Insect Morphology Research Articles

Mayfly emergence production and body length response to hydrology in a tropical lowland stream.

BackgroundHydrological impacts on aquatic biota have been assessed in numerous empirical studies. Aquatic insects are severely affected by population declines and consequent diversity loss. However, many uncertainties remain regarding the effects of hydrology on insect production and the consequences of energy transfer to the terrestrial ecosystem. Likewise, sublethal effects on insect morphology remain poorly quantified in highly variable environments. Here, we characterized monthly fluctuation in benthic and emerged biomass of Ephemeroptera in a tropical lowland stream. We quantified the proportion of mayfly production that emerges into the riparian forest. We also examined the potential morphological changes in Farrodes caribbianus (the most abundant mayfly in our samples) due to environmental stress.MethodsWe collected mayflies (nymphs and adults) in a first-order stream in Costa Rica. We compared benthic and adult biomass from two years’ worth of samples, collected with a core sampler (0.006 m2) and a 2 m2-emergence trap. The relationship between emergence and annual secondary production (E/P) was used to estimate the Ephemeroptera production that emerged as adults. A model selection approach was used to determine the relationship between environmental variables that were collected monthly and the emergent biomass. To determine potential departures from perfect bilateral symmetry, we evaluated the symmetry of two morphological traits (forceps and forewing) of F. caribbianus adults. We used Spearman’s rank correlation coefficients (ρ) to examine potential changes in adult body length as a possible response to environmental stress.ResultsBenthic biomass was variable, with peaks throughout the study period. However, peaks in benthic biomass did not lead to increases in mayfly emergence, which remained stable over time. Relatively constant mayfly emergence suggests that they were aseasonal in tropical lowland streams. Our E/P estimate indicated that approximately 39% and 20% (for 2002 and 2003, respectively) of the nymph production emerged as adults. Our estimated proportion of mayfly production transferred to terrestrial ecosystems was high relative to reports from temperate regions. We observed a strong negative response of F. caribbianus body length to increased hydrology (Spearman: ρ = −0.51, p < 0.001), while slight departures from perfect symmetry were observed in all traits.ConclusionOur two years study demonstrates that there was large temporal variability in mayfly biomass that was unrelated to hydrological fluctuations, but potentially related to trophic interactions (e.g., fish predation). Body length was a good indicator of environmental stress, which could have severe associated costs for mayfly fitness in ecosystems with high temporal variation. Our results highlight the complex ecological and evolutionary dynamics of tropical aquatic insects, and the intricate connection between aquatic and terrestrial ecosystems.

A geochemical model for the preservation of insects in the Crato Formation (Lower Cretaceous) of Brazil

The Crato Formation Lagerstätte of NE Brazil is well known for the exceptional preservation of its fossil assemblage. A wide variety of plants and animals are preserved with a high degree of fidelity, revealing structures of labile tissues at the micron scale, or even smaller. Chemical analyses and descriptions of replacement fabrics observed in insect fossils from the formation are here re-evaluated. Two mineral phases with three distinct fabrics are identified replacing soft tissues: 1) nano-crystalline high-fidelity pyrite replacements of insect epicuticle (pseudomorphed in goethite); 2) pyrite framboids and pseudoframboids obliterating original insect morphology (pseudomorphed in goethite); 3) globular replacements and encrustations of internal labile tissues in calcium phosphate. A revised taphonomic and geochemical model is presented that accounts for both the high fidelity of preservation and the micro-fabrics observed. In addition, we consider aspects of the depositional environment, including substrate consistency, water depth and light penetration. We conclude that the water depth was likely in excess of 50 m, but within the photic zone, and the sediment was bound by stratified microbial communities.

