Compound Eye Research Articles

Laser-based 3D printing and optical characterization of optical micro-nanostructures inspired by nocturnal insects compound eyes

Nature offers unique examples that help humans produce artificial systems which mimic specific functions of living organisms and provide solutions to complex technical problems of the modern world. For example, the development of 3D micro-nanostructures that mimic nocturnal insect eyes (optimized for night vision), emerges as promising technology for detection in IR spectral region. Here, we report a proof of principle concerning the design and laser 3D printing of all ultrastructural details of nocturnal moth Grapholita Funebrana eyes, for potential use as microlens arrays for IR detection systems. Optimized computer-aided design and laser writing parameters enabled us to reproduce the entire complex architecture of moth compound eyes, with submicrometric spatial accuracy. As such, the laser-imprinted structures consisted in ommatidia-like microstructures with average diameter of about 14 μm, decorated with nipple-like nanopillars between 200 and 400 nm in height and average periodicity of around 450 nm. The dimensions of moth-eye inspired structures deviated by less than 10% from the natural corresponding structures. The optical properties of the moth eyes-inspired microlens arrays were investigated in the infrared (IR) range, between 1000 and 1700 nm. The optical transmission of microlens arrays with nanopillars was up to 17.55% higher than the transmission through microlens arrays without nanopillars. Moreover, the reflection of nanopillar-decorated microlens arrays was up to 0.91% lower than the reflection for microlenses without nanopillars. In addition, the focal spot diameter at 1/e2 for nanopillar—decorated microlens arrays was of 7.64 μm, representing and improvement of 16.5% of focal spot diameter as compared to microlens arrays without nanopillars. Similarly with the IR region, the reflection measured in the Visible range was higher for microlense arrays with nanopillars than the reflection through microlenses arrays without nanopillars. In contrast, in the Visible range the transmission of nanopillar-decorated microlens arrays was lower than the one for microlense arrays without nanopillars, which could be, most likely, assigned to diffraction losses on the nanopillars.

Stomatopods compound eye structure-inspired circular polarization quantum well infrared photodetectors

Stomatopods compound eye structure-inspired circular polarization quantum well infrared photodetectors

Fabrication of Artificial Compound Eyes with Biplanar Focal Planes on a Curved Surface.

Inspired by ancient trilobites, novel curved microlens arrays (CMLAs) were designed. Direct, fast, and low-cost CMLAs with two focal planes were fabricated using ultraprecision machining technology and hot embossing technology. We designed four pairs of artificial compound eyes (ACEs) composed of large and small lenses with four different curvatures to achieve focusing and imaging on two focal planes. A test system was constructed to capture the first-order and second-order images for each level of the ACEs. Additionally, we analyzed the deformation patterns in the first-order and second-order images. The wide field of view (FOV) value was 68°, which aligns with the theoretical prediction. The focusing performance was also investigated, and the experimental results indicate that each lens achieves uniform focusing within the FOV range. These results confirm that microlens arrays with two focal planes possess advanced imaging and focusing capabilities, enabling a wide depth-of-field function. This opens new avenues for the development of advanced detectors and optical imaging devices.

External morphology and ultrastructure of the compound eyes of Ricania speculum (Hemiptera: Fulgoroidea: Ricaniidae)

External morphology and ultrastructure of the compound eyes of Ricania speculum (Hemiptera: Fulgoroidea: Ricaniidae)

Deep conservation complemented by novelty and innovation in the insect eye ground plan

A spectacular diversity of forms and features allow species to thrive in different environments, yet some structures remain relatively unchanged. Insect compound eyes are easily recognizable despite dramatic differences in visual abilities across species. It is unknown whether distant insect species use similar or different mechanisms to pattern their eyes or what types of genetic changes produce diversity of form and function. We find that flies, mosquitos, butterflies, moths, beetles, wasps, honeybees, and crickets use homologous developmental programs to pattern their retinas. Transcription factor expression can be used to establish homology of different photoreceptor (PR) types across the insects: Prospero (Pros) for R7, Spalt (Sal) for R7+R8, and Defective proventriculus (Dve) for R1-6. Using gene knockout (CRISPR/Cas9) in houseflies, butterflies, and crickets and gene knockdown (RNAi) in beetles, we found that like Drosophila, EGFR and Sevenless (Sev) signaling pathways are required to recruit motion and color vision PRs, though Drosophila have a decreased reliance on Sev signaling relative to other insects. Despite morphological and physiological variation across species, retina development passes through a highly conserved phylotypic stage when the unit eyes (ommatidia) are first patterned. This patterning process likely represents an "insect eye ground plan" that is established by an ancient developmental program. We identify three types of developmental patterning modifications (ground plan modification, nonstochastic patterns, and specialized regions) that allow for the diversification of insect eyes. We suggest that developmental divergence after the ground plan is established is responsible for the exceptional diversity observed across insect visual systems.

