DOI: 10.5061/dryad.fqz612k0x
title: Data from: Mechanisms for polyandry evolution in a complex social bee

description: Polyandry in social Hymenoptera is associated with reduced within-colony
 relatedness and increased colony-level ecologic fitness. One explanation
 for this sees increasing within-nest genetic diversity as a mechanism for
 improving group task efficiency and colony competitiveness. A queen on her
 mating flight captures nearly 90% of her breeding population’s allele
 potential by her tenth effective mating (me~10 males). Under this
 population allele capture (PAC) model, colony fitness gains track mating
 number in an asymptotic manner, leveling out after about the tenth mating.
 A supporting theory we call the genotype composition (GC) model sees
 genetic novelty at mating levels higher than the me~10 asymptote, the
 hyperpolyandry zone, resulting from unique genotype compositions whose
 number are potentially infinite. Colony fitness gains under the GC model
 will track mating number in a linear manner. We set up field colonies with
 Apis mellifera queens each instrumentally mated with 1, 2, 4, 8, 16, or 32
 males, creating a polyandry gradient bracketing the qualitative divide of
 me~10, measured tokens of colony level fitness, and collected observation
 hive data. Our results lead us to conclude that (1) ancestral colony
 traits fundamental to eusociality (cooperative brood care) respond to
 mating level changes at or below me~10 in a manner consistent with the PAC
 model, whereas (2) more derived specialized colony phenotypes (resistance
 to the non-native parasite Varroa destructor) continue improving with
 increasing me in a manner consistent with the GC model. By either model,
 (3) the mechanism for increasing colony fitness is an increase in worker
 task specialisms and task efficiency.
description: <strong>Brood production and parasite
 numbers</strong><br>Holistic colony strength measures,
 considered proxies for fitness, were taken at roughly monthly intervals in
 Jun, Jul, Aug, Sep, and Oct 2019. Brood area was
 derived by visually summing proportions of whole deep frames covered by
 brood (Delaplane et al. 2013) and converting frames of brood to cm2 by the
 observation that one deep Langstroth comb (both sides) = 1760
 cm2. Relative numbers of parasitic Varroa destructor
 mites were found by inserting sticky sampling sheets into bottom board
 hive inserts and recording the number of Varroa mites trapped after 24
 hours (Dietemann et al. 2013). <strong>Worker
 task distributions</strong><br>In Mar 2020, we removed combs
 of emerging brood from one overwintered experimental field colony whose
 queen was mated at the mo=16 level and from another colony whose queen was
 mated at the mo=32 level. These were the only two surviving colonies with
 enough brood to perform the experiment. These combs were labeled by colony
 of origin, bagged individually, and kept overnight in an incubator at
 35°C. The next morning, 100 newly emerged worker bees from each colony
 were individually numbered with thoracic tags (Mann Lake) color-coded by
 colony of origin, and all 200 workers introduced to one observation bee
 hive (day=0) with a non-experimental open-mated queen and 311 of her
 daughter workers whose number was estimated from a photograph. The
 resident workers were therefore surrogate hosts to two embedded cohorts
 for whom we have knowledge of mo. The disadvantage of this arrangement is
 that it is devoid of the complexity of thigmotaxic and social cues that
 govern polyandry effects in a normal whole colony. The advantage is that
 it allows us to compare how different polyandry levels can capture and
 express specialisms in a common experimental environment. The comb in the
 observation hive was 1-sided to restrict bees to one surface and ease
 observations. Beginning on day=1 (27 Mar 2020) and for 18 more days until
 14 Apr 2020 one investigator, naïve to the bee labeling designations,
 observed the marked cohort through the glass for 15 min and recorded each
 incidence when a focal bee performed one of 18 unambiguously identifiable
 behaviors: tending queen, watching recruitment dance, dancing,
 administering vibration dance, receiving vibration dance, shaping
 cappings, shaping cell edges, receiving grooming, autogrooming,
 allogrooming, pollen foraging (possessing pollen on its corbiculum),
 building comb, fanning entrance, engaging in trophallaxis, capping cells,
 cleaning emerged brood cells, trimming cappings, and antennating another
 bee.
description: # Data from: Mechanisms for polyandry evolution in a complex social bee
 [https://doi.org/10.5061/dryad.fqz612k0x](https://doi.org/10.5061/dryad.fqz612k0x) Two datasets are attached: (1) Delaplane et al. 2024 BEAS colony strength data and (2) Delaplane et al. 2024 BEAS observation hive data/ ## Description of the data and file structure Column identifiers for "Delaplane et al. 2024 BEAS colony strength data" 1. A, timepoint. Each of five colony sampling episodes at roughly monthly intervals, June, July, August, September, October, numbered consecutively 1-5. Data were collected from all surviving colonies at each timepoint. 2. B, unique field colony identifier 3. C, polyandry treatment of queen. Each was instrumentally inseminated with the semen of 1, 2, 4, 8, 16, or 32 males. 4. D, unique queen identifier with colored plastic thoracic disks 5. E, 24-hr colony counts of parasitic *Varroa destructor* mites on hive bottom board sticky sheets 6. F, colony area (cm2) of brood, all stages Column identifiers for "Delaplane et al. 2024 BEAS observation hive data" 1. A, date of observation 2. B, experimental day 3. C, field study source colony for labeled experimental young bee cohort 4. D, polyandry treatment of queen. In this experiment this value was limited to polyandry=16 or 32 males. Only these two source colonies survived over winter from the field study and were available for the observation hive study. 5. E, unique color label for bee cohort. All workers from field colony 49 (poly=16) were marked blue, and all workers from field colony 33 (poly=32) were marked white. 6. F, unique bee number within cohort (thoracic labels are both colored and numbered) 7. G, patriline ID, genotyping never completed 8. H, sum of behaviors reported for focal bee/day 9. Columns I-L, for several variables we attempted to observe location in the observation hive where focal bee was observed. These abbreviations here and elsewhere are SBr (on sealed brood), OpHon (on open cells of honey), OpBr (on open brood), or EOE (empty cell on edge of nest). For the published paper we only analyzed summed behaviors across hive locations so that, for instance, we used and reported "daily sum of observed instances of focal bee tending queen" in column M, constituting the sum for that bee/day of columns I-L. This convention follows hereafter. Other variables were recorded without regard to location or only occurred in one location and omit the marker "SUM" (for instance, AE). Yellow highlighted columns N-onward correspond to the 18 objectively observable (ie., we didn't try to guess what "bee with head inside cell" was doing) behaviors named and analyzed in the paper.