**2. Routes of exposures to different pesticides**

The different types of pesticidal formulations travel across the plant through different ways in order to protect the plant or part of it from different factors such as weeds, pathogen, insect pests or rodents, etc. According to the nature of the different pesticides, three principal application methods that are often used to treat crops are: direct spray, which is often used around homes and gardens; soil applications and seed applications, typically used in larger treatment systems. These different methods of application play a crucial role in the exposure of these chemicals to the insect pollinators, visiting a crop (**Figure 1**).

Thus, on the basis of different application methods and the persistence of different pesticides in nature, bees get exposed to different pesticides through these major routes:


These different routes for exposure of various pesticides to honey bees facilitate their entry into a honey bee colony system, but still the mode by which, these

**15**

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

chemicals are pulled out by the forager bees from the fields are quite different being either by oral, respiratory or dermal intake. These different modes of intake of such

Oral intake of chemical pesticides from fields is facilitated through the foraging worker bees. Plants treated with different systemic insecticides, produce nectar and pollen containing these insecticides and thus, worker bees collecting this floral resource carries to the colonies to store it into the colony and further use to feed the young developing brood [13]. Several reports of an extremely high concentration of different pesticidal compounds, including insecticides, fungicides, miticides and herbicides have been reported from pollen samples of several crops [12, 14]. These events, from collecting the pollen in the field to feeding to the developing brood results in to a chain of catastrophic events as: foragers are killed during collecting and transporting such contaminated pollen, nurse bees are killed while storing and feeding pollen and the brood are killed by

Respiration of pure oxygen plays a vital role in an organism's growth and development since it ensures proper functioning of various organs in the organism. But, respiration of air admixture with toxicants causes various abnormalities such as abrupt behavioral changes and degradation of learning ability [15]. Pesticide formulations like, dust and fumigants travels through the air called 'drift' can either be carried out onto the body surface of foraging bees or can be absorbed through trachea (respira-

consuming the toxic pollen, thus, leading to a total collapse of the colony.

tory organs) in sufficient concentrations to be toxic to the bees (**Table 1**).

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

chemicals are described here.

**3.1 Oral intake**

**Figure 1.**

**3.2 Respiratory intake**

**3. Mode of intake of toxicants**

*Different routes of pesticidal exposure to honey bees.*

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

**Figure 1.** *Different routes of pesticidal exposure to honey bees.*

chemicals are pulled out by the forager bees from the fields are quite different being either by oral, respiratory or dermal intake. These different modes of intake of such chemicals are described here.
