and disappear before you know anything is wrong,” he says. “Most growers don’t walk every single block every day. As a result, they may see no damage in a field one week and a week later the damage shows up. So they spray, but by then the bug is gone.”
This year, Doll expects the threat of stink bug damage in almonds will have subsided, for the most part, by the middle of May. By now thickening hulls will prevent the insect from eating through and reaching the embryo of the fruit.
With its bigger feeding tube, the leaffooted plant bug can punch through a harder shell. So, it is likely to pose a threat to almond growers in his county until around the end of May or first part of June, Doll says.
“By then, feeding can still stain the kernel and require extra processing after harvest. But, that’s not as costly as killing the embryo and having almonds falling off the tree in May.”