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Title:A Text-book of Entomology
Including the Anatomy, Physiology, Embryology and Metamorphoses of Insects for Use in Agricultural and
Technical Schools and Colleges As Well As by the Working Entomologist
Author: Alpheus S. Packard
Release Date: March 02, 2021 [eBook #64677]
Language: English
Character set encoding: UTF-8
Produced by: Richard Tonsing and the Online Distributed Proofreading Team at https://www.pgdp.net
(This file was produced from images generously made available by The Internet Archive)
*** START OF THE PROJECT GUTENBERG EBOOK A TEXT-BOOK OF ENTOMOLOGY ***
A TEXT-BOOK OF ENTOMOLOGY
A
TEXT-BOOK OF ENTOMOLOGY
INCLUDING
THE ANATOMY, PHYSIOLOGY, EMBRYOLOGY AND METAMORPHOSES
OF
INSECTS
FOR USE IN AGRICULTURAL AND TECHNICAL SCHOOLS AND COLLEGES
AS WELL AS BY THE WORKING ENTOMOLOGIST
BY
ALPHEUS S. PACKARD, M.D., Ph.D.
PROFESSOR OF ZOÖLOGY AND GEOLOGY, BROWN UNIVERSITY AUTHOR OF “GUIDE TO STUDY OF INSECTS,”
“ENTOMOLOGY FOR BEGINNERS,” ETC.
New York
THE MACMILLAN COMPANY
LONDON: MACMILLAN & CO., Ltd.
1898
All rights reserved
Copyright, 1898,
By THE MACMILLAN COMPANY.
Norwood Press
J. S. Cushing & Co.—Berwick & Smith
Norwood Mass. U.S.A.
PREFACE
In preparing this book the author had in mind the wants both of the student and the teacher. For the
student’s use the more difficult portions, particularly that on the embryology, may be omitted. The work
has grown in part out of the writer’s experience in class work.
In instructing small classes in the anatomy and metamorphoses of insects, it was strongly felt that the
mere dissection and drawing of a few types, comprising some of our common insects, were by no means
sufficient for broad, thorough work. Plainly enough the laboratory work is all important, being rigidly
disciplinary in its methods, and affording the foundation for any farther work. But to this should be
added frequent explanations or formal lectures, and the student should be required to do collateral
reading in some general work on structural and developmental entomology. With this aim in view, the
present work has been prepared.
It might be said in explanation of the plan of this book, that the students having previously taken a
lecture course in the zoölogy of the invertebrates, were first instructed in the facts and conclusions
bearing on the relations of insects to other Arthropoda, and more especially the anatomy of Peripatus, of
the Myriopoda, and of Scolopendrella. Then the structure of Campodea, Machilis, and Lepisma was
described, after which a few types of winged insects, beginning with the locust and ending with the bee,
were drawn and dissected; the nymph of the locust, and the larva and pupa of a moth and of a wasp and
bee being drawn and examined. Had time permitted, an outline of the embryology and of the internal
changes in flies during their metamorphoses would have been added.
This book gives, of course with much greater fulness and detail for reference and collateral reading,
what we roughly outlined in our class work. The aim has been to afford a broad foundation for future
more special work by any one who may want to carry on the study of some group of insects, or to extend
in any special direction our present knowledge of insect morphology and growth.
Many of our entomologists begin their studies without any previous knowledge of the structure of
animals, taking it up as an amusement. They may be mere collectors and satisfied simply to know the
name of their captures, but it is hoped that with this book in their hands they may be led to desire
farther information regarding what has already been done on the structure and mode of growth of the
common insects. For practical details as to how to dissect, to make microscopic slides, and to mount and
preserve insects generally, they are referred to the author’s “Entomology for Beginners.”
It may also be acknowledged that even in our best and latest general treatises on zoölogy, or
comparative anatomy, or morphology, the portion related to insects is scarcely so thoroughly done as
those parts devoted to other phyla, that of Lang, however, his invaluable Comparative Anatomy, being
an exception. On this account, therefore, it is hoped that this hiatus in our literature may be in a degree
filled.