Nonlinear Oscillator-Based Gait Generation for a Novel Aero-Terrestrial Bioinspired Robotic System

AbstractThis paper focuses on the design of a novel aero-terrestrial robotic system based on the morphology of the Hymenoptera order insects and, particularly, on a strategy based on nonlinear oscillators for the coordination of its 12 terrestrial degrees-of-freedom (DoF). The ability of this new aero-terrestrial robot to, successfully, perform the walking process is validated through numerical simulations and tests performed on an experimental platform in which the gait speed was varied from 0.04 to 0.2 m/s. Some of the most important qualities of this robotic system are a relatively simple design with only 2 DoF per leg and a versatile terrestrial locomotion with the ability to vary its speed and direction in real-time with smooth transitions. Furthermore, unlike existent similar systems, the robot is designed to initiate a flight phase in any position without adopting particular postures avoiding undesirable interferences with the walking configuration.

Dispersal and migration have contrasting effects on butterfly flight morphology and reproduction

Movement may fundamentally alter morphology and reproductive states in insects. In long-distance migrants, reproductive diapause is associated with trade-offs between diverse life-history traits such as flight morphology and lifespan. However, many non-diapausing insects engage in shorter resource-driven dispersals. How diapause and other reproductive states alter flight morphology in migrating versus dispersing insects is poorly understood. To find out, we compared flight morphology in different reproductive states of multiple butterfly species. We found that dispersers consisted of ovulating females with higher egg loads compared with non-dispersing females. This trend was in stark contrast with that of migrating female butterflies in reproductive diapause, which made substantially higher investment in flight tissue compared with reproductively active, non-migrating females. Thus, long-distance migration and shorter resource-driven dispersals had contrasting effects on flight morphology and egg loads. By contrast, male flight morphology was not affected by dispersal, migration or associated reproductive states. Thus, dispersal and migration affected resource allocation in flight and reproductive tissue in a sex-specific manner across relatively mobile versus non-dispersing individuals of different species. These findings suggest that dispersals between fragmented habitats may put extra stress on egg-carrying females by increasing their flight burdens.

IDENTIFIKASI HAMA PENGGEREK DAUN Liromiza spp. (Diptera: Agromyzidae) DAN PARASITOIDNYA YANG BERASOSIASI PADA BERBAGAI JENIS TANAMAN SAYURAN DI KECAMATAN DETUSOKO DAN KELIMUTU KABUPATEN ENDE

The aim of this research is to identify Liromiza spp. And the parasitoid is associated with various types of vegetable plants in Detusoko and Kelimutu Districts in Ende Regency. Data were analyzed by matching morphology of existing specimens with insect morphology books written by Bhorror 1970 and matching with standard specimens originating from Bali and Bogor. The results obtained from two vegetable producing districts in Ende, namely Detusoko and Kelimutu, show the following: There are two types of Liriomyza spp associated with several types of host plants in Ende Regency. L. huidobrensis (Diptera: Agromyzydae) is located in Kelimutu District and L Sativae (Diptera: Agromyzydae) is in Detusoko District. The diversity of parasitoids found in Detusoko Subdistrict were as many as four species from the Eulopidae family while in Kelimutu District there were five types of parasitoids originating from two families namely Braconidae and Euiopidae. Neosacharis okazaki is the most dominant type of parasitoid in each plant in Detusoko District. Opiits sp dominant in Kelimutu Subdistrict on the long bean, green beans, mustard greens, chicory and cabbage. While H. varicornis is dominant in Kelimutu District in tomato plants.

Tools of the trade: MicroCT reveals native structure and functional morphology of organs that drive caterpillar\u2013ant interactions

Caterpillars of many lycaenid butterflies are tended by ants that offer protection from predators and parasitoids. Specialized structures such as glands, ciliary organs and chitinous ornamentation in caterpillars play key roles in the underlying tactile, acoustic, and chemical communication between caterpillars and ants. Although the ecological, evolutionary, and behavioural aspects of these interactions are well studied, the mechanisms (i.e., the functional morphology) that drive the specialized interactive organs are poorly characterized. We used advanced X-ray microtomography (MicroCT) to delineate internal, native morphology of specialized larval dew patches, nectar glands, and tactile ciliary organs that mediate interactions between Crematogaster ants and caterpillars of the obligate myrmecophilous Apharitis lilacinus butterfly. Our non-destructive MicroCT analysis provided novel 3-D insights into the native structure and positions of these specialized organs in unmatched detail. This analysis also suggested a functional relationship between organ structures and surrounding muscles and nervation that operate the glands and tactile organs, including a ‘lasso bag’ control mechanism for dew patches and muscle control for other organs. This provided a holistic understanding of the organs that drive very close caterpillar–ant interactions. Our MicroCT analysis opens a door for similar structural and functional analysis of adaptive insect morphology.

