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Author Kelber, A.
Title Light intensity limits foraging activity in nocturnal and crepuscular bees Type Journal Article
Year 2005 Publication Behavioral Ecology Abbreviated Journal Behavioral Ecology
Volume (down) 17 Issue 1 Pages 63-72
Keywords bees; eyes; foraging; insects; ocelli; sensitivity; visual ecology
Abstract A crepuscular or nocturnal lifestyle has evolved in bees several times independently, probably to explore rewarding pollen sources without competition and to minimize predation and nest parasites. Despite these obvious advantages, only few bee species are nocturnal. Here we show that the sensitivity of the bee apposition eye is a major factor limiting the ability to forage in dim light. We present data on eye size, foraging times, and light levels for Megalopta genalis (Augochlorini, Halictidae) in Panama, and Lasioglossum (Sphecodogastra) sp. (Halictini, Halictidae) in Utah, USA. M. genalis females forage exclusively during twilight, but as a result of dim light levels in the rain forest, they are adapted to extremely low intensities. The likely factor limiting their foraging activity is finding their nest entrance on return from a foraging trip. The lowest light intensity at which they can do this, both in the morning and the evening, is 0.0001 cd m−2. Therefore, they leave the nest at dimmer light levels in the morning than in the evening. Lasioglossum (Sphecodogastra) foraging is limited by light intensity in the evening, but probably by temperature in the morning in the temperate climate of Utah. We propose that the evolution of nocturnality in bees was favored by the large variance in the size of females.
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ISSN 1045-2249 ISBN Medium
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Notes Approved no
Call Number IDA @ john @ Serial 119
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Author Rydin, C; Bolinder, K
Title Moonlight pollination in the gymnosperm Ephedra (Gnetales) Type Journal Article
Year 2015 Publication Biology Letters Abbreviated Journal Biol. Lett.
Volume (down) 11 Issue 4 Pages 20140993
Keywords Plants; anemophily; entomophily; lunar phases; nocturnal insects; lunar cycle; light at night; Ephedra; Ephedra distachya; pollination
Abstract Most gymnosperms are wind-pollinated, but some are insect-pollinated, and in Ephedra (Gnetales), both wind pollination and insect pollination occur. Little is, however, known about mechanisms and evolution of pollination syndromes in gymnosperms. Based on four seasons of field studies, we show an unexpected correlation between pollination and the phases of the moon in one of our studied species, Ephedra foeminea. It is pollinated by dipterans and lepidopterans, most of them nocturnal, and its pollination coincides with the full moon of July. This may be adaptive in two ways. Many nocturnal insects navigate using the moon. Further, the spectacular reflection of the full-moonlight in the pollination drops is the only apparent means of nocturnal attraction of insects in these plants. In the sympatric but wind-pollinated Ephedra distachya, pollination is not correlated to the full moon but occurs at approximately the same dates every year. The lunar correlation has probably been lost in most species of Ephedra subsequent an evolutionary shift to wind pollination in the clade. When the services of insects are no longer needed for successful pollination, the adaptive value of correlating pollination with the full moon is lost, and conceivably also the trait.
Address Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm 106 91, Sweden
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Publisher Royal Society Place of Publication Editor
Language English Summary Language English Original Title
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ISSN ISBN Medium
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Notes Approved no
Call Number IDA @ john @ Serial 1143
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Author Narendra, A.; Reid, S.F.; Raderschall, C.A.
Title Navigational efficiency of nocturnal Myrmecia ants suffers at low light levels Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume (down) 8 Issue 3 Pages e58801
Keywords Adaptation, Biological/*physiology; Animals; Ants/*physiology; Australian Capital Territory; *Cues; Geographic Information Systems; Homing Behavior/*physiology; *Light; Locomotion/*physiology; Orientation/*physiology; insects
Abstract Insects face the challenge of navigating to specific goals in both bright sun-lit and dim-lit environments. Both diurnal and nocturnal insects use quite similar navigation strategies. This is despite the signal-to-noise ratio of the navigational cues being poor at low light conditions. To better understand the evolution of nocturnal life, we investigated the navigational efficiency of a nocturnal ant, Myrmecia pyriformis, at different light levels. Workers of M. pyriformis leave the nest individually in a narrow light-window in the evening twilight to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, while few attempt to return to the nest throughout the night. We found that as light levels dropped, ants paused for longer, walked more slowly, the success in finding the nest reduced and their paths became less straight. We found that in both bright and dark conditions ants relied predominantly on visual landmark information for navigation and that landmark guidance became less reliable at low light conditions. It is perhaps due to the poor navigational efficiency at low light levels that the majority of foragers restrict navigational tasks to the twilight periods, where sufficient navigational information is still available.
