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1963 Diatraea Saccharalis (Fabr.) and Some Related Pyralid Stem Borers in Louisiana. Ram Autar Agarwal Louisiana State University and Agricultural & Mechanical College
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AGARWAL, Ram Autar, 1925— DIATRAEA SACCHARALIS (FABR.) AND SOME RELATED PYRAUD STEM BORERS IN LOUISIANA.
Louisiana State University, Ph.D., 1963 Zoology
University Microfilms, Inc., Ann Arbor, Michigan
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DIATRAEA SACCHARALIS (FABR.) AND SCME RELATED PYRALID STEM BORERS IN LOUISIANA
A Dissertation
Submitted to the Graduate Faculty of the Louisiana State University and A gricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy
in
The Department of Zoology, Physiology and Entomology
by Ram Autar Agarwal B.Sc. Ag., Assoc. I.A.R.I. (New D elhi), 1952 Ju n e , 1963
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENT
The w riter wishes to express his sincere gratitude to his
major professor, Dr. W. H. Long for the guidance during the course
of this study and for assistance in the preparation of this
manuscript. Special thanks are extended to Dr. L. D. Newsom,
Head of the Department of Entomology, Louisiana State University
for providing the opportunity to study at L. S. U. and for
reviewing the manuscript, and to Mr. H. W. Capps of the U. S.
National Museum, Washington D. C., for kindly identifying insects
sent to him.
Gratitude is acknowledged to Dr. Bruce Boudreaux, Dr. S. D.
Hensley, Dr. R. L. M iller and Dr. Wm. T. Spink for helpful sug
gestions offered during the course of these investigations and
for their criticism of the manuscript. Special appreciation is
expressed to Dr. J. H. Roberts and Dr. J. P. Woodring for their
assistance in making drawings and photographic work, and to
Dr. C. A. Brown for assistance with identification of plants.
The w riter is very grateful to Mr. E. J. Concienne for help
in collecting insect specimens from different parts of the state,
and to Mrs. E. J. Poirier for the excellent job of typing this
dissertation.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS
Page
ACKNOWLEDGEMENT ...... i i
TABLE OF CONTENTS...... iii
LIST OF TABLES ...... v
LIST OF PLA TES ...... v i i
ABSTRACT ...... ix
INTRODUCTION . 1
REVIEW OF LITERATURE ...... 3
MATERIALS AND METHODS...... 14
RESULTS ...... 21
Chaetotaxy of Diatraea saccharalis Larvae .... 21
Morphological Variation in Diatraea saccharalis . . . 25
L a r v a e ...... 25
P u p a e ...... 28
A d u lts ...... 36
Physiological Variation in Diatraea saccharalis . . . 38
Comparative Morphology of Species Studied .... 38
E ggs...... 38
L arv ae ...... 40
Pupae ...... 45
A d u l t s ...... 47
Keys for Identification of Pyralid Stem Borers . . . 50
i i i
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Mature Larvae 50
Pupae ...... 52
A d u l t s ...... 53
D IS C U S S IO N ...... 56
SUMMARY AND CONCLUSION ...... 61
SELECTED BIBLIOGRAPHY...... 65
APPENDIX...... 71
BIOGRAPHY...... 87
iv
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF TABLES
Page
I. Systems of nomenclature proposed by different
workers for setae on the head of Lepidopterous larvae . 7
II. Systems of nomenclature proposed by different
workers for setae on the thorax and abdomen of
Lepidopterous larvae ...... 9
III. Host plants, localities and dates of collection
of different species of Pyralid larvae, Louisiana,
1960-1961 ...... 15
IV. Names assigned to body pinaculi of Diatraea
saccharalis (F.) larvae ...... 18
V. Number and distribution of setae and punctures
on the head of typical mature Diatraea saccharalis
la r v a e ...... 22
VI. Number and distribution of setae on the body
of typical mature Diatraea saccharalis larvae . . . 26
VII. Number and distribution of pinaculi on the
body of typical mature Diatraea saccharalis
l a r v a e ...... 27
VIII. Percentages of setae with indicated abnormalities
on 1G1 Diatraea saccharalis larvae ...... 29
v
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. IX. Percentages of pinaculi with indicated
abnormalities on 181 Diatraea saccharalis larvae .
X. Percentages of total setal and pinacular
abnormalities for each body segment on 181
Diatraea saccharalis larvae examined .....
XI. Average weights of field-collected and
laboratory-reared female Diatraea saccharalis
pupae from different varieties of sugarcane . . .
XII. Average weights of field-collected and laboratory-
reared male Diatraea saccharalis pupae from
different varieties of sugarcane ......
XIII. Survival of larvae and weights of pupae obtained
by rearing 50 newly hatched Diatraea saccharalis
larvae in the laboratory on the cut stems of
each of six different host plants, Baton Rouge,
Louisiana, May-June, 1961......
XIV. Sizes of various body parts of male and female
Diatraea saccharalis moths collected from a light
trap at Baton Rouge, Louisiana, 1960-1961 . . . .
XV. Survival percentages and developmental periods
for strains of Diatraea saccharalis reared in
field cages on 2 different host plants, Baton Rouge,
Louisiana, 1962 ......
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF PLATES
Page
I. Arrangement of setae on head and crochets on 71
abdominal prolegs of several species of Pyralid
larvae......
II. Setal maps of body segments of D. saccharalis 72
la r v a e ......
III. Pinacular maps of body segments of D. saccharalis 73
larvae......
IV. Variations in the shape of mandibles encountered 74
among D. saccharalis larvae showing different
degrees of erosion of dentes ......
V. Pupae of D. saccharalis, D. evanescens, and
Z, grandiosella . 75
VI. Pupal characters in different Pyralid species . . . 76
VII. Variations in venation of fore wings of
D. saccharalis...... 77
VIII. Setal map of C. plejadellus larv a ...... 78
IX. Setal maps of larvae of Chilo sp. and D. crambidoides . 79
X. Setal maps of larvae of D. evanescens and
■E. d e n se lla ...... 80
XI. Setal map of thorax and abdominal segments 1-2
of 0. n u b ilalis ...... 81
v i i
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XII. Setal map of thorax and abdominal segments
1-2 of Z. grandiosella ...... 82
XIII. Mouthparts of adults of different Pyralid
s p e c ie s ...... 83
XIV. Wing venation of different Pyralid species. . . . 84
v i i i
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT
A survey of Diatraea species and other closely related or
economically important species of Lepidopterous stem borers in
Louisiana was made between October, 1960 and June, 1962. Diatraea
saccharalis (Fabr.) larvae were collected in fields from sugarcane,
corn, rice, sorghum, Johnson grass, and goosegrass. Larvae of
D. evanescens Dyar were collected in the field only from vasey
grass. Zeadiatraea grandiosella (Dyar) and Ostrinia nubilalis
(Hubner) were collected only from corn. Larvae of an unnamed
Chilo sp. were found only in wooly beard grass. C. pleiadellus
Zincken larvae were found only in rice. Larvae of Eoreuma densella
Zeller were found in broomsedge and vasey grass. Adults of the species
D. saccharalis, D. evanescens, D. venosalis (Dyar), D. lisetta (Dyar),
and E. densella were collected from a light trap at Baton Rouge,
Louisiana between March, 1961 and August, 1962. Winter form larvae
of D. crambidoides (Grote) were obtained from Dr. V. M. Kirk, Clemson,
South- Carolina.
Larvae of D. saccharalis were reared in the laboratory on freshly
cut stems of corn, sugarcane, rice, sorghum, goosegrass and Johnson
grass, and were collected on successive sampling dates from 12
varieties of sugarcane grown in small randomized replicated field
plots. Johnson grass was found to be a poor host, and goosegrass
was only slightly better. Pupae collected from C.P. 56-25 sugarcane
were scarcer and noticeably smaller than those from other varieties.
ix
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Tentative keys were prepared for separating the larvae of 8
species, pupae of 7 species, and adults of 9 species. The relative
shapes, sizes and distances between pinaculi were much more useful
than setal characters for separating species. For this reason names
were assigned to the body pinaculi. Eggs of D. evanescens and
Z. grandiosella were identified by distinctive patterns of red
stripes which occur for a short period of time during embryonic
development.
Iesta should be recognized as a genus separate from Diatraea
on the basis of the wing venation characters originally described
by Dyar (1909), and should not be included in the genus Diatraea
as recommended by Box (1931).
Pupae of all species studied may be sexed on the basis of the
location of the suture marking the genital opening which is visible
on the venter of the eighth abdominal segment in females and on the
ninth in males.
Studies were made of larval chaetotaxy and of morphological and
physiological variation in D. saccharalis. Abnormal variations in
number and arrangement of setae and pinaculi were 4.5 and 1,6 times
more frequent on the left than on the right side,respectively, of
the bodies of larvae. The frequencies of observed setal and pinacular
abnormalities for any particular seta or pinaculum seldom exceeded 17.
and n e v e r re a c h e d 37..
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. INTRODUCTION
The sugare&ne borer, Diatraea saccharalis (Fabr.), has been an
important pest of sugarcane in Louisiana for many years. Further
more, Louisiana farmers have long been aware of its ability to damage
corn and rice, particularly corn. The closely related southwestern
corn borer, Zeadiatraea grandiosella (Dyar), has been reported as an
important pest of sugarcane in Mexico (Box, 1955), but presently is
known in the United States primarily as a pest of corn, although
its distribution extends into areas where sugarcane is grown.
Several other species of Diatraea previously have been reported
from Louisiana and the United States. D, crambidoides (Grote) is
known as an occasional pest of corn in the eastern United States,
but the limits of its distribution are not definite. D. lisetta
(Dyar) and D. venosalis (Dyar) have not been reported since their
original descriptions by Dyar in 1909 and 1917, respectively (Hensley,
1 9 6 0 ).
Chilo plejadellus Zincken has long been known as a minor pest
of rice in Louisiana. D. saccharalis is also found infesting rice
in the state. The larvae of these two species sometimes closely
resemble each other.
There is much confusion in the literature regarding the Diatraea
complex. The most significant taxonomic studies have been those of
1
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Dyar and Heinrich (1927) and Box (1931, 1955).
A taxonomic study of the Diatraea complex in Louisiana has been
needed for a long time. These studies are limited to Louisiana
species of Diatraea and other closely related or important species
of Lepidopterous stem borers which might be found in the state.
The broad objectives undertaken were to: (1) Describe morphologi
cal and physiological variations of possible taxonomic significance
in D. saccharalis. (2) Study the host plant relationships of D.
saccharalis and other related species. (3) Construct keys for
separating different stages of the borer species encountered.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. REVIEW OF LITERATURE
Nine of the 10 species studied in this dissertation belong to
what is now generally accepted as the family Crambidae. The excep
tion of this is Ostrinia (Pyrausta) nubilalis (Hubner) in the family
Pyraustidae. Comstock (1950) and Borror and Delong (1957) recognized
several subfamilies including the Crambinae and Pyraustinae of the
family Pyralidae. Essig (1951) and Richards and Davies (1957) , on
the other hand, recognized these groups as families of the super
family Pyralidoidea, and Laffoon (1960) lists the Crambidae and
Pyraustidae as families under the Lepidoptera. The term Pyralid
frequently has been used as a stem of Pyralidoidea. Therefore,
"the Pyralids" may be considered to include all of the 10 species
studied in this dissertation.
Adult keys to the families of Pyralidoidea have been published
by Forbes (1923), Comstock (1950) , Essig (1951) and Richards and
Davies (1957) . The work of Forbes (ibid.) also contains keys for
separating genera of Crambinae including Chilo, Diatraea and Eoreuma,
and genera and species of Pyraustinae, including Pyrausta nubilalis.
According to Fernald (1888) a monograph of the genus Chilo was w ritten
in 1817 by Zincken but was not available to the present w riter.
A comprehensive study of Diatraea and closely related genera
of the Crambidae was reported by Dyar and Heinrich (1927) who prepared
3
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 4
generic keys to the adults of 8 genera including Diatraea, and to
the species of 3 of these genera. They recognized 32 American species
of Diatraea including saccharalis, zeacolella (crambidoides),
evanescens, venosalis and grandiosella. They separated the genus
Iesta, including I. lisetta. from Diatraea on the basis of wing
venation characters. In the same publication illustrations are given
of the male and female genitalia of many of the species covered.
Box (1931) published keys and descriptions of adults of Diatraea,
and revised the genus to include Iesta. He illustrated the male and
female genitalia of some of the species studied, and gave distribution
by countries of the American species. He indicated at this time that
about 90 species of Diatraea were recognized. The same author (1949)
later published an adult key to 4 genera including D iatraea, under
which he listed 75 species or subspecies with geographical distribu
tion .fof 52 of these. He reported D. crambidoides, D. evanescens,
D. grandiosella, D. lise tta, D. saccharalis and D. venosalis as the
only species of Diatraea known to occur in the continental United States.
He indicated that the genus Diatraea should be restricted to include
only American species, and this concept apparently is generally
accepted, although he did not make clear his reason for this. Tams
(1942) previously had changed the name of a stem borer species in
M auritius from D. m auriciella (Walk.) to Proceras sacchariphagus.
Kapur (1950) transferred all Indian species of Diatraea to either
Proceras or Chilotraea. Box (1960) states emphatically that the
genus Diatraea is now restricted to include only American species.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 5
Finally, Box (1955) erected a new genus, Zeadiatraea, for reasons
which he did not make clear, and transferred 4 species including
grandiosella from Diatraea to this genus.
