ArticlePDF Available

Adult longevity of workers of the bumble bees Bombus fervidus (F.) and Bombus pennsylvanicus (De Geer) (Hymenoptera: Apidae)

Authors:

Abstract and Figures

We studied worker longevity in two colonies of Bombus fervidus (F.) and two colonies of Bombus pennsylvanicus (De Geer). In 1981, adult life expectation for B. fervidus workers was 21.8 days. In 1982, mean expectation of life at adult emergence was 34.1 days for workers of B. fervidus and 33.0 days for workers of B. pennsylvanicus. The longevities observed in 1982 are the highest yet recorded for temperate bumble bee species, and are intermediate between the previously described extremes of short life-span in north temperate species and high longevity in a tropical species. This study suggests that bumble bee life expectancy tends to decrease as one progresses northward. However, variation in life expectancy within B. fervidus at a single location in two consecutive years was almost as great as previously described differences in longevity between tropical and temperate species. Shortened life-span may therefore be associated with increased intensity of foraging activity during periods of low forage availability as well as with latitude. In both years, survivorship of late-emerging worker cohorts was consistently low, possibly because a larger proportion of late-emerging workers become foragers.
Content may be subject to copyright.
A preview of the PDF is not available
... Furthermore, demonstrated that honey bee gut microbiotas can remain disturbed for up to four weeks after Roundup R exposure, though it is possible that bees were still being exposed during this time due to pesticide accumulation in hive materials. As adult worker bees generally live around 30-40 days (though longevity varies widely between species and individuals) (Free and Spencer-Booth 1959;Fukuda and Sekiguchi 1966;Goldblatt and Fell 1986;Giannini 1997;Smeets et al. 2003;Gomes, Menezes and Contrera 2015), these disturbance durations can represent a significant portion of an adult bee's life span. On the other hand, some evidence suggests that bee gut microbiotas can recover quickly from disturbance. ...
Article
Social bee gut microbiotas play key roles in host health and performance. Worryingly, a growing body of literature shows that pesticide exposure can disturb these microbiotas. Most studies examine changes in taxonomic composition in Western honey bee (Apis mellifera) gut microbiotas caused by insecticide exposure. Core bee gut microbiota taxa shift in abundance after exposure but are rarely eliminated, with declines in Bifidobacteriales and Lactobacillus near melliventris abundance being the most common shifts. Pesticide concentration, exposure duration, season and concurrent stressors all influence whether and how bee gut microbiotas are disturbed. Also, the mechanism of disturbance-i.e. whether a pesticide directly affects microbial growth or indirectly affects the microbiota by altering host health-likely affects disturbance consistency. Despite growing interest in this topic, important questions remain unanswered. Specifically, metabolic shifts in bee gut microbiotas remain largely uninvestigated, as do effects of pesticide-disturbed gut microbiotas on bee host performance. Furthermore, few bee species have been studied other than A. mellifera, and few herbicides and fungicides have been examined. We call for these knowledge gaps to be addressed so that we may obtain a comprehensive picture of how pesticides alter bee gut microbiotas, and of the functional consequences of these changes.
... We modeled the influence of landscape variables on the morphology (thorax, wing, head, tibia) and dry weight of bumble bee workers using linear mixed models. All models included Julian date as a potential confounding variable given that workers' size varies through the course of the season [82]. Site (quad) identity was included as a random factor in all models. ...
Article
Full-text available
Bumble bee communities are strongly disrupted worldwide through the population decline of many species; a phenomenon that has been generally attributed to landscape modification, pesticide use, pathogens, and climate change. The mechanisms by which these causes act on bumble bee colonies are, however, likely to be complex and to involve many levels of organization spanning from the community down to the least understood individual level. Here, we assessed how the morphology, weight and foraging behavior of individual workers are affected by their surrounding landscape. We hypothesized that colonies established in landscapes showing high cover of intensive crops and low cover of flowering crops, as well as low amounts of local floral resources, would produce smaller workers, which would perform fewer foraging trips and collect pollen loads less constant in species composition. We tested these predictions with 80 colonies of commercially reared Bombus impatiens Cresson placed in 20 landscapes spanning a gradient of agricultural intensification in southern Québec, Canada. We estimated weekly rate at which workers entered and exited colonies and captured eight workers per colony over a period of 14 weeks during the spring and summer of 2016. Captured workers had their wing, thorax, head, tibia, and dry weight measured, as well as their pollen load extracted and identified to the lowest possible taxonomic level. We did not detect any effect of landscape habitat composition on worker morphology or body weight, but found that foraging activity decreased with intensive crops. Moreover, higher diversity of local floral resources led to lower pollen constancy in intensively cultivated landscapes. Finally, we found a negative correlation between the size of workers and the diversity of their pollen load. Our results provide additional evidence that conservation actions regarding pollinators in arable landscapes should be made at the landscape rather than at the farm level.
