P.-Th. Georgiadis¹, J. Pistorius¹, U. Heimbach¹, M. Stähler 2, K. Schwabe 3

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1 Dust drift during sowing of maize and oilseed rape - effects on honey bees P.-Th. Georgiadis¹, J. Pistorius¹, U. Heimbach¹, M. Stähler 2, K. Schwabe 3 ¹ Julius Kühn-Institut, Institute for Plant Protection in Field Crops and Grassland 2 Julius Kühn-Institut, Institute for Ecological Chemistry, Plant Analysis and Stored Products Protection 3 State Institute for Agriculture, Forestry and Horticulture Saxony-Anhalt 1 Institut für Pflanzenschutz in Ackerbau und Grünland

2 Risk assessment and state of art on the risk for honey bees from dust drift of insecticidal dusts during sowing J. Pistorius¹, P.-Th. Georgiadis¹U. Heimbach¹, M. Stähler 2, K. Schwabe 3 ¹ Julius Kühn-Institut, Institute for Plant Protection in Field Crops and Grassland 2 Julius Kühn-Institut, Institute for Ecological Chemistry, Plant Analysis and Stored Products Protection 3 State Institute for Agriculture, Forestry and Horticulture Saxony-Anhalt 2 Institut für Pflanzenschutz in Ackerbau und Grünland

3 Bee Poisoning incidents 2008 Baden-Württemberg, Upper Rhine-valley 700 beekeeper, bee colonies Bavaria, region Passau 36 beekeeper, ~460 bee colonies Large bee poisoning incidents with spatial + temporal link to local maize sowing Sowing of Clothianidin-treated maize seeds (Poncho Pro : high rate (125 g a.i. / ha) for eradication of Diabrotica v. v. Residues of Clothianidin in samples of dead bees Emissions of insecticidal dust by pneumatic vacuum operated precision air planters during sowing of maize K. Schwabe, JKI D. Rautmann, JKI 3 Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

4 Exposure and risk of insecticidal dust for bees under realistic conditions Dust emission depends on many factors such as the quality of seed, sowing technology, wind conditions,... Exposure depends on dust emission as well as on distance of sown areas to bee attractive plants filter capacity of adjacent flora for dust particles soil moisture of sown area (secondary drift) Risk for bees depends on exposure as well as on supply of alternative, uncontaminated forage within the flight range attractiveness of the forage source and weather conditions (bee flight) 4 Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

5 5 Institut für Pflanzenschutz in Ackerbau und Grünland

6 Drift trials with honey bees Flowering neighbouring crop mustard/oilseed rape Control >>> Wind direction >>> Sowing of maize or winter oilseed rape Flowering neighbouring crop mustard/oilseed rape Treatment Remote location >500 m distance to sowing area Field colonies Semi-field Wire cages Petridishes Plant samples Institut für Pflanzenschutz in Ackerbau und Grünland

7 Semi-field honey bee colonies ~5000 bees Petridishes with paper, leafs, honey Flower samples in neighbouring crops Small bee cages exposed to drift 7 Institut für Pflanzenschutz in Ackerbau und Grünland Field exposure, bee colonies ~25000 bees Drilling experiment

8 Potential routes of exposure Contact Flying through clouds of dust during sowing Contact during foraging activity on flowers Oral Foraging & Uptake of contaminated nectar Foraging & Uptake of contaminated pollen Other routes of exposure Deposition on puddles 8 Institut für Pflanzenschutz in Ackerbau und Grünland

9 Potential routes of exposure - how are they covered in JKI- trials? Contact Free flying field colonies, sowing during full bee flight Semi-field sowing: no flight act. during sowing Semi-field tests: application before/during bee flight Caged bees in different distances to treated crop Oral Nectar: Foraging on treated crop Pollen: Foraging on treated crop- long term effects Other routes of exposure Puddles/ water sources: realistic field scenario 9 Institut für Pflanzenschutz in Ackerbau und Grünland

10 crop and year of sowing g.a.i. sown /ha in the experiment Heubach dust in g a.i. sown / ha g a.i./ ha (petri dishes, mean of 1-5 m distance) g a.i./ ha (adjacent crop, mean of 1-5 m distance) Effects observed on honey bees maize No experiment maize maize maize , rape Institut für Pflanzenschutz in Ackerbau und Grünland not determined rape barley not analysed yet Effects in tent and field exposure Effects in tent and field exposure Small effects in tent and field exposure No/ very small effects in tent and field exposure No/ very small effects in tent and field exposure No effects in tent and field exposure

11 Drift trial, sowing of Maize, 2010 Average wind speed: 2010: 2,30 m/sec. 11 Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

12 Mortality in treatments: 3 drift trials, sowing of Maize, Average wind speed: 2010: 2,30 m/sec. 2011: 2,25 m/sec. 2012: 2,34 m/sec. Pneumatic driller (vacuum singling) with deflector used in all trials Seed treatment quality: 2010: g a.i. in Heubach filter dust in seeds/ha sown 2011: g a.i. in Heubach filter dust in seeds/ha sown 2012: g a.i. in Heubach filter dust in seeds/ha sown Mortality 2010 > 2011 > Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

13 Semi-field, maize Institut für Pflanzenschutz in Ackerbau und Grünland Days before (-) and after (+) sowing International Conference on the German Diabrotica Research Program, Berlin 2012

14 Drift trial, sowing of WOSR, 2011 Average wind speed: 2011: 2,10 m / sec. 2011: 0,021 g a.i. in Heubach filter dust Field: all Mortality data in the range of natural mortality semi-field: very small effects? No adverse effects on bee colonies in realistic conditions?! 14 Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

