Transcriber Notes
Emphasized text displayed as: _Italic_ and =Bold=
AN ACCOUNT
OF THE
INSECTS NOXIOUS TO AGRICULTURE AND PLANTS
IN
NEW ZEALAND.
THE SCALE-INSECTS
(COCCIDIDÆ).
By W. M. MASKELL, F.R.M.S.,
REGISTRAR OF THE UNIVERSITY OF NEW ZEALAND.
WELLINGTON:
BY AUTHORITY: GEO. DIDSBURY, GOVERNMENT PRINTER.
1887.
Mr. Maskell's Account of the Scale-Insects occurring in New Zealand is
published by the State Forests and Agricultural Department, under the
instructions of the Hon. John Ballance, Commissioner of State Forests.
Wellington, 31st March, 1887.
CONTENTS.
Chapter. Page
Glossary of Terms and Phrases 1
I. Introductory 5
II. Characters, Life-history, and Metamorphoses of Coccididæ 8
III. Products of the Coccididæ (Honeydew; Black Fungus) 14
IV. Checks to Increase of Coccididæ, Parasites, etc. 18
V. Remedies against Coccididæ 24
VI. Catalogue of Insects and Diagnosis of Species 37
Groups--
Diaspidinæ 39
Lecanidinæ 62
Hemicoccidinæ 87
Coccidinæ 88
Index of Plants and the Coccididæ attacking each 111
Index of Genera and Species 115
PREFACE.
The number and variety of the insect pests which live on the plants of
New Zealand, whether native or introduced, and the damage which they
frequently do, form the excuse for the appearance of this work. The
descriptions of these insects in the Transactions of the New Zealand
Institute, or in works published in Europe and America, are not easily
accessible to the general reader, and are also much scattered and
fragmentary. It was thought therefore that the time had arrived when
the information which might be useful to gardeners and tree-growers,
as well as to students, might be summarized and brought together in a
compendious form, and the present volume is an attempt towards this.
In order to render this work complete a second volume is necessary,
which should include the large number of other destructive insects
preying upon various plants. For example, the "pine-blight"
(_Kermaphis_), the "American blight" (_Eriosoma_), the "black leech"
(_Tenthredo_), the cabbage caterpillar, the turnip "fly," the various
aphides on roses, geraniums, &c., the grass-grub (_Odontria_), the
codlin-moth, the borers, weevils, wireworms, and a number of others are
in different places damaging trees and plants, and it would be useful
to collect in one volume information regarding them. The author has had
in contemplation the preparation of such a volume, and it is hoped that
it may be at some future time published.
Meanwhile the present is offered as, at least as far as it goes, a full
description of one of the most general as well as the most noxious
families of plant-parasites. The plates have been especially prepared
with a double object: first, that gardeners and tree-growers might be
able easily to recognize the kind of insect which might happen to
be damaging their plants; and, secondly, that the student who should
desire to know more of this curious family might have enough details
indicated to guide him in his investigation. For the first purpose
the figures have been coloured as near to nature as possible; for the
second a few anatomical details have been introduced. The printing
of these plates has been executed by Mr. Potts, lithographer to Mr.
A. Willis, of Wanganui, and it is hoped that the reader may be well
satisfied with the care and trouble which have been bestowed upon them.
The author is sensible that this volume may contain numerous
imperfections; but these will not, he trusts, be attributed to culpable
ignorance or carelessness.
EXPLANATION OF TERMS USED IN THE FOLLOWING PAGES.
_Abdomen._ The posterior half of the body of male or female, whether
joined to the anterior half or slightly separated, segmented or
not.
_Abdominal cleft._ A narrow slit in the extremity of the abdomen of
Lecanidinæ and the full-grown _Hemicoccidinæ_ only. (Plate ix.,
Fig. 1, _b_, _c_.) On the upper side of the body are seen the
_Abdominal lobes_, two minute, divergent, triangular or conical,
excrescences, one on each side of the cleft, in _Lecanidinæ_,
usually bearing one or more hairs. (Plate xi., Fig. 3, _b_, _c_.)
