NACREW August, Quebec Crop protection in cranberry crops and honeybee safety Madeleine Chagnon, entomologist, Ph.D. Jean-Pierre Deland, Agr., M.Sc.

SITUATION Severe honeybee losses have been reported up to 3 days after pesticide treatments. Dead honeybees were found in front of hives and in field margins.

Insect pollination can increase cranberry fruit yield by 30-50%. To ensure a good production, cranberry producers rent honeybee hives For beekeepers, hive rentals provide very interesting additional income FACTS

Photo credit: daamaaextweb.gnb.ca FACTS … on the other hand … during flowering It is important to protect this crop against the Cranberry fruit worm (Acrobasis vaccinii) at risk of losing 20% to 35% of the harvest In organic production, the potential loss can reach up to $ $ 5000 per acre. The Blackheaded fireworm( Rhopobota naevana) can also cause considerable dammage

This 4 part study aims to find ways to use pesticides registered to control pests in cranberry by ways that can be … safer for honeybees and all pollinators while remaining effective for crop protection OBJECTIVES

PART 2. NEW PRODUCTS Test new insecticides registered (or being registered) for cranberry pest control on honeybee safety. PART 1. ENTRUST-DOSES Test different methods of applying a pesticide(Entrust) in cranberry so that it can be for bees. PART 3. DRIFT Estimate spraying methods to reduce drift and find the ideal distance from field to place hives.

Test different methods of applying a pesticide(Entrust) in cranberry so that it can be safer for all bees. Entrust (Spinosad) treatments 1 : CONTROL (0 g m.a./ha). 2 : USUAL DOSE_ 218 g/ha Entrust (175g m.a./ha) 3 : HALF DOSE_109 g/ha de Entrust (87.4g m.a./ha) (registered) 4 : USUAL DOSE_RINCED_218 g/ha de Entrust (175g m.a./ha) Rinced the next morning during 1 hour. Treatments PART 1. ENTRUST-DOSES

Treatments were done on different fields (or field sections) The 3m X 6m treated plots are covered by a screen house Nuclei with a laying queen, 4 frames of brood and reserves are introduced into each tent. The honeybee colonies were introduced only in covered areas. EXPERIENCE IN CAGED SEMI-FIELD CONDITIONS PART 1. ENTRUST-DOSES

Sprinklers were blocked to prevent rinsing after some treatments Protection of control plots (3m X 6m) during pesticide treatments METHODOLOGY –THE FIELD PART 1. ENTRUST-DOSES

Brood and the number of honeybees: Before and after treatments Number of dead bees in front of the hives Abnormal behaviour of bees was noted (tremor, lethargy, inactivity, overactivity). METHODOLOGY –THE HONEYBEES PART 1. ENTRUST-DOSES

Transport of mini hives (Nuclei) at night ( 5 frames) Installation of shelters in very early morning, after pesticide had dried and before honeybees started foraging PART 1. ENTRUST-DOSES METHODOLOGY – THE TRIALS Pesticide treatments after sunset

Establishment of 16 plots (3 treatments + 1 control X 4 replicates) PART 1. ENTRUST-DOSES METHODOLOGY – THE TRIAL

Blackheaded Fireworm: On 100 stems per plot Count small larvae or eggs. Sample taken before treatments, and 7 days after. Yields and fruit damage were estimated by collecting 5 times one square foot, for a total of 0.45 m2 of fruit per plot. Fruits were weighed and measured in the laboratory. Cranberry Fruitworm, On 200 fruits per plot Count the eggs and larvae Yields and pest damage assessments were done as for the Fireworm. METHODOLOGY –FRUIT DAMMAGE PART 1. ENTRUST-DOSES

Two fields (2) Four (4)repetitions for each treatment, in each field Cranberry Fruitworm Twelve (12) plots were used in fields with high infestation Three (3) treatments :Control, Entrust 1X et Entrust 1X rinsed. Blackheaded Fireworm Sixteen (16) plots were samples in fields with low infestation Four (4) treatments: Control, Entrust 1X, Entrust 1X rinsed and Entrust ½X. Monitoring was done before and after pesticide treatments in four (4) smaller plots (1 m 2 ), defined within the treated area. PART 1. ENTRUST-DOSES METHODOLOGY –FRUIT DAMMAGE

Healthy fruitDamaged fruit - FirewormDamaged fruit - Fruitworm NumberWeightNumber% of totalWeight % total weightNumber% of totalWeight % total weight 122,94147,901,000,740,550,3610,507,628,085,17 107,38128,151,060,860,710,4811,388,678,405,64 90,63104,291,561,341,140,8921,8120,3915,8113,97 RESULTS – FRUIT DAMMAGE Entrust 1X Entrust rinced Control TREATMENTS PART 1. ENTRUST-DOSES

a a a a b RESULTS – FRUIT DAMMAGE Blackheaded Fireworm (Rhopobota naevana). PART 1. ENTRUST-DOSES % of damaged fruit (numbers) % of total weight

a a a a b b PART 1. ENTRUST-DOSES RESULTS – FRUIT DAMMAGE- Cranberry Fruitworm ( Acrobasis vaccinii) % of dammaged fruit (numbers) % of total weight