Adults of Eoreuma densella (Zeller) were described by Forbes
(1923). Adults and immature stages of C. plejadellus Zincken have
been described by Riley (1882), Ingram (1927) and Douglas and Ingram
(1942). Heinrich (1918), Flint and Malloch (1920) and Caffrey and
Worthley (1927) described the adult and immature stages of 0. nubilalis
(Hubner) under the name P. nubilalis.
Relatively less is known about recognition of the immature stages
of the species studied in this dissertation. Larval keys for separat
ing superfam ilies, families and subfamilies of Lepidoptera including
the Pyralidoidea, Pyralidae, Crambinae and Pyraustinae are available
in a publication by Fracker (1915). Mosher (1916, 1919) has given
pupal and larval characters for distinguishing several Pyralid groups
including the Crambinae and Pyraustinae, and a larval key for separat
ing 5 Pyralid genera including Diatraea and Pyrausta.
A key by Peterson (1951) to larvae of Pyralidae injurious to corn,
sugarcane and related plants was prepared to separate 8 species
including P. nubilalis, D. saccharalis, D. grandiosella and D. crambiodoides.
The characters given here for separating the Diatraea species are
concerned with the relative positions of setae on the prothorax and
on abdominal segments 2 through 6. These characters are not completely
dependable. The character described on abdominal segments 2 through 6
is the angle made by projecting imaginary lines through 2 setae on each
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 6
side of the mid-dorsal line until the projected lines intersect.
This character was first described by Holloway (1916). He also
discussed larval characters for differentiating between D. saccharalis,
which he called D. saccharalis crambidoides, and D. crambidoides.
which he called D. zeacolella.
The number and arrangement of setae on the body and head are
used in the identification of many Lepidopterous larvae. Different
workers have proposed different systems of nomenclature which has
resulted in the frequent occurrence of different names for the same
seta or group of setae. Tables I and XI summarize the systems of
nomenclature for setae of Lepidopterous larvae which have been
proposed by different workers, and indicate the synonomy of terms
u s e d .
Pupae of D. saccharalis are described by Holloway et al. (1928).
Hensley (1960) found that the paired horns on the vertex of D.
saccharalis pupae are smooth and pointed, but in Z. grandiosella
(Dyar) and D. crambidoides are rough and blunt. Davis et al. (1933)
illustrated the pupae of Z. grandiosella. showing that the sexes
could be separated by the occurrence of a suture representing the
genital opening on the venter of the eighth abdominal segment in
females and the ninth in males.
General descriptions of the eggs of D. saccharalis are available
in several publications including that of Holloway _et jd. (1928).
Davis ej: al. (1933) reported the appearance of 3 transverse orange-
red bands on the eggs of Z. grandiosella for a short time during the
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. - - 01 02 Oa 0 PI P2 Pa Pb La VI A3 A2 Aa LI Al SOI S02 S03 SOa Hinton 1946 ______Gerasimov 1935 Subommatalis secunda (S02) Subommatalis prima' (SOI) Subommatalis tertia (S03) Porus ommatalis (Ob) Ommatalis tertia (03)Porus subommatalis (SOa) 03 Ommatalis secund (02) Porus anterioresOmmatalis prima (Aa) (01) Porus subommatalisPorus subommatalis (SOb) (SOc) Porus posteriores (Pa) Posteriores prima (PI) Posteriores secundaPorus posteriores (P2) (Pb) A n te rio re s p rimAnteriores a (AL) tertia (A3) Lateralis (LI) Anteriores secunda (A2) V erticalis prima (VI) (V6) (V ll) (V I2) (V10) (V7) (VI) ______- - Porus ommatalis (Oa) - - - Porus lateralis (La) Ripley 1923 Seta of vertex Sensorium of vertex (SV3) Seta ofSeta vertex of Seta vertex (V9) of vertex (V8) (V4) Seta of vertex Seta of vertex Seta of vertex Sensorium of vertex (SV2) Seta of vertex Seta of vertex (V5) Seta of vertex (V3) Seta of vertexSensorium of vertex (SV1) Seta of vertex (V2) Occipital seta (03) ______— - la r v a e . Suboceller (SO-1) Suboceller (SO-2) SubocellarSubocellar (SO-3) (S0-2a) Ocellar (0-1) Ocellar (0-2) Secondary tubercles Ocellar (0-la) Posterodorsal Posterodorsal (Pd-2) (Pd-2a) Posterodorsal (Pd-1) Posterodorsal (Pd-la) Anterodorsal (Ad-2a) Lateral (L-l) Lateral (L-la) AnterodorsalAnterodorsal (Ad-2) (Ad-3) Anterodorsal (AD-1) I X V - _ IV _ - _ - _ _-- - IX II - XI VI Table I. Systems of nomenclature proposed by different workers for setae on the head of Lepidopterous. III VII Ocellar (0-3) /III Forbes 1910 Heinrich 1916 D yar 1896
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. G2 Fa Cl Gl V2 V3 AF1 AFa - Gerasimov 1935 Hinton 1946 Porus verticalis (Va) Pb P o ru s g e n a lis (Ga) Ga Porus verticalis (Vb) Va Verticalis tertia (V3) Fronto-lat. prima (Fr-1.1) - - Ripley 1923 Seta of vertex (V13) Genalis (Gl) OccipitalOccipital seta seta(02) (01) Verticalis secunda (V2) Clypeal seta (Cl) Clypealis prima (Cl2) C2 Postgenal sensorium (PAS) Frontal seta (FI) Frontalis (FI) FI Frontal sensorium Porus frontalis (Fa) AdfrontalAdfrontal setaAdrontal seta (A2) sensorium(Al) (ADS) Porus fronto-lat. Fronto secunda (Fa-1.a) (Fr-1.2) AF2 Heinrich 1916 Secondary tubercles Secondary tubercles Secondary Secondary tubercles tubercles Occipital sensorium (SO) Ep-2 Genal (G-la) Ep-1 Clypeal seta (C2) Clypealis prima (Cll) Genal (G-l) F r-1 F r - a A df-1 A df-2 A d f-a - - -- _ ------“ - - Table I. (Continued) Forbes 1910 D yar 1896
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. I SV2 D1 LI L2 SD1 MXD1 MV3 XD2 L3 MV2 D2 LI D1 Hinton 1946 ______I I D2 I I l i aI I IIV SD1 SD2 IX Xa III II V V iib V l l l VI I l i a SD2 X XD1 V lld VI Gerasimov 1935 ______- - P ro th o ra x l i b IVIV III l i b I a I V l l l VI V ila SV1 V I1 V ile Meso- and metathorax Heinrich 1916 ______- - - Sigma E p s ilo nE ta Ic V Kappa IV B e taD e lta I i a RhoNu l i e VI GammaT h eta lb E p s ilo n H a Kappa B e ta Ib Fracker 1915 thorax and abdomen of Lepidopterous larvae. ______iv i i i i i i a - ix A lpha l a i i b Rho - i aib A lpha iv i i a X v i i i V v i i av ii b P i Table II. Systems of nomenclature proposed by different workers for setae on the Forbes 1910
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SV2 SD1 SD2 L2 SV3 L3 MSD1 MV1 D1 LI MSD2 MV2 MD1 D2 L2 MV3 MV1 MV2 Hinton 1946 - lXa lXb I Xb MD2 VI III IV Xa VI lbVI V ile V lld MV3 V ile Xa V ilalbVI SV1 SV2 V lllXb V lld VI Gerasimov 1935 1-9 segm ents ------III VV V lll V lll VI VI VV V I1 Abdominal - - - Sigma T h eta Pi VI Vila SV1 Nu VI Sigma V lll E ta P i Tau VI1 Omega RhoKappa I I I IV Fracker 1915 Heinrich 1916 i i i - - i A lpha I ------V E ta - --- j i iiiiaiv B eta Epsilon I I Ilia Ilia I I v i i i i i v i i i --- -- V v i Mu VI VI L3 v i i v i i Nu V I1 v i i v i i i Table II. (Continued) Forbes 1910
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period between deposition and hatching. Hensley (1960) stated that
eggs of Z. grandiosella could be distinguished by the transient
occurrence of red transverse stripes from those of D. crambidoides
and D. saccharalis, in which the stripes are a very pale orange.
Kevan (1944) mentioned the occurrence of bright red transverse bands
on eggs 2 days after their deposition by D. lineolata moths. The
eggs of C. plejadellus have been described by Ingram (1927) and Douglas
and Ingram (1942). Egg masses of 0. nubilalis are well illustrated by
Pfadt (1962).
Synonomy for the previously described species studied in this
dissertation has been given by the following workers for the species
indicated: Box (1931), D. crambidoides. D. evanescens, D. lisetta.
D. venosalis; Box (1949), D. saccharalis; Box (1955), Z. grandiosella;
Ely (1910), E. densella; Fernald (1888), C. plejadellus; and Caffrey
and Worthley (1927), P. nubilalis. According to Wressell (1961),
the name P. nubilalis was changed to 0. nubilalis in 1957 by Marion,
although American authors have been slow to recognize the new name.
The reason for the change was that Hubner had described both 0.
palustris and P. nubilalis, which later were determined by Marion to
be congeneric species. Since he had defined the gouts Ostrinia
earlier than Pyrausta. the former now has priority over the latter.
D. saccharalis has been reported to occur in the United States
in Texas, Louisiana, M ississippi, Georgia and Florida by Box (1949).
Outside the United States he reported it to be widely distributed
throughout the West Indies, Central and South America. The same
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author (1935) listed host plants for the species to include sugarcane,
corn, rice, Johnson grass, goosegrass, broomsedge, vasey grass and
51 other species of wild and cultivated grasses.
The known distribution of D. crambideides was stated by Hensley
(1960) to include Maryland, Virginia, North Carolina, South Carolina,
Georgia, Florida, Alabama, Kansas and Wisconsin. Box (1931) states
that its preferred host is corn, although it occasionally may attack
s u g a rc a n e .
Box (1949) gives the distribution of D. lisetta to include the / southern United States, Mexico and Panama. He indicates that D.
venosalis has been found only in Louisiana and Texas, and D. evanescens
only in Louisiana and Guatemala. The same author^(1931) lists
Paspalum larranagae as the only known host plant of D. evanescens.
According to Hensley (1960) , Z_. grandiosella occurs in Arizona,
New Mexico, Texas, Louisiana, M ississippi, Arkansas, M issouri,
Nebraska, Colorado and Mexico. Box (1960) states that the species is
a major pest of corn in the United States, and the dominant borer in
sugarcane in one area of northwestern Mexico. In an earlier paper
he (1955) mentioned that it had been reported severely attacking
sugarcane in southern Texas.
Forbes (1923) indicated that E. densella was known from Texas,
Florida, Connecticut and Illinois.
P. nubilalis is known to occur in many countries around the world
on many plant hosts, although it is best known as a pest of corn.
According to Pfadt (1962), it has extended its range in North America
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from the A tlantic to the Rocky Mountains and from Canada to the
southern United States. He states that it infests corn, sorghum,
soybeans, m illet, buckwheat, oats, barley, potatoes, beans and many
large stemmed flowers and weeds including in all more than 200
different plant species.
Studies of the biology of D. saccharalis have been published
by Morgan (1891), Stubbs and Morgan (1902), Box (1925), Holloway
ejt jil. (1928) ,. Meadows (1938), Katiyar (1960) and Katiyar and Long
(1961) . Similar studies for D. grandiosella have been reported by
Todd and Thomas (1930) , Davis et: a l. (1933) and Walton and Bieberdorf
(1948), and for D. crambidoides by Phillips et al. (1921), Ainslie
(1925) and Cartwright (1934).. Biological studies on C. plejadellus
were reported by Ingram (1927) and Douglas and Ingram (1942)• Vinal
and Caffrey (1919) , Caffrey and Worthley (1927) and S tirrett (1938)
reported studies on the biology of P. nubilalis. Arbuthnot (1944)
demonstrated the existence of genetically different uni- and multi-
voltine strains of P. nubilalis.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. MATERIALS AMD METHODS
Larvae of D. saccharalis, D. evanescens, Z. grandiosella, Chilo
sp., C. plejadellus, E, densella and 0. nubilalis were collected
from different cultivated and wild grasses at various times and
places in Louisiana from October, 1960 to August, 1962 as shown
in table III. Mature or nearly mature larvae were either fixed in
KAAD as suggested by Peterson (1951) before being preserved in 707.
ethyl alcohol, or they were reared to obtain additional stages for
study. In the latter case larvae were reared individually in glass
vials on stems of their host plants, or on an artificial diet
developed by Pan (1960) and modified by Isa (1961)•
Approximately 2,530 adults of D. saccharalis, 34 of D. evanescens,
21 of D. lisetta. 6 of D. venosalis and 6 of E. densella were collected
between March, 1961 and August, 1962 during regular examinations of
a light trap at Baton Rouge, Louisiana. This trap was located in a
field of experimental plots on the Louisiana State University campus
near plantings of corn and sugarcane, and with considerable amounts
of goosegrass and Johnson grass in the vicinity. Adults of all species
were pinned with wings spread. Additional moths of D. saccharalis
were preserved in 57. formalin.
Preserved specimens as well as stained mounted skins of larvae
were studied for morphological variation and taxonomic characters.
Skins were prepared for mounting by opening the larvae longitudinally
14
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table III. Host plants, localities and dates of collection of different species of Pyralid larvae, Louisiana, 1960-1962.
