Data from: Adapting overwintering honey bee (<i>Apis mellifera</i> L.) colony management in response to warmer fall temperatures associated with climate change

<p dir="ltr">The data represent estimates of honey bee colony sizes expressed as combs (frames) of adult bees and combs of brood (eggs, larvae and pupae). Colony sizes were estimated by dividing combs into one-tenth sections and counting the number covered with bees or brood on both sides of a comb. The values from each comb were summed and used as an estimate of combs with bees or brood for each colony. During pre-cold storage measurement in October, colonies were comprised of two deep Langstroth hive boxes. Temperatures were below 10<sup>o </sup>C so the one-tenth of the comb area method for comb evaluations was not used. Instead, estimates of adult bee populations were made by tilting the top hive body forward on the pallet and frames with at least 75% bee coverage on the top and bottom of the comb were counted as a comb of bees. In the lower hive body, adult populations were estimated from adult bees covering the top of the combs. Combs with bees were totaled for the colony as an estimate of colony size. Estimates of Varroa mites (<i>Varroa destructor </i>Anderson & Trueman) per 100 adult bees were made using approximately 300 worker bees per colony that were brushed from brood comb into jars containing 50 ml of 70% ethanol. Mites were counted by vigorously shaking the sample jars, and pouring the bees and alcohol into a strainer positioned over a pan. The mites that went through the strainer and into the pan were counted. Bees in the strainer also were examined for mites. All the bees in the sample were counted to estimate mites per 100 bees. Nosema (<i>Vairimorpha </i>(Microsporidia: Nosematidae) spore counts per colony were based on samples of 20 bees per colony. Samples were placed in a test tube containing ultra-pure water and homogenized for 5s. Samples equilibrated in 30-60 s, and the supernatant was removed from the center of the sample in the test tube (clear area) and placed into a 1.5ml Eppendorf tube. Spores per colony was estimated by transferring a 15 µl sample of supernatant to a hemocytometer, and examining it using a compound microscope at 400x with phase-contrast lighting. <i>Nosema</i> spores were counted in 16 small squares within five larger squares. The final spore count was calculated by multiplying the hemocytometer counts by 50,000. Fat body metrics (weight and lipid and protein concentrations) are based on pooled samples of 10 bees per colony. Fat bodies were removed by placing an adult worker bee onto a block of dry ice, and removing the abdomen. The entire gut was removed and the remaining abdominal carcass with fat body attached was rinsed to remove remaining gut contents and blotted dry. Fat body weight was estimated after drying the abdominal carcass at 60<sup>o</sup>C for four days. Fat body protein concentration was estimated with a BCA Protein Assay kit. Samples were analyzed in triplicate and read in a microplate reader at a wave length of 562nm. The absorbance values of blank wells were subtracted from each standard and sample. Protein concentration (µg/µl) was estimated using the absorbance and standard curve. Lipid concentrations were estimated by placing the fat body sample into a tube containing a 2:1 mixture of chloroform:methanol (1 ml) along with 210 µl of 0.25% KCI. The sample was vortexed, and centrifuged at 2,000 rpm for 15 min. The bottom chloroform layer was removed and placed into a 2ml glass screw cap vial. Serial dilutions of corn oil dissolved in chloroform were prepared to construct a standard curve for lipid concentrations. The negative control consisted of 100 µl of chloroform. Samples, standards, and the negative control were dried to completion for approximately 1.5h. Dried samples were reacted with 182 µl of concentrated sulfuric acid at 100<sup>o</sup>C for 15 min and 1478 µl of vanillin-phosphoric acid for 15 min in the dark at room temperature. Each of the negative controls, standards, and samples (100µl) were plated in triplicate and read using a spectrophotometer at 525nm. The average absorbance value for the negative control was subtracted from each standard and sample. A linear equation of the standards was derived to infer the µg/µl of lipid per sample from the absorbance values.</p>

Tags: almond-pollination, climate-change, cold-storage, fat-body, grand-challenge, honey-bee, insect-nutrition, lipid, overwintering, queen, varroa, varroa-resistant-russian-bees
Organization: Department of Agriculture