P1842THE HISTORY OF VETERINARY RENAL PHYSIOLOGY AND NOSOLOGY IN ANCIENT AND MIDDLE AGES GREEK TEXTS

Abstract ackground and Aims Background and Aims: To present the ideas of Ancient and Byzantine Greek authors about the renal anatomy, physiology and nosology of mammals, birds, insects and fishes. Method Method: We searched for the appropriate passages in the works of Aristotle, Aristophanes Byzantius, Galen, Cladius Aelianus, Alexander Aphrodisiensis, Basilius Caesariensis, Gregorius Nyssensus, Nemesius Emesenus, Hippiatrica Berolinensia, Hippiatrica Parisiana, Hippiatrica Cantabergiensia, Michael Ephesius and Michael Glycas. These texts extended from the 4th cent. BC until the 12th cent. AD. Results Aristotle elaborates on the varied number of kidneys in several animals and on the abundance of perirenal fat. The last tissue is essential for protecting and warming the animal but, in excess, it may be lethal, as in the case of sheep. He then describes the multilubular kidneys of some animals and the supposed lack of a bladder in birds and marine animals, with the exception of the sea turtle. Aristophanes adds the issue of the deer’s ectopic kidneys and their number in canines. Basilius and Gregorius elaborate on the minute details of some animals’ organs, like the kidneys and feathers of flying ants and the moral rationale of all these. Nemesius discusses the possibility of some animals surviving without kidneys. The monumental work “Hippiatrica” deals exclusively with horse health and refers, inter alia, to kidney afflictions. It describes the clinical signs of what it calls “nephritis”, with oedema and predominating neurological symptoms. For treatment it recommends several methods of causing renal hyperaemia, like massaging, ointments, warm rooms, heated irons, but also bloodletting. Michael Ephesius returns on the absence of proper kidneys in birds and their substitution with kidney-like organs called “nephroids”. Glycas “justifies” the lack of bladder and kidneys in birds as useless because they secrete their excess water via the feathers, a long flying time and watery stools. Conclusion The Ancient and Byzantine Greek authors had understood well several topics of the anatomy, physiology and nosology of the veterinary renal system but they also made some very great mistakes. We will present the above conclusions in length.

A Tale of Winglets: Evolution of Flight Morphology in Stick Insects

Author(s): Zeng, Yu; O'Malley, Connor; Singhal, Sonal; Rahim, Faszly; Park, Sehoon; Chen, Xin; Dudley, Robert | Abstract: The evolutionary transition between winglessness and a full-winged morphology requires selective advantage for intermediate forms. Conversely, repeated secondary wing reductions among the pterygotes indicates relaxation of such selection. However, evolutionary trajectories of such transitions are not well-characterized. The stick insects (Phasmatodea) exhibit diverse wing sizes at both interspecific and intersexual levels, and thus provide a system for examining how selection on flight capability, along with other selective forces, drives the evolution of flight-related morphology. Here, we examine variation in relevant morphology for stick insects using data from 1,100+ individuals representing 765 species. Although wing size varies along a continuous spectrum, taxa with either long or miniaturized wings are the most common, whereas those with intermediate-sized wings are relatively rare. In a morphological space defined by wing and body size, the aerodynamically relevant parameter termed wing loading (the average pressure exerted on the air by the wings) varies according to sex-specific scaling laws; volant but also flightless forms are the most common outcomes in both sexes. Using phylogenetically-informed analyses, we show that relative wing size and body size are inversely correlated in long-winged insects regardless of sexual differences in morphology and ecology. These results demonstrate the diversity of flight-related morphology in stick insects, and also provide a general framework for addressing evolutionary coupling between wing and body dimensions. We also find indirect evidence for a “fitness valley” associated with intermediate-sized wings, suggesting relatively rapid evolutionary transitions between wingless and volant forms.

