Hive orientation and colony strength affect honey bee colony activity during almond pollination

Authors: EVANS, SANDRA - Canetis Srl; EVANS, HUW - Beehero, Inc; Meikle, William; CLOUSTON, GEORGE - Beehero, Inc

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2024
Publication Date: 2/5/2024
Citation: Evans, S.K., Evans, H., Meikle, W.G., Clouston, G. 2024. Hive orientation and colony strength affect honey bee colony activity during almond pollination. Insects. 15(2):112. https://doi.org/10.3390/insects15020112.
DOI: https://doi.org/10.3390/insects15020112

Interpretive Summary: Foraging activity of honey bees is crucial, both in terms of pollination and in terms of honey production, and factors that influence that activity are likewise important. In this study hives were set up with bee counters that counted the rate of bees leaving the hive. The hives were also placed on hive scales, set to record weight every 10 minutes. The entire experiment took place in an almond orchard in California during almond pollination, which is a very important time of year for commercial beekeepers. We found that hive orientation (East or West, because hives are often placed next to North-South roads) and hive strength (strong or weak, using a standard colony assessment) both affected how early the colonies started foraging, with East-facing hives starting earlier than West-facing hives, and strong colonies earlier than weak colonies. Only colony strength affected how late the colonies foraged, with strong colonies foraging later than weak ones. Previous work had shown that data from hive scales can also determine the start and stop of foraging effort, but the bee counter was more sensitive than hive scales in this study. Hive weight gain, after controlling for colony size, was not affected by either orientation or strength in this study, but that may be because there is so much bee forage during almond pollination that in that situation start and stop times do not matter very much.

Technical Abstract: Foraging activity of honey bees used to pollinate almonds was examined in relation to their hive entrance orientation and colony strength. Twenty four colonies of honey bees, twelve in each group, were situated with their entrances facing east and west cardinal points. Bee out-counts were recorded continuously and hive weight data at ~ 10 min intervals from 17 February to 15 March 2023. Colony strength was assessed using frames of adult bees (FOB) metric. East facing hives started flight 44.2 min earlier than west facing hives. Hive direction did not affect the timing of cessation of foraging activity. Hive strength also played a significant role: hives assessed as weak (= 3.0 FOB) commenced foraging activity 45 minutes later than strong hives (> 3.0 FOB), and ceased foraging activity 38.3 minutes earlier. Hive weight data did not detect effects of either hive direction or colony strength on start and stop of foraging activity, as determined using piecewise regression on 24 h datasets. However, hive weight loss due to foraging activity at the start of foraging activity was significantly affected by both direction (East>West) and colony strength (Strong>Weak). Our study showed that during almond pollination both hive entrance exposure and hive strength have quantifiable effects on colony foraging behaviour and that these effects combine to regulate the overall foraging activity of the pollinating colonies