Effect of diet lipids and omega-6:3 ratio on honey bee brood development, adult survival and body composition

The effects of queen mandibular pheromone on nurse-aged honey bee (Apis mellifera) hypopharyngeal gland size and lipid metabolism

Queen honey bees (Apis mellifera) release Queen Mandibular Pheromone (QMP) to regulate traits in the caste of female helpers called workers. QMP signals the queen's presence and suppresses worker reproduction. In the absence of reproduction, young workers take care of the queen and her larvae (nurse tasks), while older workers forage. In nurses, QMP increases lipid stores in abdominal fat tissue (fat body) and protein content in hypopharyngeal glands (HPG). HPG are worker-specific head glands that can synthesize proteinaceous jelly used in colony nourishment. Larger HPG signifies ability to secrete proteinaceous jelly, while shrunken glands characterize foragers that do not make jelly. While it is known that QMP increases abdominal lipid stores, the mechanism is unclear: Does QMP make workers consume more pollen which provides lipids, or does QMP increase lipogenic capacity? Here, we measure abdominal lipogenic capacity as fatty acid synthase (FAS) activity while monitoring abdominal protein content and HPG size in caged workers. Cages allow us to rigorously control worker age, pheromone exposure, and diet. In our 2-factorial design, 3- vs. 8-day-old workers (age factor) were exposed to synthetic QMP or not (pheromone factor) while consuming a lipid deficient diet. We found that QMP did not influence abdominal FAS activity or protein content, but QMP still increased HPG size in the absence of dietary lipids. Our data revealed a positive correlation between abdominal protein content and HPG size. Our findings show that QMP is not a strong modulator of lipogenic capacity in caged worker bees. However, our data may reflect that QMP mobilizes abdominal protein for production of jelly, in line with previous findings on effects of honey bee Brood Pheromone. Overall, our study expands the understanding of how QMP can affect honey bee workers. Such insights are important beyond regulatory biology, as QMP is used in various aspects of beekeeping.

Effects of floral resources on honey bee populations in Mexico: Using dietary metabarcoding to examine landscape quality in agroecosystems

The decline of honey bee populations significantly impacts the human food supply due to poor pollination and yield decreases of essential crop species. Given the reduction of pollinators, research into critical landscape components, such as floral resource availability and land use change, might provide valuable information about the nutritional status and health of honey bee colonies. To address this issue, we examine the effects of landscape factors like agricultural area, urban area, and climatic factors, including maximum temperature, minimum temperature, relative humidity, and precipitation, on honey bee hive populations and nutritional health of 326 honey bee colonies across varying landscapes in Mexico. DNA metabarcoding facilitated the precise identification of pollen from 267 plant species, encompassing 243 genera and 80 families, revealing a primary herb-based diet. Areas characterized by high landscape diversity exhibited greater pollen diversity within the colony. Conversely, colonies situated in regions with higher proportions of agricultural and urban landscapes demonstrated lower bee density. The maximum ambient temperature outside hives positively correlated with pollen diversity, aligning with a simultaneous decrease in bee density. Conversely, higher relative humidity positively influenced both the bee density of the colony and the diversity of foraged pollen. Our national-level study investigated pollen dietary availability and colony size in different habitat types, latitudes, climatic conditions, and varied levels and types of disturbances. This effort was taken to gain a better insight into the mechanisms driving declines in honey bee populations. This study illustrates the need for more biodiverse agricultural landscapes, the preservation of diverse habitats, and the conservation of natural and semi-natural spaces. These measures can help to improve the habitat quality of other bee species, as well as restore essential ecosystem processes, such as pollination and pest control.

Pollen nutrition structures bee and plant community interactions

As bees' main source of protein and lipids, pollen is critical for their development, reproduction, and health. Plant species vary considerably in the macronutrient content of their pollen, and research in bee model systems has established that this variation both modulates performance and guides floral choice. Yet, how variation in pollen chemistry shapes interactions between plants and bees in natural communities is an open question, essential for both understanding the nutritional dynamics of plant-pollinator mutualisms and informing their conservation. To fill this gap, we asked how pollen nutrition (relative protein and lipid content) sampled from 109 co-flowering plant species structured visitation patterns observed among 75 subgenera of pollen-collecting bees in the Great Basin/Eastern Sierra region (USA). We found that the degree of similarity in co-flowering plant species' pollen nutrition predicted similarity among their visitor communities, even after accounting for floral morphology and phylogeny. Consideration of pollen nutrition also shed light on the structure of this interaction network: Bee subgenera and plant genera were arranged into distinct, interconnected groups, delineated by differences in pollen macronutrient values, revealing potential nutritional niches. Importantly, variation in pollen nutrition alone (high in protein, high in lipid, or balanced) did not predict the diversity of bee visitors, indicating that plant species offering complementary pollen nutrition may be equally valuable in supporting bee diversity. Nutritional diversity should thus be a key consideration when selecting plants for habitat restoration, and a nutritionally explicit perspective is needed when considering reward systems involved in the community ecology of pollination.

