Exposition Paths of Neonicotinoids Hedwig Riebe, DBIB Paris, - PowerPoint PPT Presentation

Observations 2009 Exposition Paths of Neonicotinoids Hedwig Riebe, DBIB Paris, 10.12.2009

Wintering problems as acute symptoms • Recommendation for nucs 15 years ago: 30 % • Nuc recommendation 2009: 100 % Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 2 / 10.12.09

Possible Causes? • Pollen and nectar contamination (sublethal doses) • Increase of neonicotinoid usage in agriculture • Guttation Drops as possible cause in discussion in Germany since beginning of 2009 • Exposure to neonics through other water sources Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 3 / 10.12.09

Activities in Germany regarding guttation/water/clothi in 2009 • Feb.: Girolami • Apr.: Call for pictures of drinking bees • May: guttating crops • July: Presentation at BVL • Aug.: Viewed Poncho files • Sep.: Presentation at Agric. Ministry • Oct.: Tests of canola guttation Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 4 / 10.12.09

Guttation ./. Dew Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 5 / 10.12.09

Guttation ./. Dew – 2 hours later Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 6 / 10.12.09

Plant sap & Seed coating • Xylem = Water from roots to leaves • Phloem = Water from leaves downwards • Seed coating = Poison dissolves in water, dissolves in dressing zone, absorbed through roots and distributed in entire plant Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 7 / 10.12.09

Guttation Droplets • Guttation droplets = Xylem Minerals, proteins, Minerals, proteins, sugars sugars, Insecticide, Fungicide Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 8 / 10.12.09

Studies / thesis / publications • Doc. Thesis Michael Schneider, 1988: „Aufnahme von ( 14 C) Triadimenol über Korn und Wurzel nach Flüssigbeizung von Wintergerste: Einfluss von Bodenfeuchte und Saattermin auf Radioaktivitätsverteilung und Wirkstoffgehalt in Pflanze und Boden“ • Doc. Thesis. Ulrike Stein-Döneke, 1993: „Beizhofausbildung, Aufnahme, Translokation und Wirkung von [ 14 C]Imidacloprid bei Winterweizen und Zuckerrüben nach Saatgutbehandlung und unter dem Einfluss verschiedener Bodenfeuchten“ (Infuence of soil moisture on the formation of dressing zones and uptake of imidacloprid after seed treatment of winter wheat) • Hughes R. N., Brimblecombe P., 1994: „Dew and guttation: formation and environmental significance“ • Guttation water content 1966; various studies mentioning guttation referenced in thesis Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 9 / 10.12.09

A few facts about guttation • Not limited to a specific time of year or specific groups of plants – Spring (observed) – Summer (observed) – Fall (observed, also Doc. The. Schneider) – Winter ? (unless frozen) (guttation observed on Dec. 9, 2009) – Guttation and dew available for at least two hours in the morning (Pub. UK) Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 10 / 10.12.09

Water requirements of bees • Why water in the morning?? – Dilution of honey/nectar to feed larvae – Water reserve against ‚thirst‘ after heating at night – High water demand by nurse bees digesting pollen for jelly production (average water content is 67 %) Water homeostasis in bees, with the emphasis von sociality , S. W. Nicolson, Journal of Experimental Biology 212, Feb. 2009 Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 11 / 10.12.09

Observations 2009 • Neonicotinoid seed coatings – Exposure of bees – (Sublethale Effects) • Exposition in non-relevant crops • Brood damage through blossom treatments? • Residues in honeys after blossom treatments Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 12 / 10.12.09

Known danger? Doc. The. USD, p. 149: „Es gilt zu prüfen, inwieweit die Wirkstoffausscheidung mit der Guttation neben einem Wirkungsverlust für die Pflanze auch eine Gefährdung von Nützlingen wie Marienkäfer und Bienen darstellen kann, da diese die Guttationstropfen als Wasserquelle nutzen (Poehling, 1992; Schmidt, 1992b).“ „It still needs to be tested in how far the loss of a. i. through guttation poses a danger to beneficial insects like ladybugs and bees, because they use guttation drops as a water source (oral communication, Poehling, 1992; Schmidt, 1992b).“ Poehling, M.-H. (1992): Pers. Mitteilung. Institut für Pflanzenpathologie und Pflanzenschutz, Universität Göttingen Schmidt, H.-W. (1992b): Pers. Mitteilung. Bayer AG, Geschäftsbereich Pflanzenschutz, Entwicklung/Insektizide, 5090 Leverkusen, Bayerwerk. Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 13 / 10.12.09

Documentation of Guttation • 1 beekeeper • 1 canola field • 2 apiaries • Small digital camera • Location: northern area of county Düren, Germany • 85 % agricultural use Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 14 / 10.12.09

Canola field & surroundings Cer Pota Pota Cer Cer SugB 8 ha Canola Pota Cer Pota SugB Pota Corn Cer Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 15 / 10.12.09

Everything‘s guttating! Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 16 / 10.12.09

Some observations ... • Water puddle, but bees collect guttation drops as long as available • Bees prefer sunny spots for water collection • Water collectors in sunny field seam strips up to 40 m from hives • Dew in shaded spots (driving lanes) still available after everything else dries Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 17 / 10.12.09

Bee drinking guttation drop They do drink it! Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 18 / 10.12.09

Everything‘s guttating: Canola Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 19 / 10.12.09

Everything‘s guttating: Sugar Beet Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 20 / 10.12.09

Everything‘s guttating: Potatoes Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 21 / 10.12.09

Everything‘s guttating: Cereals Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 22 / 10.12.09

Everything‘s guttating: Corn Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 23 / 10.12.09

Active Ingredients • Per sugar beet seed 0,9 mg Neonicotiniode (Poncho Beta+) • Per Corn seed 0,5 mg Neonicotinoid (PONCHO) resp. 1,25 mg (PONCHO PRO) • Main distribution in top 5 cm of soil with r = 5-6 cm around plant Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 24 / 10.12.09

Dressing zones • Bilder USD 80 % in top fraction Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 25 / 10.12.09

Concentration of seed coating • Concentration in first few drops acc. USD 0,3 % of total a.i. per seed • Higher concentration of a.i. in leaf tips (and thus in guttation drops) than compared to rest of plant and xylem Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 26 / 10.12.09

Distribution of A. I. Makroautoradiographie wheat plant (45 days after seeding) Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 27 / 10.12.09

Distribution of A. I. Makroautoradiog- raphie of sugar beet plant in 6-leaves stage (32 days after seeding) Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 28 / 10.12.09

Bon appetit! Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 29 / 10.12.09

Weeds in dressing zones Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 30 / 10.12.09

Weeds in Corn Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 31 / 10.12.09

Long term poisoning effects • Concentration of a. i. in guttation droplets in fall and spring? • Which concentrations in the different crops? • Potatoes, salads, other plants? • How much a. i. remains in soil and becomes available later on, e. g. fertilizer plants like ‚Senf‘ (sinapis alba)? Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 32 / 10.12.09

Seed coating expositon • Guttation droplets of crops – Direct consumption of drops by bees – Dried and re-soluted remains of guttation drops on leaf surfaces • „Leaching“ • Water collection from soil in dressing zone, eventually increased by fallen guttation droplets? • Guttation of weeds growing in dressing zones Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 33 / 10.12.09

Guttating Canola Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 34 / 10.12.09

Dried residues of guttation droplets • Bild Girolami Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 35 / 10.12.09

Guttating Cereals Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 36 / 10.12.09

Dried residues of ? on potatoes – Pesticide Spray? Exposition paths of neonicotinoids – Paris 2009 DBIB – H. Riebe 37 / 10.12.09