Scale-insects in New Mexico

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BULLETIN NO. 7. /r/7^^, 1892

Scale-Insects in New Mexico

LAS ('RUCKS. N. M.

Kro (JRANDK RKPTJI'.MC\N

1892.

The Agricultural Experiment Station.

BOARD OF CONTROL:
Board of Regents of the College.

STATION STAFF. '

Hiram Hadley, A.M., Director.

Aiiisworth E. Blount, A.M., Horticulturist and Agriculturist.
Elmer O. Wooton, B.S., Botanist.
C. H. Tyler Townseiid, Entomologist and Zoologist,
Arthur Goss, B.S., A.C., Chemist,

Harvey H. Griffin, B.S., First Assistant to Agriculturist and
Horticulturist,

Watt Gilmore, Assistant in Meteorology.

SCALE-INSECTS IN NEW MEXICO.

By ('. H. Tyler TowiiHeml.

The question of scale-insects is a vital one to the fruit-grower.
A considerable number of scales infest our fruit and shade trees, as
well as our various native ornamental shrubs and plants; and in
view of the recent recognition and quite rapid spread of the San
Jose scale in the southern part of this territory, it becomes very
desirable that accounts of our species be embodied in a bulletin for
the benefit of the horticultural public. The people of southern
California years ago set the example of arousing public opinion and
securing valid legislation for the suppression of scale-insects and
other pests, and it is gratifying to note that we have had in
this territory, for one year, a similar law which compels fruit-own-
ers to rid their orchards of all such pests. Being practically in
close proximity to southern California, it is rather to be wondered
at that we have not more of the fruit enemies which abound
there, and which may at any time make their appearance within
our limits. It is only by the greatest vigilance, and by measures of
the utmost precaution on. the part of all concerned, that such a con-
tingency can be prevented. The action which California has taken
in the matter is commendable, and demonstrates the entire practica-
bility of proper legislation on this point. We may well follow the
example set us. and no pains should be spared, nor any feasible
means neglected, to accomplish the suppression of such insects as
the Smi Jose scale and kindred species.

CLASSIFICATION OF SCALE-INSECTS.

Iii order that the fruit-grower may be better enabled to recognize
the various genera and species of scale-insects, a few paragraphs
are devoted to their classification.

SCALE INSKCTS

They constitute the family known as the Coccidae, and belong to
the Homoptera, which, is generally accepted by entomologists as a
division of the order Hemiptera. Other familiar examples of the
Homoptera are the plant-lice (Aphididae), the seventeen-year Cicada,
the vine leaf -hopper, and the tree-hoppers. The cochineal and
lac insects belong to the Coccidae.

As there is considerable diversity of structure among the species
of Coccidae, this family has been divided into five sub-families.
One of these, the Bfachyscelinae, includes species which live in galls,
and are wholly confined to Australia. The four remaining sub-fam-
ilies may be ordinarily distinguished by the following table:

1. Scale composed partly of .molted skins, and partly of a secre-
tion of the insect

Scale composed of a secretion of the insect alone, or else absent;
never in part composed of molted skins ........... . '2

2. Individuals usually fixed to plant on which they live ; the body

of the female scale-like or rather globular, with segmen-
tation absent or indistinct ................ L<>canhi(t<>.

Individuals usually retaining the power of motion ; the body of
female usually distinctly segmented .............. 3

3. Abdomen never terminating in two long caudal filaments ....

................................ Monophloebinae.

Abdomen always terminating in two long caudal filaments . .
....................................... Cocci n( ic.

Diaspinae. — Examples are the various species of Aspidiotus, to
which belong the San Jose scale, the greedy scale, and the red
scale of the orange in California. The genus Aspidiotus is distin-
guished by the female scale being circular, or nearly so, with the
exuviae either central or more or less marginal ; and the male scale
somewhat elongated, with the exuvia more or less central. The fe-
male scale may be distinguished by having two cast skins or exuviae
beneath it, while the scale of the male has but one. Near the cen-
ter of the scale, or between the center and the margin, will be seen

IN NEW MEXICO.

a small dot of a darker color than the rest of the scale. This marks
the location of the cast skin or skins (exuviae) lying beneath the
scale, and its position serves as a character for distinguishing differ-
ent species and even genera of this sub-family.

Lecaninae. — Examples are the various species of Lecanium, to
which belong the black scale of California; the cottony maple-
scale (Pnlvinaria innumerabilis Rathv. ) ; and the lac insect (Carter ia
lacca Ker. ). In the genus Lecanium the female lays her eggs be-
neath the scale, and secretes no cottony material. In the genus
Pulvinaria the female secretes a mass of cottony material, in which
the eggs are deposited.