Lipidomic features of honey bee and colony health during limited supplementary feeding

Honey bee nutritional health depends on nectar and pollen, which provide the main source of carbohydrates, proteins and lipids to individual bees. During malnutrition, insect metabolism accesses fat body reserves. However, this process in bees and its repercussions at the colony level are poorly understood. Using untargeted lipidomics and gene expression analysis, we examined the effects of different feeding treatments (starvation, sugar feeding and sugar + pollen feeding) on bees and correlated them with colony health indicators. We found that nutritional stress led to an increase in unsaturated triacylglycerols and diacylglycerols, as well as a decrease in free fatty acids in the bee fat body. Here, we hypothesise that stored lipids are made available through a process where unsaturations change lipid's structure. Increased gene expression of three lipid desaturases in response to malnutrition supports this hypothesis, as these desaturases may be involved in releasing fatty acyl chains for lipolysis. Although nutritional stress was evident in starving and sugar-fed bees at the colony and physiological level, only starved colonies presented long-term effects in honey production.

Toxicity and sublethal effects of lead (Pb) intake on honey bees (Apis mellifera)

Heavy metal pollution is becoming a worldwide problem affecting pollinators. The massive use of lead (Pb), the most harmful metal for the biosphere, in industries has increased the risk for honey bees. Pb exerts toxicity on living organisms inducing mainly oxidative stress. We assessed the toxicity and sublethal effects of Pb ingestion on protein content, catalase (CAT) activity, fat content and fatty acid (FA) profile of honey bee workers (Apis mellifera L.) under different nutritional conditions during chronic exposure tests. The LD50 was 15.13 ± 6.11 μg Pb2+/bee, similar to other reports. A single oral sublethal dose of 15 μg of Pb2+ affected the survival of bees fed with sugary food for ten days after Pb ingestion while supplementing the diet with bee bread improved Pb tolerance. The highest protein content was found in bees fed with the sugar paste and bee bread diet without Pb. CAT activity tended to decrease in bees of Pb groups independently of diet. Fat content was not affected by the diet type received by bees or Pb ingestion, but the FAs profile varied according to the nutritional quality of the diet. The results highlight that a single sublethal dose of Pb negatively affected the body proteins of bees despite the nutritional condition but did not disturb the FAs profile of workers. Nutrition plays an important role in preventing Pb-induced toxicity in honey bees.

The ecology of nutrient sensation and perception in insects

Insects are equipped with neurological, physiological, and behavioral tools to locate potential food sources and assess their nutritional quality based on volatile and chemotactile cues. We summarize current knowledge on insect taste perception and the different modalities of reception and perception. We suggest that the neurophysiological mechanisms of reception and perception are closely linked to the species-specific ecology of different insects. Understanding these links consequently requires a multidisciplinary approach. We also highlight existing knowledge gaps, especially in terms of the exact ligands of receptors, and provide evidence for a perceptional hierarchy suggesting that insects have adapted their reception and perception to preferentially perceive nutrient stimuli that are important for their fitness.

The fa(c)ts that matter: Bumble bees differentially allocate and oxidate three common fatty acids in pollen

Pollen serves as a crucial source of protein and lipids for numerous insects. Despite the importance of pollen lipids for nutrient regulation in bees, the digestibility and absorption of different fatty acids (FAs) by bees remain poorly understood. We used 13C labeled fatty acids (FAs) to investigate the absorption and allocation of three common dietary FAs in pollen by bumble bees. Palmitic acid, the most common saturated FA in pollen, was poorly absorbed, even when supplied as tripalmitate, emulsified, or mixed in vegetable oil. In contrast, the essential linoleic acid was absorbed and allocated at the highest rate among the three FAs tested. Oleic acid, a non-essential monounsaturated FA, was absorbed and oxidized at lower rates than linoleic acid. Notably, a feeding rate experiment revealed that different fatty acids did not affect the consumption rate of pollen. This results suggests that the specific FA's absorption efficiency and allocation differ in bumble bees, impacting their utilization. These findings demonstrate the importance of considering the digestibility and absorption of different FAs. Furthermore, the study highlights the influence of pollen lipid composition on the nutritional content for pollinators and raises questions about the utilization of polyunsaturated FAs in insect metabolism.

