They are principally based on protocols for honey ... For the solitary bee studies the whole life cycle of the adults will take place in tunnels during the flowering of ...
Summary of an ICPPR Non-Apis Workshop Subgroup Higher Tier (Bumble bees and Solitary bees) with Recommendations for a Semi-Field experimental Design Authors: Silvio Knäbe , Olaf Klein, Lea Franke & Julian Fricke Eurofins Agroscience Services Ecotox GmbH, Eutinger Str. 24, 75223 Niefern-Öschelbronn, Germany
ABSTRACT The newly proposed EFSA guidance document on the risk assessment of plant protection products on bees includes for the first time not only honey bees as test organisms but also non-Apis pollinators. However, no official guideline exists for standardized semi-field tests so far. Therefore a non-Apis ICPPR workshop was held from 29 Feb - 01 Mar 2016 at the Julius-Kühn Institute (JKI), Braunschweig, Germany. 47 participants took part representing industry, CRO, authorities and academia. One part of the workshop discussed the laboratory testing design, the other part the higher tier semi-field experimental design presented here.
INTRODUCTION Since there is no official guideline for standardized semi-field trials for non-Apis pollinators, it remains unclear which species and which endpoints should be used for evaluation. Furthermore it is not clear which variation between test results will be acceptable. In this ring test proposal endpoints are considered based on their relevance. All endpoints were discussed and agreed upon. The first consideration for the ring test was a general test system set-up (i.e. timing, number of replicates, tunnel size, type of nesting material, size of colonies, release ratio males/females) in order to guarantee feasible and reproducible test conditions. At the higher tier part of the workshop participants presented their experiences in field and semi-field studies with the test organisms: one representative of a semi-social bumble bee Bombus terrestris, and one representative of a solitary mason bee species Osmia bicornis. Seven laboratories conducted semi-field or field tests. 10 semi-field and 6 field tests were done with B. terrestris. 6 semi-field and 2 field tests were done with O. bicornis. As no guidance on the design or endpoints was available, all tests followed different designs or set-ups. Furthermore, several studies were designed to answer specific questions in a plant protection product registration. The following test protocols are proposed experimental methods for semi-field trials, designed to assess potential effects of pesticides and other chemicals to bumble bees and solitary bees. They are principally based on protocols for honey bee semi-field studies (OEPP/EPPO Guideline No. 170) and on results of the discussions regarding testing solitary bees during the meetings of the ICPPR non-Apis working group.
METHODS Test protocols for semi-field trials are based on experience with European bee species presented at the meetings. Bumble bee studies in Europe are performed using the buff-tailed bumble bee (B. terrestris, L). This species is widespread in Europe and one of the most common of this genus. Bumble bee colonies are easily available from commercial breeders. There are also first laboratory test protocols developed. Test organism for solitary bee studies is the red mason bee (O. bicornis, L) which is also widespread and very common in Europe. Cocoons of both sexes are commercially available. For O. bicornis also first laboratory test protocols are developed. Both species have very generalist food resource requirements and are adapted to forage in a wide range of different flowers so that they can easily be used in a diverse spectrum of crops. In addition, both species have simple behaviour characteristics which are good to observe and are therefore suitable for reproducible biological assessments. The semi-field trial supports a good start comparable with a habitat which offers all needed resources like nesting material, food availability and sexual partners and provides controlled standardised conditions. For the bumble bee studies only the first part of the colony development will take place during the exposure in the tunnels. After the flowering period in the tunnels, bumble bee colonies are transferred to a monitoring site where the so called “switch-point” will be reached and the production of young queens and males will be achieved. For the solitary bee studies the whole life cycle of the adults will take place in tunnels during the flowering of the crop. Only the hatching success of the progeny will be assessed in the following year. Chemicals tested were and will be Dimethoate and an insect growth regulator (IGR) like Fenoxycarb. Both were chosen because of their mode of action and the long term experience available in honey bee trials. Application will be performed during bee flight.