Monophloebinae.— Examples are the various species of Icerya, to
which belongs the famous fluted scale, so destructive to the orange
in California and originally brought from Australia ; also the mes-
quite scale mentioned in this bulletin, and which will probably form
a new genus. There are some gigantic species of this sub-family in
Australia, some of them reaching, the length of nearly two inches !

Coccinae. — Examples are the cochineal insect (Coccus cadi L.);
and the mealy bugs (Daotylopiu8\.

GENERAL HABITS OF SCALE-INSECTS.

The female scale-insect is always wingless, and does not undergo
a complete metamorphosis. She fixes her beak in the bark, stem,
leaf, or fruit while young, and becomes stationary (except the Mon-
ophlochlnac and Coccinae), excreting and forming her scale as she
grows.

The male, however, of all scale-insects undergoes a complete
metamorphosis, and is furnished in the adult state with a single pair
of wings. The hind pair is wanting, but is represented by a pair of
club-like appendages called halteres or balancers. Each of these
appendages is furnished with a hooked bristle, which fits into a
pocket on the margin of the wing of the same side, and doubtless
serves to brace and strengthen the flight. The adult male has no
organs for obtaining food, and takes no nourishment, his sole

SCALE-INSECTS

object in life being to impregnate the female, which is soon accom-
plished. The mouth parts are lost during the metamorphosis, and
what is strange enough, their place is supplied by a second pair of
eyes !

As soon as the female scale-insect is fertilized, her body increases
in size and becomes distended with eggs. These are deposited
either beneath the scale, the body of the female meantime shrivel-
ing until it remains but a shrunken skin beside the mass of eggs ;
or a cottony sac is excreted by the female posteriorly to contain the
eggs, and in which they hatch.

When the young insects hatch, they may be seen with a lens
crawling over the surface of the bark or leaf, preparatory to set-
tling down and fixing their beaks therein (except the two sub-fam-
ilies above mentioned, which do not become stationary). At this
time, their bodies are very tender, but shortly after fixing themselves
they begin to exude a scaly covering to serve as a protection to
themselves.

Scale-insects can spread from one orchard to another by the female
crawling, or being carried by birds or the wind. She may even be
carried by attaching herself to bees, and other insects. The larger
species of scales more frequently spread by crawling ; but the smaller
ones, such as the species of Aspidiotus, are no doubt often spread by
the other means referred to.

NO. i. THE SAN JOSE SCALE (Aspidio1n-x pemiriosus Conistock).

Plate I. fig. 1.

Scale of Female. — The female scale is flat and circular, with the
exuviae central or nearly so. It is grayish in color, except the ex-
uvial spot which varies from yellowish to blackish. In some spec-
imens, according- to Comstock, the outer part of the scale is marked
with radiating ridges. Diameter, 2 mm. (.08 inch).

Female. — Body yellowish and nearly circular in outline, segmen-
tation distinct. The last segment presents the following characters :
Only two pairs of lobes visible, first pair converging at tip, notched

IN NEW MEXICO.

about midway their length on lateral margin, and often bearing a
slight second marginal notch near tip. Second pair notched once
on lateral margin.

Scale of Male. — Smaller, quite different in appearance, being
somewhat elongated instead of circular, blackish in color, and with
the exuvia between the center and the anterior margin.

^99' — According to Comstock,the eggs are white ; but according
to my own observation, they turn to an orange-yellow color in the
spring. They hatch here about the first or second week in May.

Food-plants. —Found here on apple, pear, plum, peach, quince,
and rose. Attacks bark, leaves, and fruit. It has not yet occurred
here on the apricot, but has been reported on this fruit in Califor-
nia. It also infests the cherry; in fact, all the deciduous fruits
are liable to its attacks.

- This species is also known as the pernicious scale, and has been
brought into New Mexico on young trees from California. It was
first noticed as injurious in San Jose, whence the popular name. In
California, it has proven to be the most destructive scale known on
deciduous fruits, and also the most difficult to kill. It spreads
rapidly.

A reliable characteristic by which this scale may be recognized,
when numerous, consists in the red discoloration of the bark occa-
sioned by its attacks. The discoloration appears in reddish blotches
over the bark, and when the latter is badly infested, extends through
the bark and into the sapwood. It seems that the weather during
the past winter has had some effect on the scales, many of them ap-
pearing winter-killed.

Parasites. — Three species of minute hymenopterous parasites of
this scale are known in California. They are :

Aphelinus myUlaspidis Le Baron (Plate I, fig. 4) : This is a little
four- winged fly, the female of which is about 0.64 of a millimeter in
length, with a wing expanse of 1.28 mm. Its general color is bright
lemon-yellow; the base of the antennae or feelers is more or less dusky,
the eyes blackish, the ocelli or simple eyes carmine, mandibles or

SCALE-INSECTS

jaws brown, and legs and wing- veins bright yellow. The wings are
delicate and hyaline, but sometimes with a pale yellowish shade.
The males average slightly smaller in size, and the club of anten-
nae is a little more truncate at tip. With these exceptions they can
hardly be distinguished from the female. (Drawn from Howard's
description.)