A bilateral gynandromorph of Tenodera sinensis Saussure, 1871 (Mantodea: Mantidae) from Japan

This is a first description of a complete bilateral gynandromorph in Mantodea, as well as the first description of a complete gynandromorph of Tenodera sinensis Saussure. This specimen, collected from Kasai-Rinkai Park in Tokyo, Japan, exhibits predominantly male characteristics on the left side of its body and female characteristics on the right side. The left lateral has some features of male, and the notable differences between right and left lateral were found on the antennae, the ocelli, the compound eyes, the forewings and abdominal sternites VII to IX.

Bioinspired single-shot polarization photodetector based on four-directional grating arrays capped perovskite single-crystal thin film.

Polarization photodetectors (pol-PDs) have widespread applications in geological remote sensing, machine vision, biological medicine, and so on. However, commercial pol-PDs use bulky and complicated optical systems with lenses, polarizers, and mechanical spools, which are complex and cumbersome, and respond slowly. Inspired by the desert ants' compound eyes, we developed a single-shot pol-PD based on four-directional grating arrays capped perovskite single-crystal thin film without other standard polarization optics. Our pol-PD has a high detectivity, two orders of magnitude greater than that of commercial photodetectors, and exhibits high polarization sensitivity. The high performance of our pol-PD is due to the highly crystalline perovskite single-crystal thin film and regular nanograting structure, made by a nanoimprinting crystallization method. Our single-shot pol-PD is a compact on-chip optoelectronic device that demonstrates excellent performance in a wide range of applications including accurate bionic navigation, sharp image restoration in hazy scenes, stress visualization of polymers, and detection of cancerous areas in tissues without histological staining.

A wide-angle compound eye in CMOS

A wide-angle compound eye in CMOS

The Interplay Between Visual Traits and Forest in Bumblebee Communities Across Sweden

ABSTRACTUnderstanding how ecological communities assemble in relation to natural and human‐induced environmental changes is critical, particularly for communities of pollinators that deliver essential ecosystem services. Despite widespread attention to interactions between functional traits and community responses to environmental changes, the importance of sensory traits has received little attention. To address this, we asked whether visual traits of bumblebee communities varied at large geographical scales along a habitat gradient of increased tree cover. Because trees generate challenging light conditions for flying insects, in particular a reduced light intensity, we hypothesised that differences in tree cover would correlate with shifts in the visual and taxonomical composition of bumblebee communities. We quantified 11 visual traits across 36 specimens from 20 species of bumblebees using micro‐CT and optical modelling of compound eyes and ocelli, and investigated how these traits scale with body size. Using an inventory of bumblebee communities across Sweden and our visual trait dataset, we then explored how visual traits (both absolute and relative to body size) differed in relation to tree cover. We found positive shifts of the community weighted means of visual traits along the increasingly forested habitat gradient (facet diameter, inter‐ommatidial angle, eye parameter of the compound eye and alignment of the three ocelli) that were consistent regardless of body size, while other traits decreased when more forest was present in the landscape (facet number). These functional patterns were associated with differences in the abundance of six common species that likely explains the community‐wide shift of visual traits along the habitat gradient. Our study demonstrates the interaction between vision, habitat and community assembly in bumblebees, while highlighting a promising research topic at the interface between sensory biology and landscape ecology.

Microtubule-Rab5 mutual-influential system screening based on gene-regulatory networks map in Rab5 RNAi eye-degeneration model

Rabs are involved in neuronal development and protrusion formation. Existing studies support the notion that manipulation or mutation of Rab genes could lead to functional changes in neurons. However, whether Rabs gene-manipulation induced Drosophila eye-degeneration remains unknown. By down-regulating Rab5, but not Rab7, we first constructed a compound eye injury model in Drosophila. As the distribution, content, and even maturation of Rab5-positive endosomes are influenced by cytoskeletal proteins, like actin or tubulin-related proteins, the existence of a bidirectional regulatory relationship between Rab5 and the cytoskeleton remains unclear and worth researching. Through complete transcriptome sequencing combined immunofluorescence testing, we confirmed that down-regulation of Rab5 affected the increase of α-Tub84B (alternatively named TubA84B) but not γ-tubulin. Based on Weighted Gene Co-Expression Network Analysis (WGCNA) and multi-tissue screening verification, this study proposes that the apoptosis-related factors–Rab5–TubA84B have conserved regulatory functions with cooperative expression. Gene manipulation confirmed that apoptotic factors, especially rpr, strongly regulate Rab5, and may ultimately influence microtubule structure through complex routes, including the Rab5 variance and the intracellular configuration ratio of α-Tubulin to Glyceraldehyde-3-phosphate dehydrogenase.