The author has made free use of the excellent article “Insecta” of Newport, of Lang’s comprehensive
summary in his most useful Text-book of Comparative Anatomy, of Graber’s excellent Die Insecten, of
Miall and Denny’s The Structure and Life-History of the Cockroach, and of Sharp’s Insecta. Kolbe’s
Einführung has been most helpful. But besides these helps, liberal use has been made of the very
numerous memoirs and monographic articles which adorn our entomological literature. The account of
the embryology of insects is based on Korschelt and Heider’s elaborate work, Lehrbuch der
Vergleichenden Entwicklungsgeschichte der Wirbellosen Thiere, the illustrations of this portion being
mainly taken from it, through the Messrs. Swan Sonnenschein & Co., London.
Professor H. S. Pratt has kindly read over the manuscript and also the proofs of the portion on
embryology and metamorphoses, and the author is happy to acknowledge the essential service he has
rendered.
The bibliographical lists are arranged by dates, so as to give an idea of the historical development of
each subject. The aim has been to make these lists tolerably complete and to include the earliest, almost
forgotten works and articles as well as the most recent.
Much care has been taken to give due credit either to the original sources from which the illustrations
are copied, or to the artist; about ninety of the simpler figures were drawn by the author, many of them
for this work. For the use of certain figures acknowledgments are due to the Boston Society of Natural
History, to the Division of Entomology, U. S. Department of Agriculture, through the kind offices of Mr.
L. O. Howard, and to the Illinois State Laboratory of Natural History, through Professor S. A. Forbes and
Mr. C. A. Hart. Professor W. M. Wheeler, of the University of Chicago, has kindly loaned for reproduction
several of his original drawings published in the Journal of Morphology. A number are reproduced from
figures in the reports of the United States Entomological Commission.
Providence, R. I.,
March 4, 1898.
v
vi
vii
TABLE OF CONTENTS
PART I. MORPHOLOGY AND PHYSIOLOGY
PAGE
Position of Insects in the Animal Kingdom
1
Relations of Insects to Other Arthropoda
2
The Crustacea
4
The Merostomata
5
The Trilobita
5
The Arachnida
6
Relations of Peripatus to insects
9
Relation of Myriopods to insects
11
Relations of the Symphyla to insects
18
Diagnostic or essential characters of Symphyla
22
Insecta (Hexapoda)
26
Diagnostic characters of insects
26
1. EXTERNAL ANATOMY
a. Regions of the body
27
b. The integument (exoskeleton)
28
Chitin
29
c. Mechanical origin and structure of the segments (somites, arthromeres, etc.)
30
d. Mechanical origin of the limbs and of their jointed structure
35
The Head and its Appendages
42
a. The head
42
The labrum
42
The epipharynx and labrum-epipharynx
43
Attachment of the head to the trunk
46
The basal or gular region of the head
46
The occiput
48
The tentorium
49
Number of segments in the head
50
The composition of the head in the Hymenoptera
55
b. Appendages of the head
57
The antennæ
57
The mandibles
59
The first maxillæ
62
The second maxillæ
68
The hypopharynx
70
Does the hypopharynx represent a distinct segment?
82
The Thorax and its Appendages
86
ix
x
a. The thorax: its external anatomy
86
The patagia
89
The tegulæ
89
The apodemes
92
The acetabula
94
b. The legs: their structure and functions
95
Tenent hairs
99
Why do insects have but six legs?
100
Loss of limbs by disuse
101
c. Locomotion (walking, climbing, and swimming)
103
Mechanics of walking
103
Locomotion on smooth surfaces
111
Climbing
116
The mode of swimming of insects
116
d. The wings and their structure
120
The veins
121
The squamæ
123
The halteres
124
The thyridium
124
The tegmina and hemelytra
124
The elytra
124
e. Development and mode of origin of the wings
126
Embryonic development of the wings
126
Evagination of the wing outside of the body
132
Extension of the wing; drawing out of the tracheoles
133
f. The primitive origin of the wings
137
The development and structure of the tracheæ and veins of the wing
144
g. Mechanism of flight
148
Theory of insect flight
150
Graber’s views as to the mechanism of the wings, flight, etc.
