Table 1.
The likelihood of pesticide exposure, by route, to commercially important Apis and non-Apis pollinators to be considered for future risk assessment protocols.
| Exposure Route | Life Stage | A. mellifera | Bombus spp. | Osmia spp. | M. rotundata | N. melanderi | Meliponini |
|---|---|---|---|---|---|---|---|
| Air Particles | Adults | 4/0/1 | 4/4 | 4 | 4 | 4 | 4 |
| (Contact) | Larvaea | 0 | 0 | 0 | 0 | 0 | 0 |
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| Nectar | Adults | 4/3/2 | 4/4 | 4 | 4 | 4 | 4 |
| (Oral) | Larvaeb | 4 | 4 | 4 | 4 | 4 | 3 |
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| Pollen | Adults | 1/3/1 | 4/4 | 4 | 4 | 4 | 4 |
| (Oral) | Larvae | 4 | 4 | 4 | 4 | 4 | 4 |
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| Mud/Soil | Adultsc | 0/0/0 | 1/2 | 2 | 0 | 4 | 4 |
| (Contact) | Larvae | 0 | 0 | 1 | 0 | 4 | 4 |
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| Wax d | Adults | 1/3/3 | 1/1 | 0 | 0 | 0 | 4 |
| (Contact) | Larvae | 4 | 4 | 0 | 0 | 0 | 4 |
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| Water | Adults | 4/1/1 | 1/1 | 1 | 1 | 1 | 4 |
| (Oral) | Larvae | 1 | 0 | 0 | 0 | 2 | 2 |
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| Plant Surfaces | Adults | 3/0/0 | 3/3 | 3 | 4e | 3 | 4 |
| (Contact) | Larvae | 0 | 0 | 0 | 4f | 0 | 0 |
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| Propolis/Resin | Adults | 3/1/1 | 1/1 | 0 | 0 | 0 | 4 |
| (Contact) | Larvae | 0 | 0 | 0 | 0 | 0 | 4 |
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| Honeydew g | Adults | 4/2/0 | 1/1 | 0 | 0 | 0 | 4 |
| (Oral) | - | - | - | - | - | - | |
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| Gutattion Fluid h | Adults | 1/1/1 | 0/0 | 0 | 0 | 0 | 1 |
| (Oral) | - | - | - | - | - | - | |
Designated values rank from 0 (marginal or no likelihood of exposure) to 4 (high likelihood of exposure) for both adults and larval bees. Under each exposure route identified, the primary category of exposure (contact or oral) is specified. For Apis mellifera, relative values are provided for foragers, in-hive bees and overwintering bees, respectively. For Bombus spp., values are provided for foraging workers and queen bees, respectively. Values presented here are intended for cross-subgroup comparison (rows), and not within-subgroup comparisons (columns).
All larvae would also experience contact exposure through both nectar and pollen
Adult Osmia spp., N. melanderi, and Meliponini would also experience oral exposure through mud/soil
Exposure to wax would occur only for pollinators that produce wax (Apis mellifera, Bombus spp., and Meliponini)
M. rotundata adults are subject to both oral and contact exposure via plant surfaces, as they forage upon leaf pieces with which to line their nests
Larval M. rotundata exposure via plant surfaces is primarily by contact and not oral exposure, as they reside in leaf-lined cells for the entirety of their development
Larval exposure to pesticides in honeydew and guttation fluid were presumed to be minimal and were not discussed at length by workshop participants