How to Dwell in Garbage Patches? Waste Communities in the Aftermath of Ancestral Catastrophe in Chen Qiufan’s The Waste Tide (2013) and Wu Ming-yi’s The Man with the Compound Eyes (2011)

How to Dwell in Garbage Patches? Waste Communities in the Aftermath of Ancestral Catastrophe in Chen Qiufan’s The Waste Tide (2013) and Wu Ming-yi’s The Man with the Compound Eyes (2011)

Vision guides the twilight search for oviposition sites of the Asian tiger mosquito, Aedes albopictus.

Oviposition site selection is an important component of vector mosquito reproductive biology. The Asian Tiger mosquito, Aedes albopictus, is a major and important vector of arboviruses including Dengue. Previous studies documented the preference of gravid females for small, dark-colored water containers as oviposition sites, which they sought during the twilight period (dusk) of their locomotor activity. Vision plays an important role in this behavior, and factors such as the shape, size, and color of the container, light intensity, polarization, spectrum, and other visual cues guide the search for suitable oviposition sites, but the mechanistic factors driving this behavior are unclear. We blindfolded adult female compound eyes and observed the effects of a lack of vision on the ability to discriminate and utilize preferred oviposition sites. Furthermore, the transcriptomes of blindfolded mosquitoes were screened to identify genes with vision-sensitive expression profiles and gene-editing was used to create non-functional mutations in two of them, rhodopsin-like (mutation designated 'rho-l△807') and kynurenine hydroxylase (mutation designated 'khw'). Behavioral tests of both mutant and control strains revealed that the rho-l△807 mutant mosquitoes had a significant decrease in their ability to search for preferred oviposition sites that correlated with a reduced ability to recognize long-wavelength red light. The khw mutant mosquitoes also had a reduced ability to identify preferred oviposition sites that correlated with reductions in their ability to respond to variations in daily brightness and their ability to discriminate among different color options of the containers and background monochromatic light. This study underscores the importance of visual cues in the oviposition site selection behavior of adult female Ae. albopictus. We demonstrate that wild-type rho-l and kh gene products play a crucial role in this behavior, as mutants exhibit altered sensitivity or recognition of light intensity and substrate colors.

Screening of the highly pathogenic Beauveria bassiana BEdy1 against Sogatella furcifera and exploration of its infection mode.

The white-backed planthopper (WBPH, Sogatella furcifera) is a notorious pest affecting rice production in many Asian countries. Beauveria bassiana, as the most extensively studied and applied insect pathogenic fungus, is a type of green and safe biological control fungus compared to chemical insecticides, and it does not pose the "3R" problem. In this study, the strain BEdy1, which had better pathogenicity to WBPH, was screened out from eight strains of B. bassiana. The daily growth rate, sporulation, and germination rate of BEdy1 strain were 3.74 mm/d, 1.37 × 108 spores/cm2, and 96.00%, respectively, which were significantly better than those of other strains. At a concentration of 1 × 108 spores/mL, the BEdy1 strain exhibited the smallest LT50 value (5.12 d) against the WBPH, and it caused the highest cumulative mortality and muscardine cadaver rates of the pest, which were 77.67 and 57.78%, respectively. Additionally, BEdy1 exhibited a significant time-dose effect on WBPH. This study further investigated the pathogenic process of BEdy1. The results showed that BEdy1 invaded by penetrating the body wall of the WBPH, with its spores mostly distributed in the insect's abdominal gland pores, compound eyes on the head, and other locations. At 36 h, the germinated hyphae penetrated the insect's body wall and entered the body cavity. At 84 h, the hyphae emerged from the body wall and accumulated in the insect's abdomen, leading to a significant number of insect deaths at this stage. At 120 h, the hyphae entangled the insect's compound eyes and produced new conidia on the insect's body wall, entering a new cycle of infection. These findings indicate that BEdy1 has a strong infection ability against WBPH. In summary, this study provides a new highly pathogenic strain of B. bassiana, BEdy1, for the biological control of WBPH, which is of great significance for the green prevention and control of rice pests.