This species has been found parasitic on Mytilaspis pomorum
(in 111., Mo., N. Y. ?, Calif.) ; Chionaspis pinifoliae (in Mo. ?, B.C.);
Mytilaspis sp. on linden (D. C.) ; Diaspis carueli on juniper (D.C.);
and Aspidiotus p&rniciosus. It was bred from the last scale by Mr.
E. M. Ehrhorn, of California (see Insect Life, vol. iii, p. 487).

In order to show the efficiency of this parasite, Mr Howard has
compiled the following table from Dr. Le Baron's tables, showing
that it alone destroyed more than 63 per cent, of the whole number
of scales. .

Whole number of scales collected from apple in different

gardens 844

Number with round holes through which this parasite had

escaped 289

Number having larvae of this parasite under them .... 244

Number destroyed by mites or unknown cause 254

Number of healthy and sound scales 57

Whole number 844

Aphelinus fusdpennis Howard : This is a very much smaller par-
asite, only 0.06 of a millimeter in length, and with a wing expanse of
1.3 mm. Its general color is dull honey-yellow ; the antennae are
smoky, blackish at tip ; eyes blackish, ocelli dark crimson ; a distinct
transverse black band on occiput behind eyes, scutellum somewhat
blackish at tip, abdomen with five dusky transverse lateral bands,
legs and wing-veins honey-yellow. Front wings with an indefinite
smoky patch below the stigma (spot near front border of wing), and
another darker crescent-shaped streak near base of wing, convex on

inside. (Drawn from Howard's description.) The male was un-
known to Mr. Howard.

This species is also widespread and quite a general feeder. It has
been bred from Axpidiofus pcrnlclos/is (Cal.); Chionaspis euontjnn
(Ma.); MyHlaspi* </lorerii on orange (D.C.) ; and Mytilaspib pomorum
(Gal.). Mr. E. M. Ehrhorn suspects that it is also parasitic on the
greedy scale (Aspidwhis rapcu-). See Insect Life, vol. iii, p. 487.

Coccaphagus cih'iiui* Craw MS.: This parasite has appar-
ently never been described. It is 0.03 of an inch in length. Ke-
garding the value of this species as a parasite, the following letter
from Mr. D. W. Coquillett, published in the "California Fruit
Grower," Sept. 1889, is quoted:

Concerning the parasite of the red scale in the San Gabriel Valley, Acting
Entomologist Howard writes me that it is probably a new species belonging to
the genus Coccophagus. It is a minute four-winged fly scarcely as large as the
head <>f a small pin; its eggs are laid singly in or upon the scales, and the larva
or grub that hatches from this egg feeds upon the scale insect, and after com-
pleting its growth arid passing through its preparatory stage, it gnaws a round hole
through the scale and thus makes its escape. This parasite occurs in nearly all of
the orange groves in the San Gabriel Valley, and in some of them its work is very
noticeable. This is especially the case in the large. Chapman groves, in which I de-
tected this parasite two years ago. During a visit to this grove a few days ago
it was almost impossible to find any young red scales on the infested trees, while
in other localities where this parasite does not occur, almost every leaf contains
one or more of the young scales, this being the season of the year when they are
most abundant. Mr. A. B. Chapman informs me that there is less red scale on
his fruit this year than there has been since first his trees became so seriously in-
fested with these pests. I have taken the necessary steps for introducing this par-
asite into a locality where it did not previously exist, but it will be several months
yet before the result of this experiment can be determined.

This parasite destroys the red scale of the orange (Aspldiotus
auranfii), and its yellow variety (A. citrinus) in California; and
Mr. E. M. Ehrhorn has also bred it in California from the San
Jose Scale (A. perniciosus). See Insect Life, vol. iii, p. 487.

NO. n. THE WHITE PEAR SCALE (Aspidiotus rapax Comstock).

Plate I, fig. 2.

Scale of Female. — Very convex; exuviae between center and one
side, and covered with secretion. Scale is gray, somewhat trans-

10 SCALE-INSECTS

parent so that it appears yellowish when covering a living female;
prominence covering exuviae is dark brown or black, usually with a
central dot and concentric ring which are white. Ventral scale snowy
white, usually entire. Diameter 1.5 mm. (0.06 inch).

Female. — Body nearly circular in outline, bright yellow in
color with more or less translucent blotches. The last segment
presents the following characters: Groups of spinnerets wanting.
Only one pair of well-developed lobes, the median, present. These
are prominent, and each one is furnished with a notch on each side.
Second and third pairs of lobes represented by minute pointed pro-
jections of margin of body.

