Bulletin of The California Insect Survey: Volume 5 The Armored Scale Insects of California [Reprint 2020 ed.] 9780520345775

Citation preview

OREGON

SISKIYOU

SHASTA HUMBOLDT

TRINITY

TEHAMA PLUMAS

BUTTE

GLENN

SIERRA NEVADA

COLUSA

KYUBA

NEVADA YOLO SONOMA

ALPINE

NAPA [AMADOR

TUOLUMNE

CONTRA COSTA

LALAM£DA

MONO JOAQUIN

STANISLAUS

MARIPOSA

MADERA

TULARE

MONTEREY KINGS

SAN L U I S O B I S P O

KERN

SAN

BERNARDINO

VENTURA

RIVERSIDE X>RANGE

IMPERIAL

Map of California, showing county boundaries,

BULLETIN OF THE CALIFORNIA INSECT SURVEY VOLUME 5

THE ARMORED SCALE INSECTS OF CALIFORNIA BY

HOWARD L. McKENZIE (State of California Department of Agriculture, Bureau of Entomology)

UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES

1956

B U L L E T I N OF T H E CALIFORNIA INSECT SURVEY E d i t o r s : E . G . LINSLEY, S. B . FREEBORN, R . L . USINCER

Volume 5, pp. l - i i o , plates 1-3, 133 figures in text Submitted by Editors April 4, 1955 Issued, August 30, 1956 Price, Cloth, $6.00; Paper, $4.50

University of California Press Berkeley and Los Angeles California

Cambridge University Press London, England

COPYRIGHT, 19J6 BY THE REGENTS OF THE UNIVERSITY OF CALIFORNIA

Printed by Offset in the United States of America

LIST OF COLORED PHOTOGRAPHS Many of the specimens used to produce the accompanying colored photographs were collected by various individuals at my request. For those who participated in this project acknowledgments are here made. W i t h the exception of the colored photograph of Hall scale, Nilotaspis halli (Green) which has been enlarged three diameters (x3), the remainder have been photographed actual size on the infested plant part. It is hoped these colored photographs will help in identifying a few of our more common California diaspidids as they are seen in the field. Plate 1 and the top row of plate 2 include those diaspidids belonging to the tribe Aspidiotini; the remainder are referable to the tribe Diaspidini. T h e species have not been arranged chronologically under each tribe, but instead are assembled more for the purpose of eye appeal and beauty. T h e following list includes specific collection data for each photograph:

PLATE 2 Aonidomytilus ceanothi Ferris, Larson Valley, El Dorado Co., December 27, 1954, on Ceanothus integerrimus (L. Mobley). Aulacaspis rosae (Bouché), Sacramento, May 28, 1954, on sp. (mammoth blackberry) (H. H. Keifer).

Rubus

Carulaspis visci (Schrank), Sacramento, May 26, 1954, on perus sp. (juniper) (H. L . McKenzie). Diaspis bromeliae (Kerner), San Diego, February Bromeliad (G. Hill and R . J . Buckner).

Juni-

23, 1954, on

Diaspis echinocacti (Bouché), Norco, Riverside Co., J u n e 28, 1954, on Opuntia hamiltoniae (cactus) (R. M . Hawthorne and H . L . McKenzie). Diaspis manzanitae (Whitney), Magalia, B u t t e Co., October 30, 1939, on Arctostaphylos sp. (manzanita) (H. H . Keifer). Quadraspidiotus juglans-regiae (Comstock), Greenspot, San Bernardino Co., J u n e 27, 1955, on Juglans sp. (walnut) (G. M . Harper). Quadraspidiotus perniciosus (Comstock), San L e a n d r o , Alameda Co., M a y 26, 1954, on Prunus sp. (plum) (E. K. Strobridge). Selenaspidus albus McKenzie, Norco, Riverside Co., J u n e 28, 1954, on Euphorbia submammillaris (succulent) (R. M . Hawthorne and H. L . McKenzie).

PLATE 1 Aonidiella aurantii (Maskell), Pomona, Los Angeles Co., December 26, 1953, on Citrus limon (lemon) (H. L . McKenzie). Aonidiella citrina (Coquillett), Reedley Area, Fresno Co., J a n u a r y , 1954, on Citrus sinensis (orange) ( T . E. Corn). Aspidiotus hederae (Vallot), Sacramento, November, Hedera helix (ivy) (R. Z. Rollins).

1953, on

Chrysomphalus bifasciculatus Ferris, Sacramento, November, 1953, on Hedera helix (ivy) (R. Z. Rollins). Diaspidiotus ancylus (Putnam), Hemet, Riverside Co., J u n e 28, 1954, on Prunns armeniaca (apricot) (H. L . McKenzie). Hemiberlesia degenerata (Leonardi), Sanger, Fresno Co., May 13, 1954, on Camellia sp. (J. C. Bedford). Hemiberlesia lataniae (Signoret), Orange Co., May 30, 1954, on Persea sp. (avocado) (D. Bishop). IJndingaspis rossi (Maskell), Montecito, Santa B a r b a r a Co., December 6, 1954, on Sequoia sempervirens (redwood) and Araucaria sp. (W. S. Cummings). Nuculaspis californica (Coleman), L a k e Gregory, San Bernardino Co., March 9, 1954, on Pinus ponderosa (yellow pine) (G. L . Downing).

PLATE 3 Chionaspis salicis-nigrae (Walsh), Alturas, Modoc Co., August 6, 1936, on Cornus sp. (dogwood). Lepidosaphes beckii (Newman), Santa B a r b a r a , December 16, 1954, on Citrus sinensis (orange) (W. S. Cummings). Lepidosaphes ulmi (Linnaeus), Sacramento, November 5, 1953, on Salix sp. (willow) (H. H . Keifer). Nilotaspis halli (Green), Chico, Butte Co., May 10, 1950, on Prunus amygdalus (almond) (E. F. Fosen). Parlatoria camelliae (Comstock), Hickman, Stanislaus Co., February, 1954, on Camellia sp. Parlatoria oleae (Colvée), Madera Co., J a n u a r y 7, 1954, on Olea europaea (olive) ( T . B . Gallion). Parlatoria pittospori Maskell, San Diego, December 9, 1954, on Pittosporum sp. (R. F. Wilkey). Phenacaspis

pinifoliae

(Fitch), Crestline, San Bernardino

Co.,

March 9, 1954, on Pinus ponderosa (yellow pine) (C. L . Downing)Unaspis euonymi (Comstock), Sacramento, November 4, 1954, on Euonymus sp. (H. L . McKenzie).

