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Biological Pest Control

Intergrated Pest Management (IPM) aims to achieve long-term pest control with minimal impact on the environment and non-target organisms. Emphasis is put on control of pests, not eradication, as the latter is more or less impossible as well as prohibitively expensive and damaging. Prevention through monitoring, planting hardy varieties and maintenance of healthy orchard ecosystem is critical to the success of IPM.     

Control of pests with IPM is through integration of multiple controls including mechanical, biological, and chemical, Chemical intervention is kept to a minimum, with pesticides used mostly when certain action thresholds are met and often only at certain times. For more on chemical intervention, check out the Pesticides and Fertilizers page.

Part of a sucessful IPM program is also using biological control and working with beneficial wildlife to naturally reduce pest populations.  Attracting these animals and isnects to the farm may take a bit of effort but can pay off in future pest control.

swaisons hawk with prey item

Beneficial Wildlife

Beneficial Birds

Attracting natural predators to the orchard is paramount in an Integrated Pest Management program.  Bluebirds, Tree Swallows, and other cavity-nesting species are often the darlings of biological insect control because they take so readily to human-made nesting boxes. A single pair of Western Bluebirds will feed their nestlings up to 5000 insects over a season, and that does not include the additional insects eaten by fledglings after they leave the nest.

To attract cavity-nesting songbirds, nestboxes must be installed around the vineyard, not within the vines themselves. Many bird species won't tolerate human activity too close to their nests and would greatly prefer to be off to the side, ideally closer to natural habitats. There are several types of nest box plans, but the main thing to keep in mind is to use a box design approved by a bird-friendly source (e.g. Audubon Society or Birds Canada) and do not use any kind of extra adornment whatsoever (e.g. perches, decorations, porches). Find plans in the Further Reading section. 

Keeping invasive birds out of nest boxes may be a challenge, but Starlings can easily be eliminated from boxes by keeping nest box openings to1.5 inches or smaller. House sparrows are more difficult as they are a similar size to bluebirds, but using slot boxes with an opening of exactly 1 5/16 inches can make it slightly more difficult for sparrows to enter. Read more on managing invasive birds

Bats are also excellent insect predators, however the use of bat boxes is far more complex than simple nailing a box to a pole. Bats are exceptionally picky with their roost location and boxes must be placed in multiples in open areas, at least 15 feet high, with each box facing different aspects to create a proper temperature gradient. They cannot be placed near lights, in shaded areas, or further than 500m from an adequate water source.  Alternatively, one can simply leave areas of natural habitat around the farm for bat roosting.

Birds of prey are also incredibly useful in an orchard, although they are harder to attract than songbirds and will occasionally prey on other beneficials (e.g. bluebirds or dragonflies).  Different raptors have preferences for different types of prey.   Red-tailed Hawks, Cooper's Hawks, and most owls prefer to eat rodents such as mice and voles, whereas several smaller hawks such as Merlins and Sharp-shinned Hawks tend to eat small songbirds. Large hawks and owls will often make use of tall T-posts in the vineyard, using them as roosts from which to look for prey.  Smaller hawks are susceptible to depredation by larger animals so do not like the exposure of a T-post. Natural habitat or tall hedgerows are important to attract small hawks, as they often hunt from concealed roosts in trees and other similar structures.

Note: many sources tout Barn Owls as a useful bird of prey for which to build nest boxes, but there are very few records of Barn Owls in the Okanagan and Simlkameen, so these boxes are not recommended here

Beneficial Insects

Many beneficial insects help reduce pests by getting to the root of the problem and either eating or parasitizing eggs and larvae of pest insects before the pests can reproduce further. While no beneficial wildlife, whether insects or larger animals, can completely eliminate pest species, they can help reduce the population to a level manageable by mechanical means and with little to no chemical intervention For more on attracting and maintaining populations of helpful insects, see the Pollinators page

Predatory Insects

Other helpful wildlife

There are several other wildlife species that sometimes get an undeserved bad rap in agricultural settings. Properly managed, they can provide excellent bird and rodent control in the orchard.

Badgers were once hated by ranchers for their deep burrows but it is now know that they are excellent predators of gophers and other rodents. They are critically endangered due to habitat loss and persecution, so seeing a badger on the farm is a special occurrence indeed

Snakes, also often reviled due to fears and misconceptions, also provide valuable rodent control. Non-venemous Gophersnakes (left) are excellent climbers and will also feast on eggs and nestlings of birds such as starlings and robins. Although Rattlesnakes are venomous, they are also very shy and do not seek out humans. Safe coexistence can be achieved with a little knowledge, management, and respect for personal space. Gartersnakes and Yellow-bellied Racers also eat grasshoppers and other large defoliating insects.

(Okanagan Similkameen Stewardship offers free or low-cost Snake Smart workshops to local farms and farm crews to help reduce fears and conflict around snakes. Contact us to learn more)

Coyotes, weasels, and bobcats will also all chow down on pest rodents if present on the farm, though if there are chickens or other small animals on the property, extra care must be taken to protect the coop or enclosure.

Other Helpful Wildlife

Natural habitats on the farm

Leaving large natural habitat areas undisturbed is the best practice to encourage helpful songbirds and birds of prey in the orchard, as it providfes the best quality area for nesting, roosting and resting. They provide food for the birds when food in the orchard is scarce, eg in winter, and they also provide shelter from predators, orchard sprays, and inclement weather.

Natural areas act as windbreaks and provide soil stability.  If there is a natural water source nearby, such as a pond or seepage area, the water can act as a temperature regulator, cooling the air during heat waves and reducing the severity of cold snaps. Beneficial insects are also found in abundance in natural habitat areas.

showy phlox in small forest opening

Further Reading

The following resources are information-only. Find the Financial Assistance page here

NestWatch: All About Birdhouses

Alberta Ministry of Agriculture and Irrigation: Integrated Pest Management module$department/deptdocs.nsf/all/prm12233/$FILE/farmer_pesticide_5.pdf

US National Institute of Food and Agriculture: Integrated Pest Management (bottom of page has excellent external resources)