How to study enhancers in non-traditional insect models

Transcriptional enhancers are central to the function and evolution of genes and gene regulation. At the organismal level, enhancers play a crucial role in coordinating tissue- and context-dependent gene expression. At the population level, changes in enhancers are thought to be a major driving force that facilitates evolution of diverse traits. An amazing array of diverse traits seen in insect morphology, physiology and behavior has been the subject of research for centuries. Although enhancer studies in insects outside of Drosophila have been limited, recent advances in functional genomic approaches have begun to make such studies possible in an increasing selection of insect species. Here, instead of comprehensively reviewing currently available technologies for enhancer studies in established model organisms such as Drosophila, we focus on a subset of computational and experimental approaches that are likely applicable to non-Drosophila insects, and discuss the pros and cons of each approach. We discuss the importance of validating enhancer function and evaluate several possible validation methods, such as reporter assays and genome editing. Key points and potential pitfalls when establishing a reporter assay system in non-traditional insect models are also discussed. We close with a discussion of how to advance enhancer studies in insects, both by improving computational approaches and by expanding the genetic toolbox in various insects. Through these discussions, this Review provides a conceptual framework for studying the function and evolution of enhancers in non-traditional insect models.

Bionomic notes on parthenogenetic females and a record of parasitism by Forcipomyia Meigen (Diptera: Ceratopogonidae) in the stick insect Cladoxerus cryphaleus (Westwood) (Phasmatodea: Phasmatidae)

ABSTRACT Stick insects (Phasmatodea) are among the least studied insect groups in Brazil. Although in recent years there has been an increase in the number of published studies on taxonomy and morphology of Brazilian stick insects, they remain very little-known concerning biological and bionomic aspects. From five females of Cladoxerus cryphaleus (Phasmatidae: Cladomorphinae) collected in the Iguacu National Park, Parana, Brazil, a captive colony of parthenogenetic females was started, based on which data on longevity, fertility, and viability of eggs of this species were recorded for the first time. After imaginal molting, the 21 females studied had an average longevity of 103.7 days. Each female produced on average 125.3 eggs, which had a hatching rate of 34.2%. In addition, we recorded a C. cryphaleus male nymph being parasitized by a biting midge of the subgenus Forcipomyia (Microhelea) (Diptera: Ceratopogonidae). The male, in pre-imaginal instar and already parasitized, was collected in the municipality of Petropolis, Rio de Janeiro.

Revealing the respiratory system of the coffee berry borer (Hypothenemus hampei; Coleoptera: Curculionidae: Scolytinae) using micro-computed tomography

The coffee berry borer (Hypothenemus hampei) is the most economically important insect pest of coffee globally. Micro-computed tomography (micro-CT) was used to reconstruct the respiratory system of this species for the first time; this is the smallest insect (ca. 2 mm long) for which this has been done to date. Anatomical details of the spiracles and tracheal tubes are described, images presented, and new terms introduced. The total volume and the relationship between tracheal lumen diameter, length and volume are also presented. The total length of the tracheal tubes are seventy times the length of the entire animal. Videos and a 3D model for use with mobile devices are included as supplementary information; these could be useful for future research and for teaching insect anatomy to students and the public in general.

Anatomical study of the coffee berry borer (Hypothenemus hampei) using micro-computed tomography

Traditionally, the study of anatomy in insects has been based on dissection techniques. Micro-computed tomography (micro-CT) is an X-ray based technique that allows visualization of the internal anatomy of insects in situ and does not require dissections. We report on the use of micro-CT scans to study, in detail, the internal structures and organs of the coffee berry borer (Hypothenemus hampei), the most damaging insect pest of coffee worldwide. Detailed images and videos allowed us to make the first description of the aedeagus and the first report of differences between the sexes based on internal anatomy (flight musculature, midgut shape, hindgut convolutions, brain shape and size) and external morphology (lateral outline of the pronotum and number of abdominal tergites). This study is the first complete micro-CT reconstruction of the anatomy of an insect and is also the smallest insect to have been evaluated in this way. High quality rendered images, and additional supplementary videos and 3D models are suitable for use with mobile devices and are useful tools for future research and as teaching aids.