H ost P la n t Insect Species Locality D ate o f (P a ris h ) C o lle c tio n Broomsedge (Andropogon glomeratus) E. densella I b e r i a 2 /1 4 /6 1 Broomsedge (Andropogon glomeratus) E. densella Iberville 1 /1 2 /6 1 Broomsedge (Andropogon glomeratus) E. densella L a f a y e tte 2 /1 4 /6 1 Broomsedge (Andropogon glomeratus) ,E. densella St. James 1 /1 9 /6 1 Broomsedge (Andropogon glomeratus) E. densella St. Mary 9 /1 8 /6 1 Broomsedge (Andropogon glomeratus) E. densella T errebonne 2 /1 3 /6 1 Broomsedge (Andropogon glomeratus) E. densella Terrebonne 2/23/61 Wooly beard grass (Erianthus sp.) Chilo sp. Lafayette 1 /3 0 /6 1 Woolv beard grass (Erianthus sp.) C h ilo s p . S t. L andry 1 /2 0 /6 1 Wooly beard grass (Erianthus sp.) Chilo sp. St. Landry 2 /1 3 /6 1 Wooly beard grass (Erianthus sp.) Chilo sp. T erreb o n n e 1 /1 9 /6 1 Corn (Zea mays) D. saccharalis East Baton Rouge 10/17/60 Corn (Zea mays) 0. nubilalis Caddo 8 /1 5 /6 2 Corn (Zea mays) Z. grandiosella East Carroll 7 /1 9 /6 2 Goosegrass (Eleusine indica) D. saccharalis East Baton Rouge 10/17/60 Johnson grass (Sorghum halepense) D. saccharalis S t. Mary 2 /9 /6 1 Rice (Oryza sativa) C. ple,1adellus Acadia 8 /1 3 /6 1 Rice (Oryza sativa) C. pleiadellus East Baton Rouge 8 /3 1 /6 1 Rice (Oryza sativa) 0. saccharalis Acadia 2/10/61 Rice (Oryza sativa) D. saccharalis East Baton Rouge 10/17/61 Rice (Oryza sativa) D. saccharalis S t . L andry 8 /3 1 /6 1 Sorghum (Sorghum vulgare) D. saccharalis East Baton Rouge 10/17/60 Sugarcane (Saccharum officinarum) D. saccharalis East Baton Rouge 1 0 /1 7 /6 0 Sugarcane (Saccharum officinarum) D. saccharalis Lafayette 12/10/60 Vasey grass (Paspalum urvillei) D. evanescens St. Mary 2/10/61 Vasey grass (Paspalum urvillei) D. evanescens St. Martin 9/18/61 Vasey grass (Paspalum urvillei) D. evanescens V erm ilio n 7 /1 4 /6 1 Vasey grass (Paspalum urvillei) E. densella I b e r v i l l e 1 /1 9 /6 1 Vasey grass (Paspalum urvillei) E. densella St. Mary 2/10/61 16
on the right side just below the spiracles before putting them into
a 107. potassium hydroxide solution for 12 to 16 hours. After removal
from this solution the heads were removed and the skins were cleaned
in tap water. They were then stained by placing them 2 to 3 minutes
in a solution of 107. acid fuchsin in alcohol. These skins were next
dehydrated in glacial acetic acid for 2 to 3 minutes prior to trans
fer for a similar period of time into a mixture of equal volumes of
phenol and xylol. From the phenol-xylol mixture they were mounted
directly in Canada balsam on glass slides.
Heads of larvae were mounted with mouthparts intact, or were
dissected for separate mounting of mandibles, epicrania, and frons
with cylpeus and adfrontal sclerites attached. Head mounts were also
made in Canada balsam as described above, but were not stained.
More than 200 mounted slides of genitalia of D. saccharalis
males and females were made- in addition to from 4 to 20 of each of
the other adult species studied. Genitalia were dissected as des
cribed by Busch (1942). The entire abdomen was removed from the
thorax and placed in a 107. potassium hydroxide solution for 24 to
48 hours. It was then washed several times in tap water prior to
removal of the genitalia with forceps under low magnification.
Genitalia were then stained in 107. acid fuchsin in alcohol for 2
minutes, passed through glacial acetic acid and phenol-xylol mixture
as described above, and mounted in Canada balsam. With male genitalia
it was necessary to spread the harpes and separate the aedeagus and
tegumen after staining.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 17
Permanent mounts of antennae, labial and maxillary palps,
frons and abdomens of male and female specimens of D. saccharalis
also were made in Canada balsam. Similar mounts were made of egg
masses of D. saccharalis, D. evanescens, Z, grandiosella and C.
plejadellus at different stages in their embryonic development.
The number and arrangement of setae and pinaculi on the bodies
of larvae of different species are illustrated by line drawings as
are mouthparts and wing venation. These were prepared by projecting
microscope slides onto a sheet of paper through a special prism
attached to an X2 occular of a microscope equipped with an X4 stage
lens. Slide mounts of genitalia were photographed.
The nomenclature used to describe setae on the head and body
of larvae is that proposed by Hinton (1946) for the Lepidoptera
(tables X and II). Based on Hinton's names for setae, a special
nomenclature for pinaculi was devised, the details of which are
given in table IV. Since Hinton's names designating setae always
have numerical suffixes, the new names for pinaculi employ only
capital letters of the alphabet.
To determine whether physiological differences could be detected
between Florida and Louisiana strains of D. saccharalis, newly hatched
progeny of borers collected from sugarcane at Belle Glade, Florida
and Franklin, Louisiana were confined on corn in two screen cages
at Baton Rouge, Louisiana. Similarly, progeny of borers from Belle
Glade, Florida and Baton Rouge, Louisiana also were released on
sugarcane in 2 screen cages. These cages were 12 feet long, 5 feet
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. oo P ro th o ra x Pro-, meso-, and metathorax, and abdominal 1 to 9 Abdominal 1 to 8 Pro-, meso- andPro-, metathorax meso- and and metathorax abdominalProthorax, 1 to 9 meso- and metathorax, and abdominal 1 to 9 Meso- and metathorax and abdominal 1 to 8 Meso- and metathorax and abdominal 1 to 9 Meso- and metathorax and abdominal segments 1 to 8 Meso- and metathorax (PS) (LP) (LA) (MVM) (MVD)(V) Meso- and metathorax Table IV. Names assigned to body pinaculi of Diatraea saccharalis (F.) larvae. Pinaculi Body Segments on Which Pinaculi Are Present Sub-dorsal-dorsal (SDD) Meso- and metathorax and abdominal 1 to 9 S u b - d o r s a l- v e n tr a l (SDV) Sub-ventral (SV) Prothoracic shield Dorsal-anterior (DA) Meso-, metathorax, and abdominal 1 to 9 Lateral-anterior Lateral-posterior V e n tra l Dorsal-posterior (DP) Mid-dorsal (MD) Mid-ventral-ventralMid-ventral-medianM id-ventral-dorsalMid-sub-dorsal (MW) (MSD) Pro-, meso- and metathorax and abdominal 1 to 9
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 19
wide, 8 feet high, and covered with wire screen having 252 meshes
per square inch. Two cages contained 20 corn plants each in 2 rows
of 10 plants per row, and 2 cages contained 40 sugarcane stalks
each in a single row. The varieties planted were Louisiana-521 corn
and C.P. 44-101 sugarcane.
Five larvae were released on each corn plant near the base of
the youngest whorl leaf when plants were approximately 3 to 4 feet
ta ll, and similarly 2 or 3 larvae on each sugarcane stalk. Data on
survival, weight and rate of development of the strains on the 2
different hosts were obtained by dissecting approximately 1/3 of
the plants in each cage on each of 3 successive dates. These were
20, 25 and 30 days after the larvae were released on corn, and 25,
30 and 35 days after their release on sugarcane. All larvae re
covered were reared subsequently in the laboratory on the same host
plant until moth emergence.
D ifferential effects of host plants on development of D. saccharalis
were studied by successively sampling borer populations in sugarcane
variety plots, and by rearing larvae in the laboratory on the cut
stems of various plant hosts. Two replications of each of 12 varieties
of sugarcane planted in the fall of 1960 in 1/100-acre plots in a
randomized complete block design were sampled bi-weekly on 7 occasions
from June 22 to September 23, 1961. A total of 20 stalks from each
variety (10 from each of 2 plots) were dissected each week for all
borer stages. Pupae recovered were sexed and weighed individually,
and mature or nearly mature larvae were reared in the laboratory on
freshly cut stems of the same host until pupation.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 20
Newly hatched larvae also were reared in the laboratory on
freshly cut stems of the same 12 sugarcane varieties as well as on
corn, sorghum, goosegrass, Johnson grass, and rice. Five or 10
larvae were placed in a cotton stoppered glass vial 8 cm tall and
2 cm in diameter. Each vial was provided with several strips of
tender leaves and with 2 to 3 ml Of tap water to keep the leaf sec
tions fresh. Larvae were transferred to clean vials with fresh food
every 2 or 3 days for the first 10 days, after which they were kept
in individual vials on freshly cut pieces of stems of their host
plants. Pupae were weighed and transferred to vials containing only
moist cotton to await moth emergence.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. RESULTS
Chaetotaxy of Diatraea saccharalis Larvae
There are 32 setae and 11 punctures on each side of the head.
They are illustrated in Plate I, Figs. 1, 2, 4 and 7, and their
number and distribution are given in table V. The epicranium
(Plate I, Fig. 1) bears 16 setae and 8 punctures on each side.
The ad frontal sclerite (Plate I, Fig. 4) bears 2 setae, AFl and
AF2, of approximately equal size, and a puncture, AFa, between these
setae on each side. There are 2 FI setae and 2 Fa punctures on the
frons. The lower portions of the adfrontal sclerites form the
clypeus which is darker in color than the frons. The clypeus bears
a short outer pair of Cl setae, and a longer inner pair of C2 setae.
There are 6 named and 3 unnamed setae plus 1 puncture on each side
of the labrum (Plate I, Fig. 2). A heavily sclerotized epipharyngeal
plate is present around the median notch, and can be seen only after
staining. Each mandible (Plate I, Fig. 7) bears 2 setae, Ml and M2,
on the anterior margin near the condyle. Seta Ml is longer and is
located anterior to M2.
The relative location, size, and shape of setae and pinaculi
on thoracic and abdominal segments 1 through 9 are diagrammed in
Plates II and III, respectively. Frequent reference to either or
both of these plates w ill be necessary to follow the results presented
21
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 22
Table V. Number and distribution of setae and punctures on the head of typical mature Diatraea saccharalis la r v a e .
T o ta l Name o f P o s itio n Names o f S e ta e Number P u n c tu re
O cu lar 01 02 03 3 Oa
S u b -o c u la r SOI S02 S03 3 SOa
A n te rio r A1 A2 A3 3 Aa
L a te r a l LI - - 1 La
P o s te r io r PI P2 - 2 P b, Pa
G enal G1 -- 1 Ga
V e n tra l VI V2 V3 3 Va
Adfrontal AF1 AF2 - 2 AFa
C lypeus Cl C2 - 2 -
F ron FI - - 1 Fa
Labrum LI L2 L3 3 P
Labrum Ml M2 M3 3
Epipharyngeal no names 3 -
M andible Ml M2 2 -
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 23
in the remainder of this section on the thorax and abdomen.
The cervical shield bears setae Dl, D2, XDl, XD2, SD1, SD2 and
MXD1 (Plate II). The spiracle is oblong and is located ventrally
below the prothoracic shield. Setae LI, L2, SV1, SV2, MV2 and MV3
are located below the spiracle. From 6 to 8 oblong specks are
visible on the mid-ventral-median (MVM) pinaculum. Ventral seta VI
is found on the ventral (V) pinaculum between the leg and the mid-
ventral line of the body.
The mesothoracic and metathoracic segments have 16 setae and
11 pinaculi on each side plus a dorsal posterior (DP) pinaculum on
the mid-dorsal line (Plates II and III). Both segments have a
sim ilar arrangement of setae and pinaculi. Dorsal setae Dl and D2
are located on a bisetose dorsal-anterior (DA) pinaculum. Seta Dl
is dorsal to D2. Two sub-dorsal setae SD1 and SD2 are found on the
bisetose sub-dorsal-dorsal (SDD) pinaculum. Lateral setae LI and
L2 occur on the lateral-anterior (LA) pinaculum and L3 on the lateral-
posterior (LP) pinaculum. Sub-ventral setae SV1 and SV2 are on the
bisetose sub-ventral (SV) pinaculum between the lateral-posterior
(LP) pinaculum and the leg. Seta VI is between the base of the leg
and the mid-ventral line on the ventral (V) pinaculum. Near the
anterior margin of each of the 2 segments there are 6 minute setae,
MD1, MSD1, MSD2, MV1, MV2 and MV3. The s e ta e MD1, MV1, MV2 and MV3
are on the unisetose mid-dorsal (MD) , mid-ventral-dorsal (MVD), mid-
ventral-medium (MVM) and m id-ventral-ventral (MW) pinaculi, respectively.
