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Author Shymanovich, T.; Faw, L.; Hajhashemi, N.; Teague, J.; Schal, C.; Ponnusamy, L.; Apperson, C.S.; Hatano, E.; Wasserberg, G.
Title Diel periodicity and visual cues guide oviposition behavior in Phlebotomus papatasi, vector of old-world cutaneous leishmaniasis Type Journal Article
Year (down) 2019 Publication PLoS Neglected Tropical Diseases Abbreviated Journal PLoS Negl Trop Dis
Volume 13 Issue 3 Pages e0007165
Keywords Animals
Abstract BACKGROUND: Phlebotomine sand flies are vectors of human leishmaniases, important neglected tropical diseases. In this study, we investigated diel patterns of oviposition behavior, effects of visual cues on oviposition-site selection, and whether these affect the attraction of gravid Phlebotomus papatasi (Scopoli), the vector of old-world cutaneous leishmaniasis, to olfactory cues from oviposition sites. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate these questions, we conducted a series of experiments using attraction and oviposition assays within free-flight test chambers containing gravid females entrained under a 14:10 hrs light:dark photoperiod. By replacing sticky-screens or moist filter papers every three hours, we showed that oviposition site search occurs mainly in the latest part of the night whereas peak oviposition occurs during the early part of the night. Behavioral responses to olfactory oviposition cues are regulated by time-of-day and can be disrupted by transient exposure to a constant darkness photoperiod. Gravid females, but not any other stage, age, or sex, were attracted to dark, round oviposition jars, possibly resembling rodent burrow openings. This visual attraction disappeared in the absence of an illumination source. Egg deposition rate was not affected by jar color. Olfactory cues had the strongest effect when the visual cues were minimal. CONCLUSION AND SIGNIFICANCE: Our study showed, for the first time, that visual cues in the form of oviposition-site color, lighting level, and photoperiod are important in guiding the oviposition behavior of phlebotomine sand flies. Furthermore, such visual cues could modify the flies' sensitivity to olfactory oviposition cues. Our results suggest that chemosensory and visual cues are complementary, with visual cues used to orient gravid females towards oviposition sites, possibly at long- to medium-ranges during crepuscular periods, while olfactory cues are used to approach the burrow in darkness and assess its suitability at close-range. Implications to sand fly control are discussed.
Address Department of Biology, University of North Carolina at Greensboro, 235 Eberhart Bldg., Greensboro, North Carolina, United States of America
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1935-2727 ISBN Medium
Area Expedition Conference
Notes PMID:30835733 Approved no
Call Number GFZ @ kyba @ Serial 2251
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Author Cochard, P.; Galstian, T.; Cloutier, C.
Title The proportion of blue light affects parasitoid wasp behavior in LED-extended photoperiod in greenhouses: Increased parasitism and offspring sex ratio bias Type Journal Article
Year (down) 2019 Publication Biological Control Abbreviated Journal Biological Control
Volume 133 Issue Pages 9-17
Keywords Animals
Abstract The increasing use of specific wavelengths involving light-emitting diodes (LEDs) under greenhouses enables to overcome the lack of light during winter months, helping crops photosynthesis or vegetative growth. However, modification of the light environment as well as the photoperiod may also alter directly or indirectly the activity of both beneficial and pest insects that depend on plants. Here, we submitted the parasitic wasp Aphidius ervi and its main host the pea aphid, to 4 ratios of red(R): blue(B) LEDs used to lengthen the photoperiod inside a growth chamber. We recorded the parasitism rate of aphids and the sex ratio of newly emerged wasps to evaluate if A. ervi could remain an efficient biological control agent under modified light environments. We found that increasing the 8 h of photophase to 16 h by supplementing with R/B LEDs increased the daily parasitic activity of the wasp as well as their egg laying behavior. Under the 100R light supplement, about 80% of the emerged adults were males, against 50% under 25R:75B light treatment. These results indicate that A. ervi remains a good biological control agent when the light environment is modified. However, the use of red light to extend the photophase has the potential to negatively affect population dynamics of these parasitoids due to its male-bias impact on the sex ratio.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1049-9644 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2253
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Author Gaston, K.J.