... Bumble bee species vary in their nesting behaviors (Hobbs et al. 1962, Macfarlane et al. 1994, Knight et al. 2005, basic reproductive parameters (Asada andOno 2000, Cnaani et al. 2002), and life expectancy (Goldblatt and Fell 1987). Within the same species, preexperiment commercial-animal husbandry practices and colony quality (e.g., queen status, colony age, colony strength, colony life stage, disease status) vary, potentially impacting data interpretation and study reproducibility. ...
Article
Bumble bees provide valuable pollination services to many wild and agricultural plants. Populations of some bumble bee species are in decline, prompting the need to better understand bumble bee biology and to develop methodologies for assessing the effects of environmental stressors on these bees. Use of bumble bee microcolonies as an experimental tool is steadily increasing. This review closely examines the microcolony model using peer-reviewed published literature identified by searching three databases through November 2018. Microcolonies have been successfully used for investigating a range of endpoints including behavior, the gut microbiome, nutrition, development, pathogens, chemical biology, and pesticides/xenobiotics. Methods for the initiation and monitoring of microcolonies, as well as the recorded variables were catalogued and described. From this information, we identified a series of recommendations for standardizing core elements of microcolony studies. Standardization is critical to establishing the foundation needed to support use of this model for biological response investigations and particularly for supporting use in pesticide risk assessment.
... The size variation arises due to differential feeding during development (Couvillon and Dornhaus 2009; Kelemen and Dornhaus 2018) enabling us to compare how body mass relates metabolic rate and lifespan. Additionally, bumble bee colonies can be maintained easily under laboratory conditions thereby allowing workers to be tracked over their lifespan (an average of 22-69 days depending on species; Goldblatt and Fell 1987;Smeets and Duchateau 2003;Karise et al. 2016) and eliminating effects due to extrinsic mortality factors (Ricklefs 2001). ...
... A side note unrelated to the focus of the study is that the marked worker on the Abelia was observed 23 days after its initial capture and release, which indicates that foraging workers can live for at least three weeks. Earlier studies (Goldblatt & Fell, 1987;Rodd, Plowright, & Owen, 1980;da Silva-Matos & Gar ofalo, 2000) have examined longevity of bumble bee workers that remain in colonies but little is known of foraging worker longevity due to the challenges of tracking workers in flight. The expectation is that foragers will not live as long as workers that remain in the nest due to exposure to diverse risks. ...
Article
Bumble bees are believed to minimize travel distance and time while seeking foraging resources, and to memorize landmarks and return to forage patches visited earlier. Given these abilities, if a worker is displaced, will it switch to a new forage resource close by or will it navigate back to the original forage patch? To address this question we collected 210 Bombus vosnesenskii workers from an ornamental Spirea patch, marked them with numbered tags, transported them in a cooler, and released them at seven distances, from 1.5 km to 16 km, in each of two directions. Each worker that returned to the Spirea patch was recaptured, and re-released at its first release location. Over 8 observation days, 54 workers from 11 release locations returned to the Spirea patch. Of these, 16 were recaptured twice, 13 three times, 5 four times and 1 five times. Nine workers returned from release distances ≥10 km, including one from 16 km, despite the presence of multiple rewarding resources between the release location and the Spirea patch. Returns were rapid—three workers released up to 5 km away were recaptured within 4 h, while a worker from 13 km returned within 30 h of release. Wind direction, wind speed, and release direction had significant (P < 0.05) impacts on release-to-recapture-times. Also, workers returned significantly (P < 0.001) more quickly during subsequent trips compared to their first return. These findings highlight the ability of displaced bumble bee workers to travel long distances, and to navigate back to familiar forage patches.