Oleic Acid Promotes the Biosynthesis of 10-Hydroxy-2-decenoic Acid via Species-Selective Remodeling of TAGs in Apis mellifera ligustica

This study aimed to assess the impact of oleic acid (OA) supplementation on the biosynthesis of 10-hydroxy-2-decenoic acid (10-HDA) in Apis mellifera ligustica. In experiment 1, varying concentrations of OA (2%, 4%, 6% and 8%) were added to an artificial diet for newly emerged bees reared in cages. Analysis of 10-HDA content and gene expression in the mandibular gland (MG) revealed that the 8% OA treatment had the greatest impact on promoting the synthesis of 10-HDA. Subsequent investigations utilized RNA-seq and lipidomics to characterize the molecular signature in the MG after feeding the 8% OA diet. Phosphatidylcholine (PC) and triacylglycerol (TAG) were found to be the predominant lipids in the MG of worker bees. A total of 154 TAGs were identified, with TAG (18:1-18:1-18:1) exhibiting the highest abundance, which increased by 1.5 times. The major TAG species contained palmitic acid (16:0) and oleic acid (18:1) in their structure, which was associated with fatty acid composition of diet. The increase in abundance of main TAGs may be attributed to the upregulation of glycerol-3-phosphate acyltransferase (Gpat) and glycerol kinase (GK) gene expression at the transcriptional level. The upregulation of differentially expressed genes (DEGs) related to carbohydrate metabolism may contribute to meeting the heightened metabolic demands of the MGs in worker bees. Royal jelly (RJ) samples from bee colonies fed with the 8% OA diet exhibited higher 10-HDA level than RJ collected from bee colonies fed with the artificial diet. These results indicate that 8% OA addition in the diet enhanced biosynthesis of 10-HDA in the mandibular gland, which was accompanied by significant and highly species-selective remodeling of TAGs.

The survival and growth of honey bee (Hymenoptera: Apidae) colonies overwintered in cold storage: the effects of time and colony location

For over a decade, high percentages of honey bee colonies have been perishing during the winter creating economic hardship to beekeepers and growers of early-season crops requiring pollination. A way to reduce colony losses might be moving hives into cold storage facilities for the winter. We explored factors that could affect the size and survival of colonies overwintered in cold storage and then used for almond pollination. The factors were when hives were put into cold storage and their location prior to overwintering. We found that colonies summered in North Dakota, USA and moved to cold storage in October were larger after cold storage and almond pollination than those moved in November. Colony location prior to overwintering also affected size and survival. Colonies summered in southern Texas, USA and moved to cold storage in November were smaller after cold storage and almond pollination than those from North Dakota. The colonies also were smaller than those overwintered in Texas apiaries. Fat body metrics of bees entering cold storage differed between summer locations. North Dakota bees had higher lipid and lower protein concentrations than Texas bees. While in cold storage, fat bodies gained weight, protein concentrations increased, and lipids decreased. The decrease in lipid concentrations was correlated with the amount of brood reared while colonies were in cold storage. Our study indicates that in northern latitudes, overwintering survival might be affected by when colonies are put into cold storage and that colonies summered in southern latitudes should be overwintered there.

Temporal Changes in Gut Microbiota Composition and Pollen Diet Associated with Colony Weakness of a Stingless Bee

