1. Effects of Pesticides on Honey bees
Yahya Al Naggar, PhD
Lecturer of Entomology
Faculty of Science, Tanta University,
Tanta , Egypt.

2. Outlines: Importance of bees. Pollinator decline. pesticides.
Sub-lethal and chronic effects of pesticides on bees.
Risk assessment of pesticides to honey bees.
Recommendations and Conclusion.

3. Importance of bees: Egypt has about 1.3 million hives :
Honeybees pollinate a third of the food we eat.
Bees play an essential role in biodiversity.
Apitherapy (Bee venom, Propolis, Royal jelly) are antimicrobial and anticancer agents.
Bee wax has a lot of uses in cosmetic products.
Egypt has about 1.3 million hives :
7,700 are mud hive
There are 270,000 beekeepers.

4. What’s wrong with honey bees?
There is a global concern about the decline of populations of the honey bee.
Typically 15% of hives fail over winter, today its >30%.
No clear single factor to date explains colony loss in bees.
The term Colony collapse disorders (CCD) have been coined to identify this issue.

6. The symptoms of CCD are defined as follows:
Collapsed colonies:
Complete absence of adult bees in colonies, with few or no dead bees in or around colonies.
The presence of capped brood, and presence of food stores (both honey and bee bread)
Collapsing colonies
An insufficient number of bees to maintain the amount of brood in the colony,
The workforce is composed largely of younger adult bees, the queen is present, and the cluster is reluctant to consume food provided to them by the beekeeper.

7. Why are we Interested in CCD?
Egypt has report incidence of CCD along River Nile .

8. CCD Proposed Causes Parasites and Pathogens.
Malnutrition and Loss of habitat.
Genetic factors and Beekeeping practice.
Pesticides
Combination of all factors.
The extensive use of chemical pesticides against pest insects for crop protection may have contributed to the loss of pollinators.

9. pesticides:
Neonicotinoides

10. Application of pesticides
Pesticides may applied as: spray or soil drench and used on field and orchard crops, on trees on gardens, parks and streets.
Some used as seed treatment and as coating that conifers protection to youngest seedlings and as chemigation.

11. Insects like honey bees, that rely on nectar, pollen, or other floral resources have increased oral exposure to pesticides especially neonicotinoids and their metabolites.

12. Exposure scenarios of honey bees to pesticides in the field:

13. Effects of pesticides on honeybees
Acute intoxication (LD 50):
Toxicity is dependent on the route of exposure with contact being less toxic than oral.
Effects of pesticides on honeybees
Chronic intoxication:
Sub-lethal effects of pesticides on bees:
1- Sub-lethal effects on behavior.
homing ability, Impaired memory and learning.
Reduce the grooming and foraging.
Failure to communicate properly with nest mates.
2- Sub-lethal effects on reproduction.
Delaying of Brood and Larval development.
3- Sub-lethal effects on Immunity and Nutrition.
Exposure to Pesticide can impact the expression of genes that are sensitive to diet and nutrition.
Exposure to sub-lethal doses of neonicotinoids makes bees more susceptible to a variety of common infectious diseases.

14. Assessment of Hazard of organophosphorus pesticides to honey bees:
The hazard characterization scheme applied was based on methods proposed by the USEPAs Office of Chemical Safety and Pollution Prevention for assessing risks of foliar sprayed pesticides.
Total daily intake (TDI) of pesticides received by bees via food was calculated :
TDI = OP concentration detected in honey and pollen x total food consumption rate ( 9.6 mg d-1 pollen and 292 mg d-1 honey)
HQs for individual OPs was calculated:
HQs = TDI (honey) + TDI (pollen )/ Acute oral LD 50
HQs based on lethality of bees exposed to OPs directly was estimated:
HQs = OPs detected in bee body burden /Acute oral LD 50

15. Some selected publications for OPs pesticides and Honeybees

16. To avoid bee kills from pesticides :
Try to select a pesticide & dosage that will kill the pest & not kill bees
If this is NOT possible:
Use the pesticide in the formulation least harmful to bees.
Apply the pesticide early morning or early evening when bees are not visiting the crop.
Warn local beekeepers before applying the pesticide.
Move bee colonies away from sites where toxic pesticides are used.

17. Solution to Honey Bee Health Crisis
Effective monitoring & diagnosis of colony health.
IPM for bee pests particularly Varroa mite.
Integrated bee management.
Supportive agricultural policies.
Open, positive and collaborative stakeholder communication.
Science-based risk management for pesticides.