153
The Abdomen and its Appendages
162
The median segment
163
The cercopoda
164
The ovipositor and sting
167
The styles and genital claspers (Rhabdopoda)
176
Velum penis
181
The suranal plate
181
The podical plates or paranal lobes
182
The infra-anal lobe
183
The egg-guide
183
The Armature of Insects: Setæ, Hairs, Scales, Tubercles, Etc.
187
The cuticula
187
Setæ
188
xi
Glandular hairs and spines
190
Scales
193
Development of the scales
195
Spinules, hair-scales, hair-fields, and androconia
197
The Colors of Insects
201
Optical colors
201
Natural colors
203
Chemical and physical nature of the pigment
206
Ontogenetic and phylogenetic development of colors
207
2. INTERNAL ANATOMY
The Muscular System
211
Musculature of a caterpillar
213
Musculature of a beetle
213
Minute structure of the muscles
215
Muscular power of insects
217
The Nervous System
222
a. The nervous system as a whole
222
b. The brain
226
The optic or procerebral segment
231
Procerebral lobes
232
The mushroom or stalked bodies
233
Structure of the mushroom bodies
234
The central body
237
The antennal or olfactory lobes (Deutocerebrum)
237
The œsophageal lobes (Tritocerebrum)
237
c. Histological elements of the brain
238
d. The visceral (sympathetic or stomatogastric) system
238
e. The supraspinal cord
240
f. Modifications of the brain in different orders of insects
240
g. Functions of the nerve-centres and nerves
243
The Sensory Organs
249
a. The eyes and insect vision
249
The simple or single-lensed eye (ocellus)
249
The compound or facetted eye (ommateum)
250
The facet or cornea
250
The crystalline lens or cone
251
The pigment
253
The basilar membrane
253
The optic tract
253
Origin of the facetted eye
255
Mode of vision by single eyes or ocelli
255
Mode of vision by facetted eyes
256
The principal use of the facetted eye to perceive the movements of animals
259
xii
How far can insects see?
260
Relation of sight to the color of eyes
260
The color sense of insects
260
b. The organs of smell
264
Historical sketch of our knowledge of the organs of smell
264
Physiological experiments
268
Relation of insects to smelling substances before and after the loss of their antennæ
269
Experiments on the use of the antennæ in seeking for food
270
Experiments testing the influence of the antennæ of the males in seeking the females
270
Structure of the organs of smell in insects
271
c. The organs of taste
281
Structure of the taste organs
282
Distribution in different orders of insects
282
Experimental proof
286
d. The organs of hearing
287
The ears or tympanal and chordotonal sense-organs of Orthoptera and other insects
288
Antennal auditory hairs
292
Special sense-organs in the wings and halteres
293
e. The sounds of insects
293
The Digestive Canal and its Appendages
297
a. The digestive canal
302
The œsophagus
303
The crop or ingluvies
303
The “sucking stomach” or food-reservoir
305
The fore-stomach or proventriculus
306
The œsophageal valve
311
Proventricular valvule
313
The peritrophic membrane
313
The mid-intestine
314
Histology of the mid-intestine
316
The hind-intestine
316
Large intestine
316
The ileum
317
The gastro-ileal folds
317
The colon
317
The rectum
318
The vent (anus)
319
Histology of the digestive canal
320
b. Digestion in insects
324
The mechanism of secretion
326
Absorbent cells
328
The Glandular and Excretory Appendages of the Digestive Canal
331
a. The salivary glands
331
b. The silk or spinning glands, and the spinning apparatus
339
The process of spinning
340
xiii
How the thread is drawn out
343
Appendages of the silk-gland (Filippi’s glands)
345
c. The cæcal appendages
