scholarly journals The sensitivity of a honeybee colony to worker mortality depends on season and resource availability

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Natalie J. Lemanski ◽  
Siddhant Bansal ◽  
Nina H. Fefferman

Abstract Background Honeybees have extraordinary phenotypic plasticity in their senescence rate, making them a fascinating model system for the evolution of aging. Seasonal variation in senescence and extrinsic mortality results in a tenfold increase in worker life expectancy in winter as compared to summer. To understand the evolution of this remarkable pattern of aging, we must understand how individual longevity scales up to effects on the entire colony. In addition, threats to the health of honey bees and other social insects are typically measured at the individual level. To predict the effects of environmental change on social insect populations, we must understand how individual effects impact colony performance. We develop a matrix model of colony demographics to ask how worker age-dependent and age-independent mortality affect colony fitness and how these effects differ by seasonal conditions. Results We find that there are seasonal differences in honeybee colony elasticity to both senescent and extrinsic worker mortality. Colonies are most elastic to extrinsic (age-independent) nurse and forager mortality during periods of higher extrinsic mortality and resource availability but most elastic to age-dependent mortality during periods of lower extrinsic mortality and lower resource availability. Conclusions These results suggest that seasonal changes in the strength of selection on worker senescence partly explain the observed pattern of seasonal differences in worker aging in honey bees. More broadly, these results extend our understanding of the role of extrinsic mortality in the evolution of senescence to social animals and improve our ability to model the effects of environmental change on social insect populations of economic or conservation concern.

2020 ◽  
Author(s):  
Natalie J Lemanski ◽  
Siddhant Bansal ◽  
Nina H Fefferman

Abstract Background: Honeybees have extraordinary phenotypic plasticity in their senescence rate, making them a fascinating model system for the evolution of aging. Seasonal variation in senescence and extrinsic mortality results in a tenfold increase in worker life expectancy in winter as compared to summer. To understand the evolution of this remarkable pattern of aging, we must understand how individual longevity scales up to effects on the entire colony. In addition, threats to the health of honey bees and other social insects are typically measured at the individual level. To predict the effects of environmental change on social insect populations, we must understand how individual effects impact colony performance. We develop a matrix model of colony demographics to ask how worker age-dependent and age-independent mortality affect colony fitness and how these effects differ by seasonal conditions. Results: We find that there are seasonal differences in honeybee colony elasticity to both senescent and extrinsic worker mortality. Colonies are most elastic to extrinsic (age-independent) nurse and forager mortality during periods of higher extrinsic mortality and resource availability but most elastic to age-dependent mortality during periods of lower extrinsic mortality and lower resource availability.Conclusions: These results suggest that seasonal changes in the strength of selection on worker senescence partly explain the observed pattern of seasonal differences in worker aging in honey bees. More broadly, these results extend our understanding of the role of extrinsic mortality in the evolution of senescence to social animals and improve our ability to model the effects of environmental change on social insect populations of economic or conservation concern.


2020 ◽  
Author(s):  
Natalie J Lemanski ◽  
Siddhant Bansal ◽  
Nina H Fefferman

Abstract Background: Honeybees have extraordinary phenotypic plasticity in their senescence rate, making them a fascinating model system for the evolution of aging. Seasonal variation in senescence and extrinsic mortality results in a tenfold increase in worker life expectancy in winter as compared to summer. To understand the evolution of this remarkable pattern of aging, we must understand how individual longevity scales up to effects on the entire colony. In addition, threats to the health of honey bees and other social insects are typically measured at the individual level. To predict the effects of environmental change on social insect populations, we must understand how individual effects impact colony performance. We develop a matrix model of colony demographics to ask how worker age-dependent and age-independent mortality affect colony fitness and how these effects differ by seasonal conditions. Results: We find that there are seasonal differences in honeybee colony elasticity to both senescent and extrinsic worker mortality. Colonies are most elastic to extrinsic (age-independent) nurse and forager mortality during periods of higher extrinsic mortality and resource availability but most elastic to age-dependent mortality during periods of lower extrinsic mortality and lower resource availability.Conclusions: These results suggest that seasonal changes in the strength of selection on worker senescence partly explain the observed pattern of seasonal differences in worker aging in honey bees. More broadly, these results extend our understanding of the role of extrinsic mortality in the evolution of senescence to social animals and improve our ability to model the effects of environmental change on social insect populations of economic or conservation concern.


