European Honeybees and how our actions impact successful pollination

March 2025, 1st edition
Author Rebecca Sloan, National Pollination Industry Coordinator, NVMMP

Topics Covered:

European Honeybees
Varroa and alternative pollinators
Bee Habitat around your farm
Pesticide Use and its Impacts Bee sites on your farm

The aim of this guide is to educate growers on European Honeybees and the effects
of Varroa mite on bees and pollination. Utilising alternative pollinators and creating
a safe bee habitat on your farm will contribute to successful pollination outcomes.

This is a guide only and may be adapted as required to suit your crop time and pollination needs.

Photo: Elizabeth Frost

European Honeybees

The Varroa destructor (Varroa) incursion will change the face of pollination in Australia.

Australia’s domestic horticultural production is traditionally based on European plant species, with the vast majority of our food and fodder crops originating from introduced parentage. The European Honeybee, which evolved with these species, has become the favoured pollinator of European crops since their introduction in the early 1800’s. The European Honeybee was first brought to Australia in the early 1820’s and it was through the combined efforts of early European settlers’ establishment of crops alongside beekeepers that contributed to Australia’s national food security success.

Honeybees are generalists in their foraging behaviour, and they visit a wide variety of plants. They have adapted to a wide range of environments around the world and can be moved on mass by beekeepers. These attributes make Honeybees a valuable component of our current horticultural systems. As Honeybees forage on nectar and pollen for food, they pollinate our crops resulting in an increase in fruit, nut and seed production. This results in better fruit quality, shape, more even maturation of the crop and even contributes to improved storage quality of some fruit, especially when managed hives are incorporated into the pollination event.

European Honeybees are however in decline globally. This has been linked to:

Harmful bee parasites (e.g. Varroa destructor), diseases (e.g. American Foul Brood) and viruses (e.g. Deformed wing virus)
Declining diversity of nectar and pollen in the environment
Loss of natural habitat
Careless use of pesticide, insecticide and fungicide use and exposure
Global warming
Poor beekeeping practices

Varroa and alternative pollinators

Varroa is considered the deadliest parasite of European Honeybees and has caused widespread international devastation to the species. Once established the mite negatively impacts both managed, unmanaged and wild European Honeybees. For example, since the introduction of Varroa the mid-Atlantic has recorded up to 80% reduction in the number of wild colonies of European Honeybee.

It is estimated that Varroa mite will have a devastating negative impact on up to 95% of Australia’s wild Honeybee populations as it continues to spread across the landscape via natural and human means.

Although a myriad of alternate native pollinators can be found in Australia, from insects to animals, very few of these alternatives provide effective and reliable pollination at the same scale of delivery and versatility as the European Honeybee. Without wild European Honeybee populations, the future landscape of food security relies directly on the need for collaboration between beekeeping industry and horticultural production to ensure pollination success.

Growers in tropical and sub-tropical regions of Australia may have the ability to utilise the geographically limited native stingless bee to secure pollination options. This species can also be managed and moved in large numbers and have achieved similar pollination outcomes when used in conjunction with European Honeybees. It is believed that Australia’s native stingless bees will not be affected by Varroa. However, at this point there are not enough managed stingless bee colonies to effectively replace the expected European Honeybee colony shortfalls. They are also not suitable as a pollinator in cool, temperate or arid areas.

Paid pollination services are becoming an essential part of agricultural enterprise. Growers should be investing time now to strengthen relationships with beekeepers to secure future pollination services. In addition, consideration should also be made to provide a sanctuary for non-European Honeybee pollinators to help aid with paid pollination services.

Bee Habitat around your farm

Countries around the world have differentiated bees into two categories,

Honeybees: usually refers to European Honeybees that are managed only for honey production, and
Pollination bee: refers to managed European Honeybees used specifically for pollination purposes. This also includes other bee species that perform pollination and are mostly wild, native, solitary, and stinged, or managed or wild native stingless bees.

As mentioned, alternate pollination bees may aid in achieving good pollination when combined with traditional Honeybees. However, care must be taken with the management of some species of alternate pollinators such as native bees as they often have smaller foraging ranges which may not make them suitable in a broad scale agricultural setting. For example, apple growers in Pennsylvania, America have encouraged wild pollination bees to live and pollinate along the edges of their orchard blocks where up to 50 different wild pollination bee species have been detected visiting apple blossom. This practice has allowed growers to utilise managed Honeybees throughout the middle of the orchard. This has reduced the number of managed hives required without compromising on fruit set and quality. This method has also been adapted in Adelaide, South Australia. This same principle has also been utilised on watermelon paddocks in New Jersey and Pennsylvania with more than 90% of watermelon farms achieving full pollination requirements from wild pollination bees.