_Abdominal spike._ A more or less long, tubular or semi-tubular,
pointed process terminating the abdomen of the male in all
species, and serving as a sheath for the penis, which is a long,
white, soft tube with recurved hairs. (Plate ii., Fig. 3; Plate
xxi., Fig. 1, _k_.)
_Anal ring, anogenital ring._ An orifice situated near the abdominal
extremity of the female, either simple or compound, hairless or
bearing several hairs. (Plate ii., Fig. 1.)
_Anal tubercles._ Exhibited only by the _Coccidinæ_ and by the larvæ
of _Hemicoccidinæ_: two more or less conspicuous projecting
processes at the abdominal extremity of the female, without any
cleft, and in most instances projecting beyond the edge; usually
bearing setæ. (Plate ii., Fig. 2, _c_, _d_.)
_Antennæ._ Two jointed organs ("feelers") projecting from the
anterior portion of the body, of variable length. (Plate i.,
Figs. 9, 10, 11, types.)
_Apodous._ Without feet.
_Apterous._ Without wings.
_Bucca_, _buccal_. The mouth; belonging to the mouth.
_Carina_, _carinated_. A keel or raised-ridge; keeled.
_Cephalic region._ That part of the insect, male or female, which
bears the eyes, antennæ, and mouth, but not including the first
pair of feet.
_Clavate._ Club-shaped; somewhat knobbed.
_Claw._ The hooked terminating joint of the foot. (Plate i., Fig. 6,
_cl._, type.)
_Coxa._ The first joint of the foot, springing directly from the
under-side of the thoracic region. (Plate i., Figs. 6 _c_, 7
_c_.)
_Digitules._ Appendages observed on the feet, and often useful for
distinguishing species. Usually there are two pairs. The "upper
pair" spring from the upper side of the extremity of the tarsus,
and are generally long, fine hairs, terminating in a knob. The
"lower pair" spring from the base of the claw, and are usually
broader and more trumpet-shaped than the upper ones. (Plate i.,
Fig. 8, type.) Sometimes either pair, or both, may be absent.
In _Cœlostoma wairoense_ there are no "upper" digitules, and 24
"lower" ones on the foot of the male. (Plate xxi.)
_Dimerous._ Two-jointed.
_Dorsum._ The upper side of the body when the insect is in its
natural position.
_Dorsal._ On the upper side or dorsum.
_Eyes._ Two coloured, granular or simple, round organs on the
cephalic region of the female, near the base of the antennæ
(Plate xiv., Fig. 2, _k_.; Plate xx., _b_); two, or four,
coloured, granular, simple or facetted, on the head of the male
(Plate i., Figs. 14, 15; Plate xxi., Fig. 2, _b_).
_Femur._ The second joint of the feet, next the coxa, joined to it by
the false joint "trochanter." (Plate i., Figs. 6 _f_, 7 _f_.)
_Fringe._ A portion of the excreted substance, cotton or wax,
produced by the spinnerets on the edge of the body in certain
_Lecanidinæ_ and _Hemicoccidinæ_. It may be in the form of long
glassy threads (_Planchonia_) or of more or less broad flat
plates (_Ctenochiton_). (Plate vii., Figs. 2 _d_, 3 _a_; Plate
xii., Fig. 2, _a_, _b_, _c_.)
_Haltere._ A minute organ, situated just behind the wings of the
males, and of which the use, either in this family or in the
Diptera, has not been satisfactorily ascertained. It is often
termed the "balancer." In the house-fly it has been thought
to represent an organ of hearing. In Coccids it is furnished
with one or more hooked bristles, and Mr. Comstock affirms that
these are, probably for some purposes of flight, hooked into the
posterior edges of the wings.[A] (Plate i., Fig. 17; Plate xxi.,
Fig. 1, _m_.)
[A] Report of the Entomologist, U.S. Dep. of Agric. 1880, p.
277, note.
_Honeydew._ A substance of a glutinous character produced by many
species, and falling in spray from them on the leaves. (See
Chap. III.)
_Larva._ The first stage in the insect's life after emerging from the
egg.