Address ARC Centre of Excellence in Vision Science, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia. ajay.narendra@anu.edu.au
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Language English Summary Language Original Title
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ISSN 1932-6203 ISBN Medium
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Notes PMID:23484052; PMCID:PMC3590162 Approved no
Call Number IDA @ john @ Serial 117
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Author Solano Lamphar, H.A.; Kocifaj, M.
Title Light pollution in ultraviolet and visible spectrum: effect on different visual perceptions Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume (down) 8 Issue 2 Pages e56563
Keywords Lighting; Animals; *Environmental Pollution; Humans; Insects; Light; Lighting/*adverse effects; Models, Theoretical; *Visual Perception
Abstract In general terms, lighting research has been focused in the development of artificial light with the purpose of saving energy and having more durable lamps. However, the consequences that artificial night lighting could bring to the human being and living organisms have become an important issue recently. Light pollution represents a significant problem to both the environment and human health causing a disruption of biological rhythms related not only to the visible spectrum, but also to other parts of the electromagnetic spectrum. Since the lamps emit across a wide range of the electromagnetic spectrum, all photobiological species may be exposed to another type of light pollution. By comparing five different lamps, the present study attempts to evaluate UV radiative fluxes relative to what humans and two species of insects perceive as sky glow level. We have analyzed three atmospheric situations: clear sky, overcast sky and evolving precipitable water content. One important finding suggests that when a constant illuminance of urban spaces has to be guaranteed the sky glow from the low pressure sodium lamps has the most significant effect to the visual perception of the insects tested. But having the fixed number of luminaires the situation changes and the low pressure sodium lamp would be the best choice for all three species. The sky glow effects can be interpreted correctly only if the lamp types and the required amount of scotopic luxes at the ground are taken into account simultaneously. If these two factors are combined properly, then the ecological consequences of sky glow can be partly reduced. The results of this research may be equally useful for lighting engineers, architects, biologists and researchers who are studying the effects of sky glow on humans and biodiversity.
Address ICA, Slovak Academy of Sciences, Bratislava, Slovak Republic. lamphar@gmail.com
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Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:23441205; PMCID:PMC3575508 Approved no
Call Number LoNNe @ schroer @ Serial 578
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Author Degen, T.; Hovestadt, T.; Mitesser, O.; Hölker, F.
Title Altered sex-specific mortality and female mating success: ecological effects and evolutionary responses Type Journal Article
Year 2017 Publication Ecosphere Abbreviated Journal Ecosphere
Volume (down) 8 Issue 5 Pages e01820
Keywords Insects; nocturnal insects; mating behaviour
Abstract Theory predicts that males and females should often join the mating pool at different times (sexual dimorphism in timing of emergence [SDT]) as the degree of SDT affects female mating success. We utilize an analytical model to explore (1) how important SDT is for female mating success, (2) how mating success might change if either sex's mortality (abruptly) increases, and (3) to what degree evolutionary responses in SDT may be able to mitigate the consequences of such mortality increase. Increasing male pre-mating mortality has a non-linear effect on the fraction of females mated: The effect is initially weak, but at some critical level a further increase in male mortality has a stronger effect than a similar increase in female mortality. Such a change is expected to impose selection for reduced SDT. Increasing mortality during the mating season has always a stronger effect on female mating success if the mortality affects the sex that emerges first. This bias results from the fact that enhancing mortality of the earlier emerging sex reduces femaleâ??male encounter rates. However, an evolutionary response in SDT may effectively mitigate such consequences. Further , if considered independently for females and males, the predicted evolutionary response in SDT could be quite dissimilar. The difference between female and male evolutionary response in SDT leads to marked differences in the fraction of fertilized females under certain conditions. Our model may provide general guidelines for improving harvesting of populations, conservation management of rare species under altered environmental conditions, or maintaining long-term efficiency of pest-control measures.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2150-8925 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ schroer @ Serial 1663
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