15 Worst case -scenario semi-field, Drift trials WOSR + Maize 2011 Average wind speed: WOSR 2011: 2,10 m/sec. Maize 2011: 2,25 m/sec. Mortality in Treatment-Variant is significantly higher for maize seeds than for winter oil seed rape seed, both crops with improved treatment quality! 15 Institut für Pflanzenschutz in Ackerbau und Grünland International Conference on the German Diabrotica Research Program, Berlin 2012

16 Different dust particle sizes: manual application semi-field experiments Standard soil (LUFA 2.2) Fractioning of abrasion dust of maize (seed batch 2009) Particle size [µm] Clothianidin [%] Ratio of fractions [%] x ,33 80 < x , < x , < x , < x , < x ,76 x > ,57 X 80µm Maize (Clothianidin) 250 µm < X 355 µm X > 500µm 16 Institut für Pflanzenschutz in Ackerbau und Grünland Fractions of abraded dust

17 More Data: please see Poster Georgiadis et al., e.g. : Effects following application on different crops NOER/LOER Effects on bee brood 17 Institut für Pflanzenschutz in Ackerbau und Grünland

18 dead bees in bee trap Long term effects on mortality of adult bees? Control T1 (1.0 g a.i./ha) T2 (2.0 g a.i./ha) Institut für Pflanzenschutz in Ackerbau und Grünland Days before/after application 4-5 weeks after exposure: mortality still slightly increased

19 Importance/ Relevance of potential routes of exposure Contact -/+ Flying through clouds of dust during sowing +++ Contact during foraging activity on flowers Oral ++ Foraging & Uptake of contaminated nectar +++ Foraging & Uptake of contaminated pollen / particles Other routes of exposure -/+ Deposition on puddles 19 Institut für Pflanzenschutz in Ackerbau und Grünland

20 Conclusions- effects on bees Differences in routes of exposure for sprays and dusts Dusts cause higher effects on bees than sprays for same application rate (g a.i./ha) Semi-field methodology with dust application by hand looks promising for risk assessment purposes Smaller dust fractions cause higher effects High mortality in semi-field but also field-trials with sowing of maize: Deflectors do not solve the issue completely 20 Institut für Pflanzenschutz in Ackerbau und Grünland

21 Conclusions effects on bees Symptoms of poisoning clearly visible at the hive, no surprising hive depopulation (no link with CCD) High effects on adults, low direct effects on bee brood. Breeding behaviour, larval and bee brood development not directly affected - in line with newer research data, indicating LD 50 of ~3000 ng/larve (in vitro) compared to 3.7 ng/adult Effects predominantly by contact during foraging activity and uptake of contaminated nectar and pollen, (no or) low effects by flying through dust clouds and other routes of exposure, e.g. puddles 21 Institut für Pflanzenschutz in Ackerbau und Grünland 21

22 Data gained in Germany used to inform risk assessment and r. management globally Dust exposure and bees: possibly relevant for other insecticides and other seed treatments of important crops (maize, oilseed rape, cereals, legumes.) Dust exposure also relevant for some other RA areas (aquatics, NTA, operator exposure ) Specific risk assessment for bees & dusts needed National risk assessment EU & EFSA US-EPA PMRA, Canada 22 Institut für Pflanzenschutz in Ackerbau und Grünland

23 Risk assessment Worst case scenarios need to be covered High risk- high portion of small fields, field margins High risk- high portion of maize and winter oilseed rape Higher risk for crops sown in spring, as many flowers are present near fields Higher risk for bee colonies survival in autumn as damage to smaller numbers of bees can hardly be compensated e.g. Baden-Württemberg Small fields- higher potential risk e.g. eastern Germany: bigger field sizes- lower potential risk 200 m 2km 1000 ft 23 Institut für Pflanzenschutz in Ackerbau und Grünland 1 mile Source: google maps

24 Conclusion: seed treatments, risk for bees in different crops, solutions for Diabrotica? Sowing of different crops: different exposure, different risk! No poisoning incidents with sowing of treated winter oilseed rape & sugar beet (>15 years)! use of methiocarb as seed treatment in maize on a large scale for >20 years with no/very few poisonings Clothianidin: LD 50 oral 3.7 ng, contact 44 ng/bee Methiocarb: LD 50 oral 47 ng, contact 280 ng/bee Highly toxic neonic s currently not safe enough for seed treatments: necessity for further improvements of the seed dressing quality of maize and/or of the sowing technique Granules: no (or very low) dust emission Actives with lower bee toxicity but sufficient efficacy against Diabrotica in development for seed treatments 24 Institut für Pflanzenschutz in Ackerbau und Grünland

25 Conclusions- Dust from seeds Both, amount of dust and residue content of dust are relevant for exposure Dust amount and residue content of dust differs depending on crop type, dosing, treatment recipe and treatment facility Improving seed quality (change of recipes) may also change % of a.s. in dust An intensive cleaning of seeds before the coating process is essential Quality of seed treatment facilities and use of adequate stickers and coating recipes are key factors to improve quality, therefore a certification of seed coating facilities plus quality checks of seed samples are a good option Dust emission depends on machinery 25 Institut für Pflanzenschutz in Ackerbau und Grünland

26 Thank you for the attention! Acknowledgements: BMELV (Federal Ministry for Food, Agriculture and Consumer Protection), LfL (Bavarian State Ministry of Food, Agriculture and Forestry)! Practical support by breeders Many very dedicated colleagues in the JKI (A, AT,ÖPV, VB)! 26 Institut für Pflanzenschutz in Ackerbau und Grünland