IMPACTS OF TREATMENTS ON HONEYBEES IN CAGED PLOTS (shelters) There was no significant difference between the number of dead bees in from of the hives, according to the treatments. Fewer bees were observed on flowers of rinsed Entrust treatment. However, flowering was more advanced in these fields and the number of open flowers was lower. Observation: 10 minutes m2 (1/8 of the cage) PART 1. ENTRUST-DOSES RESULTS – HONEYBEES

Initial populationFinal populationGain Half dose Entrust (1/2 X) Entrust 1x Entrust 1x rinced Control Honeybee populations RESULTS – HONEYBEES PART 1. ENTRUST-DOSES

PART 2. NEW PESTICIDES Test new insecticides registered (or being registered) for cranberry pest control on honeybee safety. Dead honeybees in front of hives Repulsively Estimation of impact on honeybees

Insecticides Insects controlledApplication period Actara Thiamthoxam Neonicotinoid By Syngenta Cranberry WeevilHook stage, before flowering Altacor Chlorantraniliprole By DuPont Canada Cranberry Fruitworm Blackheaded Fireworm Sparganothis Fruitworm Cranberry Fruitworm at 50% fruit set 2nd generation of the Blackheaded Fireworm may need to be made at different times during flowering. Treatment for Sparganothis Fruitworm is usually applied later, towards the end of flowering INSECTICIDES TESTED PART 2. NEW PESTICIDES

Insecticides Insects controlledApplication period Delegate Spinetoram Spinosyn Dow Agrosciences Canada Blackheaded Fireworm Sparganothis Fruitworm Cranberry Tipworm 2 nd generation of the Blackheaded Fireworm 2 nd generation of the Cranberry Tipworm may have to be made at different times during flowering. Treatment for Sparganothis Fruitworm is usually applied later, towards the end of flowering. Movento Spirotetramate Bayers Crop Science Cranberry Tipworm Treatment for the 2nd generation of the Cranberry Tipworm may have to be made at different times during flowering. INSECTICIDES TESTED PART 2. NEW PESTICIDES

Hook stageFlowering beginning of fruit set and end of flowering Blakheaded Fireworm 2G Tipworm Cranberry Weevil Blackheaded Fireworm Sparganothis Fruitworm Cranberry Fruitworm 2G Tipworm Fireworm– Fruitworms Cranberry Weevil Tipworm Tipworm -Fruitworms PART 2. NEW PESTICIDES

C1C2C3C4C4C5C5 B1B2B3B4B4B5B5 A1A2A3A4A4A5A Témoin 2 Delegate 3 Actara 4 Movento 5 Altacor Expérimental design PART 2. NEW PESTICIDES METHODOLOGY

Data collection in shelters The treated plots are covered by a screen house (shelter style Tempo) Nuclei with a laying queen and 4 frames of brood and reserves are introduced into each tent. The bee colony foraging introduced only in covered areas. METHODOLOGY PART 2. NEW PESTICIDES

ESTIMATIONS of number of dead bee in front of the hives twice a day for 72 hours once on the last day: = 7 observation periods METHODOLOGY PART 2. NEW PESTICIDES

Behavioural observations Drinking water (thirst) Behaviour in shelters METHODOLOGY PART 2. NEW PESTICIDES

RESULTS – Repulsion-Attractivity Number of foragers (10 minutes – 1/8 shelter) PART 2. NEW PESTICIDES

RESULTS- BEHAVIOR Fewer bees were drinking in Movento and Delegate treatments There was no difference in the aggregation behaviour on the roof between treatments PART 3. NEW PESTICIDES

RESULTS-MORTALITY Nombre abeilles mortes par 24h PART 3. NEW PESTICIDES ACTARA ALTACOR DELEGATE MOVENTO CONTROL Number of dead honeybees by 24h 4 hours 24 hours 48 hours 72 hours Time after treatment

CONCLUSIONS Insecticides and Movento and Actara did not cause mortality after application. They seemed to have a higher mortality after 48 hours. THESE RESULTS ARE SIGNIFICANT PART 2. NEW PESTICIDES The ALTACOR (Chlorantraniliprole 35%) proved insecticide against pests present during flowering that caused the least mortality in bees. However, it should be used with caution because it is toxic to aquatic organisms. Chlorantraniliprole is persistent and may leach into surronding water. We recommend: DO NOT apply this product directly to freshwater habitats Do not apply an insecticide on more than 2 successive generations of a same insect species. After the treatment, the highest dead bee count was found with Delegate. Accumulation of moisture in the shelters could explain for this because it is known that this product should be allowed to dry on leaves in order to be safe to bees.

PART 3. DRIFT Pesticide drift and distance from field borders CETAQ Joseph Bertrand Desrouilleres and Jean-Pierre Deland Quantify the deposition of pesticides beyond the targeted treatment area; Evaluate the distribution of the drift (distance transport and deposition of droplets); Compare the effects of droplet size and the height of the ramp on the size and distribution of drift. Testing an anti drift noozel At different hights

Spectrophotometer analysis Still a lot of work to do !!!

Thank you Fédération des apiculteurs du Québec