PLATE 1

T o p row. L e f t : Aonidiella aurantìi (Maskell), C a l i f o r n i a red scale; center: Aonidiella citrina (Coquillett), yellow scale; r i g h t : Chrysomphalus bifascicidatus Ferris, B i f a s c i c u l a t e scale. M i d d l e row. L e f t : Aspidiotus hederae (Vallot), ivy scale; center: Hemiberlesia degenerata ( L e o n a r d i ) , d e g e n e r a t e scale; r i g h t : Hemiberlesia lataniae (Signoret), L a t a n i a scale. B o t t o m r o w . L e f t : Nucuiaspis califomica (Coleman), black p i n e leaf scale; c e n t e r : Lindingaspis rossi (Maskell), black a r a u c a r i a scale; r i g h t : Diaspidiotus ancylus ( P u t n a m ) , P u t n a m scale.

PLATE 2

T o p row. Left: Quadraspidiotus juglans-regiae (Comstock), walnut scale; center: Qiiadraspidiotus perniciosus (Comstock), San Jose scale; right: Selenaspidus albus McKenzie, white euphorbia scale. Middle row. Left: AonidomytUus ceanothi (Ferris), Ceanothus scale; center: Aulacaspis rosae (Houché), rose scale; right: Carulaspis visci (Schrank), juniper scale. Bottom row. Left: Diaspis manzatiilae (Whitney), manzanita scale; center: Diaspis bromeliat (Kerner), pineapple scale; right: Diaspis prhinorarti /'Rr>iirhr'\ rnrtiis srnle.

PLATE 3

Top row. Left: Chionaspis salicis-nigrae (Walsh), black willow scale; center: Nilotaspis halli (Green), Hall scale (enlargement xg); right: Lepidosaphes beckii (Newman), purple scale. Middle row. Left: Parlatorio camelliae Comstock, camellia parlatoria scale; center: Lepidosaphes ulmi (Linnaeus), oystershell scale; right: Parlaloria oleae (Colvée), olive parlatoria scale. Bottom row. Left: Parlatoria pittospori Maskell, Pittosporum diaspidid; center: Phenacaspis pinifoliae (Fitch), pine needle scale; right: Unaspis euonymi (Comstock), Euonymus scale.

CONTENTS L i s t of colored photographs

v

Introduction

1

Acknowledgments

1

Scope of study

2

Description and general biology

2

Collecting and preserving d i a s p i d i d s

3

Preparation of mounts

4

Habit and morphological characters

5

Morphology

8

Classification

17

Subfamily Phoenicococcinae

19

Subfamily Diaspidinae

19

Tribe Diaspidini

20

Tribe Aspidiotini

20

Tribe Odonaspidini

21

Systematics Treatment of s p e c i e s

.. ,

21 ,....

37

Tribe Aspidiotini

37

Tribe Diaspidini

87

Tribe Odonaspidini

163

Subfamily P h e n i c o c o c c i n a e

167

Distribution table

169

Literature cited

172

Host l i s t

173

Host index

193

Index to genera, s p e c i e s , and higher c a t e g o r i e s

203

E X P L A N A T I O N OF A B B R E V I A T I O N S IN F I G U R E S Except for the first three figures which are purely morphological and which are explained independently, a standard system of labeling the illustrations has been employed. T h i s system of labeling will be a s follows: A. B. C. D.

E. EE. F. G. H. I. J.

Antenna and cephalic margin of first s t a g e . Habitat sketch. Antenna of adult female. Anterior spiracle of adult female. The anterior spiracle has been chosen for illustration b e c a u s e significant d i f f e r e n c e s , such a s pore arrangement, occur with these rather than in the posterior pair. Pygidium of second-stage female. General outline of second stage in those forms which are pupillarial. General features of adult female. Pygidium of adult female. Dorsal a s p e c t of detail of pygidial margin of adult female. Ventral a s p e c t of detail of pygidial margin of adult female. Outline of exuvium of first s t a g e in a few forms.

Unlettered figures of d e t a i l s are connected with their points of origin by guide lines and should be readily identifiable.

INTRODUCTION One of the groups of i n s e c t s most important to the agriculturalist today is that family including the creatures popularly known a s the "armored s c a l e s " or " d i a s p i d i d s . " T h i s study deals s p e c i f i c a l l y with the s c a l e i n s e c t s belonging to the homopterous family Diaspididae. Unfortunately, they are very unattractive to the average entomologist, and even more so to the agriculturalist; yet a knowledge of each s p e c i e s , together with the best methods of control, is an e s s e n t i a l part of the education of every fruit grower. Furthermore, there is s c a r c e l y any tree or shrub that is not subject to their attack. The minute size of these creatures, their wonderful reproductive powers, and the difficulty of destroying them, all unite to place them among the most formidable p e s t s of the orchard, grove, nursery, or field in which they have gained a foothold. It should be remembered that each s c a l e i n s e c t , after having settled on the trunk, branch, stem, or leaf of the host plant, e s s e n t i a l l y turns i t s e l f into an automatic pump extracting the sap so vital to the life and growth of the tree. Injury to the plant tissue is often aggravated by toxic enzymes in the saliva of certain of these s p e c i e s . T h e s e enzymes are sometimes responsible for chlorophyll removal and discoloration of leaves a s well a s malformation and other growth irregularities of plant t i s s u e . Since many of our fruit growers are without knowledge of armored s c a l e i n s e c t s , damage is usually done before the infestation is discovered. The attacked tree or shrub will put forth every effort to sustain itself against the attack of the s c a l e i n s e c t and will not, at first, show any immediate damage. Ultimately, however, even the strongest tree wili yield to the persistent pumping of its sap by the feeding individuals, and will show evidences of leaf, twig, and branch killing or will suddenly collapse and die. To

e s t a b l i s h this fact, it is only n e c e s s a r y to c i t e the a c t i v i t i e s of California red s c a l e , Aonidiella aurantii (Maskell), so destructive to citrus in California. Some s p e c i e s are restricted to a single host, others to a single genus or family of host s p e c i e s , but many are extremely omnivorous and infest many plants of unrelated groups. The diaspidids are generally distributed throughout the world wherever suitable food plants are grown. It has been proven, that though many genera are native to certain regions they have been distributed in commerce to other parts of the world. Carnes ( 1 9 0 7 ) presented a t r e a t i s e , The Coccidae of California, in which he included thirty-two diaspidid s c a l e s established in this s t a t e . At this writing ( 1 9 5 5 ) some forty-nine years later, the number of established s p e c i e s of this family stands at one hundred and thirty-two, an increase of one hundred s p e c i e s . T h i s is largely owing to the activi t i e s of P r o f e s s o r G. F . F e r r i s , who, in 1937-1942, described and clarified the status of many of our California diaspidids in his monumental treatment the Atlas of the Scale Insects of North America.

