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.
Let's hear it for biocontrol. You've seen lady beetles, aka ladybugs, preying on aphids. But have you seen an assassin bug attack a spotted...
An assassin bug drills a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)
A lady beetle, aka ladybug, snares an aphid. (Photo by Kathy Keatley Garvey)
A crab spider munches on a stink bug. (Photo by Kathy Keatley Garvey)
A great blue heron engages in a little pest management: it catches a rodent at Bodega Bay. (Photo by Kathy Keatley Garvey)
The great blue heron gets its prey in position before swallowing it whole. (Photo by Kathy Keatley Garvey)
2019 Annual Alfalfa and Forage Field Day Thursday, September 19, 2019 UC Kearney Agricultural Research and Extension Center, Parlier 9240 S....
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UC ANR urban entomologist Vernard Lewis stands by his Villa Termiti, built just for termite research. (UC ANR Photo)
Madagascar hissing cockroaches at the Bohart Museum of Entomology, UC Davis. (Photo by Kathy Keatley Garvey)
2015 Western Alfalfa & Forage Symposium will be held in Reno, Nevada on December 2-4 at the Silver Legacy Hotel, with a focus on water,...