Setae MSDl and MSD2 are on the bisetose mid-sub-dorsal (MSD) pinaculum.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 24
The number and arrangement of setae and pinaculi on abdominal
segments 2 through 6 are sim ilar, each having 13 setae and 10 pinaculi
on each side. The first abdominal segment has 13 setae and 9
pinaculi on each side. Dorsal setae Dl and D2 occur on the separate
unisetose dorsal-posterior (DP) and dorsal-anterior (DA) pinaculi,
respectively. Seta D2 is longer than Dl, Subdorsal setae SD1 and
SD2 of the first abdominal segment occur above the spiracle on the
bisetose sub-dorsal-dorsal (SDD) pinaculum. Setae SD1 and SD2 of
abdominal segments 2 through 6 occur separately on the unisetose
sub-dorsal-dorsal (SDD) and sub-dorsal-ventral (SDV) pinaculi,
respectively. The latter is generally in front of the spiracle,
while the former is above the spiracle'. Lateral setae LI and L2 are
located just below the spiracle on the lateral-anterior (LA) pinaculum.
Lateral seta L3 is found on the lateral-posterior (LP) pinaculum.
The sub-ventral group consists of setae SV1, SV2 and SV3. All 3 of
these setae are on the trisetose sub-ventral (SV) pinaculum which
partially surrounds the proleg on abdominal segments 2 through 6.
Ventral seta VI occupies the same position as it does on the thoracic
seg m en ts.
The arrangement of setae and pinaculi on abdominal segments 7
and 8 is identical to that of the preceeding segments except that
the sub-ventral seta SV3 is absent on segment 7, and both SV2 and
SV3 are absent on segment 8.
The ninth abdominal segment bears only 8 setae: Dl, D2, SD1, LI,
SV1, VI, MD1 and MV3. The first 6 named are almost linear in
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 25
arrangement. The seta D2 is on the dorsal-anterior (DA) pinaculum
and setae Dl and SD1 are on the sub-dorsal-dorsal (SDD) pinaculum.
The other setae are located as in the preceeding segments.
Tables VI and VII summarize the number and distribution of
setae and pinaculi on the body of typical mature Diatraea saccharalis
l a r v a e .
Morphological Variation in Diatraea saccharalis
L arv a e
Each mandible (Plate I, Fig. 7) of a newly moulted larva bears
4 pointed dorsal teeth and 2 rounded ventral teeth along the anterior
margin. The last rounded tooth is sometimes small and indistinct.
Examination of the mandibles of 100 larvae indicated considerable
variation in the shape of the dentes in different individuals.
Much of this variation undoubtedly results from erosion of the
dentes with use. An idea of the amount of variation encountered
may be found in Plate IV which contains outline drawings of mandibles
from 7 different larvae.
Other variations such as the absence of a seta from either 1 or
both sides of the body, their migration to a nearby pinaculum, or
the occurrence of extra setae were occasionally found. Pinacular
variations also were observed such as the coalescence of 1 with
another adjacent pinaculum, or the complete absence of a normally
occurring pinaculum. However, an extra pinaculum never was observed. v
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. O' to 8 14 13 16 16 13 13 13 11 12 13 13 T o ta l + + + + + + + + + + - + - a* - - + V e n tra l ------+ + + + MSD2 MV3 MV2 MV1 d o rs a l ------M id-sub- + ++ + + + + - - - - + - - - + MD1 MSD1 Mid d o rs a l - - - - + - - + MXD1 VI + + - + - + + + + + + + + + V e n tra l MXD - - - _ - + + + + + - + -- + + + + ++ + - + + + + + + + + + + + - + - + + Sub'-ventral - + + + + + + + L2 L3 SV1 SV2 SV3 -- + + + + + + + + L a te r a l + + + + + + + + + - + + + + + + + + + + + + + + Sub- d o r s a l + + + + + + + + + + + + + + + + + + + + + + + + + + + + Dl D2 SD1 SD2 LI + + + + + + + + + + + + + + + + + + + + + ------XD D o rsa l ------—- + + XD1 XD2 #5 in #9 aPresent (+), Absent (-) Table VI. Number and distribution of setae on the body of typical mature Diatraea saccharalis larvae. Segment Prothoracic Body Mesothoracic Abdominal #1 Abdominal #3 Abdominal #4 Metathoracic - Abdominal Abdominal #6 Abdominal Abdominal Abdominal #8 - - Abdominal #7
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. N> 6 9 7 12 12 10 10 10 10 10 10 10 + U + U + U f U + U +U +u Ventral Total + B +B + T + U + B +T + U + U + T + U + U + U -fU + U +T+ U +U+U +B +U +u +u + u + U + u - - + U - - +U +U MVM MWMVM V e n tra l + U + U mm mm ------rnm -- + U + U -- +u + u +U + u +B + B + U +B +U +8 +B +U +B +U ------+B - mm +B +B + U - - +B + U - mm + U + U +U + u +u + B +u +U +B +u + u + u +U +U +U +u +U +U +U +u +u +B Dorsal Dorsal tral dorsal erior erior MVD .N ----- mm + u + U T +N +U +B - +B +B +U + u + U + U +U +u + u +U e r i o r - Dorsal Sub-dorsal Mid- Lateral +B +B + U +U + U +U + u +U + U + U +u +U + u +U + u t e r i o r ------_ + S h ie ld Pro- Pro- Thoracic An- Post- Mid Ven- sub- Ant- Post- Mid-Ventral Sub- #4 #1 #3 #7 #5 #9 aAbsent (-), Present (+), Unisetose (U), Bisetose (B), Trisetose (T), No setae (N). Table VII. Number and distribution of pinaculi on the body of typical mature Diatraea saccharalis larvae.3 Segment P ro th o ra x Abdominal A bdominal Abdominal #6 - M etath o rax Abdominal Abdominal #8 Abdominal #2 Abdominal Abdominal M esothorax Abdominal
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 28
A critical study of the stained and mounted skins of 181 larvae
yielded data on setae and pinacular abnormalities which are summarized
in tables VIII, IX, and X. Table VIII indicates that setae of the
XD and SD groups are most subject to abnormal variations, and that
abnormalities occurred more frequently on the left than on the right
sides of the larvae. Table IX shows that the frequency of abnor
mality was greater for the sub-dorsal-ventral (SDV) pinaculi than
for any others, and that pinaculi also vary more often on the left
than on the right sides of the larvae. Table X indicates that setae
and pinaculi vary more often on abdominal segments 7 and 8 than on
any other body segments.
In 1 specimen the spiracle on the left side of the third
abdominal segment, and in another specimen both spiracles on the
sixth abdominal segment were missing. In another larva the crochets
were missing from the left proleg of the third abdominal segment.
Seasonal variations in the color of D. saccharalis larvae are
fairly conspicuous. Larvae found in the spring and summer months
normally have distinctly pigmented pinaculi, while the pinaculi of
larvae found during the fall and winter months usually are much
lighter in color approaching the dirty white or yellow general body
c o l o r .
Pupae
Studies of D. saccharalis pupae were based on examination of
80 pupae and 178 pupal skins from both field collections and laboratory
r e a r i n g .
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 29
Table VIII. Percentages of setae with indicated abnormalities on 181 Diatraea saccharalis larvae.
Setae Absent Extra Setae ______Migrated to Name of Left Right Both Left Right Both Adjoining S e ta e Side Side Sides S id e S id e Sides Pinaculum
Dl 0 .5 8 0 .0 5 0.20 0.00 0.00 0 .0 0 0 .0 0 D2 0 .5 0 0 .2 0 0 .0 5 0 .0 0 0.05 0.00 0.00 MD1 0 .0 0 0 .0 5 0 .0 0 0 .0 0 0.00 0.00 0.00 SD1 1.02 0.13 0.13 0.04 0.00 0.00 0.00 SD2 0.75 0.15 0.05 0 .0 0 0 .0 0 0 .0 0 0 .7 0 LI 0.55 0.05 0.05 0 .0 0 0 .0 0 0 .0 0 0 .0 9 L2 0 .6 0 0 .0 5 0.05 0.00 0.00 0.00 0 .0 5 L3 0 .7 2 0 .1 1 0 .0 5 0 .0 0 0 .0 0 0 .0 0 0 .0 0 SV1 0 .5 5 0.00 0.05 0.05 0.00 0.00 0.00 SV2 0 .5 5 0.00 0.06 0.00 0.00 0.00 0.00 SV3 0 .6 4 0 .0 0 0 .0 9 0 .0 9 0 .0 0 0 .0 0 0 .0 0 MV1 0 .0 0 0 .0 0 0 .0 0 0 .0 0 0 .0 0 o.oe 0 .0 0 MV2 0.00 0.00 0.00 0.00 0.00 0 .0 0 0 .0 0 MV3 0 .1 4 0 .0 0 0 .0 0 0.00 0.00 0.00 0.00 XD1 0.00 0.00 0.00 1.10 0.00 0 .0 0 0 .0 0 XD2 2 .7 2 1 .1 0 0 .0 0 0.06 0.00 0.00 0 .0 0 VI 0.0 9 0.00 0.05 0.00 0 .0 0 0 .0 0 0 .0 5 MXD1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MSD2 0 .0 0 0.00 0.30 0.30 0 .0 0 0 .0 0 0 .0 0 MSD2 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 30
Table IX. Percentages of pinaculi with indicated abnormalities on 181 Diatraea saccharalis larvae.
Pinaculum Joined With Pinaculum Absent Adjacent Pinaculum Left Right Both Left Right Both Names of Pinaculi S id e S id e S id e s S id e S id e S id e s
D orsal-anterior (DA) 0 .2 5 0 .3 0 0 .0 0 0.15 0.00 0.00
Dorsal-posterior (DP) 0.30 0 .1 1 0 .0 0 0 .0 0 0 .0 0 0 .0 0
Mid-dorsal (MD) 0.00 0.00 0.00 0.00 0 .0 0 0 .0 0
S u b - d o r s a l- d o r s a l (SDD) 0 .0 0 0 .5 1 0 .0 0 0 .0 0 0 .0 0 0 .0 0
S u b - d o r s a l- v e n tr a l (SDV) 0 .3 0 0 .7 1 0 .7 1 1.08 0.00 0.00
M id-sub-dorsal (MSD) 0 .1 5 0 .0 0 0 .0 0 0 .0 0 0 .0 0 0 .0 0
L a t e r a l - a n t e r i o r (LA) 0 .3 7 0.00 0.37 0.00 0.00 0.00
Lateral-posterior (LP) 0 .3 5 0 .0 0 0 .2 7 0 .0 0 0 .0 0 0 .0 0
Mid-ventral (MV) 0.09 0 .0 9 0 .0 0 0.09 0.00 0.00
Sub-ventral (SV) 0.3 1 0.00 0.00 0.00 0 .0 0 0 .0 0
Ventral (V) 0.09 0 .0 0 0 .0 0 0 .0 0 0 .0 0 0 .0 0
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 31
Table X. Percentages of total setal and pinacular abnormalities for each body segment on 181 Diatraea saccharalis larvae examined.
P in a c u li S e ta e J o in e d T o ta l to T o ta l Body O ut o f A bnor Adjacent Abnor- Segment A bsent Place Extra malities Absent Pinaculum m alities
P ro th o ra x 0 .1 2 0 .0 0 0 .0 8 0.20 0.00 0.00 0.00
Mesothorax 0.24 0.00 0.00 0 .2 4 0 .0 0 0 .0 9 0.09
M e ta th o ra x 0 .4 5 0 .0 0 0 .0 0 0 .4 5 0 .1 4 0 .0 0 0 .1 4
Abdominal 1 0 .6 8 0.08 0.00 0.76 0 .3 1 0 .0 6 0 .3 7
Abdominal 2 0.51 0.13 0 .0 0 0 .6 4 0.17 0.34 0.51
Abdominal 3 0.55 0.04 0.00 0 .5 9 0 .2 2 0 .0 5 0 .2 7
Abdominal 4 0 .5 9 0 .1 3 O'. 00 0 .7 2 0 .5 6 0 .1 7 0 .7 3
Abdominal 5 0 .4 7 0 .0 0 0 .0 0 0 .4 7 0.33 0.00 0.33
Abdominal 6 0 .4 2 0 .0 0 0 .0 0 0 .4 2 0 .4 4 0 .0 0 0 .4 4
Abdominal 7 1.43 0.12 0.04 1.59 0.83 0.00 0.83
Abdominal 8 0.70 0.30 0.05 1 .0 5 0 .4 4 0 .7 7 1.21
Abdominal 9 0.55 0.00 0 .0 0 0 .5 5 0 .0 8 0 .0 8 0 .1 6
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 32
In all male pupae the antennae extend almost to the cephalic
margin of the metathoracic legs (Plate VI, Fig. 1). In female
pupae the antennae extend to a point approximately halfway between
the prothoracic and metathoracic legs (Plate VI, Fig. 2). In females
the slit-like suture marking the genital opening occurs on the
venter of the eighth abdominal segment (Plate VI, Fig. 9). In
males this suture occurs between 2 small papillae on the venter of
the ninth abdominal segment (Plate VI, Fig. 10). Female pupae are
generally larger and heavier than male pupae (tables XI, XII and
XIII).
The cephalic margin of the labrum forms a straight line in all
D. saccharalis pupae (Plate VI, Fig. 11). However, the caudal margin
was found to be convex posteriorly with a small notch near the
center in approximately 1/3 of the specimens, and with no such
notch in the remaining specimens examined.
The data in tables XI and XII show that pupae reared in the
laboratory from eggs on different varieties of sugarcane generally
weighed less than field-collected pupae. It also appears that the
relative abilities of the different sugarcane varieties to produce
heavy pupae were not the same for males and females. However, the
data are so scant that little significance can be attached to the
indicated differences between sugarcane varieties.