ACKNOWLEDGMENTS T h i s study on the armored s c a l e s of California has been prepared on invitation of the University of California, Department of Entomology and Parasitology, a s a contribution to the California Insect Survey s e r i e s . My position a s taxonomist in the California Department of Agriculture has given me a c c e s s to a tremendous amount of material, submitted from various sources for identification. Furthermore, this Department has maintained extensive and accurate collection records of diaspidids taken in this s t a t e , and these data have

2

BULLETIN OF THE CALIFORNIA INSECT SURVEY

been e x t e n s i v e l y used in this p u b l i c a t i o n . As a matter of f a c t , without this information a solution of the problem would have been g r o s s l y incomplete, obviously resulting in a distorted picture of the California diaspidid fauna. T h e State Department of Agriculture has very generously permitted the diversion of c o n s i d e r a b l e time from my regular duties for preparation of this study. Distribution and host records have been made a v a i l a b l e from diaspidid s c a l e c o l l e c t i o n s of the Natural History Museum at Stanford University, and the United S t a t e s Department of Agriculture, Agricultural R e s e a r c h S e r v i c e , Crops R e s e a r c h , Entomology R e s e a r c h Branch, I n s e c t Identification Section at Washington, D . C . T h e s c i e n t i f i c libraries of the University of California, Stanford University, and the California Department of Agriculture were consulted during the preparation of this study. Acknowledgments are made to P r o f e s s o r s R . L . Usinger and £ . Gorton L i n s l e y , both of the University of California, Department of Entomology and P a r a s i t o l o g y , B e r k e l e y , who asked me to undertake this p r o j e c t . Bureau of Entomology personnel of the California State Department of Agriculture, including H. M. Armitage, Chief, and R . W. Harper, A s s i s t ant Chief, have been aware of this p r o j e c t and have offered advice and encouragement during i t s preparation. Hartford H. Keifer, Supervisor in Charge Taxonomy O f f i c e , has aided in many ways, particularly in constructive i d e a s relative to arrangement of the i n d i c e s . P r o f e s s o r G. F . F e r r i s , C o c c i d o l o g i s t of Stanford University, a s s i s t e d me in straightening out certain c o m p l e x i t i e s in taxonomic literature pertaining to certain s p e c i e s . He a l s o generously loaned his e x c e l l e n t diaspidid s c a l e pen and ink i l l u s t r a t i o n s ( o r i g i n a l s ) which are used together with those prepared by me. Appreciation is exp r e s s e d to P r o f e s s o r F e r r i s and to Stanford University P r e s s for granting permission to use t h e s e i l l u s t r a t i o n s and certain s e c t i o n s of the text from the Atlas of the Scale Insects of North America. Dr. A. M. B o y c e , Director of the University of California Citrus Experiment Station at R i v e r s i d e , made a direct and s u c c e s s f u l effort to j u s t i f y the printing of the colored p l a t e s of certain California diaspidids incorporated in this publication. A sinc e r e appreciation of h i s effort i s here e x p r e s s e d . De Witt Bishop of the California State Department of Agriculture, Bureau of Chemistry, gave s p e c i f i c instructions n e c e s s a r y to produce the colored photographs of the various diaspidids. To him I am grateful, and I here acknowledge his kind a s s i s t a n c e .

SCOPE OF STUDY Among the wide range of s p e c i e s of the armored s c a l e s are many which are primary p e s t s of major agricultural crops in C a l i f o r n i a . Knowledge of the complex taxonomy of the entire group is n e c e s sary to identify a c c u r a t e l y the thousands of s p e c i mens received annually in the Sacramento o f f i c e of the State Department of Agriculture and to record their occurrence within the s t a t e and e v a l u a t e their economic importance. The present study includes treatment of all known diaspidid s c a l e i n s e c t s found in C a l i f o r n i a . A dichotomous k e y to genera and s p e c i e s i s presented to aid the identifier. P e r t i n e n t taxonomic literature chronologically arranged, type l o c a l i t y and host, other known h o s t s , and s p e c i f i c l o c a l i t i e s in various California c o u n t i e s , together with the date c o l l e c t e d and the c o l l e c t o r , are included herein. Whenever p o s s i b l e the present s t a t u s of e a c h s p e c i e s is indicated under the " D i s c u s s i o n " paragraph, and its relationship to allied s p e c i e s is implied. Only s e l e c t e d taxonomic r e f e r e n c e s are included for e a c h s p e c i e s . An index t o g e n e r a , s p e c i e s , and higher c a t e g o r i e s of California D i a s p i d i d a e , a host index, and f i n a l l y a host l i s t including the Diaspididae species arranged alphabetically by plant f a m i l i e s are incorporated herein to aid the reader in locating desired information. With the e x c e p t i o n of the omnivorous s p e c i e s (p. 173) an attempt has been made to record every known host for e a c h form. A detailed drawing of each s p e c i e s is presented and should be used in identifying the form. Colored photographs of some of the armored s c a l e s p e c i e s have been included. It i s hoped that these illustrations which have been taken actual s i z e in situ on the h o s t , will enable field workers to r e c o g n i z e our more important d i a s p i d i d s .

DESCRIPTION AND GENERAL BIOLOGY In an armored s c a l e or diaspidid, a protective covering of wax i s excreted from tubular ducts situated at the posterior region of the body (pygidium). T h i s wax forms two protective s c a l e s ; the one above the body of the diaspidid is usually very hard and brittle and the one beneath, lying c l o s e to the surface of the plant where the i n s e c t is feeding, i s thin and d e l i c a t e . T h e body of the adult female l i e s between t h e s e two s c a l e l a y e r s . T h u s , if the top covering i s carefully removed with a needle or thin knife blade, the adult female

ARMORED SCALE INSECTS OF CALIFORNIA

3

diaspidid may be observed beneath, like a tiny clam between two s h e l l s . Armored s c a l e i n s e c t s vary markedly in shape; some s p e c i e s being circular to subcircular, oval, elongated, linear, threadlike, oyster shell-shaped, or fluted. The surface may be flat, convex, coneshaped, smooth or ridged, thin and delicate. They are variously colored from white to gray, yellow and various shades of brown, dull red, or black. Diaspidids range in size from l e s s than 1 mm. to more than 3 mm. in diameter. The young of armored s c a l e i n s e c t s are either born alive (viviparous) or hatched from eggs (oviparous), and are the only motile forms except the adult male of this large group. The eggs are laid beneath the s c a l e s , and after the adult female dies the s c a l e covering provides protection. The eggs are generally bean-shaped and are s c a r c e l y v i s i b l e to the naked eye. They are variously colored, ranging from white to yellow, reddish to purple.