Egg. — The eggs and newly hatched larvae are yellow. (From
Comstock's description.)

Food-plants. — This scale attacks a great number of plants,
trees and shrubs. In California it has been found on olive, moun-
tain laurel ( Umbellularia californica), almond, quince, fig, willow,
eucalyptus, acacia, apple, pear, and others. In Florida, on Euony-
mus japonicus. It has been found here on apple, pear, and peach.
Like the preceding scale, it affects not only the bark of the trunk
and limbs but the leaves and fruit as well.

This species is also known as the greedy scale. It sometimes
occurs in a locality in great numbers, when it becomes very destruct-
ive, but as a rule it does not spread rapidly and is not to be com-
pared with the San Jose scale. If, however, it is allowed to gain
a good foothold, it will be troublesome to exterminate it, owing
to the large number of plants upon which it subsists.

Parasites. — Aphelinus fuscipennis Howard, mentioned under
San Jose scale, is suspected by Mr. E. M. Ehrhorn of being a
parasite of this species also. (See Insect Life, vol. iii, p. 487.)

NO. in. THE CONVEX SCALE (Aspidiotus coiii'cxus Comstock).

Plate I, fig. 3.

This species very closely resembles A. rapcur. in the shape and
color of its scale. It is only by a careful study and comparison of
the two forms that it can be distinguished. A careful examination

IN NEW MEXICO. 11

of their structure shows them to be specifically distinct. This
species may be distinguished from A. rapax by the following char-
acters of the last abdominal segment of the female : Four groups
of spinnerets (none in A. rapax)', the superior lateral groups con-
sist of about seven, and the inferior lateral groups of about four
spinnerets.

Food-plants. — Very common in California on the bark of the
trunk and limbs of the native willows. It has been found in great
numbers here on the bark of trunk and branches of our native
cottoiiwood (Populus fremontii). The bark of the trunk of one
tree was entirely covered. It has also been found here in great num-
bers on the limbs and twigs of an ash (Fraxinus sp/).

Parasites. — Great numbers of the scales on cottonwood showed
minute holes from which some hymeiiopterous parasite had emerged.
There were no living insects under such scales, showing that the
parasite had done much good work in keeping the scales in check.
Those on ash were also well parasitized.

NO. iv. CHILOPSIS SCALE ( Aspidiotus n. sp. ?).

This species bears some resemblance to Aspidiotus nerii
Bouche, but is probably a new species. Professor Comstock, after an
examination of specimens, writes that it is an Aspidiotus unknown
to him, and probably undescribed. Further material is necessary
before a description can be drawn up, therefore nothing more than
a mere notice of its occurrence is given here. -__ .

Food-plants. — This species was found plentifully infesting the
leaves, mostly on the upper side, of a bush of Chilopsis saligna in
the yard of Hon. A. L. Christy, of Las Cruces, who first called my
attention to this scale. At date of examination, August 25, 1891,
the scales were nearly all very small, and some orange-yellow young
were seen outside. There were a few larger scales, containing eggs
beneath them. The scales seemed to be confined to the leaves.

NO. v. THE LOCUST SCALE (Lecanium robiniae Riley MS.).
This is an entirely different scale, in appearance and size, from
all of the preceding species, which belong to the genus Aspidiotus.

12 SCALE-INSECTS

It is a brown, or reddish-brown scale, hemispherical in form, hard
in texture, and varies from 3 to 5 mm. in breadth and 4 to (>
mm. in length. Some of them are very dark brown in color. Be-
neath this scale, as in the preceding species, is to be found either the
soft insect or the eggs. The species has not been described, and I
will not attempt to give other than the above brief description here.
Professor Riley, who has seen specimens, has furnished the above
manuscript name to be used in referring to the species. The short
description and the food-plant will doubtless enable its recognition.

Egg. — The eggs are pale reddish-pink in color, very small,
and a great many are to be found under one scale. They were ob-
served to be hatching May 22.

Food-plants. — This scale has been found here only on im-
ported trees of black locust (Rob In id jwinldcdcid), the branches
and twigs of which it very plentifully infests. It is more or less
unnoticeable on account of its color being much the same as that
of the twigs upon which it occurs.

Parasites. — No true parasites have been observed. A locust
tree which was infested with the scale was found to be well stocked
with the California Cooclnella oculata, and its ashy gray variety
(C. abdominalis). These undoubtedly prey upon this and other
scales. The variety seemed to predominate, and though all stages
from eggs to adults were to be found May 22, the pupae were by
far the most abundant.

NO. VI.

SOFT PEACH SCALE (LcCfllUHIK Sp.).

A single specimen of a soft, brownish, more or less hemispher-
ical scale-insect, about 5 mm. in length, was found April 11, 011 a
branch of the peach. No others were found, and it is simply men-
tioned here so it may be looked for by fruit-growers. We shall
be glad to receive any specimens of it that may be found. Unlike
all the preceding species, it is simply the bare, soft insect that must
be looked for, as it apparently does not cover itself with a scale.