Genome assembly of an endemic butterfly (Minois aurata) shed light on the genetic mechanisms underlying ecological adaptation to arid valley habitat

BackgroundThe Hengduan Mountains, one of the global biodiversity hotspots with exceptional species richness and high endemism, contains numerous arid valleys that create a distinctive geographical and ecological landscape. However, the adaptive evolutionary mechanisms of organism in the arid valley remain poorly understood. Minois aurata, an endemic butterfly species found exclusively in the arid valley of the upper Minjiang River, represents an attractive model system for studying adaptive evolutionary mechanisms to arid valley environments.ResultsHere, we present the first chromosome-level genome assembly for Minois aurata, with a total size of approximately 609.17 Mb, and a scaffold N50 size of 23.88 Mb. These scaffolds were further clustered and anchored onto 29 chromosomes based on Hi-C data. A total of 16,163 protein-coding genes were predicted, of which 91.83% were functionally annotated. The expansion of transposable elements (TEs) accounts for the relatively large genome size of M. aurata, potentially aiding its adaptation to environmental conditions. Phylogenomic analyses based on 3,785 single-copy genes revealed that M. aurata is most closely related to Hipparchia semele. Further mitochondrial genome analysis of four Minois species placed M. aurata in a basal position within the genus, supporting it as an independent species. A total of 185 rapidly evolving and 232 specific gene families were identified in M. aurata. Functional enrichment analysis indicated that these gene families were mainly associated with ultraviolet radiation, heat and hypoxia responses. We also identified 234 positive selected genes in M. aurata, some of which are related to compound eye photoreceptor development, osmotic stress, and light stimulus response. Demographic analysis indicated that the effective population size of M. aurata decreased around 0.4 and 0.04 million years ago, respectively, coinciding with the localized sub-glaciation.ConclusionThe chromosome-level genome offers a comprehensive genomic basis for understanding the evolutionary and adaptive strategies of Minois aurata in the unique arid valley environment of the Hengduan Mountains, while also providing valuable insights into the broader mechanisms of organism adaptation to such habitats.

Compensation to visual impairments and behavioral plasticity in navigating ants

Desert ants are known to rely heavily on vision while venturing for food and returning to the nest. During these foraging trips, ants memorize and recognize their visual surroundings, which enables them to recapitulate individually learned routes in a fast and effective manner. The compound eyes are crucial for such visual navigation; however, it remains unclear how information from both eyes are integrated and how ants cope with visual impairment. Here, we manipulated the ants' visual system by covering one of the two compound eyes and analyzed their ability to recognize familiar views. Monocular ants showed an immediate disruption of their ability to recapitulate their familiar route. However, they were able to compensate for this nonnatural impairment in a few hours by engaging in an extensive route-relearning ontogeny, composed of more learning walks than what naïve ants typically do. This relearning process with one eye forms novel memories, without erasing the previous memories acquired with two eyes. Additionally, ants having learned a route with one eye only are unable to recognize it with two eyes, even though more information is available. Together, this shows that visual memories are encoded and recalled in an egocentric and fundamentally binocular way, where the visual input as a whole must be matched to enable recognition. We show how this kind of visual processing fits with their neural circuitry.

Scanning electron microscopy, morphometric and energy dispersive X-Ray analysis of cephalothoracic structures exploring defensive and sensory features in kuruma shrimp (Marsupenaeus japonicus Spence Bate, 1888)

BackgroundKuruma shrimp (Marsupenaeus japonicus) is a commercially important crustacean and a valuable global food source. This study employed scanning electron microscopy (SEM) to explore the morphology and morphometric features of the Marsupenaeus japonicus cephalothoracic structures, including antennules, antennas, scaphocerite, rostrums, and eye stalks. The primary focus was on understanding the role of each part, especially through the examination of setae, which are crucial for chemoreception and defense. Additionally, energy dispersive X-ray spectroscopy (EDX) analysis was utilized to identify the elemental composition of these structures.Material and methodsThe samples from the heads of fifteen Marsupenaeus japonicus were studied by gross morphology and morphometry, SEM, and EDX analysis. This study is the first to integrate both SEM and EDX techniques for a detailed analysis of these cephalothoracic structures, offering an innovative approach to understanding both morphological and elemental characteristics.ResultsMarsupenaeus japonicus exhibited two antennules and two antennae. The antenna featured four basal segments: basicerite, ischiocerite, merocerite, and carpocerite, each with distinctive articulations and setae distribution. The antennule, with three segments covered by plumose setae, displayed curved cone-shaped flagellae. The scaphocerite, resembling a paddle, showcased plumose setae, while the rostrum exhibited dorsal and ventral spines, lateral grooves, and unique setal arrangements. Setal measurements across structures revealed diverse lengths and widths, indicating functional specialization. The compound eyes were connected to an optic stalk adorned with plumose setae. EDX analysis revealed higher percentages of calcium and phosphorus in the spear-like structures of the scaphocerite, rostrum, and antenna, respectively.ConclusionThis investigation provides a thorough examination of the intricate morphological features of the cephalothoracic region of Marsupenaeus japonicus, shedding light on its sensory and defensive capabilities. The novel application of both SEM and EDX not only deepens our insights into these structures but also lays the groundwork for future studies using this dual approach to explore crustacean morphology, with potential advantages for sustainable aquaculture and the conservation of marine ecosystems.