2020 ◽  
Author(s):  
Natalie J Lemanski ◽  
Siddhant Bansal ◽  
Nina H Fefferman

Abstract Background: Honeybees have extraordinary phenotypic plasticity in their senescence rate, making them a fascinating model system for the evolution of aging. Seasonal variation in senescence and extrinsic mortality results in a tenfold increase in worker life expectancy in winter as compared to summer. To understand the evolution of this remarkable pattern of aging, we must understand how individual longevity scales up to effects on the entire colony. We develop a matrix model of colony demographics to ask how worker age-dependent and age-independent mortality affect colony fitness and how these effects differ by seasonal conditions.Results: We find that there are seasonal differences in honeybee colony sensitivity to both senescent and extrinsic worker mortality. Colonies are most sensitive to extrinsic (age-independent) nurse and forager mortality during periods of higher extrinsic mortality and resource availability but most sensitive to age-dependent mortality during periods of lower extrinsic mortality and lower resource availability.Conclusions: These results suggest that seasonal changes in the strength of selection on worker senescence partly explain the observed pattern of seasonal differences in worker aging in honey bees. More broadly, these results extend our understanding of the role of extrinsic mortality in the evolution of senescence to social animals.


2021 ◽  
Vol 65 (2) ◽  
pp. 279-290
Author(s):  
Ricardo Alberto Toledo-Hernández ◽  
Mónica Pulido-Enríquez ◽  
Francisco Landeros-Pedro ◽  
Douglas Rodríguez ◽  
Daniel Sánchez

Abstract Crop protection substances are continuously developed to prevent the decimation of non-target insect populations through insecticide use. The bait formulation Acttra SWD was created to attract the adult spotted-wing drosophila, a generalist pest of berries, and when mixed with insecticide would cause a reduction in the volume of insecticide applied, thus avoiding a complete coverage of crops and resulting in economic and ecological benefits to society. However, Acttra SWD has some compounds, including sugars and fruit odors, that might attract non-target fauna, especially insect pollinators. Therefore this study aimed (1) to investigate if Acttra SWD mixed with the recommended pesticide, i.e. spinosad (Entrust), is attractive to the honey bee, which is extensively used for berry pollination and (2) to evaluate the insecticidal activity of Acttra/Entrust in oral and contact tests on the same species. In all replicates, most foragers rejected feeders that offered Acttra/Entrust, and some switched to Acttra/Entrust-free feeders. Accordingly, mortality caused by this mixture in oral tests was low and did not differ from control, since the majority of bees did not consume the Acttra/Entrust treatment. However, mortality caused by this mixture was higher than in control groups in topical tests. Our results indicate that honey bees will not be attracted to and poisoned by crops sprayed with Acttra/Entrust, but contact with the bait would result in lethal or sub-lethal effects.


JURNAL ELTEK ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 9
Author(s):  
Vivien Arief Wardhany ◽  
Vivien Arief Wardhany ◽  
Alfin Hidayat