IN NEW MEXICO. 13

NO. vii. THE YUCCA SCALE (LecanocUaspis yuccae Kiley MS.).

This is a round, hemispherical, whitish scale, about 3 to 4 mm.
in diameter, and of hard texture. The scale bears a median longi-
tudinal carina or keel above, and is a little narrower than long.
This species is also undescribed, and the above manuscript name
was furnished by Professor Riley. It can be easily recognized
when seen.

Egg. — The eggs under dried scales are pale yellowish or
whitish, and a considerable number occur under one scale.

Food-plants, — This scale was found on leaves of DasyUrion
tvheeleri, March 14, 1891, in the Organ mountains. It was later
found on the large-leaved yuccas (probably Yucca macrocarpa), in
the same mountains. In both plants, it infests the upper side of
the leaves very plentifully, chiefly at and near their bases. These
plants are highly ornamental, and the yuccas especially may be
used to advantage on lawns. Therefore this scale becomes of con-
siderable importance from an economic standpoint.

Parasites. — Some of the scales which have been collected were
found infested with a hymenopterous parasite, the black perfect in-
sect of which could be seen inside the scale through a small round
hole where it was about to emerge.

NO. vin. THE LARREA SCALE (Signoretia sp. ? ).

This scale is enclosed in a white felted or cottony covering. The
insect itself is of a light reddish-brown, with the legs and antennae
concolorous. The adult female has apparently 8 joints in the anten-
nae, and the legs are present. The first antennal joint is short. The
larva has only six antennal joints. The dimensions are as follows:
Length of adult female, about 4 mm ; width, 2 mm. Length of
felted sac, 5 to 6 mm; width, 2 to 2.5 mm.

Egg.— The eggs are whitish in color and are enclosed in the
end of the felted sac, behind the body of the female, the head of the
female being usually more or less thrust through the anterior end of
the sac.

14 SCALE-INSECTS

Food-plants. — Found abundantly, May 13, on leaves of the
creosote bush (Larrea mexicana) ; occasionally on the stems also.
It is usually on the underside of the leaf, which is small and very
nearly covered by the felted sac. Young specimens were also found
this date, which were beginning to exude a sac, though the eggs
found in the sacs of adult females were unhatched. It was ob-
served that the whitish sacs were likely to escape notice among
the young fruit of the Larrea, which was just setting and was cov-
ered with a whitish, woolly pubescence.

NO. ix. PALMER'S ICERYA (leery a palmer i Riley and Howard ).

Plate II, figs. 1 and 2.

This scale does not, so far as the writer is aware, occur in New
Mexico. As will be seen, however, it becomes very desir-
able to treat it here, since it is not unlikely that it may some
day reach us. The adult stages are as yet unknown to science, and
consequently can not be described. A description of the first and
second larval stages will be found in Insect Life, vol. iii, pp. 104-5,
but is too technical to be inserted here. The larvae are apparently
reddish-yellow in color, but their cast skins are white.

Food-plants. — This species was found by Dr. Edward Palmer
July 30, 1887, on the Muscat of Alexandria grape, at San Jose de
Guaymas, nine miles north of Guaymas proper, in Sonora, Mexico.
The specimens found were only the younger stages, and were fixed
alon^the main ribs of the leaf, principally on the under side. This
would prove a new and most undesirable pest to our Muscat grapes
if introduced here, and with the Santa Fe K. R. connections be-
tween Guaymas and this territory it is by no means an impossibil-
ity. All vines brought from Old Mexico should be most thoroughly
overhauled before they are allowed to enter American territory.

Parasites. — It is reported in Insect Life, 1. c., that the pupa-
rium of a dipterous parasite, apparently of the family Phoridae,
was plainly to be seen within one of the mounted larvae of the
second stage.

IN NEW MEXICO. 15

NO. X. COTTONY MESQUITE SCALE (n. gen. et n. Sp.).

This is a large, soft scale, red or brick-red in color, and bear-
ing a snow-white, more or less distinctly fluted, cotton-like, but
compact egg-sac, which is attached to the postero- ventral portion of
the insect, and is cylindrical in general form. The insect is en-
tirely red, except the legs, antennae and proboscis, which are
black ; and the egg-sac, which is white. Pinned specimens usually
become reddish-yellow in color, while alcoholic specimens acquire a
reddish-brown color. This scale also exudes, particularly around
the edge of its body, a certain number of curled white cottony fila-
ments, in addition to the egg-sac. The dimensions of the larger spec-
imens collected in July, 1891, and May, 1892, are as follows: Length
of body, 5 to 7 mm. ; anterior width of body, 2 to 3 mm. ; posterior
width 4 to 5 mm. Length of egg-case, 5 to 6 mm. ; width, about
4 mm. Specimens collected June 8, 1892, measure 12 to 13 mm. in
length, including egg-sac; sac measures 10 mm.