Title Nighttime Ecology: The “Nocturnal Problem” Revisited Type Journal Article
Year (down) 2019 Publication The American Naturalist Abbreviated Journal The American Naturalist
Volume 193 Issue 4 Pages
Keywords Ecology; activity; diel; ecosystems; macroecology; nighttime; nocturnal; time partitioning
Abstract The existence of a synthetic program of research on what was then termed the “nocturnal problem” and that we might now call “nighttime ecology” was declared more than 70 years ago. In reality, this failed to materialize, arguably as a consequence of practical challenges in studying organisms at night and instead concentrating on the existence of circadian rhythms, the mechanisms that give rise to them, and their consequences. This legacy is evident to this day, with consideration of the ecology of the nighttime markedly underrepresented in ecological research and literature. However, several factors suggest that it would be timely to revive the vision of a comprehensive research program in nighttime ecology. These include (i) that the study of the ecology of the night is being revolutionized by new and improved technologies; (ii) suggestions that, far from being a minor component of biodiversity, a high proportion of animal species are active at night; (iii) that fundamental questions about differences and connections between the ecology of the daytime and the nighttime remain largely unanswered; and (iv) that the nighttime environment is coming under severe anthropogenic pressure. In this article, I seek to reestablish nighttime ecology as a synthetic program of research, highlighting key focal topics and questions and providing an overview of the current state of understanding and developments.
Address Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, United Kingdom; and Wissenschaftskolleg zu Berlin, Institute for Advanced Study, Wallotstrasse 19, 14193 Berlin, Germany; k.j.gaston(at)exeter.ac.uk
Corporate Author Thesis
Publisher University of Chicago Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-0147 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2254
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Author Rebke, M.; Dierschke, V.; Weiner, C.N.; Aumüller, R.; Hill, K.; Hill, R.
Title Attraction of nocturnally migrating birds to artificial light: The influence of colour, intensity and blinking mode under different cloud cover conditions Type Journal Article
Year (down) 2019 Publication Biological Conservation Abbreviated Journal Biological Conservation
Volume 233 Issue Pages 220-227
Keywords Animals
Abstract A growing number of offshore wind farms have led to a tremendous increase in artificial lighting in the marine environment. This study disentangles the connection of light characteristics, which potentially influence the reaction of nocturnally migrating passerines to artificial illumination under different cloud cover conditions. In a spotlight experiment on a North Sea island, birds were exposed to combinations of light colour (red, yellow, green, blue, white), intensity (half, full) and blinking mode (intermittent, continuous) while measuring their number close to the light source with thermal imaging cameras.

We found that no light variant was constantly avoided by nocturnally migrating passerines crossing the sea. The number of birds did neither differ between observation periods with blinking light of different colours nor compared to darkness. While intensity did not influence the number attracted, birds were drawn more towards continuous than towards blinking illumination, when stars were not visible. Red continuous light was the only exception that did not differ from the blinking counterpart. Continuous green, blue and white light attracted significantly more birds than continuous red light in overcast situations.

Our results suggest that light sources offshore should be restricted to a minimum, but if lighting is needed, blinking light is to be preferred over continuous light, and if continuous light is required, red light should be applied.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3207 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2255
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Author Murphy, B.A.
Title Circadian and circannual regulation in the horse: Internal timing in an elite athlete Type Journal Article
Year (down) 2019 Publication Journal of Equine Veterinary Science Abbreviated Journal Journal of Equine Veterinary Science
Volume Issue Pages
Keywords Animals
Abstract Biological rhythms evolved to provide temporal coordination across all tissues and organs and allow synchronisation of physiology with predictable environmental cycles. Most important of these are circadian and circannual rhythms, primarily regulated via photoperiod signals from the retina. Understanding the nature of physiological rhythms in horses is crucially important for equine management. Predominantly, we have removed them from exposure to their natural environmental stimuli; the seasonally changing photoperiod, continuous foraging and feeding activity, social herd interactions and the continuous low intensity exercise of a grassland dweller. These have been replaced in many cases with confined indoor housing, regimental feeding and exercise times, social isolation and exposure to lighting that is often erratic and does not come close to mimicking the spectral composition of sunlight. We have further altered seasonal timing cues through the use of artificial lighting programs that impact reproductive behaviour, breeding efficiency and the development of youngstock. Understanding how these new environmental cues (some stronger, some weaker) impact the internal physiology of the horse in the context of the natural endogenous rhythms that evolved over millennia, is key to helping to improve equine health, welfare and performance, now and into the future. This review provides an overview of the field, highlights the recent discoveries related to biological timing in horses and discusses the implications that these findings may have for the production and management of the elite equine athlete.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0737-0806 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2257
Permanent link to this record