The value of pollinators

Pollination is a valuable service provided by both managed bees and wild native bees. Bee pollination is essential to produce fruits, nuts, vegetables, spices, stimulants (such as coffee), and edible oils (such as sunflower and canola). Estimates of the economic contribution of pollination vary widely, but a 2009 estimated that the contribution of pollination to the world economy is approximately $170 billion annually [1]. Looking at only US data, a 2012 report found that pollination contributes over $15 billion per year to the US economy [2].

In New York, many important, high-value crops are dependent on pollinators for successful production. Some of these crops include apples, soybeans, squash and pumpkins, cucumbers, strawberries, peaches, raspberries and blackberries, pears, and blueberries. Using these crops’ total value in New York State along with the proportion that each of these crops relies on animal pollination, pollinators contribute between $308 million/year and $439 million/year to New York’s economy [3].


Leafcutter Bee on Blackeyed Susan


of NY's native pollinators risk extinction

according to the 2022 Empire State Native Pollinator Survey. This is only using conservative criteria. Under worst-case scenarios, up to 60% of these species risk extinction.

The Empire State Native Pollinator Survey

Cornell researchers collaborated with the New York Natural Heritage Program to document the conservation status of pollinators in New York. They combined field sampling, citizen science surveys, and museum insect collections to produce a first-of-its-kind study for New York State.

A graduate student poses in a lab

Threats to pollinators

Recent scientific literature reviews have shown that changing habitats are the greatest driver of insect and pollinator decline [6].

Habitat loss reduces the availability of the floral resources (such as nectar, pollen, floral oils, and resins), nest materials, and nest sites that pollinators need. Changes in habitat can also shift the normal parasites and predators a pollinator may be exposed to in an area [7]. When habitat loss isolates pollinators in one area or prevents them from moving between remaining habitats, this can reduce population sizes and genetic diversity. As a result, there is a greater chance that pollinators will become locally extinct and become less able to adapt to changing environments. Pollinators who can’t move far distances between these extant patches, or those who specialize in a specific habitat are particularly threatened by habitat loss [6].

Most of today’s habitat losses are driven by expanding agriculture and urbanization. The main drivers of pollinator habitat loss include agriculture and urbanization. Agriculture accounts for a huge portion – 37% – of global land use according to recent FAO estimates [8]. Oftentimes, agricultural land is a poorer habitat for pollinators. For example, one study that compared farm fields to regional bee diversity found that 95% of bees are not present in agricultural fields [9]. This is because agriculture replaces diverse communities of native host plants with few crop species and frequent disturbance and pollution from mechanical tilling, crop rotation, and pesticides [7]. Likewise, expanding urban landscapes are heavily transformed compared to the natural landscapes they replace. Many square miles of pavement, commercial and residential developments, and introduced garden plant species do not provide the floral resources or nest sites that pollinators need [7].


are an integral part of conventional agriculture. Insecticides, herbicides and fungicides help maximize crop quantity and quality by reducing the pests and diseases that cause damage. Unfortunately, non-target organisms such as pollinators can come in contact with these pesticides while foraging. In addition, beekeepers also apply pesticides to their colonies to control Varroa mites.

Pollinator exposure to pesticides is pervasive. For example, scientists have found traces of pesticides in honey bee hives including in the pollen, honey, wax, and adult bees [10–13]. Cornell’s own New York State Beekeeper Tech Team found thiamethoxam, a neonicotinoid insecticide posing high risk to bees, present in 39% honey bee colonies across New York in 2021 [3, 14]. While pesticide testing almost always occurs in honey bees (a pollinator that is not native to North America), one study found 19 out of the 136 pesticides they screened for in the bodies of foraging wild bees. These pesticides included neonicotinoid insecticides, fungicides, and herbicides [15].

Unfortunately, research is becoming clear that some pesticides are harmful for pollinators. Even if a pollinator doesn’t die soon after contact with a pesticide, there can be many less-than-lethal (or sublethal) effects on pollinators. These include reductions in brain function, foraging and nest locating ability, growth, and reproduction, and even reductions in egg laying [6, 7, 16]. In social pollinators, pesticides can impact colony growth, overwintering, and honey production. Pesticides can even impact bee immune systems [17, 18], and indirectly make bees more susceptible to pathogens and disease, particularly those spread by non-native or managed bee species [19].

For more information about the impacts of pesticides, particularly neonicotinoid insecticides on New York’s pollinators, please review our 2020 Neonicotinoid report.


Oftentimes, humans move plants and animals from their native region to places they are not normally found for their agricultural or aesthetic value, including pollinators and plants.

A recent survey in Rochester, NY, found that, on average, 72% of the plants in suburban gardens are not native to the Eastern US [20]. While garden plants have aesthetic value for humans, they have been bred for their showy blooms, and provide little, if any, nectar or pollen for pollinators. Without natural predators or diseases, introduced plants can become invasive and displace populations of native plants. This is a problem, because New York’s native pollinators have evolved with native plants and cannot forage on exotic species.

Many important agricultural pollinators are not native to New York, either. Several species of leafcutting bees (genus Megachile), mason bees (genus Osmia), and bumble bees (genus Bombus) have been introduced to the US for crop pollination. Even the western honey bee (Apis mellifera) was once introduced to North America.

Sometimes, introduced pollinators and native pollinators depend on the same host plants. This is called interspecific competition and is the most studied interaction between native and non-native bees. A recent review of scientific literature found that most studies – 53% – report managed bee species have a negative effect on wild bees through interspecific competition [21]. With non-native bees using the host plants native bees prefer, wild bees can be forced to shift to less desirable and nutritious plants, or forage longer and farther from their nest to find unoccupied resources [21]. This is especially true when floral resources are scarce.

Introduced bees can also transmit diseases to native bees in a process called spillover. Studies show that introduced honey bees are the source of viruses and parasites in wild bumble bee colonies [22, 23]. In Upstate New York, honey bees share parasites with 46 other bee species [24]. A growing body of research including studies like these point to a clear conclusion: that diseases in managed bees pose risks to wild bees [21].

That said, factors such as habitat quality, landscape heterogeneity, and prevalence of diseases within managed bee populations likely determine whether and how much introduced plants and pollinators impact native pollinators.


Scientists are already beginning to see the impact of changing climates on pollinator populations. As average temperatures rise, the geographic distribution of pollinators and other insects adapted to warm environments has increased, while the species that are adapted to colder environments are decreasing [19]. For example, one long-term study found that climate change reduced the number of butterfly species and the amount of habitat available within California’s Sierra Nevada mountains [25]. As the climate changes, we can expect this trend to continue: climate change may alter the geographic distribution of bee species, and cause range reductions or habitat fragmentation.

Shifts in temperatures and precipitation can even change the plants that pollinators depend on. This can change quantity or quality of floral resources. For example, the number and size of flowers, and the amount of pollen and nectar, and even the quality of protein in pollen are impacted by warming temperatures and rising levels of carbon dioxide [7].

Changing climates can also alter the times at which flowers bloom and when bees forage. One review of eastern North American bee specimens revealed that bees and flowering plants are active, on average, 10 days earlier in the spring, and that this relationship correlates with the rise in global temperatures [26]. If climate change continues to cause these times to differ, then both bee and plant reproduction will be impacted.


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