Lebah madu adalah jenis serangga social yang hidup berkoloni. Lebah memiliki manfaat bagi kehidupan manusia yaitu dalam proses penyerbukan tanaman serta menghasilkan madu yang dapat dikonsumsi karena memilki nilai gizi yang tinggi. Pada sistem peternakan lebah modern ada beberapa hal yang perlu diperhatikan yaitu iklim, lokasi sarang lebah dengan ketersediaan tanaman (bunga) yang menjadi sumber makan bagi lebah dan material sarang lebah. Pada penelitian ini telah dibuat suatu sistem terpadu yang terdiri dari 3 bagian penyusun sistem yaitu hardware yang terdiri dari sensor suhu, kelembaban, load cell dan geo lokasi (penentu lokasi) berikutnya adalah software yang terdiri dari Web Server dan aplikasi Android yang berisi data hasil pembacaan sensor yang disajikan dalam bentuk grafik sehingga memudahkan pembacaan hasil monitoring dari hardware, serta notifikasi apabila tiba saat pemanenan sarang atau kondisi suhu dan kelembaban yang tidak sesuai dengan standar tidak terpenuhi. Hasil pengujian sistem ini didapatkan bahwa Suhu optimal pada kandang lebah dapat dipertahankan dengan aktuator. Aktuator dapat mepertahankan suhu dari 34,4 ℃ ke 32,9℃ selama 1 menit 5 detik dan dari 31,2 ℃ ke 32,2 ℃ selama 1 menit 15 detik. Aplikasi web dan android ini mempermudah para peternak lebah untuk mengelola kondisi sarang lebah dari hasil pengujian untuk monitoring kondisi sarang lebah dapat berjalan dengan baik, dimana data yang ditampilkan adalah suhu, kelembaban dan berat. Honey bees are a type of social insect that live in colonies. Bees have benefits for human life, namely in the process of pollinating plants and producing honey that can be consumed because of their high nutritional value. In the modern beekeeping sistem, there are several things that need to be considered, namely the climate, the location of the beehive and the availability of plants (flowers) which are a source of food for bees and beehive materials. In this research, an integrated system consisting of 3 parts of the system has been created, namely Hardware consisting of temperature, humidity, load cell and geo location sensors. Next is the software consisting of a Web Server and an Android application that contains reading data. sensors are presented in graphical form to facilitate reading of monitoring results from Hardware, as well as notifications when nest harvesting arrives or temperature and humidity conditions that do not comply with standards are not met. The test results of this system show that the optimal temperature in the beehive can be maintained with an actuator. The actuator can maintain temperature from 34.4 ℃ to 32.9 ℃ for 1 minute 5 seconds and from 31.2 ℃ to 32.2 ℃ for 1 minute 15 seconds. This Web and Android application makes it easier for beekeepers to manage the conditions of the beehive. From the test results for monitoring the conditions of the beehive, it can run well, where the data displayed is temperature, humidity and weight.  


2017 ◽  
Vol 12 ◽  
pp. 47 ◽  
Author(s):  
Andreas Thrasyvoulou ◽  
Basilis Tsirakoglou

Three consecutive sowings of Phacelia tanacetifolia Bentham (Hydrophyllaceae) were examined for plant growth and attractiveness to bees and other insect-visitors over a three years’ study. Plants that were sown in March flowered uniformly for periods of 24 to 40 days, while those sown in June and July had a non-uniform anthesis that was impossible to estimate. Plants sown in early August, remained vegetative throughout winter and flowered the following spring. Maximum visits of honey bees were observed between 10:00 h and 17:00 h. Most honey bees (>70%) collected nectar. Seasonal differences in the ratio nectar/pollen gatherers were noted. Two species of bumble bee (B. terrestris and B. lucorum) and 9 species of solitary bee visited Phacelia.


Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 187 ◽  
Author(s):  
Edelfeldt ◽  
Lindell ◽  
Dahlgren

Relative to mammals and birds, little is known about the mortality trajectories of perennial plants, as there are few long-term demographic studies following multiple yearly cohorts from birth to death. This is particularly important because if reproductively mature individuals show actuarial senescence, current estimations of life spans assuming constant survival would be incorrect. There is also a lack of studies documenting how life history trade-offs and disturbance influence the mortality trajectories of plants. We conducted Bayesian survival trajectory analyses (BaSTA) of a 33-year individual-based dataset of Pulsatilla vulgaris ssp. gotlandica. Mortality trajectories corresponded to “Type III” survivorship patterns, with rapidly decreasing annual mortality rates for young plants, but with constant mortality for reproductively mature individuals. We found trade-off effects resulting in a cost of growth for non-reproductive plants but no apparent cost of reproduction. Contrarily to our expectation, young plants that had previously shrunk in size had a lower mortality. However, accounting for trade-offs and disturbance only had minor effects on the mortality trajectories. We conclude that BaSTA is a useful tool for assessing mortality patterns in plants if only partial age information is available. Furthermore, if constant mortality is a general pattern in polycarpic plants, long-term studies may not be necessary to assess their age-dependent demography.


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