Caught in the act of hatching – a group of heteropteran nymphs escaping from their eggs preserved in Dominican amber

Insects enclosed in amber can provide unique insights into the morphology, but also behavioural aspects of extinct species, due to their often exceptional preservation. This is especially true in the cases of so-called ‘frozen behaviour', were animals were caught in the fresh and viscid resin while e.g. mating, egg laying, capturing prey or in rare cases, hatching. Here, we report a group of heteropteran insect nymphs preserved together with their eggs in 15–20 million-year-old Dominican amber. Two of the nymphs were caught in the act of hatching. The eggs form a cluster of 47 individuals and possess a morphology, as occurs in the eggs of some extant Reduviidae, especially Hapactorinae. Most notable are the operculum surrounding elongated extensions of the chorion at the apical part of the elongated eggs. The cluster strongly resembles the appearance of a composite flower. Details of the egg morphology of extinct insects are very scarce, and even if fossil remains can be identified as insect eggs, the corresponding insect group can rarely be determined. Rare cases of ‘frozen behaviour’, such the herein described, allow to observe aspects of the hatching process, but can also help to shed light on the morphology of the eggs from different extinct insect groups.

A Study of Fostering Elementary School Children’s Knowledge and Scientific Skills in the Unit “Life”: Based on Children’s Recognitions of the Morphology of Insects

本研究の主目的は，腹面から描いた昆虫の体のつくりに対する小学校第2・3学年の認識状態を分析し，その結果に基づき，育成すべき子どもの資質・能力について検討を加えることにある。得られた知見は，以下の4点である。1）腹面から描いた計9種類の生き物を，昆虫とその他の生き物とに分類できた小2は約60％以上，小3は80％以上であったこと。2）腹面から描いた計6種類全ての昆虫の体を三つの部分（頭部・胸部・腹部）に正しく分けることができた小2は皆無であり，小3でも約20％であったこと。かつ，各昆虫の正答率は小2で10％未満，小3でも65％未満であったこと。3）昆虫の体のつくりに対する回答は多様であり，頭部で4類型，胸部で9類型，及び腹部で3類型が存在したこと。4）得られた結果をもとに，昆虫概念の育成を志向した学習指導方策について提案した。

昆虫標本作製法・撮影法・活用法（1）昆虫形態図の描画法

昆虫標本作製法・撮影法・活用法（1）昆虫形態図の描画法

Inferring coevolution in a plant–pollinator network

Mutualistic interactions are at the core of community dynamics, determining dispersal, colonization and differential survival and reproduction among individuals and species. Mutualistic interactions therefore affect the fitness of interaction partners, hence modifying their respective evolutionary trajectories reciprocally, potentially leading to coevolution. Although mathematical models predict coevolution in mutualistic interaction networks, no empirical data are available. By taking into account the patterns of interactions and reconstructing evolutionary change in plant and pollinator traits, we tested the hypothesis that coevolution occurs between plants and insects that interact more frequently, or more symmetrically. To test this hypothesis, we built an interaction network with data from five flowering seasons, measured plant and insect morphology, mapped morphology on the plant and insect phylogenies, and reconstructed ancestral character changes based on maximum parsimony. We calculated an index, called the coevolutionary ratio, which represents the amount of correlated change in traits that mediate the interaction between plants and pollinators (i.e. proboscis versus corolla length, and body width and corolla aperture). Our results suggest that high frequency of interaction, i.e. the number of times two species interact, does not lead to coevolution. Instead, symmetry of interaction strength, i.e. the reciprocal similarity in the mutual effect of interaction partners, may lead to coevolution, in spite of a pervasive lack of reciprocal specialization and high interaction frequency. Although the statistical signal is quite weak, our results hold for three statistical tests of very different nature. The most specialized species, expected to be under directional selection, do not show more evolutionary change than do generalist species, expected to be under different, perhaps opposing, selective pressures. By dissecting the complexity of an interaction network we show that coevolution may partially shape functional morphology of interaction partners, thus providing the closest evidence to date of mutualistic adaptation of organisms within a community.

