The Integument of Arthropods

The Integument of Arthropods: The Chemical Components and Their Properties, the Anatomy and Development, and the Permeability

Copyright Date: 1951
Edition: NED - New edition
Pages: 428
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  • Book Info
    The Integument of Arthropods
    Book Description:

    This critical monograph presents a review and synthesis of the literature on the chemical, physical, and biological aspects of the integument of arthropod animals. The volume covers and collates material published through 1949 on the chemical and physical properties, the structure and development, and the permeability of the integument of insects, crustacea, and their relatives. There is, in addition, an indexed bibliography of some 1800 references, and a subject index. The first section treats the physical and chemical properties of the entire cuticle and the cuticular components. In the second section, the structure and development of the integument are traced, with a classification of recognizable subdivision, and separate chapters on molting and specialized structures. The third section takes up the problems of permeability with emphasis on the complexity and relative scarcity of valid data on the subject. Most of the references in the bibliography relate directly to the material presented, but references to similar phenomena or structures found in other groups of organisms or in artificial models are included. To facilitate independent use of the bibliography, each reference is followed by a list of the pages where the article is cited. Fourteen tables and over two hundred line drawings, diagrams, and photomicrographs, grouped into 65 text figures, show chemical configurations, representative structural details, and properties. The book provides a much needed reference work for entomologists and those working in related fields of zoology, chemistry, biochemistry, insect physiology, and ecology.

    eISBN: 978-0-8166-6415-3
    Subjects: Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-x)
  2. Table of Contents
    (pp. xi-2)
  3. CHAPTER 1 Introduction
    (pp. 3-6)

    The integument is one of the primary organ systems of an animal. The term can be restricted to the tissue and tissue products forming the outer surface of the body or it can be used in a broader sense, as in this book, for the external covering tissue and structures which are derived from it and have a similar general structure. Epithelial tissue, derived from the embryonic ectoderm and having a structure fundamentally similar to that of the body wall, lines the fore-gut and hind-gut, the tracheae of the respiratory system, most of the reproductive ducts and the glands associated...

    • CHAPTER 2 Glucosamine, N-acetylglucosamine, Chitobiose, and Chitin
      (pp. 9-25)

      How many polysaccharide derivatives should be discussed in this section seems an open question (Haworth 46). Some would probably limit it to a discussion of the polymer called chitin, which, it is now established, is a polyacetylglucosamine, or at most, they would mention those units which have led to the identification of the polymer unit. However, if we adopt the current point of view, which seems to be gaining general acceptance, that chitin does not occur naturally as a distinct and separate chemical entity in the cuticle but is always found as one component in a chitin-protein complex, then it...

    • CHAPTER 3 Chitin Derivatives and Metabolic Sources
      (pp. 26-31)

      When chitin is fused with alkali or treated with concentrated alkali solutions at rather high temperatures (160-180°s C. is the customarily used range), it undergoes a variable amount of deacetylation to give a product that has been termed chitosan (Hoppe-Seyler 1895). The product formed is soluble in dilute acids, as was recorded by Rouget in 1859. As far as is known, chitosan does not occur naturally in arthropod cuticle. Its importance for biology lies in the fact that the conversion of chitin to chitosan does not involve changes in gross structure and that chitosan gives a distinctive violaceous color with...

    • CHAPTER 4 The Detection and Estimation of Chitin
      (pp. 32-40)

      The demonstration of the presence of chitin in a structure is still on a relatively crude qualitative basis. For strong pieces of membrane the iodine-chitosan color test is, as far as we know, completely valid when positive; negative results, however, are open to serious question, as cases are known where positive tests are obtained only a small percentage of the time (Richards 47). The other tests that will be outlined appear to be either less specific or less reliable or are not feasible for general use. The situation is even less satisfactory when one desires quantitative results, either relative or...