Data in table XIII indicate that when D. saccharalis larvae
were reared in the laboratory on the cut stems of different host
plants brought from the field, the resulting pupae were largest when
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table XI. Average weights of field-collected and laboratory-reared female Diatraea saccharalis pupae from different varieties of sugarcane.
W eight S ugarcane F ie ld c o lle c te d Laboratory-reared V a rie ty Number Mgms. Number Mgms.
C.P. 36/105 5 185.5 1 6 8 .2
C .P . 55/30 6 169.5 13 1 0 0 .2
C .P . 52/68 9 1 47.0 9 1 1 0 .4
C.P. 44/101 13 136.7 7 106.9
N. Co. 310 6 133.5 3 110.9
C .P . 43/47 6 132.6 10 9 9 .9
C.P. 48/103 14 131.6 10 1 1 9 .3
C.P. 36/13 12 130.5 7 1 11.9
C .P . 53/1 6 1 27.8 9 1 0 4 .3
C.P. 44/155 10 124.1 6 108.9
C.P. 47/193 10 115.3 3 8 1 .3
C .P . 56/25 3 9 3 .4 1 7 6 .4
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table XII. Average weights of field-collected and laboratory-reared male Diatraea saccharalis pupae from different varieties of sugarcane.
W eight S ugarcane F ie ld c o l le c t e d Laboratory-reared V a rie ty Number Mgms. Number Mgms.
C.P. 55/30 4 103.9 5 6 5 .7
C.P. 44/101 9 8 9.9 6 6 6.1
C.P. 43/47 3 89.4 10 6 3 .5
C.P. 48/103 7 8 9 .0 21 73.1
C.P. 36/13 9 8 8 .0 7 78.7
N. Co. 310 5 8 3 .8 4 6 8 .2
C.P. 53/1 4 83.0 4 7 0.3
C.P. 36/105 4 79.4 3 79 .2
C.P. 44/155 11 77s9 7 72.7
C .P . 52/68 6 76.9 4 85.7
C.P. 47/193 3 7 1 .2 4 5 7 .0
C.P. 56/25 4 7 0 .4 2 2 4.4
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. CO Ln 8 7 .7 80 .6 5 2 .6 5 1 .2 5 9 .9 (Mgms.) Average Weight 7 4 10 Pupae 0 .0 9 9 .66 5 .9 10 74.6 1 2 5 .2 110.1 10 (Mgms.) Number Average Weight Fem ale M ale 10 Number 78.0 4 7 0 .0 5 6 0 .0 10 9 2 .0 0 P e r c e n t L a rv a l M o r ta lity - - - P la n t V a rie ty C.P. 44/101 La. 521 60.0 six different host plants, Baton Rouge, Louisiana, May-June, 1961. Diatraea saccharalis larvae in the laboratory on the cut stems of each of Table XIII. Survival of larvae and weights of pupae obtained by rearing 50 newly hatched (Saccharum officinarum) (Eleusine indica) (Sorghum vulgare) (Sorghum halepense) Corn (Zea mays) S ugarcane Food Plant of Larvae Grain sorghum Goosegrass Johnson grass Rice (Orvza sativa) Lacrosse 60.0 10 71.6 10
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 36
fed corn steins. Larval m ortality on corn, sugarcane and rice were
equal, while pupae obtained on sugarcane weighed less than those
from corn, and pupae from rice weighed less than those from sugarcane.
The smallest pupae were obtained when larvae were fed stems of
goosegrass and Johnson grass, and the highest larval m ortality of
927. occurred on Johnson grass. The food value of grain sorghum may
be nearly equivalent to that of rice, although survival was less
and pupae were heavier than on rice.
A d u lts
Normal venation in the anterior portion of the forewings (Plate VII,
Fig. 1) was found in 98.77. of 2,932 D. saccharalis adults examined.
However, variations from this normal pattern were observed in 39
adults, or 1.37. of the population examined. This abnormal variation
was manifested by varying tendencies toward anastomosis or "stalking11
of vein 10 with vein 8-9 (Plate VII, Figs. 2-6).
Measurements of length of forewings, abdomen, and thorax plus
head were made on 158 female and 169 male D. saccharalis adults col
lected from a light trap (table XIV). It may be calculated from the
data in this table that the wingspread of females averaged approximately
257. greater than that of males; sim ilarly, that female bodies were
approximately 157. longer than males on the average. The ranges of
all measurements of males and females overlapped. The general color
of the smaller male moths is usually darker than that of the larger
female moths.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table XIV. Sizes of various body parts of male and female Diatraea saccharalis moths collected from a light trap at Baton Rouge, Louisiana, 1960-1961.
Fem ale M ale Range A verage S.D. Range A verage S.D. Body F a r ts Number (mm) . (mm) (mm) Number (mm) (mm) (mm)
Length of forewing 158 10.5-17.5 1 5 .0 1 .3 169 8.5-14.0 1 1 .7 1 .8
Length of abdomen 100 7.0-13.5 10 .7 1.6 100 6.0- 9.5 8 .7 1 .0
Length of thorax + head 100 3.0- 6.5 5.6 2 .3 100 3 .5 - 5 .5 5 .0 1 .0 38
Observed miscellaneous abnormalities included the occurrence
in 1 specimen of an unusual thickening of the second segment of the
labial palps (Plate XIII, Fig. 10a). In another specimen the
normally separate prothoracic coxae were joined to each other.
Physiological Variation in Diatraea saccharalis
Three different strains of D. saccharalis, constituting progeny
of field-collected insects from Belle Glade, Florida and Baton Rouge
and Franklin, Louisiana were reared in field cages on 2 different
host plants to determine if physiological differences might exist
between borer populations from different localities. The major
planned comparisons were of survival and rate of development between
the Belle Glade and Franklin strains on com, and between the Belle
Glade and Baton Rouge strains on sugarcane.
Data in table XV indicate that survival of the Belle Glade strain
on C.P. 44-101 sugarcane was poorer than for the Baton Rouge strain,
while rate of development was approximately equal for the 2 strains
on this host. On corn survival was slightly higher in the Belle
Glade than in the Franklin strain. However, from approximately 4 to
6 days more were required for development from hatching to moth
emergence by the Belle Glade Strain.
Comparative Morphology of Species Studied
Only eggs of C. plejadellus, D. evanescens, D. saccharalis and
Z. grandiosella were obtained for study. Eggs of these 4 species
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. to \ o 3 3 .0 51 .6 _____ 7 4 5 0 .0 15 3 9 .3 Fem ales Moths Emerged ______34.0 3 7 .6 5 1 .0 M ales Avg.Djv. Avg. Dev. 16 5 2 .0 9 ______35 15 33 ______Per cent Number Period Number Period ______100 August 8 100 August 13 12 6 9 9 on Host Recovered Larvae Released LarvaeJ u ly and Pupae July12 57 August 11 25 5 J u ly July 20 100 August 22 reared in field cages on 2 different host plants, Baton Rouge, Louisiana, 1962. (L a . 521) (C.P. 44/101) (C.P. 44/101) (L a . 521) S ugarcane Corn S ugarcane Corn F la . L a. • Table XV. Survival percentages and developmental periods for strains of Diatraea saccharalis ^Number of days required for development from hatching of eggs to moth emergence. Strains Host Plant Date Number Date Franklin, La Belle Glade, Fla Belle Glade, Baton Rouge,
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 40
are sim ilar in shape, and range from approximately 1.0 to 1.2 mm
in length. They are laid in clusters overlapping each other like
fish scales. Specific differences are not apparent until some
embtyonic development has occurred. The important difference is the
occurrence of transverse red stripes which appear during development
in the eggs of Z. grandiosella and D. evanescens. In the other
species studied such stripes are not found.
L arv a e
Larvae of only 8 species were studied. These were C. pleiadellus,
Chilo sp., D. crambidoides, D. evanescens, D. saccharalis, E. densella,
0. nubilalis and Z, grandiosella. The ground color of summer form
larvae of C. pleiadellus, Chilo sp., D. saccharalis and 0. nubilalis
is dirty white, but is immaculate white in D. evanescens and £.
grandiosella. Body pinaculi in summer form D. evanescens and Z.
grandiosella are brown or dark brown, and are darker in color than
those of D. saccharalis. Except for 3 very old specimens of D.
crambidoides, summer form larvae of this species and of E. densella
were not available for study. Pinaculi in 0. nubilalis are approximately
of the light general body color in the centers and fuscous or gray
around the edges. Also a mid-dorsal longitudinal gray line runs the
length of the body with broader areas of gray on each side of this
line. Mature larvae of C. pleiadellus have 5 pale purplish longitu
dinal stripes runing the length of the body. The mid-dorsal stripe
is thinner and less distinct than the 2 sub-dorsal stripes on each
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 41
side. Larvae of the undescribed Chilo sp. resemble C. pleiadellus
in general coloration, but the purplish pigment of the longitudinal
stripes is more intense, and so diffuse that there appear to be
only 2 distinct dorsal longitudinal stripes or bands. The pinaculi
of Chilo larvae are very faintly pigmented, and are less distinct
than those of D. saccharalis.
Mature larvae may attain lengths of approximately 30 mm or
slightly more except in D. evanescens and JE^ densella which may
attain only about 2/3 of this length.
Puncture P on the labrum is immediately posterior to seta M2
in £• nubilalis (Plate I, Fig. 3), while in the other species studied
its position is different. Plate I, Fig. 2 shows the position of
this puncture between setae Ml and M2 in D. saccharalis.
Puncture AFa on the adfrontal sclerite between setae AF1 and
AF2 is closer to seta AF2 in both species of Chilo than in the
other species studied (Plate I, Figs. 4, 5 and 6).
The FI setae almost form a straight transverse line with the Fa
punctures across the frontal sclerite in E. densella (Plate I, Fig. 6),
but not so in the other species studied (Plate I, Figs. 4 and 5).
Puncture Pb on the epicranium is located approximately half way
between posterior setae Pi and P2 in the 3 species of Diatraea and
in grandiosella, but is much closer to P2 than Pi in C. pleiadellus,
Chilo sp., E. densella, and 0. nubilalis (Plate I, Fig. 1).
There is a black line on the anterior margin of the prothoracic
shield in summer form larvae of Z. grandiosella (Plate XIX, Fig. 1).
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 42
However, in winter form larvae this line almost disappears. The
line is absent in the other species studied. However, since the
only good specimens of larvae obtained of D. crambidoides were in
the diapause stage, the status of this character is not certain
for this species.
On the prothorax the mid-ventral-median (MVM) pinaculum is
larger than the m id-ventral-ventral (MW) pinaculum and bears from
6 to 8 dark specks in the 3 species of Diatraea (Plate II) and in
Z. grandiosella (Plate XII), However, in C. pleiadellus (Plate VIII,
Fig. 1), Chilo sp. (Plate IX, Fig. 1), and E. densella (Plate X,
Fig. 2) the mid-ventral-median (MVM) pinaculum is much smaller and
approximately equal in size to the m id-ventral-ventral (MW) pinaculum,
and has no dark specks. In 0. nubilalis the mid-ventral-median (MVM)
pinaculum is absent (Plate XI) .
The prothoracic and abdominal spiracles are oval in 0. nubilalis
(Plate XI), but more oblong in all other species studied.
The lateral-anterior (LA) pinaculum is oblong in shape and located
below the spiracle in all the species studied except 0. nubilalis in
which it is almost round and located in front of the spiracle (Plate XI).
In the species studied in Chilo, Diatraea and Z. grandiosella
there are 14 setae on each side of the prothorax and 16 on each side
of the meso- and metathorax (Plates II,V III, IX, X and XII). The
number of setae on each side of the prothorax in 0. nubilalis is
only 13 and seta MV2 is not present. The number of setae on each
side of the meso- and metathorax in 0. nubilalis and E. densella is
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 43
15 and seta SV2 is absent from these segments (Plate XI and Plate X,
F ig . 2 ) .
The dorsal-anterior (DA) and dorsal-posterior (DP) pinaculi
are fused into a single dorsal pinaculum on each of the meso- and
metathoracic segments in E. densella (Plate X, Fig. 2) and the
undescribed Chilo sp. (Plate IX, Fig. 1). The dorsal-anterior (DA)
pinaculi are separate while the dorsal-posterior (DP) pinaculi are
fused into a single dorsal-posterior (DP) pinaculum on these segments
in D. saccharalis (Plate II), D. crambidoides, D. evanescens, Z.
grandiosella (Plate XII), and C. pleiadellus (Plate VIII, Fig. 1).
The dorsal-posterior (DP) pinaculi are absent from the thorax in
0. nubilalis (Plate XI).
The ratio of the total area of the dorsal-posterior (DP) pinaculum
of the mesothorax to that of the metathorax generally appears to be
approximately 3 for Z. grandiosella (Plate X II), and 1% for D.
saccharalis and D. evanescens. In D. crambidoides and C. pleiadellus
this ratio appears to be somewhere between 1 and 1% (Plate V III, Fig. 1).
^ The distance between the 2 dorsal-posterior (DP) pinaculi of
the first abdominal segment is distinctly less than the lateral
diameter of either pinaculum in the larvae of D. saccharalis,
C. plejadellus (Plate VIII, Fig. 1), E. densella (Plate X, Fig. 2),
and Chilo sp. (Plate IX, Fig. 1). In the undescribed Chilo sp. these
pinaculi almost touch each other. They are separated by a distance
often approximately equivalent to 1/4, 1/2, and 1/2 of the lateral
diameter of one pinaculum in E. densella, D. saccharalis and
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 44
C. pleiadellus, respectively. In D. evanescens (Plate X, Fig. 1)
this distance approximately equals the lateral diameter of 1
pinaculum. The ratio of the distance to the lateral diameter of 1
pinaculum is between 1 and 2 for Z, grandiosella (Plate XII) and
approximately 4 or 5 for 0, nubilalis (Plate XI).