segmented antennae, and anal filaments. As a consequence the second-stage nymph assumes a stationary position. The mouth parts or s t y l e t s , however, remain in a highly developed condition well fitted to perform their functions. T h e s e styl e t s serve not only to draw nourishment from the plant, but a l s o provide a means of attachment to the plant for the i n s e c t i t s e l f . Later, the females molt a second time and become adults, and the males, after further metamorphosis consisting of five instars, develop into two-winged adults. The immature male s c a l e s are very much smaller and more slender than the adult females. In general, the color of both s e x e s i s e s s e n t i a l l y the same, although the male s c a l e s may be paler. Shortly after emerging, the adult winged males mate with the females and die within a short period thereafter. After fertilization the adult females increase in size very rapidly and either commence egg laying or produce living young.

The young crawlers are oval-shaped and very minute, with distinctly segmented body, two long anal filaments, and usually, six-segmented antennae. They p o s s e s s a pair of o c e l l i , three pairs of segmented legs with two pairs of digitules at the ends of the tarsi, a one-segmented rostrum or beak, and a posterior anus. Aside from their own powers of locomotion they may be distributed by birds, i n s e c t s , and possibly by wind. They move about for a time and finally s e l e c t a favorable location on the food plant where they insert their beaks and commence feeding. If a suitable feeding place is not found within a few hours the crawlers may perish. Their habit of settling beneath and around the adult female s c a l e often results in the formation of compact colonies which may become encrusted on the host plant where they are feeding. Very little if any honeydew is excreted by armored s c a l e i n s e c t s , and usually the s c a l e covering is perfectly dry.

There may be from one to as many as six generations annually, the winter being spent in the egg, immature or adult s t a g e s , or in all three. During the warmer s e a s o n s there appears to be much overlapping of the broods, and all s t a g e s may be evident at one time.

Soon after settling, fine threads of wax, which appear cottony, begin to exude from the body of the crawler, and this waxy excretion continues until the i n s e c t is completely covered. The rate at which this excretion is produced varies according to the individual s p e c i e s . In due time the crawler begins to excrete a p e l l i c l e , which is very thin but dense and firm in texture. In certain Aspidiotine s p e c i e s the cottony fibers remain a s a central white dot or ring, hence the common name " w h i t e c a p . " The first molt soon follows, resulting in a retrogression instead of an advancement to a more highly s p e c i a l i z e d form, with the l o s s of l e g s ,

COLLECTING AND PRESERVING DIASPIDIDS The chief requisite in collecting diaspidids is keen observation and perseverance. Armored scale i n s e c t s may be found on the l e a v e s , fruit, twigs, branches, trunks, and crown not only of fruit trees but also of forest and shade trees, ornamental trees and shrubs, and, a s a matter of fact, on all types of plant life including g r a s s e s . Even garden plants are infrequently attacked, and a few hours spent in a large greenhouse where a wide variety of plants is grown usually reveal several s p e c i e s . The beginner should prepare a l i s t of diaspidids he has not found, together with the host plants they attack, and then be on the lookout for these particular h o s t s . Equipment needed to c o l l e c t diaspidids includes only a sharp, strong knife, a pair of pruning shears, paper s a c k s , and different s i z e s of coin envelopes. The larger twigs and branch material may be put into the paper s a c k s , and the coin envelopes will accommodate the smaller plant parts, such a s p i e c e s of infested bark and l e a v e s . It i s advisable to put only a single s p e c i e s from a given host into a s a c k or envelope and indicate thereon the locality, date, host, and collector.

4

B U L L E T I N OF THE CALIFORNIA INSECT SURVEY

Diaspidid s c a l e material which is brought to the laboratory from the field i s best preserved by drying. Larger stems and bark chunks may be cut to the size of the envelope for filing. The infested plant parts should be fumigated with napthalene flakes to kill the crawlers or first-stage nymphs of the scale i n s e c t s . When the s c a l e material i s thoroughly dried it may be placed between layers of Cellucotton and put into envelopes or small cardboard b o x e s . The California State Department of Agriculture u s e s a manila envelope 33/„" x 6 " with blanks for the s p e c i f i c name, a c c e s s i o n number, host, place c o l l e c t e d , origin (for Plant Quarantine material), date, and c o l l e c t o r ' s name. After genus and s p e c i e s name are printed or written, the envelopes are filed in 4 " x 6 " metal filing drawers. Stanford University uses a 3 " x 4%" cardboard box which varies in t h i c k n e s s to accommodate different s i z e infested plant parts. T h e s e are filed in s p e c i a l l y constructed wood cabinets, with partitioned drawers. It seems inadvisable to preserve diaspidid material in alcohol. Exhibit coll e c t i o n s of armored s c a l e s are best placed in flat cardboard boxes filled with cotton and covered with g l a s s tops which hold the infested plant material in p l a c e . T h e s e are called " R i k e r Mounts" and may be purchased from most biological supply houses. When diaspidids are to be submitted for determination, infested plant parts should be wrapped in soft tissue paper, sealed in a coin envelope with a few crystals of napthalene or paradichlorobenzene to assure complete kill, and the collection data written on the outside of the envelope. An identification slip is provided by the state, and the coin envelope may be clipped to it and placed in a larger envelope or mailing tube to be sent to the State Department of Agriculture, Bureau of Entomology, 1220 N Street, Sacramento, California.

PREPARATION OF MOUNTS It must be borne in mind that a study of the Diaspididae involves an examination of microscopic characters which are of taxonomic value. The ins e c t s must be s p e c i a l l y prepared for this. Two kinds of microscopic g l a s s slide mounts, temporary or permanent, 1 are made. Temporary mounts are useful in a regulatory office such as the State ' T h e following article presents an excellent treatment of mounting procedures, especially for temporary mounts and for permanent mounts of mealybugs and soft s c a l e s : H. H. Keifer, Journal of Economic Entomology, Vol. 39, no. 5, pp. 6 6 5 - 6 6 6 (1946).