_Lobes_, in the _Diaspidinæ_, are minute, flat, more or less rounded
projections, two or more, seen on the edge of the abdominal
extremity, usually interspersed with spines and hairs (Plate
iii., Figs. 1, 3, 4, 5, _l_); in the _Lecanidinæ_, are two
triangular or conical projections, usually bearing hairs, on the
dorsal side of the body, one on each side of the abdominal cleft
(Plate xi., Fig. 3, _b_, _c_).
_Mentum._ A kind of secondary rostrum, or "under-lip," not altogether
tubular, but rather a deepish trough, through which the rostral
setæ pass after leaving the rostrum. It may have one, two, or
three joints. It is not noticeable in the Diaspidinæ. (Plate i.,
Fig. 5, _b_.)
_Metamorphosis._ A change of form. For the number and characters of
these see Chap. II.
_Moniliform._ Like a string of beads.
_Monomerous._ With a single joint.
_Multilocular._ With several divisions: a term applied to the
spinneret orifices of some insects, distinguishing them from
"simple" orifices, which show only a single tube. Multilocular
orifices exhibit a bundle of tubes enclosed together. (Plate i.,
Fig. 4, _c_, _d_, _p_; Plate xviii., Fig. 2, _e_.)
_Nervure._ A strong vein which, starting from the attachment of the
wing of the male, runs along the anterior edge of the wing,
a little within it: at about half its length a branch runs
obliquely towards the posterior edge. (Plate i., 16; Plate xix.,
_f_; Plate xxi.)
_Normal._ According to rule--not exceptional.
_Ocelli._ Two, four, or six minute circular simple organs, on
the head of the male: probably organs of vision. In the
_Monophlebidæ_ they would seem to be replaced by a smooth
rounded protuberance behind the eye. (Plate i., Fig. 14, _oc._;
Plate viii., Fig. 2, _k_, _m_; Plate xxi., Fig. 2, _b_.)
_Ovisac._ The cottony bag or nest formed by certain species of
_Lecanidinæ_ and _Coccidinæ_ for the reception of their eggs.
(Plate xii., Fig. 1, _a_, _b_, _c_; Plate xix., _a_, _b_, _c_.)
_Peduncle_, _pedunculated_. A stalk; stalked.
_Pellicle._ The skin of an earlier stage, cast off at each
metamorphosis; used by the _Diaspidinæ_ and by one genus of
_Lecanidinæ_ in the formation of the puparium or test. (Plate
i., Fig. 3, _a_, _b_; Plate vii., Fig. 2, _b_.)
_Polymerous._ Many-jointed.
_Pupa._ The last stage of the male insect before emerging winged.
_Puparium._ The shield, covering, or "scale" of the _Diaspidinæ_.
(Plate i., Fig. 3, e; Plates iv., v., vi.)
_Rostral setæ._ Three or, in a few cases, four long, fine, curling,
tubular bristles springing from the rostrum, and often passing
through a mentum; used for insertion into the tissues of a plant
and sucking their contents. (Plate i., Fig. 5; Plate vi., only
one being here shown, from the smallness of the drawings.)
_Rostrum._ A more or less conical, tubular, projecting organ, or
beak, protruding from the under-side of the cephalic region, or
between the first pair of feet. It is absent in the adult female
_Cœlostoma_. It is the "mouth" of the insect. (Plate i., Fig. 5;
Plate iv., Fig. 5.)
_Sac._ The cottony, bag-like covering or nest produced by the
spinnerets and concealing the insect in many of the _Coccidinæ_
and some _Lecanidinæ_. (Plate xv., Fig. 1, _c_; Fig. 2, _b_.)
_Scale._ The shield or puparium of the _Diaspidinæ_. The word is
commonly used to designate the outward appearance of insects
of the whole family, which are indiscriminately called
"scale-insects," although many of them form no shield whatever.