Differences in the relationship between the distance separating
the 2 ventral (V) pinaculi of the second abdominal segment and the
size of these pinaculi are used in the larval key to separate
Diatraea species. In Z. grandiosella larvae the distance between
these ventral (V) pinaculi is greater than the diameter of either
pinaculum (Plate XII); while in D. crambidoides it appears to be
approximately equal to the diameter of either pinaculum (Plate IX,
Fig. 3). In D. saccharalis this distance generally is greater than
the radius of 1 pinaculum, while in D. evanescens it is less than
this radius (Plate X, Fig. 1).
The shape of the dorsal-posterior (DP) pinaculi of the abdominal
segments is relatively pointed laterally and flat toward the mid
dorsal line in the new Chilo sp, (Plate IX, Fig. 1). In all other
species studied these pinaculi generally are narrower toward the
mid-dorsal line.
Crochets are uniserial, complete and at least triordinal in
C. pleiadellus, Chilo sp., D. crambidoides, D. evanescens. D. saccharalis
and Z. grandiosella (Plate I, Fig. 8). In 0. nubilalis the crochets
are triordinal, uniserial and incomplete (Plate I, Fig. 9), while
in E. densella they are uni- or biordinal, uniserial and complete
(Plate I, Fig. 10).
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 45
Seta SD2 invariably occurs with SD1 on the bisetose pinaculum
SDD of the first abdominal segment in C. pleiadellus (Plate VIII,
Fig, 1), Chilo sp. (Plate IX, Fig, 1), D. evenescens (Plate X, Fig. 1)
and D. saccharalis (Plate II). Ih only 80, 33, 20 and 0 per cent,
respectively, of IS. densella, grandiosella. D. crambidoides and
0. nubilalis larvae examined did this same condition prevail, while
in the remaining specimens setae SD1 and SD2 occurred separately on
pinaculi SDD and SDV, respectively.
Seta SD2 occurred with SD1 on pinaculum SDD of the second abdominal
segment in all specimens of the new Chilo sp., but only in 71, 70,
25, and 67., respectively, of the D. evanescens. E. densella, C.
pleiadellus and D. saccharalis larvae examined. Setae SD1 and SD2
on the second abdominal segment were found on separate pinaculi in
all specimens examined of D. crambidoides (Plate IX, Fig. 3), 0.
nubilalis (Plate XI), and Z. grandiosella (Plate XII, Fig. 1).
The 2 ventral (V) pinaculi normally are joined on the seventh,
eighth, and ninth abdominal segments in the new Chilo sp. (Plate IX,
Fig. 2) , and on the eighth and ninth segments in C. pleiadellus
(Plate VIII, Fig. 1). In E. densella they are only approximate
on the eighth and ninth segments (Plate X, Fig. 2). In all other
species studied they are distinctly separate on the abdominal segments.
Pupae
Pupae of 7 species were obtained for study. These were £.
pleiadellus, Chilo sp., D. evanescens, D. saccharalis, E. densella,
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 46
0. nubilalis and Z . grandiosella.
The typical color of the pupae of C, pleiadellus. Chilo sp.,
D. saccharalis. D. evanescens and E. densella is brownish-yellow,
whereas pupae of Z. grandiosella are dark brown, and those of 0.
nubilalis are yellow with a slight tinge of brown color.
The maximum length of pupae of C. pleiadellus. Chilo sp.,
D. saccharalis. 0. nubilalis and Z. grandiosella is approximately
20 mm, but only approximately 13 mm for D. evanescens and E, densella.
The dorsal thoracic region of the pupae of D. evanescens,
D. saccharalis and Z. grandiosella is largely covered by a network
of chitinous ridges. The same area is smooth in E. densella. 0.
nubilalis, C. pleiadellus and Chilo sp.
A cremaster is present at the posterior end of the tenth ab
dominal segment in C. pleiadellus. Chilo sp., E. densella and 0. nubilalis.
The cremaster is absent in D. saccharalis (Plate V, Fig. 4), D.
evanescens (Plate V, Fig. 5) and in Z. grandiosella (Plate V, Fig. 6).
The cremaster in C. pleiadellus (Plate VI, Fig. 7) and in Chilo sp.
(Plate VI, Fig. 8) bears 4 spines which are directed posteriorly
in the latter species, and at an angle away from the longitudinal
axis of the body in the former. In E. densella the cremaster (Plate VI,
Fig. 12) is a flat extension with 2 small spines, 1 at each posterior
corner. In 0. nubilalis it tapers to a blunt point which bears a
short filament as represented in Plate VI, Fig. 13.
Frontal horns were present on the pupae of only 3 species. In
D. saccharalis (Plate V, Fig. 1) and D. evanescens (Plate V, Fig. 2)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 47
these horns are pointed and directed laterally. In Z. grandiosella
(Plate V, Fig. 3) they are blunt vertical ridges. In other species
the frontals -are round or convex (Plate VI, Figs. 3 and 4).
The maxillae and prothoracic legs are approximately of equal
length in C. pleiadellus and Chilo sp. (Plate VI, Fig. 3). In all
the other species studied the prothoracic legs are always longer
than the maxillae (Plate VI, Figs. 1 and 2).
Microspines cover 1/3 or more of the fifth, sixth and seventh
abdominal tergites of D. saccharalis (Plate VI, Fig. 5), and 1/4 or
less of these tergites of D. evanescens (Plate VI, Fig. 6). In
Chilo sp. small spines occur on the fifth, sixth and seventh ab
dominal tergites. E. densella pupae (Plate VI, Fig. 12) have spines
borne by scattered papillae on the fourth, fifth, sixth, and
seventh abdominal segments. Pupae of C. pleiadellus and 0. nubilalis
have relatively smooth abdomens.
Adults
Moths of 9 species were obtained for comparative studies. These
were C. pleiadellus, Chilo sp., D. evanescens, D. saccharalis. D.
venosalis. D. lisetta, E. densella, 0. nubilalis, and Z, grandiosella.
The moths of C. pleiadellus, Chilo sp., D. saccharalis, 0.
nubilalis and Z. grandiosella have a maximum wing expanse of approx
imately 40 mm and body length of approximately 20 mm. Moths of
D. evanescens, D. venosalis, D. lisetta and E. densella are relatively
smaller with maximum wing expanse of approximately 24 mm and body
length of approximately 12 mm.
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The frons in C. pleiadellus (Plate XIII, Fig. 5c) and Chilo sp.
(Plate XIII, Fig. 6c) is distinctly conical and pointed anteriorly,
while in the other 7 species it is convex or only very slightly
c o n ic a l.
Ocelli are present in C. pleiadellus, Chilo sp., E. densella,
and 0. nubilalis, and are not present in Z. grandiosella and the
Diatraea species.
Partial anastomosis of veins 11 and 12 of the fore wings as
< shown in Plate XIV, Fig. la is characteristic of the wing venation
in D. evanescens, D. 'saccharalis, D. venosalis, and Z. grandiosella.
Further anastomosis of veins 10 with 8 + 9 is found in D. lisetta
(Plate XIV, Fig. 3a). In C. pleiadellus and Chilo sp. veins 11 and
12 are not anastomosed, nor is vein 10 joined with 8 + 9 in the
fori wings (Plate XIV, Fig. 2a). In E. densella vein 10 is joined
w ith 8 + 9, but vein 11 i,8 not anastomosed with 12 (Plate XIII,
Fig. 4A) . In 0. nubilalis vein 10 is closely approximate to 8 + 9,
and vein 11 originates from the middle of the anterior margin of the
d is c a l c e l l (P la te XIV, F ig . 5 a ).
In the male genitalia the lateral lobes, uncus, gnathos, aedeagus,
vinculum and anellus are considered important for differentiating
the various species.
The lateral lobes of the tegumen are prominent and sub-globose
in D. saccharalis (Plate XV, Fig. 4a). They are narrow and blunt in
D. evanescens (Plate XV, Fig. 3a). They are not present in the other
species studied.
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The uncus and gnathos are pointed and beak like in D. evanescens
(Plate XV, Fig# 3a), D. saccharalis.(Plate XV, Fig. 4a), D, venosalis
(Plate XV, Fig. 5b) and D. lisetta (Plate XV, Fig. 7b). They are
broad and not pointed in Z. grandiosella (Plate XV, Fig. 9a), C.
pleiadellus (Plate XV, Fig. la), Chilo sp. (Plate XV, Fig. 2b) and
in E. densella (Plate XV, Fig. 6a ) .
The aedeagus is long and pointed at the tip in all the species
except 0 . nubilalis in which it is relatively blunt at the tip
(Plate XV, Fig. 8a). In C. pleiadellus and Chilo sp. there is a
projection from the middle which is most prominent in C. pleiadellus
(Plate XV, Figs. lc and 2a).
The vinculum is u-shaped in all species of the genus Diatraea
(Plate XV, Figs 4b and 7a) and Z. grandiosella (Plate XV, Fig. 9b).
It is v-shaped in C. pleiadellus (Plate XV, Fig. lb), Chilo sp.
(Plate XV, Fig. 2c), and 0. nubilalis (Plate XV, Fig. 8b), and notched
at the base in E. densella (Plate XV, Fig. 6c ) .
The important characters in the female genitalia are the shape
and relative size of the ductus bursae and bursa copulatfix, and the
presence or absence of the signum bursae.
The ductus bursae is narrow and 2 to 3 times longer than the
bursa copulatrix in 0. nubilalis (Plate XVI, Fig. 8). In the other
species the ductus bursae is shorter than the bursa copulatrix.
In most species studied the bursa copulatrix appears as a single
elongate or spherical membranous sack. However, in Chilo sp. it
appears to be tri-lobed or partially divided into 3 compartments
(Plate XVI, Fig. 2).
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In C. pleiadellus and Chilo sp. the signum appears as a
chitinous thorny line in the membraneous wall of the bursa cop
ulatrix (Plate XVI, Figs. 1 and 2). In 0. nubilalis it occurs as
a broad chitinous area tapering to a point proximally and distally
(P la te XVI, F ig . 8).
Keys for Identification of Pyralid Stem Borers
Mature larvae
Careful examination of the indicated numbers of specimens of
mature or nearly mature larvae led to the preparation of a key for
separating the following species: C. plejadellus, 50; Chilo sp., 15;
D. crambidoides, 20; D. evanescens, 70; D. saccharalis, more than 300;
E. densella, 10; 0. nubilalis, 20; and Z. grandiosella, 100, Following
is the key:
1. Spiracle oval, lateral-anterior (LA) pinaculum
anterior to the prothoracic spiracle (Plate XI,
Fig. 1 )------—-0. nubilalis
la. Spiracle oblong, lateral-anterior (LA)
pinaculum ventral to the prothoracic spiracle -——-—2
2. Mid-ventral median (MVM) pinaculum of prothorax
small, approximately equal in size to mid-ventral-
v e n tra l (MW) pinaculum — ------—— - - - — 3
2a. Mid-ventral median (MVM) pinaculum of
prothorax distinctly larger than mid-ventral-
v e n tra l (MW) pinaculum ------5
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3. Ventral (V) pinaculi of 8th and 9th abdominal segments
usually joined; crochets at least triordinal------4
3a. Ventral (V) pinaculi of 8th and 9th abdominal
segments approximate to each other (Plate X,
Fig. 3); crochets uni- or biordinal
(Plate I, Fig. 10)------—E. densella
4. Dorsal-anterior (DA) and dorsal-posterior (DP)
pinaculi of both sides fused into 1 pinaculum
on the meso- and metathorax (Plate IX, Fig. 1)------Chilo sp.
4a. Two dorsal-anterior (DA) and 2 dorsal-
posterior (DP) pinaculi are separate and
distinct on both the meso- and metathorax
(Plate VIII, Fig. 1)...... -C. pleiadellus
5. Distance between ventral (V) pinaculi of second
abdominal segment greater than diameter of
either pinaculum (Plate XII, Fig. 1) ------—Z. grandiosella
5a. Distance between ventral (V) pinaculi of
second abdominal segment equal to or less
than the diameter of either pinaculum-- —— — ------6
6. Distance between ventral (V) pinaculi of second
abdominal segment approximately equal to
diameter of either pinaculum (Plate IX, Fig. 3)—D. crambidoides
6a. Distance between ventral (V) pinaculi of
second abdominal segment distinctly less than
diameter of either pinaculum ------—-7
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 52
7. Distance between ventral (V) and sub-ventral (SV)
pinaculi of second abdominal segment greater than
radii of ventral (V) pinaculi (Plate II). Body
dirty white with light brown spots ------D. s a c c h a ra lis
7a. Distance between ventral (V) and sub-
ventral (SV) pinaculi of second abdominal
segment less than radii of ventral (V)
pinaculi (Plate X, Fig. 1). Body pure
white with dark brown spots---— ------D. evanescens
Pupae
Careful examination of the indicated numbers of pupae or pupal
skins led to the preparation of a key for separating the following
species: C. pleiadellus, 42; Chilo sp., 10; D. evanescens, 23;
D. saccharalis, more than 200; E. densella, 18; 0. nubilalis, 5; and
Z. grandiosella, 29. Following is the key:
1. Frontal horns present, well developed; cremaster absent——— 2
la. Frontal horns absent or poorly developed;
cremaster present——-----—-----— ------— -4
2. Frontal horns pointed, directed laterally; body brown ------3
2a. Frontal horns blunt, not directed laterally;
body dark brown (Plate V, Fig. 3)------Z. grandiosella
3. Microspines covering \ or less of the fifth,
sixth, and seventh abdominal tergites (Plate VI,
F ig . 6) ------D. evanescens
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3a. Microspines covering 1/3 or more of the
fifth, sixth, and seventh abdominal tergites
(Plate VI, Fig. 5)------D. saccharalis
4. Prothoracic legs and maxillae approximately equal
in length (Plate VI, Fig. 3) ------5
4a. Prothoracic legs and maxillae distinctly
unequal in length (Plate VI, Fig. 1)------6
5. Paired transverse ridges bearing setae and
spines on the fifth, sixth, and seventh abdominal
tergites; prominent setae bearing tubercles
ventrally on the abdomen (Plate VI, Fig. 8)------——Chilo sp.