Department of Agriculture where large quantities of scale material are sent for identification. A rapid determination of the more common forms i s p o s s i b l e within a few minutes after the temporary mounts have been made. The following procedure is used in preparing temporary mounts of the Diaspididae: 1. Remove the body of the i n s e c t from beneath the covering, or place entire armored s c a l e in a 1-inch handled crucible, filled threefourths full with distilled water to which has been added two p e l l e t s of potassium hydroxide (KOH). 2. Heat crucible until solution boils. 3. Remove s c a l e body from crucible and transfer to depression slide, rupture anterior part of body (prosoma) with edge of probe, and t e a s e out body contents until specimen appears a s a clear, membranous s a c k . 4. Transfer cleared specimen to droplet of socalled gum-chloral hydrate or chloral-hydrate media ( s e e formula below). Apply cover slip and heat slide on hot plate until media boils slightly. The specimen is then conditioned for examination under the compound microscope. Valuable specimens are recoverable from this media for permanent embedding in Canada balsam. The formula used to prepare chloral-hydrate media follows: Gum Arabic 1 gram Dextrose 1 gram Chloral hydrate . . . . 10 grams Iodine crystals . . 1/10 grams Glycerin 1 cc. Water 1 cc. Grind mixture of solid ingredients in mortar. P l a c e in screw-cap vial and add water to desired consistency.,which cannot be finally determined until all parts have dissolved. The most satisfactory method of studying diaspidids is by the use of permanent or stained mounts preserved in Canada balsam. Stained preparations present the important morphological details for specific identification and preserve the specimens almost indefinitely. With the method described below it is p o s s i b l e to prepare a permanent stained mount within a fifteen-minute period, although twice this time is recommended. The following steps used in the preparation of permanent diaspidid s c a l e mounts are: 1. Remove body of diaspidid female from beneath s c a l e covering, or place entire specimen in a 1-inch handled crucible, filled threefourths full with distilled water to which have been added two p e l l e t s of potassium

ARMORED SCALE INSECTS OF CALIFORNIA hydroxide (KOH). Heat crucible until solution b o i l s . 2. With an eye dropper, remove s c a l e body from hot KOH in crucible and transfer to depression s l i d e . With the edge of a probe or needle rupture anterior part of body (prosoma) and t e a s e out body contents until specimen appears a s a c l e a r , membranous s a c k . 3. T r a n s f e r c l e a r e d specimen to d i s t i l l e d water in clean depression s l i d e . Wash thoroughly and let stand in water for two or three minutes. 4 . F i l l c l e a n depression s l i d e with 50 per c e n t ethyl a l c o h o l , add b a s i c fuchsin (magenta) c r y s t a l s and stir until solution becomes a deep blood-red color. T r a n s f e r washed s p e c imen to a l c o h o l - b a s i c fuchsin and l e a v e in stain for at l e a s t five minutes. 5. T r a n s f e r to g l a c i a l a c e t i c acid in c l e a n dep r e s s i o n slide and carefully t e a s e out e x c e s s stain from specimen. S i n c e g l a c i a l a c e t i c acid is extremely a c t i v e a s a destainer, care should be e x e r c i s e d not to destain too much. 6. T r a n s f e r destained specimen to oil of c l o v e s in c l e a n depression s l i d e , and leave in this solution for .not l e s s than five—preferably twenty—minutes. 7. T r a n s f e r to xylene in c l e a n depression slide and wash thoroughly for one or two minutes. 8. P l a c e specimen in droplet of Canada balsam on a g l a s s microscope slide and apply g l a s s cover s l i p . Use a s l i t t l e balsam a s p o s s i b l e to f a c i l i t a t e examination under compound microscope, e s p e c i a l l y under the oil-emersion magnification. When the balsam has hardened the cover slip may be ringed with s h e l l a c or other s u i t a b l e medium to prevent later checking of the balsam.

HABIT AND DETAILED MORPHOLOGICAL CHARACTERS P r o f e s s o r G. F . F e r r i s ( 1 9 4 2 ) has very adequately dealt with the habit and morphological d e t a i l s of the Diaspididae in h i s Atlas of the Scale Insects of North America. I am in complete accord with P r o f e s s o r F e r r i s ' o b s e r v a t i o n s and i d e a s , and t h e s e are here presented verbatim, e x c e p t for certain o m i s s i o n s , a s they occur in the Atlas. T H E NORMAL DIASPIDID P A T T E R N

Habit " T h e habit pattern of the majority of the D i a s p i d i dae i s e x c e e d i n g l y well marked and c o n s t i t u t e s

5

the c h i e f b a s i s for the s u p e r f i c i a l recognition of the group, it involving normally the formation of the s c a l e which i s composed of exuviae and of secretionary m a t e r i a l . "

T h e S c a l e of the F e m a l e " T h e normal procedure is for the larva to insert i t s mouthparts into the t i s s u e s of the h o s t , to grow to a c e r t a i n e x t e n t , and then to shed its skin. During this period of growth a certain amount of waxy s e c r e t i o n is usually produced over and around the body. T h e derm of the dorsum b e c o m e s more or l e s s heavily s e l e r o t i z e d , while that of the venter remains membranous. Exuviation involves the rupturing of the ventral derm, usually around the anterior margin of the body; it being then pushed back to the posterior end. " A t this molt the l e g s are entirely l o s t , e x c e p t rarely for minute v e s t i g e s , and the antennae are reduced to mere unsegmented t u b e r c l e s . " T h e i n s e c t in the second s t a g e , being legl e s s , remains beneath the exuvia of the first s t a g e , i n s e r t s i t s ' b e a k , and resumes growth. During this period of growth wax i s usually s e c r e t e d over and around the body, forming an e x t e n s i o n of the s e cretion produced during the first instar. "When the i n s e c t has reached the limit of growth of the s e c o n d instar, the derm of the dorsum becomes s c l e r o t i c . In perhaps the majority of s p e c i e s the derm of the venter remains membranous although in some s p e c i e s it may become a s s c l e r o t i c a s that of the dorsum, while in others it may be partially s e l e r o t i z e d . " E x u v i a t i o n o c c u r s in one of three w a y s . In many s p e c i e s the membranous ventral derm ruptures about the anterior region of the body and i s pushed back to the posterior extremity, remaining attached there to the dorsal derm. In some other c a s e s , when the ventral derm b e c o m e s more or l e s s s e l e r o t i z e d , the rupture may take p l a c e around the posterior portion of the body, leaving the dorsal and ventral parts attached to e a c h other at the anterior end. In t h e s e c a s e s the ventral derm becomes incorporated in a ventral s c a l e and may at times become entirely separated from the dors a l skin. T h e third method of exuviation involves an actual shrinking of the body of the adult female, which remains entirely e n c l o s e d within the exuvia of the s e c o n d s t a g e . In such c a s e s the s p e c i e s ishere c h a r a c t e r i z e d a s being ' p u p i l l a r i a l . ' " I n the non-pupillarial forms, growth is resumed by the adult female, which again i n s e r t s its beak into the t i s s u e s of the host and f e e d s . T h e i n s e c t ,