In these cases, native pollinators were encouraged through the change in farm design and layout of production areas to allow more plantings of native or non-target plant species. This native or non-target flora provides habitat and food, and maintains the varied diet, of both wild and managed hives that are used for pollination.

Growers should be aware that the monoculture system of farming is not always beneficial to the health and vitality of Honeybees. For example, cucurbit crops have lower sugars and can lead to poor nutrition in managed European Honeybee hives unless there is intervention from the beekeeper or the availability of non-target or native floral species. Diverse “bee pastures” have been shown to improve the bee health while not interfering with pollination of the targeted crop. Bee pastures may also bring added benefits like adding organic matter to the soil, increasing water infiltration, reducing erosion and providing natural weed control.

Beneficial off-target plantings are being done in some orchards to keep bees healthy directly before, during and after pollination. This is being undertaken in an effort to provide diverse sources of nutrition at this critical end of winter period, when hives are remaining onsite for an extended period before being moved to other pollination events. Sustaining managed hives nutritionally while they’re on farm helps to achieve the best pollination outcome.

Pesticide Use and its Impacts

Pesticides can affect bees in two ways, either acute or sublethal. Acute pesticide(s) affects involve direct contact/application of the pesticides onto the bee. This application can kill the bee immediately before it can return to the hive, or shortly after returning. This can subsequently expose in-hive adult and juvenile bees such as the queen and brood which can have a negative impact on the health and longevity of the entire hive. The worst possible case is the entire hive dies, if enough exposed bees return to the hive before dying.

The less severe but also damaging way pesticides can affect bees is sublethal. This happens when a bee contacts contaminated nectar or pollen and brings it back to the hive where it is stored to feed to the queen and other bees. Prolonged exposure through consumption of this food source can cause the whole hive to struggle with sublethal pesticide affects. Consequences result in reduced pollination ability and honey production and even total hive collapse.

Insecticides and some fungicides fit in this second category, that is they do not kill the bee directly. Chemicals include imidacloprid, clothianidin, thiamethoxam, thiacloprid, acetamiprid and dinotefuran which are commonly used to control scale, aphids, leaf miner and leaf hoppers. They are a common insecticide and less harmful to humans than some of the alternative treatments used to control the above-mentioned pests.

Some neonicotinoids are known as systemic pesticides. These pesticides are transported throughout the plant into the leaves, flowers, roots and stems, nectar and pollen. Neonicotinoids have been shown to lower reproductive rates in colonies, reduce bee lifetimes and hive health and ultimately lead to colony death. Impacts on bees are present on plants which have been sprayed and plants that take up water containing pesticide run off.

Growers need to be aware of the pesticides and application methods they are using and the potential impacts it can have on their pollination success.

Growers could also consider a change in the application method to those with quick drying or larger granular options. These formulations do not usually leave behind a powdery residue which can adhere to the tiny hairs found on the body surface of the bee and can be transported back to the hive.

During the pollination period it is best to avoid insecticide and fungicide application. Pesticide plans need to be discussed with the beekeeper, approved and incorporated into the pollination agreement prior to the start of the pollination period.

Prior discussions must be undertaken with all parties if pesticides are to be applied during pollination. If spraying is unavoidable, it should take place at night when bees are less active to reduce the risk of the bees coming into direct contact with the pesticide or fungicide being used. If possible, avoid spraying onto the blooms. This will reduce the likelihood of the pesticide residue making its way back to the hive. Aerial applications have the highest risk of causing bee death and should always be avoided when bees are actively pollinating. Aerial spraying has a higher chance of spray drift impacting neighbouring properties.

Bee sites on your farm

It is important to ensure that you are catering for the needs of beekeepers and their managed European Honeybee hives while also factoring in on farm activities for the duration of contract. Most agricultural systems are designed to maximise the growing area. This generally leaves the areas of land not suitable for farming the ideal place for the location of managed hives.

Unfortunately, these areas are often not suitable locations for good hive management and so careful consideration is required to make sure that the pollination site are suitable for all involved. When allocating areas for hive placement for a pollination service it is important to consider factors such as level ground, with easy and safe vehicle access. Ample room for trucks and forklifts to manoeuvre should also be considered. Hives should also be sheltered but not shaded. If you are pollinating during the late winter months, protection from frosts is also important in maintaining the temperature of the hive. Afternoon shade is also important if pollination is to occur in the late spring through summer. This will help maintain the temperature within the hive. To reduce the risk of harm, hives should also be located a safe distance from staff and other visitors to the farm.