Few tools available to control leaffooted bug in nuts
University of California Integrated Pest Management expert Kris Tollerup says monitoring for the leaffooted bug is critical to control the pest in tree nuts and other crops.
The issue isn’t about what scientists know about the leaffooted bug (LFB). It’s all they don’t know about controlling the pest that is bothersome.
The bad news, according to University of California Integrated Pest Management Advisor Kris Tollerup, is the pest is hard to kill and canh decimate an almond crop.
Scientists are still searching for good news, though not all is doom-and-gloom.
“If growers are diligent to start monitoring in March they can protect their crops with pyrethroids,” Tollerup says.
Tollerup spoke to pest control advisors at the annual California Pest Control Advisor meeting recently, telling the audience that active research continues to look for better methods to control the pest, which has the ability to effectively overwinter in popular crops and protected areas.
The pests are particularly troublesome in almonds, pistachios and tomatoes, according to Tollerup, though citrus and pomegranates can host the pest as well.
The University of Florida reports that LFB-damage in citrus can include premature color break and fruit drop.
Leaffooted bug is particularly long-lived – upwards of 60 days, and generally with three overlapping generations per year. In recent years, Tollerup says the pest has successfully bred to a fourth generation in the San Joaquin Valley because of the mild winters.
In almonds, the pest can damage maturing nuts after moving into the orchards in March and April.
Damage occurs when the pest feeds on the maturing nut causing gummosis, nut drop and kernel necrosis. University of California guidelines suggest cutting open nuts with gummosis to inspect for evidence of puncture marks from the bug’s mouthparts. Gumming can also be symptomatic of disease not related to the LFB, which is why inspecting gummed nuts is important.
Similar damage in pistachios can happen from LFB, according to Tollerup. Epicarp lesions, aborted kernels and kernel necrosis can happen by LFB feeding in late May and early June.
Later in the season as the nuts harden, particularly in almonds, Tollerup says LFB can become less of an issue as they are unable to feed through the hard shells.