Sensitivity of Larva Spodoptera litura Against the Density of Spores of Fungi Metarhizium anisopliae on the Onion Plant Red (Allium cepa) in the Laboratory

Sensitivity of Larva Spodoptera litura Against the Density of Spores of Metarhizium anisopliae Fungi On the Red Onion Plant ", aims to determine the density of Metarhizium anisopliae spores which are effective in controlling the spodoptera litura pests that attack onion plants. This research was conducted by using Randomized Complete Random (RAL) Factorial ie instar larvae and spore density. The parameters observed were behavioral and morphological changes as well as percentage mortality of Spodoptera litura larvae. The results showed that: Changes in behavior and morphology of insects in the form of slow movement, decreased appetite and larval body surface covered by the fungus is light green and dark green. The density of spores of M. anisopliae to S. litura pest has a very significant effect on the percentage of S. litura mortality since the age of 1-9 HSA. The percentage of S. litura mortality tended to increase with higher spore density of M. anisopliae and instar 1-3 being more sensitive instar than instar 4-6 Spodoptera litura larvae. Mortality of S. litura is most prevalent in I1M3 treatment (instar 1-3 with spore density 106).

The suitability of cicada’s shell for teaching material to study morphology of insects in the science education of elementary school

The suitability of cicada’s shell for teaching material to study morphology of insects in the science education of elementary school

Invasion of the oak lace bug Corythucha arcuata (Say.) in Romania: a first extended reporting

In the context of globalization, the biological invasions affect all the countries, including Romania, where this phenomenon is increasingly visible in the last years. Besides the invasive forest insects already known to be established in Romania, a new species - Corythucha arcuata (Say, 1832), commonly known as the oak lace bug and originating in North America, appeared in the last years. It was reported for the first time in Romania in 2015, and it spread across the country in 2016-2017. In order to detect the species and to draw its distribution area, a species identification sheet, as well as a working protocol were developed, considering the insect morphology and the type of attack. During the vegetation seasons 2016 and 2017, the species was found in 67 out of the 124 surveyed locations, mainly in the southern and western parts of the country, but also in the eastern part. The main host species of the oak lace bug were Quercus robur, Q. petraea, Q. cerris, Q. frainetto, and Q. pubescens. It attacked the host trees in all habitats (tree stands, parks, nurseries, isolated trees etc.) and the intensity of attack varied from 1% to 100% of the leaves.

A mosaic of independent innovations involving eyes shut are critical for the evolutionary transition from fused to open rhabdoms

A fundamental question in evolutionary biology is how developmental processes are modified to produce morphological innovations while abiding by functional constraints. Here we address this question by investigating the cellular mechanism responsible for the transition between fused and open rhabdoms in ommatidia of apposition compound eyes; a critical step required for the development of visual systems based on neural superposition. Utilizing Drosophila and Tribolium as representatives of fused and open rhabdom morphology in holometabolous insects respectively, we identified three changes required for this innovation to occur. First, the expression pattern of the extracellular matrix protein Eyes Shut (EYS) was co-opted and expanded from mechanosensory neurons to photoreceptor cells in taxa with open rhabdoms. Second, EYS homologs obtained a novel extension of the amino terminus leading to the internalization of a cleaved signal sequence. This amino terminus extension does not interfere with cleavage or function in mechanosensory neurons, but it does permit specific targeting of the EYS protein to the apical photoreceptor membrane. Finally, a specific interaction evolved between EYS and a subset of Prominin homologs that is required for the development of open, but not fused, rhabdoms. Together, our findings portray a case study wherein the evolution of a set of molecular novelties has precipitated the origin of an adaptive photoreceptor cell arrangement.