ARMORED SCALE INSECTS OF CALIFORNIA hydroxide (KOH). Heat crucible until solution b o i l s . 2. With an eye dropper, remove s c a l e body from hot KOH in crucible and transfer to depression s l i d e . With the edge of a probe or needle rupture anterior part of body (prosoma) and t e a s e out body contents until specimen appears a s a c l e a r , membranous s a c k . 3. T r a n s f e r c l e a r e d specimen to d i s t i l l e d water in clean depression s l i d e . Wash thoroughly and let stand in water for two or three minutes. 4 . F i l l c l e a n depression s l i d e with 50 per c e n t ethyl a l c o h o l , add b a s i c fuchsin (magenta) c r y s t a l s and stir until solution becomes a deep blood-red color. T r a n s f e r washed s p e c imen to a l c o h o l - b a s i c fuchsin and l e a v e in stain for at l e a s t five minutes. 5. T r a n s f e r to g l a c i a l a c e t i c acid in c l e a n dep r e s s i o n slide and carefully t e a s e out e x c e s s stain from specimen. S i n c e g l a c i a l a c e t i c acid is extremely a c t i v e a s a destainer, care should be e x e r c i s e d not to destain too much. 6. T r a n s f e r destained specimen to oil of c l o v e s in c l e a n depression s l i d e , and leave in this solution for .not l e s s than five—preferably twenty—minutes. 7. T r a n s f e r to xylene in c l e a n depression slide and wash thoroughly for one or two minutes. 8. P l a c e specimen in droplet of Canada balsam on a g l a s s microscope slide and apply g l a s s cover s l i p . Use a s l i t t l e balsam a s p o s s i b l e to f a c i l i t a t e examination under compound microscope, e s p e c i a l l y under the oil-emersion magnification. When the balsam has hardened the cover slip may be ringed with s h e l l a c or other s u i t a b l e medium to prevent later checking of the balsam.

HABIT AND DETAILED MORPHOLOGICAL CHARACTERS P r o f e s s o r G. F . F e r r i s ( 1 9 4 2 ) has very adequately dealt with the habit and morphological d e t a i l s of the Diaspididae in h i s Atlas of the Scale Insects of North America. I am in complete accord with P r o f e s s o r F e r r i s ' o b s e r v a t i o n s and i d e a s , and t h e s e are here presented verbatim, e x c e p t for certain o m i s s i o n s , a s they occur in the Atlas. T H E NORMAL DIASPIDID P A T T E R N

Habit " T h e habit pattern of the majority of the D i a s p i d i dae i s e x c e e d i n g l y well marked and c o n s t i t u t e s

5

the c h i e f b a s i s for the s u p e r f i c i a l recognition of the group, it involving normally the formation of the s c a l e which i s composed of exuviae and of secretionary m a t e r i a l . "

T h e S c a l e of the F e m a l e " T h e normal procedure is for the larva to insert i t s mouthparts into the t i s s u e s of the h o s t , to grow to a c e r t a i n e x t e n t , and then to shed its skin. During this period of growth a certain amount of waxy s e c r e t i o n is usually produced over and around the body. T h e derm of the dorsum b e c o m e s more or l e s s heavily s e l e r o t i z e d , while that of the venter remains membranous. Exuviation involves the rupturing of the ventral derm, usually around the anterior margin of the body; it being then pushed back to the posterior end. " A t this molt the l e g s are entirely l o s t , e x c e p t rarely for minute v e s t i g e s , and the antennae are reduced to mere unsegmented t u b e r c l e s . " T h e i n s e c t in the second s t a g e , being legl e s s , remains beneath the exuvia of the first s t a g e , i n s e r t s i t s ' b e a k , and resumes growth. During this period of growth wax i s usually s e c r e t e d over and around the body, forming an e x t e n s i o n of the s e cretion produced during the first instar. "When the i n s e c t has reached the limit of growth of the s e c o n d instar, the derm of the dorsum becomes s c l e r o t i c . In perhaps the majority of s p e c i e s the derm of the venter remains membranous although in some s p e c i e s it may become a s s c l e r o t i c a s that of the dorsum, while in others it may be partially s e l e r o t i z e d . " E x u v i a t i o n o c c u r s in one of three w a y s . In many s p e c i e s the membranous ventral derm ruptures about the anterior region of the body and i s pushed back to the posterior extremity, remaining attached there to the dorsal derm. In some other c a s e s , when the ventral derm b e c o m e s more or l e s s s e l e r o t i z e d , the rupture may take p l a c e around the posterior portion of the body, leaving the dorsal and ventral parts attached to e a c h other at the anterior end. In t h e s e c a s e s the ventral derm becomes incorporated in a ventral s c a l e and may at times become entirely separated from the dors a l skin. T h e third method of exuviation involves an actual shrinking of the body of the adult female, which remains entirely e n c l o s e d within the exuvia of the s e c o n d s t a g e . In such c a s e s the s p e c i e s ishere c h a r a c t e r i z e d a s being ' p u p i l l a r i a l . ' " I n the non-pupillarial forms, growth is resumed by the adult female, which again i n s e r t s its beak into the t i s s u e s of the host and f e e d s . T h e i n s e c t ,

6

B U L L E T I N OF THE CALIFORNIA INSECT SURVEY

being l e g l e s s , s t i l l l i e s beneath the s c a l e , which is now composed of two exuviae and of the s e c r e tionary material that was formed during the first two instars. T o this material is added more wax which is produced by the adult female. In some forms a certain amount of waxy material appears on the ventral side of the body and the i n s e c t may be entirely enclosed within a complete shell. In others a dorsal s c a l e alone is formed. There may be various transitions between these two conditions. " A t full maturity the female begins depositing her eggs, and a s the body contents are converted into ova and extruded, the female shrinks until finally she is reduced to a little, shrivelled body lying at one end or to one side within the enclosing s c a l e , the remainder of the space being filled with eggs. " T h e r e is some correlation between the shape of the i n s e c t and that of the s c a l e . Elongated s p e c i e s usually produce a long s c a l e , while the more rotund s p e c i e s produce a circular or oval s c a l e . In some c a s e s the exuviae may lie over or c l o s e to the center of the s c a l e , and it seems probable that in such i n s t a n c e s the i n s e c t , in at l e a s t the adult stage, has rotated about a pivot formed by the mouthparts."