... The size variation arises due to differential feeding during development (Couvillon and Dornhaus 2009;Kelemen and Dornhaus 2018) enabling us to compare how body mass relates metabolic rate and lifespan. Additionally, bumble bee colonies can be maintained easily under laboratory conditions thereby allowing workers to be tracked over their lifespan (an average of 22-69 days depending on species; Goldblatt and Fell 1987;Smeets and Duchateau 2003;Karise et al. 2016) and eliminating effects due to extrinsic mortality factors (Ricklefs 2001). ...
Article
Full-text available
The rate of living theory posits that higher metabolic rates negatively affect lifespan. This relationship would influence trade-offs among life history traits associated with energy production and allocation. These trade-offs may also apply within a species, resulting in differences among individuals in life history traits. In this study, we use the bumble bee Bombus impatiens to test for a relationship between metabolic rate and lifespan. We measured the resting metabolic rates of workers throughout their lives and noted their lifespans in the laboratory. Our results show that (1) resting metabolic rate inversely correlated with potential lifespan and (2) resting metabolic rate was not affected by age. These results suggest that within a species, individual differences in life-history trade-offs may exist as predicted by the rate of living theory.
... We assume a typical life span of workers in both groups of about 30 days yielding a mortality rate μ w of about 0.03/day. For bumble bee species, Goldblatt and Fell (1987) and 4 weeks. However, it might even be shorter when the foraging period is interrupted by pronounced activity breaks (Weissel, Mitesser, Liebig, Poethke, & Strohm, 2006). ...
Article
1.Empirical studies of annual eusocial insects in agricultural landscapes report contrasting findings with regard to colony responses to mass flowering of crops like oilseed rape. In particular, total sexual production is often unaffected by such events whereas worker number responds with a prominent increase 2.To resolve these conflicting observations we model – using an established approach – the expected change in worker and sexual numbers in response to an increased worker productivity induced by mass flowering events at different times of the season. 3.We find that the predicted response pattern is mainly shaped by the degree to which individual worker productivity is reduced by an increasing number of workers in the colony. Different environmental conditions and colony characteristics result in different levels of interference of workers, e.g. during foraging or nest construction. Reduction of individual productivity is low, when worker interference is negligible (“weak limitation”), and high when an increasing number of workers substantially decreases per‐capita efficiency (“strong limitation”). For weak limitation, any mass flowering event that ends before the production of sexuals starts has a strong multiplicative impact on both worker and sexual numbers. The magnitude of the effect is quite independent of the precise timing of such an event. After the onset of sexual production, mass flowering has a weaker effect, as the added resource supply is only linearly transferred into production of additional sexuals. 4.For colonies under strong limitation, the predicted impact of mass flowering events is generally weaker, especially on the production of sexuals, and the timing of mass flowering events becomes more influential: Production of sexuals profits more from late than from early mass flowering events. Consequently, early mass flowering events are predicted to have a prominent effect on worker numbers but a negligible one on the output of sexuals. 5.The model presented provides a mechanistic explanation of why increased worker abundances does not necessarily translate into increased production of sexuals. The model is also applicable to other eusocial insects like paper wasps whenever brief pulses of massive resource availability shortly elevate resource intake rates above the ‘normal’ levels. This article is protected by copyright. All rights reserved.
Article
Wild bees can be essential pollinators in natural, agricultural, and urban systems, but populations of some species have declined. Efforts to assess the status of wild bees are hindered by uncertainty in common sampling methods, such as pan traps and aerial netting, which may or may not provide a valid index of abundance across species and habitats. Mark-recapture methods are a common and effective means of estimating population size, widely used in vertebrates but rarely applied to bees. Here we review existing mark-recapture studies of wild bees and present a new case study comparing mark-recapture population estimates to pan trap and net capture for four taxa in a wild bee community. Net, but not trap, capture was correlated with abundance estimates across sites and taxa. Logistical limitations ensure that mark-recapture studies will not fully replace other bee sampling methods, but they do provide a feasible way to monitor selected species and measure the performance of other sampling methods.
