It’s February in California, which means many almond growers across the state are watching their almond trees blossom. This is a crucial time for the almond crop, marking the end of dormancy and the beginning of springtime bloom.
Producing the entirety of America’s commercial almond supply is no easy task, though. In California, where 80% of the entire world’s almonds are grown, plant bug infestations are becoming more common. Leaffooted plant bugs, stink bugs, Navel orangeworm, and carpophilus beetle can all threaten a healthy harvest. Below, we’ll take a quick look at some of the pests that are threatening California’s almond production, while also outlining some ways to control the spread.
Carpophilus beetle
The carpophilus beetle, or carpophilus truncatus, has become a pest in the San Joaquin Valley, where it’s been known to infest almonds and pistachios. Adults and larvae feed on the nuts’ kernel, which damages the quality of the crop and reduces yield. This local infestation was officially identified in September 2023 by UC Riverside’s Department of Entomology, and experts say the best technique for managing its spread is crop sanitation. Like navel orangeworm, carpophilus beetles spend their winters in remnant nuts (also known as “mummy nuts”) that remain on the tree or on the ground after the most recent harvest. To control their spread, it’s important to destroy those mummy nuts, which will prevent adult beetles from moving onto new nuts around hull-split.
Navel orangeworm
These moths begin their almond infestation as larvae, digging down into the nuts and feeding on the nutmeat inside. This doesn’t just damage the nut; it also increases the likelihood of Aspergillus mold. To protect your crops from navel orangeworm, experts recommend an integrated pest management approach that begins with crop sanitation. After removing mummy nuts from your orchards during the winter, expand your integrated approach with steps like mating disruption, trap monitoring, and chemical applications.
Leaffooted bug
The leaffooted bug’s piercing, needle-like mouthparts allow the pest to feed on plant seeds and other parts. Damage typically occurs in March and April. In the case of an outbreak, an effective management plan should include removing the site where the pests overwinter, as well as applying insecticides like Bifenthrin and Abamectin. The leaffooted bug is often confused with another almond-loving pest — the green stink bug — so properly treating an infestation also requires the proper identification of the pest itself.
Stink bug
The green stink bug, or Acrostenum hilare, injects almonds with a damaging enzyme that liquifies the nut and reduces fruit quality. This also causes the fruit to release gummosis, which is visible outside the hull. Although often confused with the leaffooted plant bug, stink bugs aren’t nearly as mobile and, as a result, can be more effectively controlled by a broad-spectrum insecticide. Apply the spray once every three years, which should control pest populations without causing widespread damage to pollinators.
FGS is here to help! If you’ve been battling pests, contact us here or visit one of our supply centers to speak with an expert about pesticides and other management approaches. We’ve been helping growers like you for more than 100 years.