Honey Bee Health, Pollination and Pesticides. Ramesh Sagili Department of Horticulture Oregon State University

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1 Honey Bee Health, Pollination and Pesticides Ramesh Sagili Department of Horticulture Oregon State University

2 Honey bees Honey bees: important for ecosystem / agriculture Honey bee pollination: $ 20 billion in the USA Honey bee pollination: $ 500 million in Oregon Honey bees pollinate more than 90 different crops Managed colonies in USA : 2.5 million (NAS 2007) One third of our diet depends on bee pollination

3 Honey bees are third most valuable domestic animal in Europe

4 Our diet on pollinators

5 Our diet on Wind

6 Honey bees: Work horses of pollination Courtesy: Dr. Caron

7 Honey bee pollination in Oregon Major crops dependent on bee pollination: Blueberry Cherries Pear Apple Cane berries Cranberries Strawberries Clover Meadowfoam Vegetable seeds Watermelons

8 Current challenges Colony Collapse Disorder ( CCD )

9 Symptoms of CCD Absence of adult bees in the colony, with no dead bees inside or outside the colony. Presence of capped brood. Presence of enough food stores.

10 USDA Survey on colony losses AIA / USDA Survey April 2011 Total losses : 30 % ( : 29 %, : 34 %) 10-15% loss is normal

11 Colony collapse disorder Very complex

12 Potential factors involved in CCD Initial speculations: ranged from cell phone theories to bee rapture. Buzz us later

13 Parasites and Diseases Pesticides & Fungicides In hive chemicals Malnutrition Change in habitat / intensive agriculture Migration Lack in genetic diversity

14 Varroa mite Varroa destructor

15 Bees with deformed wings Varroa mites vector DWV and few other viruses

16 Nosema Gut parasite Nosema apis Nosema ceranae Causes diarrhea Protein metabolism is disrupted Results in: Energetic stress High hunger levels

17 Cracked corn

18 In hive chemicals Fluvalinate Coumophos Miticides

19 Pesticides A broad survey of pesticide residues on bee hive samples across 23 states found 121 different pesticides and metabolites. Additive and synergistic effects of multiple pesticide exposures is a concern. Some pesticides at sub-lethal levels have been shown to impair behaviors and compromise immune system of bees. Extensive use of neonicotinoids is a concern. Neonicotinoids cause persistent activation of cholinergic receptors leading to hyperexcitation and death. Neonics differ from classic insecticides as they are systemic in the plant (interfere with orientation of bees). Neonicotinoids: most widely used insecticides in the U.S

20 Neonicotinoid s toxicity to honey bees Chemical Brand name Acute Contact Thiamethoxam Actara, Platinum, Helix, Cruiser, Adage, Meridian, Centric, Flagship Highly Toxic Acute Oral Highly Toxic Clothianidin Poncho, Titan, Clutch, Belay, Arena Highly Toxic Highly Toxic Imidacloprid Widow, Alias, Confidor, Merit, Admire, Ledgend, Pravado, Encore, Goucho, Premise Highly Toxic Highly Toxic Acetamiprid Assail, Intruder, Adjust Toxic Toxic Thiacloprid Calypso Toxic Toxic

21 Pesticides in the Hive Matrix 121 pesticides and their metabolites in wax, pollen & bees Chlorpyrifos (organophosphate insecticide) Clorothalonil (fungicide) Imidacloprid (neonicotinoid insecticide) Pendimethalin (herbicide) Endosulfan (organochlorine insecticide) Fenpropathrin (pyrethroid insecticide) Esfenvalerate (pyrethroid insecticide) Atrazine (herbicide) Miticides: Fluvalinate (pyrethroid) Coumaphos and metabolites (organophosphate) Amitraz and metabolites (triazapentadiene)

22 Insecticides and Fungicides that are under scrutiny Imidacloprid ( E.g. Alias, Widow) Chlothianidin Boscalid (Pristine) (high residual activity) Chlorothalonil (Bravo) Microencapsulated formulations are of higher concern as the particles adhere to foraging bees.

23 Direct spray Modes of exposure Exposure to contaminated pollen and nectar Pesticide delivery via irrigation water (drip tape) Guttation drops Honeydew from treated insects or plants Honey bees have fewer genes for innate immunity and detoxification. Hence are more susceptible.

24 Amounts detected in nectar and pollen of plants grown from treated seeds were lower than 10 ng/g (10 ppb) Guttation Guttation drops of corn plants:10 mg/l to 100 mg/l of thiamethoxam and clothianidin, and up to 200 mg/l of imidacloprid (GIROLAMI et al. 2009)

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26 Aphids

27 Symptoms of pesticide poisoning Excessive number of dead bees in front of the colonies Aggressiveness Lack of foraging Paralysis, abnormal jerky, wobbly movements, spinning on the back (organophosphates and organochlorines) Extension of tongue (OP and Pyrethroids) Crawler bees

28 Risk assessment protocols Effects of pesticides on beneficial arthropods are examined by running LD50 tests. EPA does not require data on sub-lethal effects for pesticide registration.

29 Dose response LC50

30 Effects on Behavior Robust association between sucrose response threshold and foraging behavior Proboscis Extension Response Assay

31 Proboscis Extension Response

32 Proboscis Extension Response

33 Application of pesticides and protection of honey bees are not mutually exclusive. Ways to reduce bee poisoning: Beekeeper and Grower cooperation. Using all pesticides in a manner consistent with label directions. Avoid insecticides with long residual toxicity. Choose insecticides with low toxicity to bees.

34 Insecticides labeled highly toxic to bees: Do not apply pre-bloom or during bloom or when bees are actively foraging.

35 How growers can help Avoid spraying during bloom periods. If possible spray in the evening or early morning. Controlling blooming weeds in crop areas before applying pesticides. Protect water sources from contamination by pesticides.

36 OSU Extension Publication How to reduce bee poisoning from pesticides (PNW 591)

37 Thanks for your kind attention Questions??