The superposition image in the eye ofEphestia k�hniella

Cleary, Patricia A.; Deichsel, G.; Kunze, Peter C.

doi:10.1007/bf00655873

Cited by 32 publications

(26 citation statements)

References 11 publications

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“…The two curves are presented as a function of the angle of incidence, ␣. Because the maximum angle of incidence ␣ max for E. kühniella is 22.5° ( Cleary et al, 1977) and for P. tristifica ␣ max =11.4° (Land, 1984), the curves virtually coincide when plotted as a function of the exit angle, ␤. The difference in optical path length, ⌬OPL, of rays through facets 2 with respect to those through facet 1 appears to be distinctly smaller than the coherence length l c =2.8·m for green receptors (see Materials and methods), but the ⌬OPLs for the other adjacent facets in a meridional section (4, 6, 9, etc.)…”

Section: Optical Path Length Differencementioning

confidence: 90%

“…The results can be compared with published experimental data for the nocturnal moth Ephestia kühniella and the skipper Toxidia peroni. For E. kühniella, Fig.·3 predicts m=2.3-2.0, but ray tracing calculations based on refractive index measurements yielded a constant m=1.32 (Cleary et al, 1977). For T. peroni, Fig.·3 predicts m=1.0-0.6, but direct measurements yielded a fairly constant m=1.6.…”

Section: Angular Magnification and Defocusmentioning

confidence: 97%

“…The quantitative evaluations are based on the anatomical data of moth and skipper eyes of Table·1, derived from various sources (Cleary et al, 1977;Horridge et al, 1972;Horridge et al, 1977;Kunze, 1979;Land, 1984).…”

Section: Anatomical Data Of Moth and Skipper Eyesmentioning

confidence: 99%

“…Rays through facet lenses with ␣>␣ max thus no longer contribute to the superposition image, because they are absorbed by the screening pigment layers that surround the crystalline cones (Fig.·1). Whereas ␣ max strongly depends on the species, ␤ max appears to be remarkably constant among a diverse range of animals with refractive superposition eyes: ␤ max Ϸ30°in the moth Ephestia kühniella (Cleary et al, 1977) Moths: E.ku., Ephestia kühniella (Cleary et al, 1977;Kunze, 1979); P.tr., Phalaenoides tristifica (Horridge et al, 1977;Land, 1984 (Horridge et al, 1972;Land, 1984); see also Fig.·2. Fig.·1.…”

Section: Theory Of Angular Magnification and Aperture Of An Idealmentioning

confidence: 99%

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Partial coherence and other optical delicacies of lepidopteran superposition eyes

Stavenga

2006

Journal of Experimental Biology

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SUMMARY Superposition eyes are generally thought to function ideally when the eye is spherical and with rhabdom tips in the focal plane of the imaging optics of facet lenses and crystalline cones. Anatomical data as well as direct optical measurements demonstrate that the superposition eyes of moths and skippers often deviate severely from the expected ideal case. Part of the deviation has been attributed to diffraction at the single facet lens, which was taken to be an essential limit to spatial resolution, because light traveling through different facet lenses was assumed to be incoherent. By considering the two-dimensional facet lens lattice, it is here demonstrated that many facets within a superposition aperture transmit coherent light, allowing a much sharper image than possible with single facet lens diffraction. Partial coherence therefore is an important aspect of superposition imaging. It is argued that broadening of the photoreceptor acceptance angles occurs because of optical errors in the facet lens-crystalline cone system other than diffraction. The transmittance of the superposition aperture of moths and skippers is improved by the corneal nipple arrays of the facet lenses, but quantitative assessment shows that the effect is minor.

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Section: Optical Path Length Differencementioning

confidence: 90%

Section: Angular Magnification and Defocusmentioning

confidence: 97%

Section: Anatomical Data Of Moth and Skipper Eyesmentioning

confidence: 99%

Section: Theory Of Angular Magnification and Aperture Of An Idealmentioning

confidence: 99%

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Partial coherence and other optical delicacies of lepidopteran superposition eyes

Stavenga

2006

Journal of Experimental Biology

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“…The non-target rhabdoms may produce an error signal and inevitably blur the image, causing a loss in resolving power. Although we do not have optical data on the position of the superposition image formed by the dioptric apparatus in the eye of O. antiqua, the superposition images from other moths like Ephestia kühniella (Cleary et al, 1977;Kunze, 1979) and Phalaenoides tristifica (Narvarro & Franceschini, 1998) are located deep in the eyes at distances of 125 µm and 137 µm respectively. The widths of the clearzone of Ephestia kühniella and Phalaeoides tristifica are about 100 µm (Fischer & Horstmann, 1971) and 137 µm, respectively (Narvarro & Franceschini, 1998) and thus agree with values from the eye of male O. antiqua (99-106 µm, Table 2).…”

Section: The Retinula and Its Photoreceptorsmentioning

confidence: 99%

The compound eye of Orgyia antiqua (Lepidoptera: Lymantriidae): Sexual dimorphism and light/dark adaptational changes

Lau¹,

Meyer‐Rochow²

2007

Eur. J. Entomol.

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Abstract. Structure and photomechanical changes upon light/dark adaptation in the superposition compound eyes of the highly sexually dimorphic Orygia antiqua were studied by light and electron microscopy. The eyes of the fully winged male differ from those of the wingless, sedentary female in several respects: they are significantly larger, display a more regular ommatidial array, have a wider clearzone and possess a much more substantial tracheal tapetum. However, the eyes of the female exhibit more pronounced photomechanical changes upon light/dark adaptation than those of the male. We believe that for females, on account of their limited mobility, it is necessary that their eyes can cope with widely fluctuating brightnesses, but that visual sensitivity and resolving power are less important to them than to the actively flying males. Although the latter may be attracted to the females by pheromones, males in their diurnal searches will have to visually avoid obstacles and predators. Moreover, because of their ability to fly, males can seek shelters or shaded areas and unlike the sedentary females avoid prolonged exposures to potentially hazardous light levels. This could explain why the eyes of the females exhibit more pronounced photomechanical responses to changes in ambient light levels.

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