| 1. |
- Achcar, JA, et al.
(författare)
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25 years of applied statistics
- 1998
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Ingår i: JOURNAL OF APPLIED STATISTICS. - : CARFAX PUBL CO. - 0266-4763. ; 25:1, s. 3-22
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Jezeera, M. Asmi, et al.
(författare)
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Spatial resolution and sensitivity of the eyes of the stingless bee, Tetragonula iridipennis
- 2022
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Ingår i: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology. - : Springer Science and Business Media LLC. - 0340-7594 .- 1432-1351. ; 208:2, s. 225-238
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Tidskriftsartikel (refereegranskat)abstract
- Stingless bees are important pollinators in the tropics. The tremendous variation in body size makes them an excellent group to study how miniaturization affects vision and visual behaviours. Using direct measurements and micro-CT, we reconstructed the eye structure, estimated anatomical spatial resolution and optical sensitivity of the stingless bee Tetragonula iridipennis. T. iridipennis is similar in size to the Australian stingless bee Tetragonula carbonaria and is smaller than honeybees. It has correspondingly small eyes (area = 0.56 mm2), few ommatidia (2451 ± 127), large inter-facet (3.0 ± 0.6°) and acceptance angles (2.8°). Theoretical estimates suggest that T. iridipennis has poorer spatial resolution (0.17 cycles degree−1) than honeybees, bumblebees, and T. carbonaria. Its optical sensitivity (0.08 µm2 sr), though higher than expected, is within the range of diurnal bees. This may provide them with greater contrast sensitivity, which is likely more relevant than the absolute sensitivity in this diurnal bee. Behaviourally determined detection thresholds for single targets using y-maze experiments were 11.5° for targets that provide chromatic contrast alone and 9.1° for targets providing chromatic and achromatic contrast. Further studies into microhabitat preferences and behaviour are required to understand how miniaturization influences its visual ecology.
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| 3. |
- Vijayan, Sajesh, et al.
(författare)
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Dim-light colour vision in the facultatively nocturnal Asian giant honeybee, Apis dorsata
- 2023
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Ingår i: Proceedings of the Royal Society B: Biological Sciences. - 0962-8452. ; 290:2004
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Tidskriftsartikel (refereegranskat)abstract
- We discovered nocturnal colour vision in the Asian giant honeybee Apis dorsata - a facultatively nocturnal species - at mesopic light intensities, down to half-moon light levels (approx. 10 -2 cd m -2). The visual threshold of nocturnality aligns with their reported nocturnal activity down to the same light levels. Nocturnal colour vision in A. dorsata is interesting because, despite being primarily diurnal, its colour vision capabilities extend into dim light, while the 'model' European honeybee Apis mellifera is reported to be colour-blind at twilight. By employing behavioural experiments with naturally nesting A. dorsata colonies, we show discrimination of the trained colour from other stimuli during the day, and significantly, even at night. Nocturnal colour vision in bees has so far only been reported in the obligately nocturnal carpenter bee Xylocopa tranquebarica. The discovery of colour vision in these two bee species, despite differences in the extent of their nocturnality and the limitations of their apposition compound eye optics, opens avenues for future studies on visual adaptations for dim-light colour vision, their role in pollination of flowers at night, and the effect of light pollution on nocturnal activity in A. dorsata, a ubiquitous pollinator in natural, agricultural and urban habitats in the Asian tropics and sub-tropics.
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