The S c a l e of the Male " T h e complete story of what happens in the development of the male has been worked out in but few s p e c i e s . We may adopt the description given by Stickney 2 of the conditions found in Parlatoria blanchardi as typical. " T h e first larval stage of the male has not been demonstrated to be different from that of the female although there is a possibility that in some forms differences may e x i s t between the s e x e s at this stage. Exuviation is similar to that of the female, the first exuvia being sclerotized in the same manner. " T h e second stage of the male has lost thé legs and antennae as in the female. In those forms JF. S. Stickney, United States Department of Agriculture, Technical Bulletin number 421 (1934).

that have been carefully studied, the i n s e c t in this stage seems to be in general very similar to the corresponding stage of the female, but some material that is at hand indicates that in at l e a s t some s p e c i e s it may be quite different in its pygidial structures. In any c a s e , the second stage produces a certain amount of secretionary material which forms a waxy appendage at one end of or surrounding the first exuvia. In many s p e c i e s the character of the waxy secretion is quite different from that of the female, it tending to be composed of individual threads which give a felted appearance to the whole. In some c a s e s , e s p e c i a l l y in the Aspidiotini, the s c a l e is in texture similar to that of the female. " T h e second instar of the male never becomes strongly sclerotized, and the exuvia does not enter into the composition of the s c a l e , being pushed back inside the s c a l e in a little crumpled bundle. " A t the second molt the mouthparts are l o s t . In some s p e c i e s , at l e a s t , there follow a prepupal and a pupal stage, the adult male emerging from the latter. In both these stages the exuviae are membranous and d e l i c a t e . " T h e s c a l e of the male, then, c o n s i s t s normally of one sclerotized exuvia and of a certain amount of waxy s e c r e t i o n . " Departures from the Normal Habit " A s has been pointed out, in a number of s p e c i e s the adult female remains within the exuvia of the preceding stage, this exuvia in such c a s e s always being more or l e s s heavily sclerotized throughout. It ruptures about the posterior end, in one way or another, to permit the escape of the larvae. " A few forms are known in the P h o e n i c o c o c c i n a e in which one or even two additional larval stages are present in the female, the exuviae of these stages being retained within the exuvia of the second s t a g e . " I n one known North American s p e c i e s , Praecocaspis diversa Ferris, the adult female i s s u e s directly from the first larval stage. In a few c a s e s , in the P h o e n i c o c o c c i n a e , the male goes through its development while encased within the first larval e x u v i a . "

ARMORED SCALE INSECTS OF C A L I F O R N I A

derm sclerotization

antenna duct 0 tubercle &

\ raised \ spui\type

s \ \

derm granulations

multilocular disk pores and anterior spiraci

derm pocket

dorsal

ventral

median dorsal ./macroducts f\perivulvar pores *À

—-abdominal i segment

mar{

=f

vulva

dorsal intermediate macroducts cicatrix Ith iVa >8 lobe abdominal T^jp =fsegments4 rt

mu paraphyses \ \tviii. second lobe

dorsal mari macroducts

microduct

median or first 7 lobe plates luith microducts

Fig. 1. genus

Generalized and semidiagrammatic drawing representing the Morphological structures of typical Diaspididae.

Parlatoria.

8

BULLETIN OF THE CALIFORNIA INSECT SURVEY

MORPHOLOGY " W e are here e s p e c i a l l y concerned with the problems of s p e c i f i c identification, and t h e s e r e s t almost entirely upon the morphology of the adult female. In a r e l a t i v e l y small number of c a s e s reference must be made to the s e c o n d s t a g e . T h e first stage larvae, while undoubtedly of aid in the development of a general c l a s s i f i c a t i o n , are a s a rule of no help in the identification of genera and s p e c i e s , although at times they furnish confirmatory or supplementary information. T h e males are entirely u s e l e s s for anything e x c e p t the broader a s p e c t s of c l a s s i f i c a t i o n . Consequently, the remarks which follow will be devoted primarily to the adult female, with l e s s e r n o t e s on the second stage and only a few remarks about the l a r v a e . T h e males will be d i s r e g a r d e d . "

T h e Adult F e m a l e Segmentation of the Body " T h r o u g h o u t the Diaspididae there is a strong tendency for the segments of the body to become more or l e s s fused into tagmata which do not entirely follow the pattern of ' h e a d , thorax, and abdomen' that i s conventionally a s c r i b e d to all insects. " A s in a l l the C o c c o i d e a , the head and the two s u c c e e d i n g segments become quite c l o s e l y fused. T h e region composed of t h e s e parts frequently b e c o m e s much enlarged, at times comprising the greater part of the body, and it i s very frequently quite definitely separated from the metathorax by c o n s t r i c t i o n . F o r this reason it i s at times convenient to have a v a i l a b l e a term c h a r a c t e r i z i n g this region, and it is here spoken of a s thè 'pros o m a ' . Figure 1 i s a generalized and semidiagrammatic drawing representing the genus Parlatorio. It i l l u s t r a t e s morphological structures of a typical Diaspididae. " T h e metathorax i s frequently more similar to the first abdominal segment than it i s to the mesothorax. It is at times convenient, therefore, to regard this segment and the abdomen a s forming a 'postsoma.' " T h e opinion i s here adopted that the i n s e c t abdomen i s composed b a s i c a l l y of e l e v e n s e g ments, the eleventh bearing the anus, and that the vulva of the female is usually between the eighth and ninth s e g m e n t s . If we adopt t h i s view

and proceed to an examination of the Diaspidid abdomen, we find that certain segments appear to be missing and that certain others have a strong tendency to fuse together. Not more than eight abdominal segments can be identified in any Diaspidid a s d i s t i n c t e n t i t i e s , t h e s e apparently being the first to eighth, and we must assume that the ninth to eleventh segments have been greatly reduced. " T h e interpretation of the abdominal segmentation, however, is somewhat difficult and in some r e s p e c t s uncertain. T h e assumption that the vulva i s between the eighth and ninth segments may be wrong, there being the p o s s i b i l i t y that it i s actually between the seventh and eighth s e g m e n t s . If it i s really between the eighth and ninth we must assume that the eighth s t e r n i t e i s very much reduced. T h e dorsal side of the body permits somewhat more definite c o n c l u s i o n s . If we r e a s o n from the conditions found in certain more generalized C o c c o i d e a , where the abdominal s p i r a c l e s are retained, and if we carefully follow the count of certain fixed s e t a e that seem in part to be s e g mentally arranged, we can arrive at rather definite c o n c l u s i o n s . T h e author differs by one segment from the interpretation given by S t i c k n e y in the paper to which r e f e r e n c e has been made. " A r e f e r e n c e to figure 1, illustrating morphology, should make the s u b j e c t c l e a r . It is here held that the median l o b e s at the apex of the body belong to the eighth abdominal segment. S i n c e the anus b e l o n g s morphologically to the eleventh segment it i s c l e a r that the ninth, tenth, and eleventh segments have become much reduced. T h e narrow median area posterior to the anus should include the morphologically ventral a r e a s of at l e a s t the eleventh and tenth s e g m e n t s . On the ventral side the area immediately posterior to the vulva should represent e i t h e r the eighth or ninth s t e r n i t e s . T h e peculiar development of the s o - c a l l e d pygidium a r i s e s from the f a c t that the segments anterior to the ninth have been bent posteriorly, thus folding around the now almost or quite o b s o l e t e ninth, tenth, and eleventh s e g m e n t s . T h i s backward folding h a s gone so far that the lateral l o b e s of the eighth tergite come almost into c o n t a c t behind the anus. In f a c t , in some forms they have a c t u a l l y fused together at their posterior e x t r e m i t i e s . In addition to t h i s , the eighth and preceding s e g ments tend to become c l o s e l y united to e a c h other, with intersegmental l i n e s being more or l e s s suppressed.