Compared to honeybees and bumblebees, the effect of diet on the gut microbiome of Neotropical corbiculate bees such as Melipona spp. is largely unknown. These bees have been managed for centuries, but recently an annual disease is affecting M. quadrifasciata, an endangered species kept exclusively by management in Southern Brazil. Here we report the results of a longitudinal metabarcoding study involving the period of M. quadrifasciata colony weakness, designed to monitor the gut microbiota and diet changes preceding an outbreak. We found increasing amounts of bacteria associated to the gut of forager bees 2 months before the first symptoms have been recorded. Simultaneously, forager bees showed decreasing body weight. The accelerated growth of gut-associated bacteria was uneven among taxa, with Bifidobacteriaceae dominating, and Lactobacillaceae decreasing in relative abundance within the bacterial community. Dominant fungi such as Candida and Starmerella also decreased in numbers, and the stingless bee obligate symbiont Zygosaccharomyces showed the lowest relative abundance during the outbreak period. Such changes were associated with pronounced diet shifts, i.e., the rise of Eucalyptus spp. pollen amount in forager bees' guts. Furthermore, there was a negative correlation between the amount of Eucalyptus pollen in diets and the abundance of some bacterial taxa in the gut-associated microbiota. We conclude that diet and subsequent interactions with the gut microbiome are key environmental components of the annual disease and propose the use of diet supplementation as means to sustain the activity of stingless bee keeping as well as native bee pollination services.

Developing Strategies to Help Bee Colony Resilience in Changing Environments

Climate change, loss of plant biodiversity, burdens caused by new pathogens, predators, and toxins due to human disturbance and activity are significant causes of the loss of bee colonies and wild bees. The aim of this review is to highlight some possible strategies that could help develop bee resilience in facing their changing environments. Scientists underline the importance of the links between nutrition, microbiota, and immune and neuroendocrine stress resistance of bees. Nutrition with special care for plant-derived molecules may play a major role in bee colony health. Studies have highlighted the importance of pollen, essential oils, plant resins, and leaves or fungi as sources of fundamental nutrients for the development and longevity of a honeybee colony. The microbiota is also considered as a key factor in bee physiology and a cornerstone between nutrition, metabolism, growth, health, and pathogen resistance. Another stressor is the varroa mite parasite. This parasite is a major concern for beekeepers and needs specific strategies to reduce its severe impact on honeybees. Here we discuss how helping bees to thrive, especially through changing environments, is of great concern for beekeepers and scientists.

Lipidomic specializations of honeybee (Apis mellifera) castes and ethotypes

Honeybees of the same colony combine a near-homogeneous genetic background with a high level of phenotypic plasticity, making them ideal models for functional lipidomics. The only external lipid source of the colony is pollen, a diet rich in polyunsaturated fatty acids (PUFA). It has been suggested that differences in exposure to pollen-derived PUFA could partly explain differences in longevity between honeybee castes. We here investigated whether the membrane composition of honeybees plays roles in the physiological adaptation to tasks of individuals within the colony. Membranes of cell heaters, a group of workers producing heat from their flight muscles to uphold brood nest temperature, were compared to those of different types of non-heaters. We found that the lipidomic profiles of these groups fall into clearly different "lipotypes", characterized by chain length and saturation of phospholipid-bound fatty acyl residues. The nutritional exposure to PUFA during early adult life and pupal development at the lower edge of the natural range of brood nest temperature both suppressed the expression of the cell heater-"lipotype". Because cardiolipins (CL) are the lipid class most clearly differentiating honeybee phenotypes, and CL plays central roles in mitochondrial function, dysfunction and aging, our findings could help to understand these processes in other animals and humans. Taken together, the lipidome analysis of different life stages of workers, fertile queens, and drones lead to the hypothesis that honeybee "lipotypes" might represent adaptations to different energetic profiles and the likelihood of exposure to low temperatures.

Characterization of Romanian Bee Pollen—An Important Nutritional Source

Bee pollen represents an important bee product, which is produced by mixing flower pollens with nectar honey and bee’s salivary substances. It represents an important source of phenolic compounds which can have great importance for importance for prophylaxis of diseases, particularly to prevent cardiovascular and neurodegenerative disorders, those having direct correlation with oxidative damage. The aim of this study was to characterize 24 bee pollen samples in terms of physicochemical parameters, organic acids, total phenolic content, total flavonoid content, individual phenolics compounds, fatty acids, and amino acids from the Nort East region of Romania, which have not been studied until now. The bee pollen can be considered as a high protein source (the mean concentration was 22.31% d.m.) with a high energy value (390.66 kcal/100 g). The total phenolic content ranged between 4.64 and 17.93 mg GAE/g, while the total flavonoid content ranged between 4.90 and 20.45 mg QE/g. The high protein content was observed in Robinia pseudoacacia, the high content of lipids was observed in Robinia pseudoacacia pollen, the high fructose content in Prunus spp. pollen while the high F/G ratio was observed in Pinaceae spp. pollen. The high TPC was observed in Prunus spp. pollen, the high TFC was observed in Robinia pseudoacacia pollen, the high free amino acid content was observed in Pinaceae spp. pollen, and the high content of PUFA was reported in Taraxacum spp. pollen. A total of 16 amino acids (eight essential and eight non-essential amino acids) were quantified in the bee pollen samples analyzed. The total content of the amino acids determined for the bee pollen samples varied between 11.31 µg/mg and 45.99 µg/mg. Our results can indicate that the bee pollen is a rich source of protein, fatty acids, amino acids and bioactive compounds.