5a. Ridges and setae absent, abdomen relatively
smooth—————— ----— — — - — ------C. pleiadellus
6. Maxillae distinctly shorter than prothoracic
legs; abdominal segments 5 to 9 with spines on
raised papillae (Plate VI, Fig. 12) ------E. densella
6a. Maxillae distinctly longer than prothoracic
legs (Plate VI, Fig. 4); abdominal segments
5 to 9 without spines-----—---—— — — — 0. nubilalis
A dults
Careful examination of the indicated numbers of adults led to
the preparation of a key for separating the following species of
moths: C. plejadellus, 29; Chilo sp., 11; D. evanescens, 97; D.
saccharalis, 2,932; D. venosalis, 6; E. densella, 34; D. lisetta, 24;
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 54
0. nubilalis. 4; and Z, grandiosella, 46, Following is the key:
1. Ocelli absent- — ———— ——-—--———— — — — — — — 2
la. Ocelli present ————— ———— ———— — 6
2. Vein 10 of fore wing stalked with veins 8-9
(P la te XIV, F ig . 3 a ); g e n ita lia as in P la te s XV
and XVI, F ig , 7 ------D. l i s e t t a
2a. Vein 10 of fore wing not stalked with
veins 8-9 (P la te XIV, F ig . l a ) ...... 3
3. Two dark parallel wavy lines on each fore wing;
genitalia as in Plates XV and XVI, Fig. 4---- — ------D. saccharalis
3a. Fore wings without dark parallel wavylines— ------——- — -4
4. Moths with fore.wings approximately 12-20 mm
long, pale buff in color, and only slightly
darker than hind wings; genitalia as in
Plates XV and XVI, Fig. 9— ——— — — — Z., grandiosella
4a. Moths with fore wings approximately 7-11 mm
long, apparently of a tan or gray color, and
distinctly darker than hind wings ------5
5. Scales forming vein and intervein stripes on fore
wings reddish-brown, scales between stripes
b u ff; g e n ita lia as in P la te s XV and XVI,
Fig. 3- ——— ——— — ———— ------d . evanescens
5a. Scales forming vein and intervein stripes
brown or grayish-brown, scales between stripes
pale buff; greater contrast between stripes
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and interstripe areas than in the
preceding species; genitalia as in
Plates XV and XVI, Fig. 5---—— ——------— D. v e n o sa lis
6. Vein 10 stalked with veins 8-9 (Plate XIV,
Fig« 4); genitalia as in Plates XV and XVI,
F ig . 6—————-————— ----— — —— — — e. densella
6a. Vein 10 not stalked with veins 8-9-——— -— — — 7
7. Fore and hind wings predominantly yellow with
tinges of orange and brown, and with several
dark wavy transverse lines; genitalia as in
P la te s XV and XVI, F ig . 8— ------0. nubilalis
' V 7a. Fore wings distinctly darker than hind wings,
not colored as in the above species--———— ——— ------8
8. Fore wings not striped, predominantly buff with
golden specks and shiny gold margins; genitalia
as in Plates XV and XVI, Fig. 1— ———------C. pleiadellus
8a. Fore wings with alternating buff and
lavender stripes and shiny gold margins;
genitalia as in Plates XV and XVI, Fig. 2— ———Chilo sp.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DISCUSSION
The best characters found for separating closely related
forms did not achieve this objective in 1007. of all specimens
examined. For example, couplet 5 in the key to larvae leads to
Z. grandiosella when the distance between the ventral pinaculi
of the second abdominal segment is greater than the diameter of
either pinaculum. This character appeared to be accurate for
Z, grandiosella in 97 out of 100 specimens examined. In the re
maining 3 this distance appeared to be approximately equal to the
diameter of these pinaculi.
The seventh couplet in the key to larvae leads to D. saccharalis
when the distance between ventral and sub-ventral pinaculi of the
second abdominal segment is greater than the radius of either
ventral pinaculum. This character appeared to be accurate for
D. s a c c h a ra lis in 967. of the larvae examined for it. The alternative
in this key couplet leads to D. evanescens, the mature larvae of
which are only slightly more than half the size of D. saccharalis
larvae. Likewise, in D. evanescens the distance between ventral and
sub-ventral pinaculi was distinctly less than the radius of either
ventral pinaculum in 64 out of 70 larvae examined.
The weakest part of the larval key may involve the identification
of D. crambidoides in couplets 5 and 6. Only 20 larvae were available
56
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for examination, and 17 of these were of the immaculate winter
form. Staining improved the visibility of the pinaculi, but
distances between pinaculi are not as accurately estimated on
slides as with whole specimens.
In the key to pupae the third couplet leads to D. saccharalis
when 1/3 or more of the fifth, sixth, and seventh abdominal tergites
are covered with microspines. This character appeared to be true
o f only 837. of the pupae examined for it. However, the first part
of this couplet leads to D. evanescens when microspines occur on
1/4 or less of these tergite areas, and this character appeared
to be true for all 23 D. evanescens pupae examined.
It is unfortunate that all stages of the 10 species studied
were not obtained. The larval key includes 8 o f the 10 b u t does
not include D. venosalis or D. linsetta. The key to pupae includes
7 species, but does not include D. crambidoides, D. venosalis, or
D. lisetta. The adult key includes 9 of the 10 species, but does
not include D. crambidoides. Only larvae of the last mentioned
species were obtained from South Carolina.
Wing venation in the 3 species of Diatraea and in Z. grandiosella
generally is identical. On the basis of venation of the fore wing
Dyar and Heinrich (1927) separated the genus Iesta from Diatraea.
The species lisetta in which vein 10 is stalked with veins 8 + 9
for some distance was placed in the genus Iesta by Dyar and Heinrich
(ibid.). Box (1931) placed the species of this genus with Diatraea
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 58
because he said that stalking of vein 10 with 8 + 9 may occasionally
occur in species in which these veins are normally separate. He
reported the occurrence of this condition in 3 different species
of Diatraea including D. saccharalis.
During the course of my studies of 2,932 D. saccharalis moths,
not a single specimen was seen in which vein 10 was com pletely
stalked with 8+9. There was always a small space between these
veins, or the width was equal to two veins.. This condition is dif
ferent from the stalking of vein 10 with 8 + 9 as found in the genus
Iesta. In this genus the width of vein 10 and 8 + 9 a t th e common
base is equal only to the width of 1 vein. Therefore, it is sug
gested that Iesta be recognized as a genus separate from Diatraea.
A ll 8 species of larvae studied were found to have a total of
32 setae and 11 punctures on the head and mouthparts. Differences
in the location of some punctures characterized most of the genera
studied. However, there were no differences in this respect between
Diatraea and Zeadiatraea.
On the body 155 setae were found on each side of the mid-dorsal
line in the species studied of Diatraea, Zeadiatraea, and Chilo
larvae, 152 body setae on each side in 0. nubilalis and 153 in
E. densella (seta SV2 is absent from the meso- and metathorax in
the 2 last mentioned species). The relative size and arrangement
of these setae were similar for all species and genera studied.
In contrast with the uniformity of body setae among the species
studied, the shape and relative size and location of various pinaculi
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on the bodies of larvae were frequently characteristic of single
species among those studied. For this reason and to facilitate
their discussion the pinaculi were named as already described in
the section on methods.
Holloway (1916) emphasized the importance of the angle made
on the third, fourth, and fifth abdominal segments by extending
imaginary lines anteriorly through setae D2 and D1 until they in
tersect. He believed that an average angle of 30.2° for D. saccharalis
distinguished this species from D. crambidoides, which he believed
to be characterized by an average angle of 53.3°. In the third,
fourth, and fifth abdominal segments of 20 D. saccharalis larvae
this angle was found to range from 32° to 62°, and from 50° to 77°
in D. crambidoides larvae. The character does not appear to be
sufficiently consistent for separating these 2 s p e c ie s.
A comparison was made of the development of Louisiana and
Florida strains of D. saccharalis on corn and sugarcane in order
to make some use of caged field plantings which had been prepared
for the purpose of comparing a Youngsville, Louisiana strain with
1 from another area of the state. The originally planned comparison
was considered desirable due to the fact that, according to various
reports, borer populations in the vicinity of Youngsville for many
years generally have not attained economic proportions as early in
the season as they have in most other areas of the state. However,
borer eggs from the Youngsville area were not available at the time
when the caged field plantings were ready for infestation. The data
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obtained on survival and rate of development on corn and sugarcane
of Florida and Louisiana strains of D. saccharalis gives no con
clusive evidence of a physiological difference between these
populations.
According to Hensley (1960) D. lisetta and D. venosalis had
not been reported since their original description by Dyar (1909, 1917).
For this reason it is of particular interest that 24 moths of the
former and 6 of the latter species were recognized during the course
of this study from light trap collections at Baton Rouge, Louisiana.
During the same period of time 2,932 moths from this trap were
counted as D. saccharalis.
The undescribed Chilo sp. found by the writer in wooly beard
grass (Erianthus sp.) at Port Barre, Louisiana was determined by
Mr. H. W. Capps (1961) of the U. S. National Museum in Washington,
D. C. as an undescribed species of Chilo near fernaldis Dyar and
Heinrich. The species will be described and published by Mr. Capps.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SUMMARY AND CONCLUSIONS
Pyralid stem borer larvae were collected from Johnson grass,
broomsedge, goosegrass, wooly beard grass, vasey grass, sorghum,
corn, and sugarcane in Louisiana from October, 1960 to June, 1962.
Moths were collected regularly in a light trap at Baton Rouge,
Louisiana from March, 1961 to August, 1962. Larvae of D. saccharalis
also were reared in the laboratory on freshly cut stems of corn,
sugarcane, rice, sorghum, goosegrass and Johnson grass, and were
collected on successive sampling dates from 12 varieties of
sugarcane grown in small randomized replicated field plots.
A study was made of larval chaetotaxy and of morphological
and physiological variation in D. saccharalis. Characters of
possible taxonomic significance were compared among available
stages of D. saccharalis, D. crambidoides, D. evanescens, D. lisetta,
D. venosalis, Z_. grandiosella, E. densella, Chilo sp., C. pleiadellus,
and 0. nubilalis. Keys were prepared for separating the larvae of
8 species, pupae of 7 species, and moths of 9 species.
The following conclusions were reached:
1. Abnormal variations in numbers and arrangement of setae
and pinaculi were 4.5 and 1.6 times more frequent on the left than
on the right sides, respectively, of the bodies of D. saccharalis
la rv a e .
61
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2. The frequencies of observed setal and pinacular
abnormalities for any particular seta or pinaculum in D. saccharalis
larvae seldom exceeded 17. and never reached 3 7 ..
3. In male D. saccharalis pupae the antennae are long,
reaching to the anterior margin of the metathoracic legs. In
females the antennae are shorter and extend only to a point between
the pro- and mesothoracic legs. Male pupae are smaller than females.
4. In the pupae of all species studied the suture marking the
genital opening is visible on the venter of the eighth abdominal
segment in females and on the ninth in males.
5. The larvae of all species studied had 32 setae and 11 named
punctures on the head and mouth parts. The normal complement of
setae on each side of the body varied from 152 to 155, and pinaculi
from 112 to 114 among th e d if f e r e n t s p e c ie s.
6. The relative shape, size, and distances between pinaculi
were much more useful than setal characters for separating species.
For this reason names were assigned to the body pinaculi.
7. Relative positions of the punctures designated as Fa, Pb,
AFa, and P on the head and labrura of larvae appeared to be useful
characters for separating the genera studied, but were not used in
the key since other more easily seen characters appeared to be just
as reliable.
8. Eggs of D. evanescens and Z. grandiosella differ from the
other species studied by the presence'of transverse red stripes
which occur for a short period of time during embryonic development.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 63
9. Iesta should be recognized as a genus separate from
Diatraea on the basis of wing venation characters originally des
cribed by Dyar (1909), and should not be included in the genus
Diatraea as recommended by Box (1931).
10. The keys constructed for separating larvae, pupae, and
moths should be considered as tentative until they have been tested
more extensively.
11. D. saccharalis larvae were collected in the field from
sugarcane (Saccharum officinarum), corn (Zea mays), rice (Oryza sativa),
sorghum (Sorghum vulgare), Johnson grass (Sorghum halepense), and
goosegrass (Eleusine indiea).