    • CHAPTER 5 The Distribution of Chitin in the Animal and Plant Kingdoms
      (pp. 41-53)

      It was originally intended to bring together for purposes of ready reference all the seemingly authentic records of the presence of chitin. Collation had not proceeded far before it became clear that this aim was not feasible, partly because many of the references are simply inserted in taxonomic monographs or morphological papers where they are not readily located, and even more because in a considerable percentage of the references, other than those specifically dealing with this point, it is not possible to tell whether the author is recording the result of a test he performed or simply stating what is...

    • CHAPTER 6 The Decomposition of Chitin and Cuticle in Nature
      (pp. 54-58)

      It seems self-evident that cuticle would have to be decomposed or its accumulation would represent a serious depletion of available carbon and nitrogen reserves. It has been estimated that the copepod Crustacea alone produce several billion tons of chitin annually (Johnstone 08); probably several times this amount is produced annually by other marine Crustacea and by terrestrial arthropods. And yet no great accumulation results, despite the fact that, as far as we know, the system does not decompose spontaneously. Also, relatively delicate laboratory measurements of electrical properties and examination by electron microscopy of cuticles kept under favorable conditions have not...

    • CHAPTER 7 Proteins
      (pp. 59-70)

      When Odier discovered chitin in the elytra of May beetles in 1823, he recognized that this represented only about 30% of the weight of the cuticle and that the remainder of the material was mostly protein. Since then a large number of workers have recognized the presence of protein by qualitative color tests. It is, however, only in the papers by Trim (41a, b) and by Fraenkel and Rudall (40, 47) that some information concerning the nature of this particular protein group is to be found.

      In soft cuticles a large portion of the protein can be removed by water...

    • CHAPTER 8 Polyphenols and Enzymes
      (pp. 71-79)

      Polyphenols and their corresponding quinone derivatives have recently come into great prominence following the demonstration by Pryor (40a, b) of their role in hardening as well as darkening of the cuticle. That they played a role had been suggested earlier by Schmalfuss and Barthmeyer (31). Orthodihydroxyphenols are readily demonstrated in arthropod cuticle by the nonspecific but convenient argentaffin reaction ¹ or more specifically by the ferric chloride test.² The argentaffin test (Fig. 64) has now been applied to a wide variety of insects (Broussy 33, Dennell 46, 47b, Kuwana 40, Lafon 41b, c, Wigglesworth 45, 47a, b, 48b) as well...

    • CHAPTER 9 Mixed Polymers
      (pp. 80-85)

      There is nothing novel in the idea that mixed polymers occur in arthropod cuticle, but there are still so few significant data that even speculative discussion should be kept conservative. In a sense a protein molecule could be called a mixed polymer since it is composed of different amino acid residues. The term mixed polymer, however, is usually restricted to polymeric molecules containing more than one type of organic chemical, such as lipoproteins or glycoproteins. Since there are strong indications that mixed polymers are of considerable significance in arthropod cuticle, the subject will be discussed briefly in terms of the...

    • CHAPTER 10 Pigments
      (pp. 86-93)

      For various reasons the subject of pigment chemistry is going to receive only restricted treatment here. Even if the author had adequate background to treat this subject critically, which he certainly does not have, there is still considerable uncertainty in many of the papers as to whether the pigment dealt with is located in the cuticle or located in some internal organ and seen through the cuticle. With very few exceptions the older papers are of only historic interest now, and even many of the recent ones seem of questionable value. Certainly we can add only hearty agreement to Uvarov’s...

    • CHAPTER 11 Lipids
      (pp. 94-99)

      The cuticular lipids, or at least those about which chemical information is available, are all waxes, ¹ but there is some evidence for the presence of sterols. That insects produce wax in the sense of secretion, for instance, beeswax, has been known since antiquity. However, the fact that waxes form an important part of arthropod cuticle is a fairly recent finding. It was recognized in the nineteenth century (Odier 1823) that the outermost layer of arthropod cuticle is a thin sheet of highly refractile material, but the lipid nature of this thin layer was not convincingly demonstrated until the work...