Assessing pollen nutrient content: a unifying approach for the study of bee nutritional ecology

Poor nutrition and landscape changes are regularly cited as key factors causing the decline of wild and managed bee populations. However, what constitutes 'poor nutrition' for bees currently is inadequately defined. Bees collect and eat pollen: it is their only solid food source and it provides a broad suite of required macro- and micronutrients. Bees are also generalist foragers and thus the different pollen types they collect and eat can be highly nutritionally variable. Therefore, characterizing the multidimensional nutrient content of different pollen types is needed to fully understand pollen as a nutritional resource. Unfortunately, the use of different analytical approaches to assess pollen nutrient content has complicated between-studies comparisons and blurred our understanding of pollen nutrient content. In the current study, we start by reviewing the common methods used to estimate protein and lipids found in pollen. Next, using monofloral Brassica and Rosa pollen, we experimentally reveal biases in results using these methods. Finally, we use our collective data to propose a unifying approach for analysing pollen nutrient content. This will help researchers better study and understand the nutritional ecology-including foraging behaviour, nutrient regulation and health-of bees and other pollen feeders. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Effects of different artificial diets on commercial honey bee colony performance, health biomarkers, and gut microbiota

Background

Honey bee colonies managed for agricultural pollination are highly dependent on human inputs, especially for disease control and supplemental nutrition. Hives are routinely fed artificial “pollen substitute” diets to compensate for insufficient nutritional forage in the environment. The aim of this study was to investigate the effects of different artificial diets in a northern California, US commercial beekeeping operation from August through February. This time period represents an extended forage dearth when supplemental nutrition is used to stimulate late winter colony growth prior to almond pollination in the early spring. A total of 144 honey bee colonies were divided into 8 feeding groups that were replicated at three apiary sites. Feeding groups received commercial diets (Global, Ultra Bee, Bulk Soft, MegaBee, AP23, Healthy Bees), a beekeeper-formulated diet (Homebrew), or a sugar negative control. Diets were analyzed for macronutrient and amino acid content then evaluated with respect to honey bee colony population size, average bee weight, nutrition-related gene expression, gut microbiota abundance, and pathogen levels.

Results

Replicated at three apiary sites, two pollen-containing diets (Global and Homebrew) produced the largest colonies and the heaviest bees per colony. Two diets (Bulk Soft and AP23) that did not contain pollen led to significantly larger colonies than a sugar negative control diet. Diet macronutrient content was not correlated with colony size or health biomarkers. The sum of dietary essential amino acid deficiencies relative to leucine content were correlated with average bee weight in November and colony size used for almond pollination in February. Nutrition-related gene expression, gut microbiota, and pathogen levels were influenced by apiary site, which overrode some diet effects. Regarding microbiota, diet had a significant impact on the abundance of Bifidobacterium and Gilliamella and trended towards effects on other prominent bee gut taxa.

Conclusions

Multiple colony and individual bee measures are necessary to test diet efficacy since honey bee nutritional responses are complex to evaluate. Balancing essential amino acid content relative to leucine instead of tryptophan may improve diet protein efficiency ratios. Optimization of bee diets could improve feed sustainability and agricultural pollination efficiency by supporting larger, healthier honey bee colonies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03151-5.

