Value chain · CLM-1152
In plain terms
Bees flew four hundred metres to a sugar dish sitting in a microwave field nearly twice the beam-centre strength, went in without hesitating, and made twenty to thirty round trips in three hours, with no significant difference from bees whose dish had no field.
The claim as recorded
Honey bees "trained to fly 400m from their colony to an indoor laboratory foraging arena exposed to 2.45 GHz continuous wave microwaves at 5 power densities (0, 5, 10, 20, and 40 mw/cm2)" kept foraging: "181 (93 and 88 for the treatment and sham chambers, respectively) of the 250 tagged bees returned to forage after tagging", "During the 3-hour observation periods bees made ca 20-30 round trips", "There was no evidence that the microwave field deterred entry into the chamber", round trips took "5.5-8.5 minutes ... including 2.5-4.0 minutes within the chambers, indicating that bees in the treated chamber were exposed to microwaves during ca half of the 3-hour treatment periods", and the authors conclude "that honey bees readily enter microwave fields at power densities similar to and exceeding those expected to be present in rectennae of the proposed SPS system", stated as "23 mw/cm2 at the antenna center to 1 mw/cm2 at the edge".
Evidence behind this: T3-a free-flying behavioural bioassay with counts stated; the first use of an indoor foraging arena to test an environmental agent, by the authors' account.
Scope and limits
A SUGAR REWARD IN THE FIELD; the test shows bees are not repelled by 5-40 mW/cm2 when food is there, not that a rectenna would attract or hold them. Five-day study, one colony of marked bees, 12-23 bees per condition after exclusions; the "unlike ... white rats" comparison on PDF 140 is the authors' aside and is not carried.
What it assumes
An illuminated indoor arena with a sugar-syrup dish stands for a rectenna field for the entry question, as the authors argue.
Where it comes from
PDF 127 / printed 120: "trained to fly 400m from their colony to an indoor laboratory foraging arena exposed to 2.45 GHz continuous wave microwaves at 5 power densities (0, 5, 10, 20, and 40 mw/cm2)" (normalised); "power levels are expected to range from 23 mw/cm2 at the antenna center to 1 mw/cm2 at the edge" (normalised). PDF 136 / printed 129: "181 (93 and 88 for the treatment and sham chambers, respectively) of the 250 tagged bees returned to forage after tagging" (normalised); "During the 3-hour observation periods bees made ca 20-30 round trips" (raw); "There was no evidence that the microwave field deterred entry into the chamber" (normalised); Fig. 7.2 (PDF 137 render reading): sham means about 20-27 and microwave about 26-32 round trips per bee, the microwave bar higher at every density; the numbers above the bars (12-23) are the bees completing at least 12 round trips; the authors report no significant difference (PDF 127, 136). PDF 140 / printed 133: "Approximately 5.5-8.5 minutes were required by most bees to complete a round trip, including 2.5-4.0 minutes within the chambers, indicating that bees in the treated chamber were exposed to microwaves during ca half of the 3-hour treatment periods" (normalised); "This study provided evidence that honey bees readily enter microwave fields at power densities similar to and exceeding those expected to be present in rectennae of the proposed SPS system" (normalised). Recomputed: 40 / 23 = 1.7 times the centre density; 181 / 250 = 72 per cent return after tagging; 2.5-4.0 of 5.5-8.5 minutes is 45-47 per cent, the "ca half".
Basis: round trips per bee per 3 h; minutes per trip; 0, 5, 10, 20 and 40 mW/cm2 CW at 2.45 GHz in the arena
Cite this
energyaperture.com/c/clm-1152
CLM-1152, Energy Aperture, as of 1980-12.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-537
- CLM-1147The 1980 programme's experiments on bees, at strengths from the edge of a rectenna to about twice its centre, found nothing: eggs hatched...CLM-1148Bee eggs, grubs and pupae zapped for half an hour at up to twice the beam-centre strength grew into normal adults at the same rate as...CLM-1149One hive lived for four weeks, a full brood cycle, under the beam strength expected at the edge of a receiving station, and behaved like...CLM-1150Six thousand bees took part, 2,500 of them dosed, and were let go a hundred metres from home; the dosed ones found their hive as often as...CLM-1151Bees kept a full day at up to twice the beam-centre strength (fifty times the beam-edge level), alone or huddled, ate and lived afterwards...CLM-1153The people who ran the bee tests said so themselves: one species, in boxes whose field strength wandered by a third across the tray, with...