In biology, a nymph is the juvenile form of some invertebrates, particularly insects, which undergoes gradual metamorphosis (hemimetabolism) before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult, except for a lack of wings and the emergence of genitalia. In addition, while a nymph moults, it never enters a pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars.
Instar
An instar is a developmental stage of arthropods, such as insects, which occurs between each moult (ecdysis) until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width.
Ecdysis
Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae.
Mohrta
Mohrta is a nonlinear FPS adventure through the strange and otherworldly. Explore a vast selection of unique environments, slay an enormous cast of bizarre creatures, and upgrade your arsenal of multifaceted weapons.
One mother for two species via obligate cross-species cloning in ants
Living organisms are assumed to produce same-species offspring1,2. Here, we report a shift from this norm in Messor ibericus, an ant that lays individuals from two distinct species. In this life cycle, females must clone males of another species because they require their sperm to produce the worker caste. As a result, males from the same mother exhibit distinct genomes and morphologies, as they belong to species that diverged over 5 million years ago. The evolutionary history of this system appears as sexual parasitism3 that evolved into a natural case of cross-species cloning4,5, resulting in the maintenance of a male-only lineage cloned through distinct species’ ova. We term females exhibiting this reproductive mode as xenoparous, meaning they give birth to other species as part of their life cycle.
Self-Organization in Biological Systems
The synchronized flashing of fireflies at night. The spiraling patterns of an aggregating slime mold. The anastomosing network of army-ant trails. The coordinated movements of a school of fish. Researchers are finding in such patterns—phenomena that have fascinated naturalists for centuries—a fertile new approach to understanding biological systems: the study of self-organization. This book, a primer on self-organization in biological systems for students and other enthusiasts, introduces readers to the basic concepts and tools for studying self-organization and then examines numerous examples of self-organization in the natural world. Self-organization refers to diverse pattern formation processes in the physical and biological world, from sand grains assembling into rippled dunes to cells combining to create highly structured tissues to individual insects working to create sophisticated societies. What these diverse systems hold in common is the proximate means by which they acquire order and structure. In self-organizing systems, pattern at the global level emerges solely from interactions among lower-level components. Remarkably, even very complex structures result from the iteration of surprisingly simple behaviors performed by individuals relying on only local information. This striking conclusion suggests important lines of inquiry: To what degree is environmental rather than individual complexity responsible for group complexity? To what extent have widely differing organisms adopted similar, convergent strategies of pattern formation? How, specifically, has natural selection determined the rules governing interactions within biological systems? Broad in scope, thorough yet accessible, this book is a self-contained introduction to self-organization and complexity in biology—a field of study at the forefront of life sciences research.
Social Insects : Ecology and Behavioural Biology
1 online resource; Here is a guide to the ecology of social insects. It is intended for general ecologists and entomologists as well as for undergraduates and those about to start research on social insects; even the experienced investigator may find the comparison between different groups of social insects illuminating. Most technical terms are translated into common language as far as can be done without loss of accuracy but scientific names are unavoidable. Readers will become familiar with the name even though they cannot visualize the animal and could reflect that only a very few of the total species have been studied so far! References too are essential and with these it should be possible to travel more deeply into the vast research literature, still increasing monthly. When I have cited an author in another author's paper, this implies that I have not read the original and the second author must take responsi bility for accuracy! Many hands and heads have helped to make this book. I thank all my colleagues past and present for their enduring though critical support, and I thank with special pleasure: E.]