_Secretion_ may be of various kinds. It is matter produced by
internal organs, and expelled through the "spinnerets." In the
_Diaspidinæ_ the secreted portion of the puparium (that is, all
except the pellicles) is made up of fine, closely-woven fibres,
forming the "scale." In the _Lecanidinæ_ it probably exudes
originally as fine fibres, but these become agglomerated in
some cases in a waxy or horny mass, or in others are loosely
collected as cotton. In the _Coccidinæ_ the secretion is
usually cottony, or powdery like meal. _Cœlostoma_ secretes all
three--wax, cotton, and meal. In some instances, as in _Carteria
lacca_, of Africa, the wax, called "shellac," is abundant enough
to be commercially valuable; or, as in the Chinese _Ericerus
Pe-la_ it can be used for making candles.
_Seta._ A bristle--a long stiff hair.
_Setose._ Bearing a few bristles.
_Spinnerets._ Organs observed in various parts of the body,
producing the waxy, cottony, or mealy matter. They consist
of cylindrical internal tubes, sometimes ending on the skin,
sometimes protruding outside it in the form of tubes, spines,
or conical hairs. In the former case the orifices show them to
be in some instances simple, and in others compound tubes.[B]
In the _Diaspidinæ_, besides being scattered over the body,
the spinnerets are arranged in groups on the last abdominal
segment, and these groups afford excellent characters for
specific distinctions. (Plate i., Fig. 4, for types of various
spinnerets; Plate iii., groups of spinnerets of _Diaspidinæ_.)
[B] Minute anatomical details are unsuitable for this work.
The student may consult Targioni-Tozzetti, "Studie sulle
Cocciniglie," cap. ii., p. 26.
_Spiracles._ "Breathing organs:" the orifices in the body of the
tracheæ or tubes conveying air to the blood. In the _Lecanidinæ_
they are usually four; simple circles, near the edge of the
body, and with a few strong spiny hairs near them. In the
_Coccidinæ_ they are often numerous. (Plate ii., Fig. 4; Plate
xx., _n_.)
_Spiracular spines._ Spiny hairs, usually three in number, of which
one is rather long, close to the spiracles, in the _Lecanidinæ_.
_Stigma_, _stigmatic spines_. Terms sometimes employed for spiracles,
&c.
_Tarsus._ The fourth joint of the feet, between the tibia and the
claw. Its consisting of one joint (monomerous) is a distinctive
character of the whole family. (Plate i., Fig. 6, _ta_.; Fig. 7,
_ta_.)
_Test._ The waxy, glassy, or horny covering produced through the
spinnerets and concealing the insect in many _Lecanidinæ_ and
some _Coccidinæ_. In this work it is not applied to the "scale"
of _Diaspidinæ_ or to cottony secretions.
_Thoracic band._ An appearance seen on the thoracic region in the
male, looking like a broad transverse ribbon.
_Thoracic region_, _thorax_. That part of the female or the male
which bears the three pairs of feet, when the feet are present;
or, if the feet are absent, the middle portion of the body,
segmented or not.
_Tibia._ The third joint of the feet, next the femur. (Plate i., Fig.
6, _ti_.; Fig. 7, _ti_.)
_Tracheæ._ Tubes ramifying throughout the body, conveying air to the
blood. Their orifices are the spiracles. The tracheæ, as in
other insects, appear as if constructed of a network of fine
spiral wires. (Plate ii., Fig. 4 _d_; Plate xx., _n_.)
_Trochanter._ A small articulation, not a distinct joint (something
like a knee-cap) of the feet, between the coxa and the femur.
(Plate i., Fig. 6, _tr_.; Fig. 7, _tr_.)
_Trimerous._ Three-jointed.
_Ventral._ On the under-side, the insect being in its proper
position.
NEW ZEALAND SCALE-INSECTS
(COCCIDIDÆ).
CHAPTER I.
INTRODUCTORY.
Insects are divided by naturalists into several principal orders, the
distinguishing marks of which are generally very well defined--for
example, the butterflies and moths belong to the order _Lepidoptera_,
the dragon-flies to the _Neuroptera_, the common house-flies to the
_Diptera_, and so on. These orders are founded upon the characters
and arrangement of the wings. They are subdivided into families, and
these again into genera and species. One of the orders is that of the
Hemiptera, which is composed of the two following sections:--
Hemiptera-Heteroptera, including the bugs, water-beetles, &c.