    • CHAPTER 12 Inorganic Constituents and Calcification
      (pp. 100-108)

      Ashing of any intact cuticle shows a few per cent of ash. Of particular interest is the small percentage of sulfur, but unfortunately little is known about it other than its presence (Lafon 43a, Trim 41b). However, in the Crustacea, the organic matter may account for anywhere from < 1% to > 99%, the remainder of the substance being referred to as lime or calcareous material. Calcareous skeletons are also found in many Diplopoda. Calcareous deposits are found on a few dipterous larvae and in the egg shells of phasmids, but in these insects do not form true calcareous skeletons. The puparium...

    • CHAPTER 13 The Percentages of Cuticular Components
      (pp. 109-114)

      A tabular presentation of the percentages of various inorganic constituents and the percentage of inorganic in relation to organic compounds has already been given in the preceding chapter (Tables 7 & 8). In the present section consideration will be limited to the percentages of organic components; for calcified species the percentages given are in relation to the organic content after removal of the mineral salts. The difficulties in the quantitative estimation of organic components are considerable (Campbell 29, Fraenkel & Rudall 47, Richards 47b). However accurate some of the more recent reports may be, it certainly seems safest to assume that these...

    • CHAPTER 14 Unknown Chemical Components
      (pp. 115-117)

      Remarks on the occurrence of unknown components are found scattered throughout the preceding sections. It might be worth while to bring these together into a single section, although little more than a listing can be given. The significance of the several per cent of ash found in insect cuticles, and probably to be found in other noncalcified cuticles, is not known. Probably much of it is simply contaminant salts which have diffused in from underlying tissues and play no real role in the cuticle itself. But this is not necessarily true, and the data seem to indicate clearly that sulfur...

    • CHAPTER 15 The Physical Properties of Cuticle and Cuticular Components
      (pp. 118-142)

      There have been relatively few studies on the physical properties of cuticle, partly, at least, because of the large range of variation in those of considerable biological interest, such as elasticity and hardness. Perhaps the chief function of Table 11 will be to emphasize the paucity of quantitative data that are available. Some properties have already been treated in the preceding sections on chemistry and will not be repeated here, namely, solubilities, melting points, molecular weights, and lattice structures. Discussion of the production of physical colors and of permeability will be deferred until after treatment of cuticle morphology. No data...

    • CHAPTER 16 The General Structure
      (pp. 145-158)

      In beginning a treatment of the general structure, or histology, of the arthropod integument (Figs. 1, 30, etc.), one is faced with the necessity of having a classification of subdivisions or subheadings and with defining the terms to be used. Definitions are by nature arbitrary, and terms tend to become indefinable by the finding of intermediates and exceptional cases, although the exceptions seem less serious in cytology and histology than in gross anatomy.

      It is not difficult to argue that the cuticle is an entity rather than a complex and, accordingly, that any set of terms for subdivisions is artificial...

    • CHAPTER 17 Historical and Taxonomic Résumé
      (pp. 159-162)

      An extensive historical review giving credit to the hundreds of authors who have published on the structure of arthropod cuticle would be prohibitively voluminous, but some mention of significant workers is desirable. To some extent, the value or at least diversity of application of the work of various authors may be judged from the number of references in the Author Index, but this favors recent authors.

      In the same paper in which he recorded the discovery of the chemical chitin, Odier in 1823 recognized the presence of protein and a covering layer which we now call the epicuticle. Adequate preliminary...

    • CHAPTER 18 The Epicuticle, or Nonchitinous Cuticle
      (pp. 163-172)

      That the outer surface of the cuticle was covered by a material distinct from that of the matrix was recognized by Odier(1823), Straus-Durckheim (1828), Burmeister (1832), and many subsequent authors. Numerous terms have been used to designate the outer layer or layers; in many cases the precise synonymizing of these with current terminology is uncertain.¹ A long list of papers document the generality that almost, if not quite, all arthropods have such an outer, nonchitinous layer. Citing only a partial list of references, epicuticles are recorded for Chilopoda (Fuhrmann 21), Diplopoda (Fuhrmann 21, Langner 37, Silvestri 03), various Arachnida, including...

