Bird netting is a common agricultural practice used to safeguard valuable fruit and vegetable crops from damage caused by birds. These protective barriers are typically draped over trees, vines, or garden rows to create a physical obstacle that prevents birds from accessing the harvest. A frequent concern for many growers involves the unintended effect of this netting on beneficial insects, particularly the bees responsible for pollination. Whether these small pollinators can navigate the netting depends entirely on specific physical variables.
How Mesh Size Determines Bee Passage
The core function of standard bird netting is to exclude avian species, which are physically much larger than most garden insects. Commercial bird netting typically features a mesh size ranging from 15 millimeters by 15 millimeters up to 28 millimeters by 28 millimeters. These dimensions are effective at blocking birds like starlings or crows.
A Western Honey Bee worker has a body width generally between 3 and 5 millimeters. Compared to a standard 15-millimeter mesh opening, the bee is small enough to pass through the barrier with ease. Even a larger bumblebee worker, measuring 11 to 17 millimeters in length, has a width accommodated by the large openings in most anti-bird nets.
The netting’s design successfully separates the target species (birds) from non-target species (bees and other pollinators) by size differentiation. If the netting is specifically marketed and sold as standard bird netting, its mesh size will almost certainly permit the free passage of bees. The fundamental principle of large gaps remains the same for all bird exclusion products.
Risks of Bee Entrapment and Injury
While the mesh size allows for easy passage, the material can still present a hazard under certain conditions. Bees primarily become entangled when the netting is not installed correctly or is damaged, creating irregular openings and slack material. A loose or sagging net increases the probability that a bee’s delicate wings or legs might catch on the strands.
Wing damage is the most common consequence of entanglement, severely impairing a bee’s ability to fly and forage. An injured bee may be unable to return to its hive or nest, leading to dehydration or exhaustion. Entrapment can also occur if a large-bodied bee, such as a queen bumblebee, tries to force its way through a small, distorted section of a loosely draped net.
To mitigate these risks, the netting should be stretched taut and secured firmly, minimizing loose areas that could snag insects. Regular inspection for tears or snags is important, as damaged sections can create smaller, dangerous loops. Proper installation and maintenance ensure the barrier remains a bird deterrent without becoming a hazard to pollinators.
Specific Methods for Pollinator Exclusion
If the goal is to prevent bees and other insects from accessing a crop, such as for seed saving or controlled breeding, standard bird netting is not appropriate. To achieve true pollinator exclusion, a barrier known as fine insect netting or exclusion netting must be used. This specialized netting is designed with a mesh size specifically to block insects, with apertures typically ranging from 0.4 millimeters to 1.5 millimeters.
This fine mesh size creates a physical barrier smaller than the body of even the smallest foraging bee. For instance, a 50-mesh product features holes as small as 0.25 millimeters, effectively excluding most pest insects. This level of detail is necessary to block insects that are only a few millimeters wide, which is required for controlled pollination or preventing insect pests.
Practical application requires the exclusion net to be completely sealed around the crop, often by burying the edges in the soil or securing them tightly to a structure. The netting must be deployed before the flowers open and removed once the period of desired exclusion is complete. This temporary use ensures the plant receives adequate light and air while preventing unwanted cross-pollination or insect damage.