347
d. The excretory system (urinary or Malpighian tubes)
348
Primitive number of tubes
353
e. Poison-glands
357
f. Adhesive or cement-glands
360
g. The wax-glands
361
h. “Honey-dew” or wax-glands of Aphids
364
i. Dermal glands in general
365
Defensive or Repugnatorial Scent-Glands
368
Eversible coxal glands
369
Fœtid glands of Orthoptera
369
Anal glands of beetles
372
The blood as a repellent fluid
374
Eversible glands of caddis-worms and caterpillars
375
The osmeterium in Papilio larvæ
377
Dorsal and lateral eversible metameric sacs in other larvæ
377
Distribution of repugnatorial or alluring scent-glands in insects
382
The Alluring or Scent-Glands
391
The Organs of Circulation
397
a. The heart
397
The propulsatory apparatus
401
The supraspinal vessel
403
The aorta
404
The pericardial cells
405
Pulsatile organs of the legs
405
b. The blood
407
The leucocytes
407
c. The circulation of the blood
409
Effects of poisons on the pulsations
412
The Blood Tissue
419
a. The fat-body
419
b. The pericardial fat-body or pericardial cells
420
Leucocytes or phagocytes in connection with the pericardial cells
421
c. The œnocytes
423
d. The phosphorescent organs
424
xiv
Physiology of the phosphorescence
426
The Respiratory System
430
a. The tracheæ
431
Distribution of the tracheæ
432
b. The spiracles or stigmata
437
The position and number of pairs of stigmata
439
The closing apparatus of the stigma
441
c. Morphology and homologies of the tracheal system
442
d. The spiral threads or tænidia
444
e. Origin of the tracheæ and of the “spiral thread”
447
Internal, hair-like bodies
451
f. The mechanism of respiration and the respiratory movements of insects
451
g. The air-sacs
456
The use of the air-sacs
457
h. The closed or partly closed tracheal system
459
i. The rectal, tracheal gills, and rectal respiration of larval Odonata and other insects
463
j. Tracheal gills of the larvæ of insects
466
Blood-gills
475
k. Tracheal gills of adult insects
476
The Organs of Reproduction
485
a. The male organs of reproduction
494
The testes
495
The seminal ducts
496
The ejaculatory duct
497
The accessory glands
497
The spermatozoa
497
Formation of the spermatozoön
498
b. The female organs of reproduction
500
The ovaries and the ovarian tubes
500
Origin of incipient eggs in the germ of the testes
504
The bursa copulatrix
505
The spermatheca
506
The colleterial glands
506
The vagina or uterus
507
Signs of copulation in insects
507
PART II. EMBRYOLOGY OF INSECTS
a. The egg
515
Mode of deposition
518
Vitality of eggs
520
Appearance and structure of the ripe egg
520
The egg-shell and yolk-membrane
520
The micropyle
522
Internal structure of the egg
524
b. Maturation or ripening of the egg
525
c. Fertilization of the egg
525
d. Division and formation of the blastoderm
526
e. Formation of the first rudiments of the embryo and of the embryonic membranes
531
Formation of the embryonic membranes
532
The gastrula stage
535
Division of the embryo or primitive band into body-segments
536
Differences between the invaginated and overgrown primitive band
538
Revolution of the embryo where the primitive band is invaginated
540
f. Formation of the external form of the body
542
Origin of the body-segments
542
The procephalic lobes
544
Fore-intestine (stomodæum) and hind-intestine (proctodæum), labrum
547
Completion of the head
548
g. The appendages
548
The cephalic appendages
548
The thoracic appendages
550
The abdominal appendages
550
Appendages of the first abdominal segment (pleuropodia)
551
Are the abdominal legs of Lepidoptera and phytophagous Hymenoptera true limbs?