Hemiptera-Homoptera, including the crickets, cuckoo-spits,
plant-lice (Aphides), leaf-hoppers (Psyllids), scale-insects
(Coccids), &c.
The insects treated of in this volume are therefore placed as follows:--
Class--Insecta.
Order--Hemiptera.
Section--Homoptera.
Family--Coccididæ.
The genera and species will be found in their places.
The common English name for this family--"scale-insects"--is not
very appropriate. Some few of them have the appearance of small thin
scales on leaves or twigs, but many have not. Nor are the German
appellations--"gall-insekten" or "schild-lause"--more appropriate.
Gardeners have given to some of them the name of "mealy-bug," which,
although decidedly neither elegant nor euphonious, very fairly
represents the character of that particular portion of the family.
The origin of the name "Coccididæ," or, as abbreviated often in this
volume, "Coccids," is found in the old Greek word "[Greek: kokkos],"
denoting a rich red dye, which was much admired by the Greeks and
Romans, and which was procured from the insect now known as _Kermes
vermilio_ (the _Coccus ilicis_ of Linnæus). When the cochineal insect
was discovered in Mexico it soon overpowered all the others, producing
commercial dyes, and from it has come the title "Coccid," now applied
to the whole family. Cochineal itself has of late years been pushed
aside to a great extent by the aniline (coal-tar) dyes; yet it is still
used for many purposes. This insect lives on the leaves of cactus.
Amongst the New Zealand species described in this work will be found
one, _Dactylopius alpinus_, which produces a red dye similar to, though
probably not equal to, cochineal. Before the discovery of aniline dyes
it might possibly have been worth while to cultivate this insect for
its dye; but this would scarcely answer now.
The Coccididæ are, in some parts of the world, very injurious to
vegetation. They seem to affect principally the warmer temperate
regions. California, Florida, the Cape of Good Hope, the southern parts
of Australia, Southern France and Northern Italy, and New Zealand
are countries in which they are found out-of-doors in the greatest
numbers. In England they are less troublesome in the open air, though
in greenhouses and hothouses they abound; but, in places under glass,
every gardener ought to be able to get rid of them without difficulty.
For its extent New Zealand seems to furnish a larger number than any
other country. The humidity of its climate and the absence of anything
like severe winters in most parts of it are quite congenial to Coccids;
and there is scarcely a tree in its forests or in its gardens, whether
native or introduced, which is not subject to their attacks.
It has not been thought necessary to include in this work a list of
the books and essays written on this family of insects. The list would
be a very long one; but, besides that many of the books would not be
obtainable here, it would be found that very many authors have done
nothing more than copy--often quite blindly and unintelligently--what
others had said before them; moreover, most of them are out of date.
The student or the horticulturist desiring to know more about Coccids
not found in New Zealand may find full details in the reports of the
Agricultural Department of the United States Government, in Dr. V.
Signoret's "Essai sur les Cochenilles" (Paris), in papers by Miss Emily
Smith (American naturalist, 1878-80), &c. The American Departmental
Reports of Professors Riley and Comstock, Mr. Hubbard, and Mr. L.
Howard contain most valuable information. English works on the subject
are mostly fragmentary or inaccurate; but Mr. Douglas, of Lewisham, has
lately begun to discuss the Coccids in England in a systematic manner,
and probably before long others will follow suit. In India, Mr. T. W.
Atkinson, of Calcutta, is studying the family.
Natural science in these days tends ever more and more towards
specialization, and the boundaries of scientific classes, orders,
families, &c., are becoming always more and more narrowed. The student
can find his time quite sufficiently occupied nowadays in the thorough
investigation of so (comparatively) small a portion of the animal
kingdom as is presented by the Coccids of even only one country; and
the present work may not be without value to future workers in this
direction. To the farmer, the gardener, the fruit-grower, and the owner
of pleasure-grounds it is believed that the following chapters will
also supply information at the same time correct, intelligible, and
useful.