Posts Tagged: integrated pest management
To control spider mites, many almond farmers have taken to routinely spraying their trees with a miticide in May. However, research by UC Integrated Pest Management advisor Kris Tollerup shows that the pesticide application could cause more harm than good.
“The preventative sprays do suppress spider mite populations, but there's no beneficial effect because the mites show up very late in the season and the population density remains well below an economic level,” Tollerup said. “A natural enemy, six-spotted thrips, will likely show up and suppress the mite population before any damage occurs.”
Tollerup recommends almond farmers monitor their orchards for spider mites and six-spotted thrips to determine whether treatment is necessary.
During the 2017 growing season, about 517,000 acres of almonds in California received a preventative miticide application in May; 93% were treated with the insecticide abamectin.
“This strategy runs counter to sustainable integrated pest management practices,” Tollerup said. “The sprays adversely impact spider mite natural enemies and are based on the calendar, not on the monitoring and economic thresholds that the UC Statewide IPM program has determined help reduce pesticide applications.”
The heavy reliance on abamectin has also caused some spider mites in the mid-San Joaquin Valley to become 16 times more resistant to the miticide than susceptible populations.
Tollerup worked with the Almond Board of California and a large grower in Kern County to compare the effectiveness of the preventative miticide spray with plots that were simply monitored for pests and natural enemies.
“Tollerup and other UCCE advisors have correctly identified the problem and spoken out both in public and private about not treating unless economic thresholds have been met,” said a pest control adviser working in Kern County. “Because of Tollerup's role, we have been able to collaborate with farmers to hold off on spring treatments at many ranches and only treat when warranted, which has essentially removed a spray treatment on a vast number of acres.”
Surveys conducted after the trial results were released showed that 80,000 acres of almonds were not treated with miticide sprays in May 2018 and May 2019. The change in strategy resulted in a savings to farmers of about $2.2 million in miticide and application costs.
Moreover, Tollerup calculated a subsequent reduction of 880,000 pounds of carbon dioxide emissions due to reduced use of diesel tractors and motor-driven application equipment associated with the miticide spray.
For more information on integrated pest management of spider mites, see the UC Integrated Pest Management website and IPM of spider mites on almond improves farm profitability and air quality.
(Editor's Note: In the midst of the coronavirus pandemic precautions--when facilities are closing down--we're taking time to spotlight some of our UC...
Agricultural entomologist and Cooperative Extension specialist Ian Grettenberger joined the faculty of the UC Davis Department of Entomology and Entomology in January 2019. (Photo by Kathy Keatley Garvey)
Agricultural entomologist and Cooperative Extension specialist Ian Grettenberger in his office in Briggs Hall, UC Davis. (Photo by Kathy Keatley Garvey)
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, a meadow vole, at Bodega Bay. (Photo by Kathy Keatley Garvey)
The great blue heron gets its prey, a meadow vole, in position before swallowing it whole. (Photo by Kathy Keatley Garvey)
Help the environment on Earth Day, which falls on April 22, by growing insectary plants. These plants attract natural enemies such as lady beetles, lacewings, and parasitic wasps. Natural enemies provide biological pest control and can reduce the need for insecticides. Visit the new UC IPM Insectary Plants webpage to learn how to use these plants to your advantage.
The buzz about insectary plants
Biological control, or the use of natural enemies to reduce pests, is an important component of integrated pest management. Fields and orchards may miss out on this control if they do not offer sufficient habitat for natural enemies to thrive. Insectary plants (or insectaries) can change that — they feed and shelter these important insects and make the environment more favorable to them. For instance, sweet alyssum planted near lettuce fields encourages syrphid flies to lay their eggs on crops. More syrphid eggs means more syrphid larvae eating aphids, and perhaps a reduced need for insecticides. Similarly, planting cover crops like buckwheat within vineyards can attract predatory insects, spiders, and parasitic wasps, ultimately keeping leafhoppers and thrips under control.
Flowering insectaries also provide food for bees and other pollinators. There are both greater numbers and more kinds of native bees in fields with an insectary consisting of a row of native shrubs planted along the field edge (called a hedgerow). Native bees also stay in fields with these shrubs longer than they do in fields without them. Therefore, not only do insectaries attract natural enemies, but they can also boost crop pollination and help keep bees healthy.
Insectary plants may attract more pests to your plants, but the benefit is greater than the risk
The possibility of creating more pest problems has been a concern when it comes to installing insectaries. Current research shows that mature hedgerows, in particular, bring more benefits than risks. Hedgerows attract far more natural enemies than insect pests. And despite the fact that birds, rabbits, and mice find refuge in hedgerows, the presence of hedgerows neither increases animal pest problems in the field, nor crop contamination by animal-vectored pathogens. Hedgerow insectaries both benefit wildlife and help to control pests.
How can I install insectary plants?
Visit the Insectary Plants webpage to learn how to establish and manage insectary plants, and determine which types of insectaries may suit your needs and situation. If you need financial assistance to establish insectaries on your farm, consider applying for Conservation Action Plan funds from the Environmental Quality Incentives Program (EQIP) offered by the Natural Resources Conservation Service.
- Flower flies (Syrphidae) and other biological control agents for aphids in vegetable crops. (PDF)
- Good news for hedgerows: no effects on food safety in the field.
- Hedgerow benefits align with food production and sustainability goals.
- Habitat restoration promotes pollinator persistence and colonization in intensively managed agriculture. (PDF)
- Reducing the abundance of leafhoppers and thrips in a northern California organic vineyard through maintenance of full season floral diversity with summer cover crops.
When you hear those three little words, "Integrated Pest Management," you immediately think of two words, "Frank Zalom." They go together like...
IPM specialist Frank Zalom, UC Davis distinguished professor of entomology and Extension entomologist, checks over a strawberry field.