This scale will probably form a new genus, according to Profes-
sor Kiley who has examined specimens. It is nearly related to the
Icerya of California, though somewhat more removed from it
than the preceding species, which is a member of the same genus.

Egg. — In color the eggs are orange-red. They were just be-
ginning to hatch within the sacs, June 8.

Food-plants. — Found on twigs and branches of mesquite
(Prosopis juliflora) rather plentifully, July 28, 1891, many of them
being at this time small. Found more sparingly, but in larger
specimens, May 13 to 18, 1892; though two or three smaller ones
without egg-sacs were also seen. A good number of large specimens
were found June 8. This scale, it is possible, may some day take
to certain cultivated plants, in which case it will prove a serious
enemy.

Parasites. — No true parasites have been found, but the two
species of lady-birds, previously mentioned, frequented the mesquite
branches where the scales were found, and doubtless prey upon them.
In the same connection, it may be mentioned that two species of

16 SCALE-INSECTS

ants, one of moderate size and the other very small, were seen at-
tending these scale-insects, from which they obtain a honey-like ex-
udation. The ants rather serve to protect the scales by warding off
parasites and predaceous insects. This scale-insect was noticed to
exude a drop of a clear honey-like fluid from the back posteriorly,
upon which the ants fed.

PARASITES AND OTHER ENEMIES OF SCALE-INSECTS.

The insect enemies of scale-insects may be divided into two cate-
gories : True parasites, which live internally in the host insect, and
predaceous insects, which attack the scales externally and devour
them bodily.

The true parasites are very small members of the orders Hy-
menoptera and Diptera, more particularly the former in the case of
scale parasites. The hymenopterous parasites belong principally
to the families Chalcididae and Prodofrupidae, two or three spe-
cies of which have been more or less briefly described in the pre-
ceding pages. The dipterous parasites belong principally to the
Ochthiphilidae, a family of acalyptrate Muscidae, and perhaps to
some other families of the same division. These parasites deposit
their eggs in or upon the scale-insects, and the newly-hatched para-
site lives within the body of its host until full grown, when it trans-
forms and issues as a perfect insect.

The chief predaceous insects, which are useful in destroying
scales, are the following: Coccinellidae, or lady-birds; and certain
predaceous lepidopterous larvae, belonging to the families Noc-
iuidae, Phyvitidae, Tineidae, and Pyralidac. The predaceous ene-
mies have proven of more value in California than the true para-
sites,

Of the Coccinellidae, or lady -birds, we have here two very efficient
forms, which are mentioned in the preceding pages. They are
Coccinella oculafa, and its ashy-gray variety ( C. abdomincdis, which
looks like an entirely different species. The former is black with
a yellow spot on each wing-cover, and the head and forward margin
of thorax whitish. The variety is entirely creamy -jjray, with eight

IN NEW MKXLCO. 17

spots normally on each whig-cover, seven on thorax with two fainter
ones on front margin, while the eyes look like two black spots on
the head. These lady-birds are California forms, and have not be-
fore been reported from New Mexico.

To the true dipterous parasites belongs the Lesfophonus
icerijfu\ which was found parasitic on leery a in Australia, and was
imported under Professor Eiley's direction into California. It has,
however, been superseded in usefulness by the Vedalia, and some
other coccinellid beetles which were imported later.

REMEDIES FOR SCALE-INSECTS.

Summer Washes. — As a summer wash for the San Jose scale,
and other species of Aspidiotus infesting deciduous trees, the fol-
lowing should be applied at various times after the young scales
have hatched and are seen crawling on the bark :

No. 1. Caustic soda (98 per cent.) . . 10 Ibs.

Potash 10 Ibs.

Tallow 40 Ibs.

Eesin . . . 40 Ibs.

Water to make 50 gals.

The above forms a soap which will fill a barrel of 50 gallons
measure, and will weigh about 450 to 500 pounds. It must be
prepared as follows:

First, dissolve the soda and potash in ten gallons of water,
then place the whole in a 50-gallon barrel. Second, dissolve the
tallow and resin together by heating it over a fire, add it to the
soda and potash in the barrel, and stir well for about five minutes.
Let it stand now for about two hours, when the barrel may be filled
up with water, but the mixture must be well stirred as every bucket
of water is added. It will be ready for use the following day, and
should be applied warm in strength of one pound of soap to a gallon
of water. This remedy is preferable for apples and pears, and was
originally recommended, I believe, by Mr. Sol. Runyon, of Court-
land, Cal.