Research on motion target detection based on infrared biomimetic compound eye camera

The cooled mid-wave infrared biomimetic compound eye camera has wide range of applications, such as industrial inspection, military project, and security. Due to the low resolution of individual eyes and the large field view of the imaging system, existing motion target enhancement and detection algorithms cannot effectively detect all potential targets. To address this issue, we propose an improved elementary motion detector model that combines a double-layer ON_OFF channel and a cross-type computational architecture, which is able to suppress a stationary background and enhance moving targets. In order to further reduce the missed detection, we designed the spatial and temporal consistency detection methods of the compound eye structure, which further improved the accuracy and stability of the detection results. The experimental results show that our method can fully utilize the features of the image and can be applied to the enhancement and detection of moving objects in complex scenes, and the detection efficiency is significantly improved.

A Rapid, Simple Workflow for Quantification of External Adult Drosophila Structures.

The Drosophila compound eye is a precisely patterned tissue that has revealed molecular mechanisms and biological processes that drive morphogenesis. It is a simple structure of repeating unit eyes, termed ommatidia, that is used to characterize genetic interactions and gene functions. Mutations that affect eye architecture can be easily detected and analyzed; hence, this system is frequently used in under-resourced institutions. Further phenotypic analysis often includes a Scanning Electron Microscope (SEM) to generate high-magnification images suitable for quantitative analysis. However, SEMs are expensive and require costly reagents; sample preparation spans days; and, often, they need full-time staff for sample preparation and instrument maintenance. This limits their utility at under-resourced institutions or during budgetary austerity. In entomology, the use of high-resolution digital imaging technology is a common practice for the identification and characterization of species. This paper describes a method that combines strategies and allows for high-resolution digital imaging of adult Drosophila structures and quantitative analysis using the open software ImageJ. The workflow is a rapid and student-friendly alternative that remedies the limitations of underfunded and under-resourced research facilities with a cost-effective and rapid approach to quantitative phenotypic analysis.

Alteration of Cytoskeletal Proteins Leads to Retinal Degeneration in Drosophila.

The eye holds a special fascination for many neuroscientists because of its meticulously organized structure. Vertebrates typically possess a simple camera-type eye, whereas the compound eye structure is predominantly observed in arthropods including model organism Drosophila melanogaster. Cell shape, cell polarization, and tissue integrity are the cell biological processes crucial for shaping the eye, which directly or indirectly depends on the cytoskeleton. Henceforth the cytoskeleton, specifically actin microfilaments, essentially has a dynamic role in the normal development and growth of eye structure. This review provides insight into the roles played by the actin cytoskeleton during the development and maintenance of the Drosophila eye.

Ultra-compact on-chip camera based on optoelectronic compound eyes with nonuniform ommatidia

Abstract Compound eyes (CEs) that feature ultra-compact structures and extraordinary versatility have revealed great potential for cutting-edge applications. However, the optoelectronic integration of CEs with available photodetectors is still challenging because the planar charge-coupled device (CCD)/complementary metal oxide semiconductor (CMOS) detector cannot match the spatially distributed images formed by CE ommatidia. To reach this end, we report here the optoelectronic integration of CEs by manufacturing 3D nonuniform ommatidia for developing an ultra-compact on-chip camera. As a proof-of-concept, we fabricated microscale CEs with uniform and nonuniform ommatidia through femtosecond laser two-photon photopolymerization, and compared their focusing/imaging performance both theoretically and experimentally. By engineering the surface profiles of the ommatidia at different positions of the CE, the images formed by all the ommatidia can be tuned on a plane. In this way, the nonuniform CE can be directly integrated with a commercial CMOS photodetector, forming an ultra-compact CE camera. Additionally, we further combine the CE camera with a microfluidic chip, which can further serve as an on-chip microscopic monitoring system. We anticipate that such an ultra-compact CE camera may find broad applications in microfluidics, robotics, and micro-optics.