Buff-tailed bumble bee (Bombus terrestris, L) Replicates Size of tunnels Colony
Nests Additional Feeding Exposure Test duration Time of testing
6 > 30m2 1 per tunnel 20-40 bumble bee workers (early season) 60-80 bumble bee workers (late season) Commercial bumble bee hive with queen excluder None during exposure Whole flowering period of crop
Set up of a semi-field trial in winter oilseed rape
Set up of a commercial bumble bee hive at the tunnel
Nest with different brood stages, workers and the foundress queen
6-15 weeks April - August
Red mason bee (Osmia bicornis, L) Replicates Size of tunnels Release rate Nesting material Exposure Test duration Time of testing
6 > 30m2 1 ♀ / m2 / 1.5 ♂ /m2
Chipboard with brood cells of O. bicornis with eggs and cocoons
Chipboard units MDF (100 cavities)
Bumble bee worker foraging on Phacelia flower
Whole flowering period of crop after first cells are produced 10-12 months April - May (-July)
Set up of semi-field trial with bumble bees (above); Set up of semi-field trial with solitary bees (below)
Nesting unit with cavities and release box
Nesting female of O. bicornis
Link to the draft semi field protocols
SUMMARY Based on the limited experience and the still ongoing discussion about exposure in field studies it was decided to proceed with the proposed semi-field study design in 2016.
Following agreements of this workshop were defined: For semi-field studies with bumble bees, obligatory endpoints that must be achieved are the colony weight and colony reproduction success (number & individual weight of young queens). Additional endpoints like flight activity (in crop and at hive entrances), and sugar solution consumption are optional but were not included in the minimum requirements of future ring tests. For semi-field studies with solitary bees, obligatory endpoints that must be achieved are the hatching success, flight activity, the establishment of brood nests with egg laying and the development of the progeny along with the cocoon production and the following offspring observation of the next year generation. Several open questions still need answers before the test system can be successfully established. The ring tests that were run in 2016 will hopefully bring new insights for a future testing procedure. Of course, this only applies for the European species tested so far. It might be different for species that have been proposed for America and Asia.
The main open questions for bumble bees are: How to choose hives that end up with a low amount of variation at the end of the test, what is the best surrounding for the post exposure period, how can the “switch point” (production of sexuals) be defined reliably, how to handle the assessment of hatched queens, what are realistic variations in queen number and queen size/weight?
The main questions for the solitary bees are: How to best synchronise incubation of cocoons and hatching of adults with crop flowering, how to provide the right building material for the cell walls, how fit are solitary bees out of season (test in summer for spring species)?
´The next meeting of the ICPPR Non-Apis working group will be in February 2017 in Wageningen, The Netherlands.´ Literature: Barrett, K.L., Grandy, N., Harrison, E.G., Hassan, S. and Oomen, P. (eds.) (1994): Guidance Document on Regulatory Testing Procedures for Pesticides with Non-Target Arthropods. From the SETAC/ESCORT Workshop (European Standard Characteristics of Beneficial Regulatory Testing); Wageningen, Holland, 28 - 30 March, 1994. Cabrera, A.R., Almanza, M.T., Cutler, G.C., Fischer, D.L., Hinarejos, S., Lewis, G., Nigro, D., Olmstead, A., Overmyer, J., Potter, D.A., Raine, N.E., Stanley-Stahr, C., Thompson, H., van der Steen, J.: Initial recommendations for higher-tier risk assessment protocols for bumble bees, Bombus spp. (Hymenoptera: Apidae), Integrated Environmental Assessment and Management DOI 10.1002/ieam.1675 June 2015. EFSA (2013): Guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees). EFSA Journal (2013) 11(7):3295, 266 pp. OEPP/EPPO (2010): Efficacy evaluation of plant protection products – Side effects on honeybees. OEPP/EPPO PP 1/170 (4), EPPO Bulletin 40, 313-319. ICPPR Non-Apis Workshop (2015): Short Overview of the ICPPR Non-Apis Workshop - Subgroup Higher Tier (Bumble bees and Solitary bees); Limburgerhof, BASF Agrarzentrum, Germany, 19-20 February, 2015. ICPPR Non-Apis Workshop (2016): Short Overview of the ICPPR Non-Apis Workshop - Subgroup Higher Tier (Bumble bees and Solitary bees); Braunschweig, Julius-Kühn Institute (JKI), Germany, 29 February - 01 March, 2016. Sedivy, C. and Dorn, S. (2014) Towards a sustainable management of bees of the subgenus Osmia (Megachilidae; Osmia) as fruit tree pollinators. Apidologie (2014) 45, 88-105.