9

ARMORED SCALE INSECTS OF CALIFORNIA " I n a l l the s p e c i e s here regarded a s belonging to the D i a s p i d i n a e , t h i s union of segments has proceeded s o far that certainly all segments forward to the fifth are involved, while in some forms even the fourth segment enters into the composition of the pygidium. In the P h o e n i c o c o c c i n a e , except for Pboeiiicococcus i t s e l f in which no fusion o c c u r s , t h i s uniting of the termal segments does not proceed farther forward than the sixth at the most, and at times perhaps not even so far. " T h e compound structure thus formed by the fusion of segments is usually rather definitely marked off from the preceding abdominal s e g m e n t s , although in some forms i t s anterior limits are not clearly definable. T h i s region forms the 'pygidium.' T h e term a s here used certainly d o e s not imply the same morphological r e l a t i o n s h i p s a s it does in some other groups, but it has been used so e x t e n s i v e l y in connection with the Diaspididae that it could not now be altered. " T h e determination of the segments can b e s t be a c c o m p l i s h e d by counting the marginal s e t a e of fixed p o s i t i o n , beginning with the s e t a at the lateral b a s a l angle of each median lobe and counting outward. T h e s e s e t a e are of very definite position and are retained even after all other evidence of segmentation has been suppressed. In some forms the segmental l i n e s are indicated, at l e a § t on the dorsum, by furrows, or by intersegmental s c l e r o t i z a t i o n s that are concerned with muscle a t t a c h m e n t s , or by rows of ducts that follow the segmental l i n e s . ( S e e fig. 2 . ) " I n general there is a tendency for the dorsum of the pygidium to be more or l e s s heavily s c l e r o tized, although t h i s s c l e r o t i z a t i o n usually d o e s not involve all the segments that are involved in the pygidium and is at times entirely l a c k i n g . "

The

Antennae

" I n all the s p e c i e s here regarded a s belonging to the Diaspididae the antennae of the adult female are reduced to unsegmented t u b e r c l e s , or even to minute, s c l e r o t i z e d p o i n t s . Normally they bear s e t a e , which at times are somewhat ' f l e s h y ' and are perhaps of a sensory nature. " F o r the most part the antennae offer r e l a t i v e l y l i t t l e a s a b a s i s for the recognition of s p e c i e s and genera, although in a few c a s e s they are modified in d i s t i n c t i v e w a y s . In a few forms they are n o t i c e a b l y enlarged or e l o n g a t e , or bear enlarged s e t a e . T h e y have some s i g n i f i c a n c e in connection with the larger groups. In general it may be said that the antennae in the tribe D i a s p i dini of the subfamily D i a s p i d i n a e tend to have

two or more s e t a e , frequently s e v e r a l , while in the Aspidiotini they rarely bear more than one s e t a . The distinction is by no means a b s o l u t e , but h a s a degree of v a l i d i t y . "

The E y e s " T h e e y e s are probably present in the adult female of all s p e c i e s , although they are frequently so reduced that they are s c a r c e l y d e t e c t a b l e in preparations. T h e i r normal appearance is that of a weakly s c l e r o t i z e d spot with a smooth surface which d i s t i n g u i s h e s it from the surrounding slightly striate derm. Ordinarily they l i e at the margin slightly anterior to or j u s t laterad of the mouthp a r t s . Usually they may, for our purposes, be d i s regarded, but they are s u b j e c t t o o c c a s i o n a l extraordinary modifications. P e r h a p s the most unusual development i s that to be s e e n in the North American s p e c i e s , Velataspis cornigera F e r r i s , where they form prominent, s c l e r o t i z e d , s p i n o s e structures, or in Velataspis mimosarum ( C o c k e r e l l ) where they are in the form of ' s t a r f i s h shaped' t u b e r c l e s . "

The L e g s " T h e D i a s p i d i d a e are usually considered to be l e g l e s s after the first molt, but in a few forms there appear structures which, on the b a s i s of their number and p o s i t i o n , seem to be leg v e s t i g e s . They never, in any known form, c o n s i s t of anything more than a s p i n e l i k e , s c l e r o t i z e d t u b e r c l e . Among North American s p e c i e s they are to be found in Dactylaspis dactylifera F e r r i s and Dactylaspis crotonis ( C o c k e r e l l ) and in the genus Opuntiaspis. T h e opinion here held i s that their p r e s e n c e has no s p e c i a l phylogenetic s i g n i f i c a n c e , other than to indicate that a s p e c i e s p o s s e s s i n g them i s in this one r e s p e c t somewhat generalized in c l a s s i f i c a t i o n . "

T h e Mouthparts " F o r the purposes of this work the mouthparts seem to have no s i g n i f i c a n c e , and they are d i s m i s s e d from c o n s i d e r a t i o n . "

The

Spiracles

" I n general the s p i r a c l e s offer but l i t t l e that i s of any importance to taxonomic work in this family.

10

BULLETIN OF THE CALIFORNIA INSECT SURVEY

setae

poriferous

furrow

, duct

orifice

¡»iraphi/ses macroduct

hth lobe (segment

basal

v)

3rd lobe (segment

vi)

2nd lobe (segment

vii)

1st or median lobe (segment

viii j ~~ - - - ^plates

A. Aspidiotini,pygidial structures

_ _..duct

spur

I

fixed seta,segment

5

:ird lobe (segment

6)

2nd lobe

sclerosis

orifices

macroduct

/

(segment

Jst or médian lobe (segment _c u

m a a os m

«

m ta a

3 Pi

ûo

•a