552
The tracheæ
553
h. Nervous system
554
Completion of the definite form of the body
555
i. Dorsal closure and involution of the embryonic membranes
556
j. Formation of the germ-layers
558
k. Farther development of the mesoderm; formation of the body-cavity
563
l. Formation of organs
566
The nervous system
566
Development of the brain
567
Development of the eyes
567
Intestinal canal and glands
569
The salivary glands
570
The urinary tubes
572
The heart
572
The blood-corpuscles
574
Musculature; connective tissue; fat-body
574
xv
The reproductive organs
575
Development of the male germinal glands
579
m. Length of embryonic life
582
n. The process of hatching
583
The hatching spines
585
PART III. THE METAMORPHOSES OF INSECTS
a. The nymph as distinguished from the larval stage
593
b. Stages or stadia of metamorphosis
594
c. Ametabolous and metabolous stages
594
The Larva
599
a. The Campodea-form type of larva
600
b. The eruciform type of larva
602
c. Growth and increase in size of the larva
608
d. The process of moulting
609
The number of moults in insects of different orders
615
Reproduction of lost limbs
619
Formation of the cocoon
619
Sanitary conditions observed by the honey-bee larva, and admission of air within the cocoon
623
The Pupa State
625
a. The pupa considered in reference to its adaptation to its surroundings and its relation to
phylogeny
631
b. Mode of escape of the pupa from its cocoon
632
c. The cremaster
636
Mode of formation of the cremaster and suspension of the chrysalis in butterflies
637
Formation of the Pupa and Imago in the Holometabolous Insects (the Diptera excepted)
640
a. The Lepidoptera
642
The changes in the head and mouth-parts
646
The change in the internal organs
647
The wings
654
Development of the feet and of the cephalic appendages
654
Embryonic cells and the phagocytes
655
Formation of the femur and of the tibia; transformation of the tarsus
656
The antennæ
657
Maxillæ and labial palpi
658
Process of pupation
660
b. The Hymenoptera
661
Ocular or oculo-cephalic buds
665
The antennal buds
665
xvi
The buds of the buccal appendages
665
The buds of the ovipositor
665
Development of the Imago in the Diptera
666
a. Development of the outer body-form
668
Formation of the imago in Corethra
668
Formation of the imago in Culex
670
Formation of the imago in Chironomus
671
Formation of the imago in Muscidæ
673
b. Development of the internal organs of the imago
678
The hypodermis
678
The muscles
680
The digestive canal
681
The tracheal system
683
The nervous system
684
The fat-body
685
Definitive fate of the leucocytes
685
The post-embryonic changes and imaginal buds in the Pupipara (Melophagus)
686
c. General summary
687
Hypermetamorphism
688
Summary of the Facts and Suggestions as to the Causes of Metamorphism
705
Theoretical conclusions; causes of metamorphosis
708
xvii
TEXT-BOOK OF ENTOMOLOGY
PART I.—MORPHOLOGY AND PHYSIOLOGY
POSITION OF INSECTS IN THE ANIMAL KINGDOM
Although the insects form but a single class of the animal kingdom, they are yet so numerous in
orders, families, genera, and species, their habits and transformations are so full of instruction to the
biologist, and they affect human interests in such a variety of ways, that they have always attracted
more attention from students than any other class of animals, the number of entomologists greatly
surpassing that of ornithologists, ichthyologists, or the special students of any other class, while the
literature has assumed immense proportions.
Insects form about four-fifths of the animal kingdom. There are about 250,000 species already named
and contained in our museums, while the number of living and fossil species in all is estimated to amount
to between one and two millions.
In their structure insects are perhaps more complicated than any other animals. This is partly due to
the serial arrangement of the segments and the consequent segmental repetition of organs, especially of
the external appendages, and of the muscles, the tracheæ, and the nerves. The brain is nearly or quite as
complicated as that of the higher vertebrates, while the sense-organs, especially those of touch, sight,
and smell are, as a rule, far more numerous and only less complex than those of vertebrates. Moreover,
in their psychical development, certain insects are equal, or even superior, to any other animals, except
birds and mammals.
The animal kingdom is primarily divided into two grand divisions, the one-celled (Protozoa) and
many-celled animals (Metazoa). In the latter group the cells and tissues forming the body are arranged
in three fundamental cell-layers; viz. the ectoderm or outer layer, the mesoderm, and endoderm. The
series of branches, or phyla, comprised under the term Metazoa are the Porifera, Cœlenterata, Vermes,
Echinodermata, Mollusca, Arthropoda, and Vertebrata. Their approximate relationships may be
provisionally expressed by the following
TABULAR VIEW OF THE EIGHT BRANCHES OR PHYLA OF THE ANIMAL KINGDOM.
1
2