Nutritive Value of 11 Bee Pollen Samples from Major Floral Sources in Taiwan

Bee pollen is a nutrient-rich food that meets the nutritional requirements of honey bees and supports human health. This study aimed to provide nutritive composition data for 11 popular bee pollen samples (Brassica napus (Bn), Bidens pilosa var. radiata (Bp), Camellia sinensis (Cs), Fraxinus griffithii (Fg), Prunus mume (Pm), Rhus chinensis var. roxburghii (Rc), Bombax ceiba (Bc), Hylocereus costaricensis (Hc), Liquidambar formosana (Lf), Nelumbo nucifera (Nn), and Zea mays (Zm)) in Taiwan for the global bee pollen database. Macronutrients, such as carbohydrates, proteins, and lipids, were analyzed, which revealed that Bp had the highest carbohydrate content of 78.8 g/100 g dry mass, Bc had the highest protein content of 32.2 g/100 g dry mass, and Hc had the highest lipid content of 8.8 g/100 g dry mass. Only the bee pollen Hc completely met the minimum requirements of essential amino acids for bees and humans, and the other bee pollen samples contained at least 1-3 different limiting essential amino acids, i.e., methionine, tryptophan, histidine, valine, and isoleucine. Regarding the fatty acid profile of bee pollen samples, palmitic acid (C_16:0), stearic acid (C_18:0), oleic acid (C_18:1), linoleic acid (C_18:2), and linolenic acid (C_18:3) were predominant fatty acids that accounted for 66.0-97.4% of total fatty acids. These data serve as an indicator of the nutritional quality and value of the 11 bee pollen samples.

Pollen Diet-Properties and Impact on a Bee Colony

Simple Summary

In order to study the effects of malnutrition in bees, attention should be drawn to the dietary composition. A pollen diet plays an important role in the life of bees. A well-balanced diet influences the development of the larvae as well as the physiology, biochemistry, immunity and histology of the workers.

Abstract

Diet is an important factor in the proper development of the individual and the entire colony. A pollen diet affects honey bees in a number of ways. It can stimulate the number and type of hemocytes, the total number of proteins, carbohydrates and lipids, affect the histology of the middle intestine, and ensure the correct ontogenesis of the larvae. Moreover, selected single-flower diets can stimulate the development of the pharyngeal glands that produce royal jelly, thus conditioning the development of secretory immunity. Selected single-species pollen may also increase the phenol oxidase concentration, which contributes to the humoral response. A honey bee diet based on multi-flower pollen is more desirable than a mono-flower diet, but must be properly balanced.

The Importance of Time and Place: Nutrient Composition and Utilization of Seasonal Pollens by European Honey Bees (Apis mellifera L.)

Simple Summary

Honey bees rely on pollen and nectar to provide nutrients to support their yearly colony cycle. Specifics of the cycle differ among geographic regions as do the species of flowering plants and the nutrients they provide. We examined responses of honey bees from two different queen lines fed pollens from locations that differed in floral species composition and yearly colony cycles. We detected differences between the queen lines in the amount of pollen they consumed and the size of their hypopharyngeal glands (HPG). There were also seasonal differences between the nutrient composition of pollens. Spring pollens collected from colonies in both locations had higher amino and fatty acid concentrations than fall pollens. There also were seasonal differences in responses to the pollens consumed by bees from both queen lines. Bees consumed more spring than fall pollen, but digested less of it so that bees consumed more protein from fall pollens. Though protein consumption was higher with fall pollen, HPG were larger in spring bees.

Abstract

Honey bee colonies have a yearly cycle that is supported nutritionally by the seasonal progression of flowering plants. In the spring, colonies grow by rearing brood, but in the fall, brood rearing declines in preparation for overwintering. Depending on where colonies are located, the yearly cycle can differ especially in overwintering activities. In temperate climates of Europe and North America, colonies reduce or end brood rearing in the fall while in warmer climates bees can rear brood and forage throughout the year. To test the hypothesis that nutrients available in seasonal pollens and honey bee responses to them can differ we analyzed pollen in the spring and fall collected by colonies in environments where brood rearing either stops in the fall (Iowa) or continues through the winter (Arizona). We fed both types of pollen to worker offspring of queens that emerged and open mated in each type of environment. We measured physiological responses to test if they differed depending on the location and season when the pollen was collected and the queen line of the workers that consumed it. Specifically, we measured pollen and protein consumption, gene expression levels (hex 70, hex 110, and vg) and hypopharyngeal gland (HPG) development. We found differences in macronutrient content and amino and fatty acids between spring and fall pollens from the same location and differences in nutrient content between locations during the same season. We also detected queen type and seasonal effects in HPG size and differences in gene expression between bees consuming spring vs. fall pollen with larger HPG and higher gene expression levels in those consuming spring pollen. The effects might have emerged from the seasonal differences in nutritional content of the pollens and genetic factors associated with the queen lines we used.