Posts Tagged: pest management
Hedgerows bordering farmland – plantings with native trees, shrubs, bunch grasses and wildflowers – support bug-eating birds, which helps with on-farm pest control, according to research by recent UC Davis graduate Sacha Heath and UC Cooperative Extension advisor Rachael Long. The study was published in the October 2019 issue of the online journal Ecosphere.
The authors glued codling moth cocoons to walnut tree trunks and covered some with cages that exclude birds to test the effect that bird predation has on controlling moth pests. If moths emerge from cocoons, they produce larvae that feed on the nuts the following spring, causing significant and costly damage to the crop.
“Permitting bird access to cocoons during the wintertime increased codling moth predation from 11% to 46%, and predation increased with an increasing amount of natural habitat within 500 meters (one-third mile) of the orchard,” the researchers wrote.
Long was not surprised by the finding. She often walks in her family's almond orchard, where a large hedgerow of native California plants grows on the field edge.
“When I walk past the hedgerow,” she said, “I hear birds singing. I see white-crowned sparrows, goldfinches and mocking birds. It's so alive. It's really important to provide habitat to ensure birds have a place to live on farms.”
Songbirds are voracious predators of bugs, including aphids, whitefly, scale, caterpillars, ants and earwigs, especially early in the season when they are feeding baby birds.
Heath said they were surprised to find that the walnut orchards also provided habitat for birds. Woodpeckers and codling moth reduction were highest in orchards where big, old walnut trees were retained.
Currently, 34% of earth's arable land is managed for agriculture. With the human population projected to reach nearly 11 billion by 2100, increased food demand will require increased agricultural area and intensity that will further diminish birds' natural habitat. Providing habitat along field crop borders benefits songbirds, which in turn helps farmers with natural pest control on farms.
Above, a Nuttall's woodpecker eats an experimental codling moth (Cydia pomonella) larvae in a California walnut orchard. (Video: Sacha Heath)
Birds' suffer a reputation as agricultural pests. But Long said that planting hedgerows along field edges won't attract more pest birds.
Heath added, “Insect-eating birds – like chickadees, nuthatches and woodpeckers – move along hedges, riparian streams, old oak trees, and among crops to feed on pests.”
Maintaining hedgerows of native plants on farms has the side benefit of attracting natural enemies and native bees for better pest control and pollination in adjacent crops.
Long is a technical advisor to the Wild Farm Alliance, which, with Heath and Sara Kross, recently published a book on birds' role in pest management. The book, Supporting Beneficial Birds and Managing Pest Birds, is available for free download from the alliance's website. A recording of a webinar on the same topic can be viewed at eOrganic.
Heath is now a biodiversity post-doctoral fellow at the Living Earth Collaborative in Missouri.
For an article "Should Wyoming livestock and ag adjust to climate?" in the Billings Gazette, reporter Paul Murray sought information about livestock animals' response to warmer temperatures from Frank Mitloehner, UC Cooperative Extension Specialist in the Department of Animal Science at UC Davis. Mitloehner talked about ways animals can cool down and discussed shade, fans, sprinklers and even alternative cattle breeds. "We're seeing more and more extreme weather. That is a tendency we're seeing more and more often. That can stress animals. Similar to animals in the wild, that can impact animals' reproductive ability and their performance," he told the reporter.
European pepper moth widespread in California
Surendra Dara for Western Farm Press
Western Farm Press published this article about European pepper moth by Surendra Dara, UC Cooperative Extension farm advisor in Santa Barbara County. Dara explains that the European pepper moth has been reported in several central and southern California counties. The pest prefers to feed at the plant base of crops such as corn, peppers, tomatoes, squash, strawberries and some ornamental plants. Dara has been appointed to the national Technical Working Group for European pepper moth, along with UC Cooperative Extension colleagues James Bethke and Steve Tjosvold.
Dara also wrote about this pest and shared photos of it on the UC Strawberries and Vegetables blog.