Article
Full-text available
Background Glyphosate is the world’s most used pesticide and it is used without the mitigation measures that could reduce the exposure of pollinators to it. However, studies are starting to suggest negative impacts of this pesticide on bees, an essential group of pollinators. Accordingly, whether glyphosate, alone or alongside other stressors, is detrimental to bee health is a vital question. Bees are suffering declines across the globe, and pesticides, including glyphosate, have been suggested as being factors in these declines. Methods Here we test, across a range of experimental paradigms, whether glyphosate impacts a wild bumble bee species, Bombus terrestris . In addition, we build upon existing work with honey bees testing glyphosate-parasite interactions by conducting fully crossed experiments with glyphosate and a common bumble bee trypanosome gut parasite, Crithidia bombi . We utilised regulatory acute toxicity testing protocols, modified to allow for exposure to multiple stressors. These protocols are expanded upon to test for effects on long term survival (20 days). Microcolony testing, using unmated workers, was employed to measure the impacts of either stressor on a proxy of reproductive success. This microcolony testing was conducted with both acute and chronic exposure to cover a range of exposure scenarios. Results We found no effects of acute or chronic exposure to glyphosate, over a range of timespans post-exposure, on mortality or a range of sublethal metrics. We also found no interaction between glyphosate and Crithidia bombi in any metric, although there was conflicting evidence of increased parasite intensity after an acute exposure to glyphosate. In contrast to published literature, we found no direct impacts of this parasite on bee health. Our testing focussed on mortality and worker reproduction, so impacts of either or both of these stressors on other sublethal metrics could still exist. Conclusions Our results expand the current knowledge on glyphosate by testing a previously untested species, Bombus terrestris , using acute exposure, and by incorporating a parasite never before tested alongside glyphosate. In conclusion our results find that glyphosate, as an active ingredient, is unlikely to be harmful to bumble bees either alone, or alongside Crithidia bombi .
Article
Conditions experienced early in development can affect the future performance of individuals and populations. Demographic theories predict persistent population impacts of past resources, but few studies have experimentally tested such carry‐over effects across generations or cohorts. We used bumble bees to test whether resource timing had persistent effects on within‐colony dynamics over sequential cohorts of workers. We simulated a resource pulse for field colonies either early or late in their development and estimated colony growth rates during pulse‐ and non‐pulse periods. During periods when resources were not supplemented, early‐pulse colonies grew faster than late‐pulse colonies; early‐pulse colonies grew larger as a result. These results reveal persistent effects of past resources on current growth and support the importance of transient dynamics in natural ecological systems. Early‐pulse colonies also produced more queen offspring, highlighting the critical nature of resource timing for the population, as well as colony, dynamics of a key pollinator.
Article
Full-text available
Survivorship data were obtained for a cohort of 274 individually marked workers of the bumble bee Bombus terricola Kirby. The mortality rate was very nearly constant for the first 14 days of adult life, after which it increased sharply. Environmental hazards, including predation, are considered the most probable causes of death, supplemented by the effects of wear and tear as the insects grow old. The life expectancy for a newly emerged adult worker bee was estimated at 13.2 days. The results, together with those of other studies, are discussed with reference to differences in mortality rates between temperate and tropical bumble bee species.
Article
Workers in the colony under observation were classified into three groups according to behaviour: foragers, house-bees, foragers, house-bees. Measurement (of wing length) showed that house-bees and foragers/house-bees were smaller than most foragers. The mean length of life was 72·6, 69·7 and 36·4 days for house-bees, foragers/house-bees and foragers respectively. The survival curves were convex for house-bees and foragers/house-bees and concave for foragers.
Article
Colonies founded by wild-caught queens were reared at either 15 C with or without an insulated nest or at 25 C for the duration of the colony cycle. Brood-maintenance and brood-incubation behaviors, brood () and nest-chamber () temperatures, and the number of bees produced were monitored. The total number of foragers was relatively fixed in young colonies. The occurrence of brood incubation varied inversely with population size and was highest at low ambient temperature (). In contrast, the occurrence of brood maintenance varied directly with population and was highest at high . All colonies had produced their maximum number of workers and started producing reproductives at 9-10 wk after the emergence of the first workers of the colony. The numbers of bees produced per colony at 15 C with insulation and at 25 C were similar. Uninsulated colonies at 15 C produced fewer bees and maintained lower . These findings suggest that low may limit population growth but has no apparent effect on the timing of events during the colony life cycle.