IS SCALE-INSECTS

The following is recommended in California for same purpose,
but for use on the peach:

No. 2. Potash 14 Ibs.

Caustic soda (98 percent.) .... 8 Ibs.

Unslacked lime 5 Ibs.

Fish oil, polar or seal 10 gals.

Water to make 50 gals.

Prepare as follows: First, dissolve thevsoda and potash in ten
gallons of water, as with the preceding formula. Then slack the
lime with two gallons of water in the 50-gallon barrel to be used,
add the fish oil and stir well until the lime and oil form a thick
batter. Now pour the soda and potash solution, boiling hot, into
the barrel containing the batter, and stir well with a dasher for five
minutes. Leave standing from 4 to 6 hours; after this length of
time the barrel may be filled up with cold water, about two buckets
full at a time, stirring well to prevent lumps. Use the following
day and apply cold, in strength of one pound to a gallon of
water.

In dissolving this soap for use do not boil, but weigh amount
to be used, place in barrel and pour hot water thereon, in propor-
tion of one pailful to every one hundred pounds of material ; then
stir briskly with a dasher until entirely dissolved. It can now be
reduced with cold water as above directed, making as many gallons
of wash as there were pounds of soap dissolved. After being well
stirred, it is ready for use. This wash is also recommended in Cali-
fornia for leery a on citrus trees and evergreens, and for Lccanhunx
on deciduous or other trees.

Another summer resin wash, recommended by Professor Riley
for the red scale on the orange in California, differs from the above
washes by containing no potash, and proportionally more than
twice as much resin. It will doubtless be efficient for all species of
Aspidioius, except the San Jose scale, but if used on deciduous
trees it should be experimented with first to determine effect 011
the foliage. If the foliage is injured, more water can be added.
The formula is as follows:

IN NEW MEXICO.

No. 3. Eesin 18 Ibs.

Caustic soda (70 per cent.). . . 5 Ibs.

Fish oil < 2J pints.

Water to make 100 gals.

It also differs from the preceding resin washes in the manner
of preparation, and in being ready for application when mixed ac-
cording to the above formula, instead of forming a soap to be dis-
solved again in water. It is prepared as follows:

Place all the ingredients in a large boiler with enough cold
water to cover them. Boil until dissolved, occasionally 'stirring,
and continue boiling for about an hour after the materials are dis-
solved, employing sufficient heat to keep the mixture in a constant
state of ebullition, and adding hot water when it is in danger of boil-
ing over. When sufficiently boiled it will assimilate perfectly
with water, which should then be added hot up to 50 gallons, slowly at
first and stirring occasionally, and then cold water until a sufficient
amount is added to make 100 gallons of the mixture. Before the
water is added the preparation is of a pale yellow color, but after
a adding it becomes dark brown. It must be strained through a
fine wire seive, or a piece of Swiss muslin, before applying to the
trees.

Virtually the same remedy as the above, only in a little
greater strength and with the addition of a little kerosene, is re-
commended by the Calif oraia State Board of Horticulture for the red
scale on orange, and other scales on evergreen trees ; while the same
thing, only a little stronger and without the kerosene, is recom-
mended for Icc-r'ijfi on the orange.

The following is the Riley-Hubbard formula for the kerosene
emulsion, which at proper strength will be found a very efficient
remedy for scales:

No. 4. Kerosene oil 2 gals.

Common soap ^ 11).

Water . . 1 gals.

o

Prepare by boiling the water and soap together until dissolved,
and then pouring it, while boiling hot, into the kerosene. The

SCALE-INSECTS.

mixture must now be pumped through a force pump for about five
minutes, directing the stream back into the pail, until it forms a
perfect emulsion. As a summer wash for San Jose and other
scales on apple, pear, etc., dilute nine times with cold water. For
use on peach, dilute fifteen times.

The following summer wash for San Jose scale on deciduous
trees is recommended by the California State Board of Horti-
culture :

No. .5. Whale oil soap (80 per cent.). 20 Ibs.

Sulphur 3 Ibs.

Caustic soda (98 per cent.) .... 1 Ib.

Commercial potash 1 Ib.

Water to make 100 Ibs.

Boil the sulphur, soda and potash in two gallons of water for
one hour, or until thoroughly dissolved. Dissolve the soap by
boiling it in water, then add to the other, mix and boil for a short
time when it may be applied hot.

Winter Washes. — In order to thoroughly destroy the San
Jose scale, it will be necessary to use the following winter wash,
which is much stronger than any of the preceding and must be ap-
plied only when the tree is dormant. If applied in the growing
season, it will cause the loss of both foliage and fruit. It is recom-
mended by Professor Riley as giving the best results of all for use
as a winter wash against this particular scale. It therefore needs-
no further commendation :

No. 0. Kesiii 30 Ibs.

Caustic soda (70 per cent.). . . 1) Ibs.