. M. Evesham who fashioned the diagrams;]. Free, D.J. Stradling and]. P.E.C. Darlington who supplied photographs; D.Y. Brian and R.A. Weller who were meticulous on the linguistic side; and G. Frith and R.M. Jones who collated the references. List of plates 1. Fungus combs of Acromyrmex octospinosus and Macrotermes michaelseni. 13 2. Mouthparts of larval Myrmica; 1 Introduction -- 2 Food -- 2.1 Termites as decomposers -- 2.2 Wasps and ants as predators -- 2.3 Sugars as fuel save prey -- 2.4 Seed eaters -- 2.5 Leaf eaters -- 2.6 Pollen eaters -- 3 Foraging by individuals -- 3.1 Foraging strategy -- 3.2 Worker variability -- 4 Foraging in groups -- 4.1 Communication about food -- 4.2 Group slave-raiding -- 4.3 Tunnels and tracks -- 4.4 Nomadic foraging -- 5 Cavity nests and soil mounds -- 5.1 Cavities and burrows -- 5.2 Soil mounds -- 6 Nests of fibre, silk and wax -- 6.1 Mounds of vegetation and tree nests -- 6.2 Combs of cells -- 7 Microclimate -- 7.1 Environmental regulation -- 7.2 Metabolic regulation -- 8 Defence -- 8.1 Painful and paralysing injections -- 8.2 Toxic smears and repellants -- 9 Food processing -- 9.1 Mastication, extraction and regurgitation -- 9.2 Yolk food supplements -- 9.3 Head food glands -- 10 Early population growth -- 10.1 Food distribution -- 10.2 Colony foundation -- 10.3 The growth spurt -- 11 Maturation -- 11.1 Simple models of reproduction -- 11.2 Social control over caste -- 11.3 Males in social Hymenoptera -- 11.4 Maturation in general -- 12 Reproduction -- 12.1 Caste morphogenesis -- 12.2 Copulation and dispersal -- 12.3 Production -- 12.4 Summary -- 13 Evolution of insect societies -- 13.1 Theories of individual selection -- 13.2 Models of these theories -- 13.3 Group selection -- 13.4 Conclusions -- 14 Colonies -- 14.1 The colony barrier -- 14.2 Queen number and species ecology -- 14.3 Queen interaction and queen relatedness -- 15 Comparative ecology of congeneric species -- 15.1 Ant and termite races -- 15.2 Desert ants and termites -- 15.3 Ants and termites in grassland -- 15.4 Forest ants and termites -- 15.5 Wasps and bumblebees -- 15.6 Advanced bees -- 16 Communities -- 16.1 Temperate zone communities in grass and woodland -- 16.2 Desert communities -- 16.3 Tropical rain forest -- 16.4 Conclusions -- 17 Two themes -- 17.1 Plant mutualism -- 17.2 Social organization -- References -- Author index
Termite
Termites are a group of eusocial insects which consume a variety of decaying plant material, generally in the form of wood, leaf litter, and soil humus. They are distinguished by their beaded (moniliform) antennae and the soft-bodied, unpigmented worker caste for which they have been commonly termed "white ants"; however, they are not ants but highly derived cockroaches; they are genetically closer to some cockroach groups than these are to other cockroaches. About 2,997 extant species are currently described, 2,125 of which are members of the family Termitidae.
EPISTEMIC STIGMERGY: NATURAL VS. ARTIFICIAL INTELLIGENCE
The article\(^{1}\) defends the thesis that intelligent behavior might require not internal complexity but complex interaction. This is demonstrated by the various forms of stigmergy that can be observed both in social insects and in humans. The exposition is structured as follows: (§0) explains how the term “intelligence” is interpreted in the following text; (§1) clarifies the relation between intelligence and complexity; (§2) shows that intelligent behavior does not require internal complexity; (§3) introduces the concept of stigmergy; (§4) presents the mechanisms that give rise to this phenomenon; (§5) distinguishes several types of stigmergic interaction; (§6) briefly discusses the evolutionary mechanisms that could have produced them; (§7) sketches the possible ways in which the concept of stigmergy is used outside biology; (§8) examines collaborative stigmergy in humans; (§9) points to its epistemic projections; (§10) outlines some conclusions concerning the role of artificial intelligence systems and their place in human society.
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules (the "scraper" or plectrum) being moved across a finely-ridged surface (the "file" or stridulitrum—sometimes called the pars stridens) or vice versa, and vibrating as it does so, like the dragging of a phonograph needle across a vinyl record. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups.[1] Common onomatopoeic words for the sounds produced by stridulation include chirp and chirrup.