Article
1. The behaviour of workers marked individually has been studied in four observation nests of B. agrorum. 2. Both large and small workers foraged and undertook house duties; the apparent division of labour previously noted results from the later age at which small workers begin to forage, about 15 days from emergence as against 5 days for the large workers. 3. By manipulation of colonies it was found that neither absence of foraging bees nor absence of nectar caused the small house-bees to begin foraging. It was therefore considered to be a matter of ontogeny. 4. The longevity of the workers was variable, 69 days being the maximum recorded. On the average 29% of the bees died every 5 days. House-bees lived slightly longer than foragers, particularly in a bad season. 5. About two-thirds of the total bee population were house-bees and one-third foragers at any particular time. 6. No trend in duties with age was observed in the house-bees, foragers, when in the nest, performing a variety of house duties. 7. The larger foragers collected pollen and nectar, 75% of pollen loads being accompanied by nectar. The smaller foragers tended to collect nectar only. 8. In all, 665 foraging trips were timed, the averages for two nests being 17.5 and 15.3 min. Pollen loads with or without nectar took longer to collect than nectar loads alone and loads were collected faster in damp weather than in dry. 9. Pollen loads from one nest were collected and identified. Out of 120 loads, sixty-seven were mixtures of from two to six plant species. The pollen collection of individual workers indicated moderately fixed foraging habits. 10. Normally the workers behaved indifferently towards each other but on a very few occasions attacks were observed in which the attacked bee was forced to disgorge liquid or leave the nest. The attacker was always a house-bee, the attacked a forager. A comparison with the dominance order in Polistes wasps is made.
Article
In laboratory colonies, 8 temperate Bombus Latreille species and the tropical montane species, B. ephippiatus Say, had significantly more first-brood workers, more rapid worker development time, and faster rates of worker production than the tropical lowland species, B. atratus Franklin. Bombus ephippiatus did not differ from most temperate species in any of the 3 characters. Differences in these bionomic characters among arctic, temperate, and tropical Bombus are assessed in terms of latitudinal trends.
Article
1. Most of the workers of a bumblebee colony are either consistent foragers or house-bees but about a third of the workers are inconsistent to either duty. The longer a worker has been carrying out either household or foraging duties the more ‘fixed’ it becomes to the duty concerned. 2. Individual workers will change their occupation and perform either household or foraging duties in accordance with the current requirements of their colonies. 3. Foragers show great constancy to the collection of either pollen loads or nectar loads during consecutive trips, but they show little constancy for periods of a day or over. 4. The amount of pollen which the foragers of a colony collect is related to the presence of larvae in their nest. 5. The type of food collected by foragers is also determined to some extent by the nature of their colonies' food-stores.
Article
The life span of worker-honeybees is determined by the duration of the hive-period and of the foraging period (Figs. 1,2). The duration of the forgaing period is regulated in the following way: Total flight performance of the individual bee seems to be fixed. Daily flight performance strongly affects total flight duration. High daily flight performance decreases maximal flight duration and vice versa. Foragers accumulate the highest glycogen reserves in the flight muscles compared to other stages (Figs. 3, 4). They use these reserves to overcome starvation or when growing old. Young foragers are able to restore glycogen reserves after sugar intake, whereas old foragers were found to have a reduced glycogen synthesizing ability (Fig. 5). The results indicate that bees exhaust their energysupplying mechanisms after a definite total flight performance.
Article
The ecology of bumblebees has been discussed under two major headings: (1) floral hosts and (2) populations. An understanding of the environmental factors that (1) affect the behavior of bumblebees in visiting flowers and (2) influence the production of a worker field force are basic to the utilisation of bumblebees in a practical way for the increased pollination, or more consistent pollination of alfalfa and red clover seed crops. Information is presented about the host plants in their seasonal succession, and the attractiveness of various flowers during the period of worker activity. Certain species of bumblebees are shown to differ in their preference of red clover and alfalfa. The initiation of colonies, the proper development of the brood, and the production of the workers have been related with ecological factors having major influence. Optimum conditions will be required for the culmination of a colony in a maximum force of worker bees at peak availability for pollination. Worker populations vary widely between species and among colonies of the same species. An elucidations of the reasons for the fluctuations will require additional biological and ecological research.
Division of labour and foraging in Bombus agrorum Fabricius
BRIAN, A. D. 1952. Division of labour and foraging in Bombus agrorum Fabricius. J. Anim. Ecol. 21: 223-240.