Fish oil 44 pints.

Water to make 100 gals.

Prepare by placing all the ingredients in a large boiler, and
pouring over them about 20 gallons of water. Boil briskly for
three hours, or until the compound is perfectly soluble in water. The
boiler must now be slowly filled up with hot water, care being taken
to stir well, until it makes 50 gallons of hot solution. This should

NEW MEXICO. 21

be strained through a fine wire seive or a piece of muslin, when it can
be diluted with an equal quantity of cold water as needed for spray-
ing. It is recommended in California for Lecaniums, as well as
San Jose scale, for winter use on deciduous trees.

In the application of this wash a very fine spray is not essen-
tial, as the object to be attained, that of thoroughly coating the
tree with the compound, can be best accomplished by the use
of a rather coarse spray, to be thrown on the tree with consid-
erable force.

The California State Board of Horticulture recommend the
following as a winter wash against the San Jose and congeneric
scales. It is claimed, and I believe with reason, that the addition
of potash to the wash is necessary to prevent the dry atmosphere
from exhausting the caustic properties of the soda. This is espec-
ially important to us in New Mexico, as our atmosphere is much
dryer than that of of California. If soda lye alone is sprayed on
trees in sunny weather, it will often be found within an hour to have
crystallized into solid carbonate of soda, and its action, so far as in-
sects are concered, is at an end. If sprayed in moist weather, its
action is prolonged. The addition of the potash, however, main-
tains the corrosive action of the soda in the dryest atmosphere, by
preventing the rapid evaporation and solidification which would
otherwise put an end to it. Besides the potash ultimately reaches
the soil, and acts as a fertilizer when needed. The above statements
are on the authority of Professor Hilgard.

No. 7. Solid concentrated American lye (80 per cent.). . 1 lb., or

Powdered caustic soda (98 per cent.) 0.8 lb., or

Powdered caustic soda (76 per cent.) 1 lb., or

Powdered caustic soda (63 per cent.) 1£ Ibs., to

Commercial potash (52 per cent.) 1 lb., and

Water 2| gals.

Simply dissolve the soda and potash in the water. First re-
commended by Mr. M. Cooke.

The following formula, recommended by Professor Hilgard, is

22 SCALE -INSECTS

undoubtedly equally as good as the last, and costs one cent less per
gallon.

No. 8. Solid concentrated American lye (80 per cent.) . . 1 lb., or
any one of the sodas in preceding formula, to

Commercial potash (52 per cent. ) i lb.

Water 2 gals.

Simply dissolve. This is just a little more than one half the
strength of potash that is given in the preceding formula.

Comments. — The above 8 washes are given so as to allow some
latitude in choice. They have been carefully selected, and will
doubtless all prove more or less efficient. Those which will be of
use for species of Aspidiotus and L&canium, are mentioned above.
The last two formulas mentioned would, I believe, be especially ad-
apted to our climate.

For Lecanodiaspis, or other scales on Dasylirion and Yucca, I
would recommend formula No. 6, to be applied at any time of the
year. No. 4 diluted five times would also be of service, and would
in all probability not affect the plants.

As far as the scale on Larrea goes, it will probably not spread
to any other plant, and doubtless the creosote bush is not valuable
enough here to call for any protection. However, No. P> and No. 4,
as above recommended, would be the proper remedies.

For species of Icerya, and for cottony scale on mesquite, No. 3 is
the formula which should be used, but the caution given above as to
trying the wash first to get the strength which will not injure such
foliage as grape or mesquite, must be heeded.

No mention is made in this bulletin of the hydrocyanic acid
gas method of destroying scale-insects, which is at the present time
unnecessary in this territory.

EXPLANATION OF PLATES.

Plate I.

( All much enlarged. )

Fig. 1. — San Jose scale, Aspidiotus pprniciosits. last abdominal segment of female
showing specific characters.

IN NEW MEXICO.

Fig. 2. — White pear scale. Aspidiotus rapax, last abdominal segment of female show-
ing same.

Fig. 3. — Convex scale, Aspidiotus convexus, last abdominal segment of female show-
ing same.

Fig. 4. — San Jose scale parasite, Aphelinus mytilaspidis.

Plate II.

Palmer's Icerya, leery a palmeri.
Fig. 1. — a, newly hatched larva; 6, larva, second stage (both greatly enlarged —

hairlines indicate natural size); c, antenna of 6 (still more enlarged).
Fig. 2. — a, cast skins of larvae of second stage (much enlarged) ; 6, s ame clustered
on ribs of grape leaf, on underside (natural size).

Plate III.

This plate shows a spraying outfit in operation, as used in orange groves in
California against the fluted scale.

NOTE. — The above plates were all received from the Agricultural Department in
Washington, and appeared either in Insect Life or in the reports of the U. S.
Entomologist.

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