Biology subjects

Agosto Rivera, J. L.

Publications and source records attributed to Agosto Rivera, J. L..

3 recordsLinked to original sources

bioRxiv2020

The Role of Temperature on the Development of Circadian Rhythms in Honey Bee Workers

Circadian rhythms in honey bees are involved in various processes that impact colony survival. For example, young nurses take care of the brood constantly throughout the day and lack circadian rhythms, while foragers use the circadian clock to remember and predict food availability in subsequent days. Previous studies suggested that development of circadian rhythms both in the field and the laboratory began around 7-9 days of age. However, not much is understood about the postembryonic development of circadian rhythms in honey bees. In the current study, we examine the effects of socially regulated colony temperature on the ontogeny of circadian rhythms of young workers under controlled laboratory conditions. We hypothesized that temperature plays a key role in the development of circadian rhythmicity in young workers. Our results show that young workers kept at 35{degrees}C develop circadian rhythmicity faster and in greater proportion than bees kept at 25{degrees}C. In addition, we examine if the effect of colony temperature during the first 48 hours after emergence is enough to observe effects on the rate and proportion of development of circadian rhythmicity. We observed that twice as many individuals that were exposed to 35{degrees}C during the first 48 hours develop circadian rhythms compared to individuals kept at 25{degrees}C. In addition, we observed differences in the average endogenous period length consistent with temperature compensation of the circadian rhythms between the 25{degrees}C and 35{degrees}C cohorts. We also observed differences in the degree of period length variation between the 25{degrees}C and 35{degrees}C cohorts, which combined with the proportion of arrhythmic individuals and survival data suggest that development of circadian rhythms is incomplete in individuals exposed to 25{degrees}C adult emergence. This study shows that temperature, which is socially regulated inside the hive, is a key factor that influences the ontogeny of circadian rhythmicity of workers.

animal behavior and cognition↗

bioRxiv2020

The Role of Colony Temperature in the Entrainment of Circadian Rhythms of Honey Bee Foragers

Honey bees utilize their circadian rhythms to accurately predict the time of day. This ability allows foragers to remember the specific timing of food availability and its location for several days. Previous studies have provided strong evidence toward light/dark cycles being the primary Zeitgeber for honey bees. Work in our laboratory described large individual variation in the endogenous period length of honey bee foragers from the same colony and differences in the endogenous rhythms under different constant temperatures. In this study, we further this work by examining temperature inside the honey bee colony. By placing temperature and light data loggers at different locations inside the colony we measured temperature at various locations within the colony. We observed significant oscillations of temperature inside the hive, that show seasonal patterns. We then simulated the observed temperature oscillations in the laboratory and found that using the temperature cycle as a Zeitgeber, foragers present large individual differences in the phase of locomotor rhythms with respect to temperature. Moreover, foragers successfully synchronize their locomotor rhythms to these simulated temperature cycles. Advancing the cycle by six hours, resulted in changes in the phase of activity in some foragers in the assay. The results shown in this study highlight the importance of temperature as a potential Zeitgeber in the field. Future studies will examine the possible functional and evolutionary role of the observed phase differences of circadian rhythms.

animal behavior and cognition↗

bioRxiv2020

Shift work dynamics and division of labor: honeybee foraging and fanning tasks

In complex societies common social needs such as vigilance, care giving, resource gathering, and production are attended around the clock. In humans, these services are constantly provided using a shift work strategy where different individuals, or groups of individuals perform their tasks at different times of the day. However, shift work strategy in job organization in other social organisms remains unclear. Previous studies in honeybees for two jobs support shift work for only pollen foragers and not for nursing behavior. Here we examined shift work dynamics for three types of jobs performed by honeybee foragers. Specifically, we studied pollen foragers, non-pollen foragers and bees fanning at the entrance of the colony, a job important for orientation and temperature control. Major features of the observed shift work were: 1) individuals can be divided into early and late shifts; 2) there are constant workers; 3) based on job, shift work is performed by fewer or greater number of individuals; 4) shift work of an individual is plastic and may change with age; 5) foraging and fanning shifts are coupled yet dissociable. This study adds to the findings that shift work is not exclusive to modern human societies and that a natural form of shift work exists in honeybees. These results suggest that shift work in honeybees is a feature of worker division of labor. Future studies aiming to further understand the structure, function and mechanism of this natural form of shift work in honey bees not only could have an impact on agriculture but also may provide insight into alternative forms of shift work strategies that may reduce the various health problems associated with shift work in humans.

animal behavior and cognition↗