    • CHAPTER 19 The Procuticle, or Chitinous Cuticle
      (pp. 173-183)

      Noncalcified cuticle is found on all species of arthropods; when calcification occurs, it is limited to certain areas and to certain sublayers. Hundreds of anatomical and histological papers include descriptions and illustrations of the integument. These serve to document only the statement that gross histological appearance is similar throughout the phylum. Few of these papers contain significant analytical data.

      From unknown precursors the cuticle components become polymerized as a solid structure with a fairly high water content (Table 10). In some cases it is definitely known that the precursors are secreted from the epidermal cells in fluid form and undergo...

    • CHAPTER 20 Differentiation of the Procuticle
      (pp. 184-195)

      In some cases (soft transparent membrane) the procuticle undergoes little or no detectable change after its formation (Fig. 30c). This does not necessarily mean it cannot be changed. For instance, in the mothEphestiaone can obtain a partial pupation with omission of the molting fluid; the soft larval cuticles is not shed: more material is added to it and the whole changed into a heavily scerotized pupal skin, albeit of abnormal appearance (Fig. 36) (Kühn 39). In general it seems to be true that the soft procuticle is capable of being sclerotized, and that it becomes sclerotized in those...

    • CHAPTER 21 Physical Colors
      (pp. 196-201)

      Space will not permit detailed treatment of the diverse optical phenomena involved in physical colors. A simplified treatment of interference, the most important source of physical colors in arthropods, will be given. Of the many papers on physical colors in insects, the ones by Malloch (11),. H Onslow (20, 21), Rayleigh (23, 30), Süffert (24), and C. W. Mason (26–29) are outstanding and should be consulted for details. The series of papers by Gentil (33–46), Kühn ( 39–46 ), and Catala (49) give good examples of how much is to be found in the way of minor...

    • CHAPTER 22 The Epidermis
      (pp. 202-216)

      One could hardly overemphasize the importance of the general epidermal cells (Lees 48, Wigglesworth 37, 40a). As the living components of the integument, they secrete the cuticle, probably even manufacturing part of its constituents, secrete the fluid which digests the old cuticle, absorb the digestion products of the old cuticle, repair wounds, and become differentiated in such a way that they control the development of pattern. Also some of the epidermal cells differentiate into various forms of sense organs and glands for many diverse purposes. There are many papers treating the general histology of the epidermis, and a few of...

    • CHAPTER 23 The Oenocytes, Blood Cells, and Basement Membrane
      (pp. 217-222)

      Oenocytes are known only in insects, where they were first adequately described by von Wielowiejski in 1886. While they are generally conceded to be an important organ of intermediary metabolism, their probable relation to molting and cuticle production is more suspected than known. Papers on oenocytes in general or including reviews of the literature are the ones by Albro (30), Gee (11), Glaser (12), Hollande (13, 14), Koller (29), Lesperon (37), Paillot (20), Verson (00), Verson and Bisson (1891), W. M. Wheeler (1892), Wigglesworth (39), and Willers and Dürken (16). Orders of insects covered include Orthoptera (Chauvin 37, Minchin 1888,...

    • CHAPTER 24 Molting
      (pp. 223-236)

      The preceding chapters in this section have been concerned with the development of component layers of the integument as well as with the structure of the fully formed exoskeleton. The loosening and shedding of the old cuticle, the sequence of stages involved in the development of the new cuticle, factors which affect molting, and certain miscellaneous additional points not covered in preceding chapters remain to be treated. The molting process, or at least initiation of the molting process, is under hormonal control. In keeping with a general hormonal stimulus, one usually finds complete synchronization of the stages throughout the integument...

    • CHAPTER 25 Muscle Attachments, Tendons, and Apophyses
      (pp. 237-242)

      The mode of attachment of muscles to arthropod cuticle was a hotly argued question near the end of the nineteenth and beginning of the twentieth centuries. Casual examination of a section of a soft cuticle through a muscle attachment is sufficient to show that the longitudinal fibrils in the muscle (myofibrillae) are continuous with fibrils extending through the epidermal cell layer and into the procuticle (tonofibrillae or tonomitomes). The argument involved whether the tonofibrillae represent the end of the muscle itself or a tendonal attachment formed by the epidermal cell layer, and whether the tonofibrillae passed through epidermal cells or...

