**7. Conclusion**

Pollinators in general, either insects or the handful of other animal species are of utmost importance for their continuous support to most of the cross pollinated plant species for their reproduction. The honey bees, which is considered as the

**27**

*Detailed Review on Pesticidal Toxicity to Honey Bees and Its Management*

most important among all the pollinators is responsible for achieving of global food production demand every year. With ever increasing population, human have constantly been searching for a way to maintain this demand of global food production and in order to achieve this goal, the conventional agriculture has evolved over the centuries. In this sequence, for the proper management of insect, plant pathogens and weed plants in agro-ecosystem various chemical pesticides were discovered in the nineteenth century. Ever since the introduction of these chemical pesticides, the serious debate on their effects on non-target insects and other organisms have also started. Thus, this chapter focuses on the different routes, modes and effects of interaction between various pesticidal applications and their toxic effects on honey bees, at both individual and colony level. Agrochemicals used in fields focusing mainly on minimize the crop losses are harmful for non-target organisms and hundreds of pollinator species, including honey bees are also no exception to this. Being the worker caste of the colony honey bee foragers visit various fields and gather pollen and nectar from different plant sources, which makes them in a phase of constant exposure to various chemicals, either natural or synthetic in nature. These foraging workers collect provisions from floral resources from chemically treated plants and carry them to their colony and thus, unknowingly with each visit they carry with them, a serious threat to their own life as well as to their colony as well. The different kinds of agrochemicals may be a fungicide residue, remaining in a plant after the seed treatment; a herbicide molecule, sprayed directly over the weed plants; an insecticide residue either coming through a direct spray or reaching the colony via air current (drift). Other than these agrochemicals, a serious threat for honey bee colonies has also been imposed by the various synthetic chemicals applied to the bees in apiaries itself for the proper management of honey bee health. Several such chemicals, used for the management of honey bee pests have also been

Although, several studies have been put forward regarding pesticidal toxicity to honey bees, but still a proper management strategy in order to minimize the honey bees exposure is still lacking. However, all pesticidal applications should be done in a way to minimize their exposure to honey bees, so as to prevent the further decline of honey bee population throughout the world. Furthermore, there exists a need of an extension program, for the farmers and beekeepers to spread the awareness regarding the hazardous effects of different agrochemicals to the honey bees, in order to make the existing management strategies more effective in future.

Gaurava Kumar\*, Swoyam Singh and Rukesh Pramod Kodigenahalli Nagarajaiah Department of Entomology, Govind Ballabh Pant University of Agriculture and

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: gauravakumarento@gmail.com

*DOI: http://dx.doi.org/10.5772/intechopen.91196*

reported to be toxic to the bees.

**Author details**

Technology, Pantnagar, Uttarakhand, India

provided the original work is properly cited.

#### *Detailed Review on Pesticidal Toxicity to Honey Bees and Its Management DOI: http://dx.doi.org/10.5772/intechopen.91196*

*Modern Beekeeping - Bases for Sustainable Production*

during the summer season.

different formulations.

with any flower visiting pollinator.

partially or totally decompose during the night.

with pesticide applied. To avoid such condition of direct contact of the pollinators with the pesticides, the application can be mostly in the early evening hours. This late application of the pesticides allows time for these chemicals to

• **Do not contaminate water**: contamination of nearby standing water through pesticides run off should be avoided to prevent the bee losses, as the bees collect water from these water sources to cool down the temperature of the colony

• **Use less toxic compounds**: if the situation allows, then the compounds which are less toxic to the bees should be given preference over the highly toxic chemicals. The pesticide labels should notify the possible hazards to honey bees. If no other alternate option remains then the variations in dosages can be applied.

• **Use less toxic formulations**: many pesticides work equally, when prepared in

• **Microencapsulated insecticides** are found to be more toxic to honey bees than any other formulation. As the size of these capsules is similar to that of pollen, thus, it facilitates their transport directly into the colony, where these compounds remain poisonous for long time and can also be fed to the developing brood. Use of this formulation should strictly be prohibited if; there is any

chance of collection of pollen by a foraging bee from the treated crop.

• Emulsifiable concentrates are less hazardous than wettable powders.

• Dusts are more hazardous than the liquid formulations as these chemicals can reach and enter a honey bee colony through drifting along with the air current. Ultra-low-volume (ULV) formulations are also more hazardous than the other liquid formulations as they can enter or reach a colony in the same manner as well.

• Granular formulation is also safer for the bees as these chemicals are provided to the lower parts of the plant canopy, which minimizes their direct contact

• **Identify attractive blooms**: attractive blooms in and around the field to be sprayed should be check before the application as most of the times such blooms of weed flora attracts the foraging bees and the pesticidal drift to such blooms can be hazardous to the visiting pollinators. In order to avoid such incidents the blooms of weed plants can be removed before the application.

• **Notify beekeepers**: beekeepers should be notified well before the application, as this time period will allow them to move their colonies to a distance where, pesticidal drift is minimal. Colonies can also be covered with the cloth to confine bees into the box itself to avoid any foraging for 1 or 2 days.

Pollinators in general, either insects or the handful of other animal species are of utmost importance for their continuous support to most of the cross pollinated plant species for their reproduction. The honey bees, which is considered as the

**26**

**7. Conclusion**

most important among all the pollinators is responsible for achieving of global food production demand every year. With ever increasing population, human have constantly been searching for a way to maintain this demand of global food production and in order to achieve this goal, the conventional agriculture has evolved over the centuries. In this sequence, for the proper management of insect, plant pathogens and weed plants in agro-ecosystem various chemical pesticides were discovered in the nineteenth century. Ever since the introduction of these chemical pesticides, the serious debate on their effects on non-target insects and other organisms have also started. Thus, this chapter focuses on the different routes, modes and effects of interaction between various pesticidal applications and their toxic effects on honey bees, at both individual and colony level. Agrochemicals used in fields focusing mainly on minimize the crop losses are harmful for non-target organisms and hundreds of pollinator species, including honey bees are also no exception to this. Being the worker caste of the colony honey bee foragers visit various fields and gather pollen and nectar from different plant sources, which makes them in a phase of constant exposure to various chemicals, either natural or synthetic in nature. These foraging workers collect provisions from floral resources from chemically treated plants and carry them to their colony and thus, unknowingly with each visit they carry with them, a serious threat to their own life as well as to their colony as well. The different kinds of agrochemicals may be a fungicide residue, remaining in a plant after the seed treatment; a herbicide molecule, sprayed directly over the weed plants; an insecticide residue either coming through a direct spray or reaching the colony via air current (drift). Other than these agrochemicals, a serious threat for honey bee colonies has also been imposed by the various synthetic chemicals applied to the bees in apiaries itself for the proper management of honey bee health. Several such chemicals, used for the management of honey bee pests have also been reported to be toxic to the bees.

Although, several studies have been put forward regarding pesticidal toxicity to honey bees, but still a proper management strategy in order to minimize the honey bees exposure is still lacking. However, all pesticidal applications should be done in a way to minimize their exposure to honey bees, so as to prevent the further decline of honey bee population throughout the world. Furthermore, there exists a need of an extension program, for the farmers and beekeepers to spread the awareness regarding the hazardous effects of different agrochemicals to the honey bees, in order to make the existing management strategies more effective in future.