L’amnésie environnementale, ou comment notre lente accommodation à une biodiversité dégradée nous fait oublier la nature foisonnante d’antan
Si nous nous souvenons des pare-brise constellés d’insectes morts après un trajet en voiture, que sait-on des loups qui rôdaient dans les campagnes au Moyen Age, ou des saumons dans la Seine au XIXᵉ siècle ? Cet oubli progressif d’une nature hier foisonnante nous empêche de protéger celle d’aujourd’hui.
Invisible Designers: Brain Evolution Through the Lens of Parasite Manipulation
AbstractThe ability of parasites to manipulate host behavior to their advantage has been studied extensively, but the impact of parasite manipulation on the evolution of neural and endocrine mechanisms has remained virtually unexplored. If selection for countermeasures has shaped the evolution of nervous systems, many aspects of neural functioning are likely to remain poorly understood until parasites—the brain’s invisible designers—are included in the picture. This article offers the first systematic discussion of brain evolution in light of parasite manipulation. After reviewing the strategies and mechanisms employed by parasites, the paper presents a taxonomy of host countermeasures with four main categories, namely: restrict access to the brain; increase the costs of manipulation; increase the complexity of signals; and increase robustness. For each category, possible examples of countermeasures are explored, and the likely evolutionary responses by parasites are considered. The article then discusses the metabolic, computational, and ecological constraints that limit the evolution of countermeasures. The final sections offer suggestions for future research and consider some implications for basic neuroscience and psychopharmacology. The paper aims to present a novel perspective on brain evolution, chart a provisional way forward, and stimulate research across the relevant disciplines.
Description of a new species of the hyperparasitic barnacle <i>Duplorbis</i> Smith, 1906 and its cypris larva, with the molecular phylogenetic placement of the enigmatic family Duplorbidae Høeg & Rybakov, 1992 (Cirripedia: Rhizocephala)
Abstract Most species of Rhizocephala are obligate parasites of decapod crustaceans, but species in three families parasitize non-decapod hosts: Chthamalophilidae Bocquet-Védrine, 1961 (parasites of barnacles), Duplorbidae Høeg & Rybakov, 1992 (parasites of isopods and cumaceans), and Thompsoniidae Høeg & Rybakov, 1992 (mostly parasites of decapods but includes one species that is a parasite of stomatopods). Hyperparasitism (form of parasitism in which a secondary parasite lives on or in a primary parasite of a host) is extremely rare in Rhizocephala, but Duplorbis Smith, 1906, the type genus of the enigmatic family Duplorbidae, currently contains two named species hyperparasitic on bopyrid isopods (abdominal and branchial parasites of decapods) and one species on free-living isopods. A lectotype is selected for Duplorbis smithi Nierstrasz & Brender à Brandis, 1923. Recent work on the parasites of squat lobsters from New Zealand revealed a putative new species of this genus, described herein as Duplorbis korun. sp., hyperparasitic on branchial bopyrids of the genera Paragigantione Barnard, 1920 and Parapleurocryptella Bourdon, 1972. Each parasitized female bopyrid contained 3–8 externae of D. korun. sp. in the brood chamber. Externae of one host contained mature cypris larvae, a stage previously poorly known in this genus. These larvae are described herein using SEM and are shown to have a pair of long frontal filaments (retained from the nauplius stage), an exclusive feature shared among Duplorbidae. The first molecular (18S rRNA sequence) analysis of the family was also conducted. Duplorbids appear nested within a well-supported monophyletic lineage also comprising of Polyascidae Høeg & Glenner in Høeg, Noever, Rees, Crandall & Glenner, 2019, Polysaccidae Lützen & Takahashi, 1996, Clistosaccidae Boschma, 1928, Thompsoniidae Høeg & Rybakov, 1992, and Chthamalophilidae Bocquet-Védrine, 1961, most closely related to chthamalophilids. The discovery of this new species expands our knowledge of the species diversity, host use, and larval development of hyperparasitic rhizocephalans.
Spiracle (arthropods)
A spiracle or stigma is the opening in the exoskeletons of insects, myriapods, velvet worms and many arachnids that admits air into the respiratory system.
When stressed, this comb jelly reverts to a larval form, then matures again when favorable conditions return. Learn more: scim.ag/4gmdt2J #ScienceMagArchives