    • CHAPTER 26 Wings, Gills, Epidermal Glands, Etc.
      (pp. 243-252)

      In terms of development insect wings are simply evaginated sacks of integument which become flattened and the two sides closely appressed to one another, as was shown by Semper in 1857 (Figs. 49–50). Wings possess some special features which are not (or not so well) shown by the integument in general; only these special features will be treated here. For the general structure and development of wings numerous papers are available; consult the larger reference sources (Snodgrass 35, Weber 33) or the special papers which are available for Neuroptera (Sundermeier 40), Diptera (Pérez 10), Hymenoptera (Schlüter 33), Coleoptera (Reuter...

    • CHAPTER 27 The Tracheal System
      (pp. 253-266)

      The literature on the tracheal system is very large, and it is not easy to decide how much should be covered here. It seems that the line between general insect anatomy and that portion of tracheal structure that belongs in a book on integument must necessarily be arbitrary. For purposes of this book, anatomy in the sense of homologies of tracheal branches, evolution of the branching systems, and distribution to the various organs will be omitted; aspects of more questionable relevance such as intracellular versus intercellular tracheoles will be simply indexed; and only the structure of the wall will be...

    • CHAPTER 28 Sculpturing, Sensillae, and Miscellaneous Structures
      (pp. 267-282)

      A number of aspects of the integument remain. These are grouped together in the present chapter for rather cursory treatment. Surface sculpturing is commonly described in taxonomic papers, especially for groups routinely examined with a compound microscope (e.g., thrips), but little is known about it. Sense organs are truly a part of the integument but, except for their cuticles, are better left for treatments on sensory physiology. Other miscellaneous structures which are not truly integumentary (egg shells, spermatophores, ootheca, lac cells, peritrophic membrane) will be mentioned only insofar as they add to material given in the preceding chapters.

      Either macroscopic...

    • CHAPTER 29 General Remarks on the Permeability of the Cuticle
      (pp. 285-297)

      The field of membrane permeability is intricate. Discussions of it are, of necessity, filled with assumptions and speculative thinking. It is easy enough to read a few treatises and then become eloquent with the language of physical chemistry, but the small amount of unequivocable data on the permeability of arthropod cuticle makes this undesirable. In this section an attempt will be made only to document the statement that it is extremely difficult to obtain valid permeability data and to make profitable deductions therefrom, to state what seem to be the major particular properties that need to be taken into account,...

    • CHAPTER 30 The Penetration of Water and Gases
      (pp. 298-307)

      In general the permeability of hard arthropod cuticle to water is decidedly low in both terrestrial and aquatic species (Maloeuf 37, Pieh 36, Wigglesworth 32a). For the crop of cockroaches (Abbott 26) and the larval cuticle of blowflies (Richards & Fan 49) penetration is so low that osmometer experiments gave negative results. In contrast a high order of permeability to water, approximating that of the plasma membrane,¹ may be found in areas with the function of water, salt, or gas exchange (Berger & Bethe 31, von Gorka 14, Jordan & Lam 18, Laszt & Siillman 36, D. A. Webb 40, Wigglesworth 32a, b, Yonge...

    • CHAPTER 31 The Penetration of Electrolytes, Nonelectrolytes, and Insecticides
      (pp. 308-320)

      Recently two papers have been published giving quantitative permeability values for the larval cuticles of higher Diptera, the values being either obtained from living individuals or accompanied by ancillary tests to validate the determinations made (Fig. 61, Table 14). The cuticles of higher dipterous larvae are particularly suitable for this purpose because they are reasonably homogeneous and do not have setae or open gland ducts or pore canals (Fig. 20A). Also sheets of sufficient size to use in diffusion cells can readily be obtained. The data available are not sufficiently extensive to warrant detailed discussion, but it may be noted...

    (pp. 321-397)
    (pp. 398-411)