12. Larvae of D. evanescens were collected in the field only
from vasey grass (Paspalum urvillei)• Z. grandiosella and 0 . nubilalis
larvae were collected only from corn (Z. mays). Larvae of the new
Chilo sp. were found only in wooly beard grass (Erianthus sp.).
C. pleiadellus larvae were found only in rice (0. sativa) . IS. densella
larvae were found in broomsedge (Andropogon glomeratus) and in vasey
grass (P. urvillei).
13. There was no conclusive evidence of a physiological
difference between Florida and Louisiana strains of D. saccharalis
when the different strains were reared on corn and sugarcane in field
cages during July and August, 1962. However, development from hatching
to moth emergence averaged 37.0 days on corn and 51.5 days on sugarcane.
14. Laboratory rearing on the cut stems of different host
plants indicated that Johnson grass is a very poor host for D. saccharalis.
and that goosegrass is only slightly better.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 15. D. saccharalis pupae collected from C.P. 56-25 sugarcane
were less abundant and noticeably smaller than pupae from other
sugarcane varieties grown in small randomized replicated plots.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. SELECTED BIBLIOGRAPHY
Ainslie, G. G. 1925. The larger corn stalk borer. U. S. Dept.
Agric. Farmer's Bull, 1025:1-11.
Arbuthnot, K. D. 1944. Strains of the European corn borer in
United States. U. S. Dept. Agric. Tech. Bull. 869:1-20.
Borror, D. J. and D. M. DeLong. 1957. An introduction to the study
of insects. 3rd ed., New York. Rinehart and Co., 1030 pp.
Box, H. E. 1925. Sugarcane moth borers (Diatraea spp.) in British
Guiana. Bull. Entomol. Res. 16:249-266.
. 1931. The crambine genera Diatraea and Xanthopherne
(Lep. Pyral.). Bull. Entomol. Res. 22(l):l-50.
______. 1935. The food plants of American Diatraea species.
(Abstracted in Rev. Appl. Entomol. Series A 24(L):22-23. 1937.)
______. 1949. Notes on the genus Diatraea Guilding (Lepid.
Pyral.). Boletin De Entomologia Venezolana. 7(1-2) :,26-59.
______. 1955. New crambine genera allied to Diatraea Guilding
(Lepidoptera:Pyralidae) III. Proc. Entomol. Soc. Lond. (B) 24
(11-12):197-200.
______. 1960. The species of Diatraea and allied genera attacking
sugarcane. Hawaii. Proc. 10th. Int. Cong. Sugar Cane Tech:
870-877.
Busch, A. 1942. On making of genitalia slides of Lepidoptera.
Proc. Hawaiian Entomol. Soc. 11(2):157-163.
65
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 66
Caffrey, D. J. and L. H. Worthley. 1927. A progress report on
the investigations of the European corn borer. U. S. Dept.
Agric. Tech. Bull. 1476:1-154.
Capp, H. W., Washington, D. C. 1961. Identification of undescribed
Chilo sp. Private communication.
Cartwright, 0. L. 1934. The southern cornstalk borer in South
Carolina. S. C. Agric. Expt. Sta. Bull. 294:1-32.
Comstock, J. H. 1950. An introduction to entomology. 9th ed.
New York, Comstock Publishing Co., Inc., 1064 pp.
Davis, E. G., J. R. Horton, C. H. Gable, E. V. Walter, R. A. Blanchard.
1933. The southwestern corn borer. U. S. Dept. Agric. Tech.
Bull. 338:1-61.
Douglas, W. A. and J. W. Ingram. 1942. Rice field insects. U. S.
Dept. Agric. Cir. 632:1-32.
Dyar, H. G. 1896. Note on the head setae of Lepidopterous larvae
with special reference to the appendages of Perophora melsheimerii.
Jour. New York Entomol. Soc. 4:92-93.
______. 1909. New species of American Lepidoptera. Proc.
Entomol. Soc. Washington 11:27-29.
______. 1917. Descriptions of new Lepidoptera from Mexico.
Proc. U. S. Nat. Mus. 51(2139):37.
______, and Carl Heinrich. 1927. The American moths of the
genus Diatraea and allies. Proc. U. S. Nat. Mus. 71(19):l-20.
Ely, C. R. 1910. New Phycitinae and crambinae. Proc. Entomol.
Soc. Washington. 12:202-204.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 67
Essig, E. 0. 1951. College entomology. 3rd ed. New York, Macmillan
Co., 900 pp.
Fernald, C. H. 1888. Notes on the Crambidae. Entomologica America.
4(3):44-45.
Flint, W. P. and J. R. Malloch. 1920. The European corn borer and
some s im ila r m ature in s e c ts . 1 1 1 . Nat. Hist. Survey Bull.
13(10):288-305.
Forbes, W. T. M. 1910. A structural study of some caterpillars.
Ann. Entomol. Soc. Amer. 3:94-143.
______. 1923, The Lepidoptera of New York and neighboring
states. Cornell Univ. Agric. Expt. Sta. Memoir 68:1-729.
Fracker, S. B. 1915. The classification of Lepidopterous larvae.
1 1 1 . Biol. Monog. 2:1-169.
Gerasimov, A. M. 1935. Zur Frage der Homodynamie der B orsten von
Schmetterlingsraupen. Zool. Anz. 112:117-194. (Original not
consulted; but adopted from Hinton 1946).
Heinrich, C. 1918. On the Lepidopterous genus Opostega and its
larval affinities. Proc. Entomol. Soc. Washington 20:27-38.
Hensley, S. D. 1960. A comparative study of the immature stages of
three species of the Diatraea complex. Ph.D. Dissertation.
Okla. State Univ. Library, Stillwater, Oklahoma, 82 pp.
Hinton, H. E. 1946. On the homology and nomenclature of the setae
of Lepidopterous larvae with some notes on the phylogeny of
the Lepidoptera. Trans. Roy..Entomol, Soc. Lond. 97:2-37.
Holloway, T. E. 1916. Larval characters and distribution of two
species of Diatraea. Jour. Agric. Res. 4(16):621-625.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 68
Holloway, T. E., W. E, Haley, U. C. Loftin and Carl Heinrich. 1928.
The sugarcane moth borer in the United States. U. S. Dept. Agric.
Tech. Bull. 41:1-76.
Ingram, J. W. 1927. Insects injurious to the rice crop. U. S. Dept.
Agric. Farmers Bull. 1543:1-16.
Isa, A. L. 1961. Nutrition and survival of the sugarcane borer in
different natural and artifical diets. M. S. Thesis. Louisiana
State University Library, Baton Rouge, Louisiana. 115 pp.
Kapur, A. P. 1950. The identity of some crambinae associated with
sugarcane in India and certain species related to them
(Lepidoptera-Pyralidae). Trans. Royal. Entomol. Soc. Lond.
101:389-434.
Katiyar, K. P. 1960. Diapause in sugarcane borer, Diatraea saccharalis
(F.). Ph.D. Dissertation. Louisiana State University Library,
Baton Rouge, Louisiana. 148 pp.
______and W. H. Long. 1961. Diapause in the sugarcane borer,
Diatraea saccharalis. Jour. Econ. Entomol. 54(2):285-287.
Kevan, D. K. McE. 1944. The binomics of the neotropical corn
stalk borer.Diatraea lineolata, Walk.' (Lep. Pyral.) in Trinidad,
B.W.I. Bull. Entomol. Res. 35:23-30.
Laffoon, J. L. 1960. Phylum, class, order and family names. Bull.
Entomol. Soc. Amer. 6(4):174-211.
Meadows, C. M. 1938. The biology of the sugarcane borer, Diatraea
saccharalis (Fabr.). M. S. Thesis, Louisiana State University
Library. Baton Rouge, Louisiana. 50 pp.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 69
Morgan, H. A. 1891. Sugarcane borer and its parasites. La. Agric.
Expt. Sta. Bull. 9:218-228.
Mosher, Edna* 1916. A classification of Lepidoptera based on the
characters of the pupa. Bull. 1 1 1 . State Lab. Nat. Hist.
12:17-159.
______. 1919. Notes on Lepidopterous borers found in plants,
with special reference to the European corn borer. Jour.
Econ. Entomol. 12:258-268.
Pan, Y. S. 1960. Diets for rearing the sugarcane borer, Diatraea
saccharalis (F.) in the laboratory. M. S. Thesis. Louisiana
State University Library, Baton Rouge, Louisiana. 88 pp.
Peterson, Alvah. 1948. Larvae of insects. Ann Arbor, Mich. Edwards
Bros. Inc. 315 pp.
Pfadt, R. E. 1962. Fundamentals of applied entomology. New York.
Macmillan Co. 668 pp.
Phillips, W. J., G. W. Underhill and F. W. Poos. 1921. The larger
corn-stalk borer in Virginia. Va. Agric. Expt. Sta. Tech.
Bull. 22:1-30.
Richards, 0. W. and R. G. Davies. 1957. A general textbook of
entomology. 9th ed. London. Methuen and Co. Ltd. 886 pp.
Riley, C. V. 1882. Rept. of the Entomologist for 1881-1882. U. S.
Dept. Agric: 133-135.
Ripley, L. B. 1923. The external morphology and postembryology of
Noctuid larvae. 1 1 1 . Biol. Monog. 8:1-169.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 70
Stirrett, G. M. 1938. A field study of the flight, oviposition and
establishment periods in the life cycle of the European corn
borer, Pyrausta nubilalis (Hbn.), and the physical factors
affecting them. Sci. Agri. 18:462-484.
Stubbs, W. C. and H. A. Morgan. 1902. Cane borer. La. Agri. Expt.
Sta. Bull. 70:888-927.
Tams, W. H. T. 1942. Notes on the name of the sugarcane borer of
Mauritius (Lepi. Pyralidae). Bull. Entomol. Res. 33(1):67.
Todd, C. J. and F. L. Thomas. 1930. Notes on the southwestern
corn borer, Diatraea grandiosella Dyar. Jour, Econ. Entomol,
23(1):118-121.
Vinal, S. C. and D. J. Caffrey. 1919. The European corn borer and
its control. Mass. Agri. Exp. Sta. Bull. 189:1-71.
Walton, R. R. and G. A. Bieberdorf. 1948. The southwestern corn
borer and its control. Okla. Agric. Exp. Sta. Bull. B-321:l-23.
Wressell, H. B. 1961. The history and development of European
corn borer, Ostrinia nubilalis (Hbn.) (Lepidoptera:Pyralidae)
as an economic pest in Ontario. Proc. Entomol. Soc. Ontario.
91:240-247.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. APPENDIX
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate I. Arrangement of setae on head and crochets on
abdominal prolegs of several species of Pyralid
larvae. Fig. 1. Setae and punctures on
epicranium of D. saccharalis. Fig. 2. Labrum of
D. saccharalis. Fig. 3. Labrum of 0. nubilalis.
Fig. 4. Clypeus, frons and adfrontal sclerites of
D. saccharalis. Fig. 5. Clypeus, frons and ad
frontal sclerites of C. pleiadellus. Fig. 6.
Clypeus, frons and adfrontal sclerites of E. densella.
Fig. 7. Left mandible of D. saccharalis. Fig. 8.
Crochets of D. saccharalis. Fig. 9. Crochets of
£• nubilalis. Fig. 10. Crochets of E. densella.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. n 71
PLATE.I
To.
0 u c Lo.
Pi
Fig Fig. 1
r' f*- 0 O o o
Fig. 5
1
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate II. Setal maps of body segments of D. saccharalis
larvae.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 72
PLATE II
vr
R>
«a:
«v
f s
fO
/ * V
W
G-* ©
CL
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate III. Pinacular maps of body segments of D. saccharalis
larvae.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE I I I
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate IV. Variations in the shape of mandibles encountered
among D. saccharalis larvae showing different
degrees of erosion of dentes. Fig. 1. Little
or no erosion of dentes. Figs. 2-7. Progressive
increase in erosion of dentes.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE IV
Fig. 2 Fig. 3
Fig. 4 Fig. 5
Fig. 6
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate V. Pupae of D. saccharalis. D. evanescens, and
Z. grandiosella. Fig. 1. Ventral cephalic
view of D. saccharalis. Fig. 2. Ventral
cephalic view of D. evanescens. Fig. 3.
Ventral cephalic view of Z. grandiosella.
Fig. 4. Ventral caudal view of D. saccharalis.
Fig. 5. Ventral caudal view of D. evanescens.
F ig . 6. Ventral caudal view of Z. grandiosella.
Fr. «= frons; 10th = tenth abdominal segment.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 75
PLATE V
■ 0 0
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate VI. Pupal characters in different Pyralid species.
Fig. 1. D. saccharalis male (ventral view).
Fig. 2. D. saccharalis female (ventral view).
Fig. 3. C, plejadellus (ventral view). Fig. 4.
Ventral-cephalic view of 0. nubilalis (ventral
view).Fig. 5. Abdominal segments 5, 6 and 7
of D. saccharalis. Fig. 6. Abdominal segments
5 , 6 and 7 of D. evanescens. Fig. 7. 10th
abdominal segment of C. plejadellus. Fig. 8.
Abdominal segments 6-10 of Chilo sp. (ventral
view). Fig. 9. Abdominal segments 8-10 of
D. saccharalis female (ventral view). Fig. 10.
Abdominal segments 8-10 of D. saccharalis male
(ventral view). Fig. 11a. Normal labrum of
D. saccharalis. Fig. lib. Notched labrum of
D. saccharalis. Fig. 12. Abdominal segments 5-10
of E. densella (ventral view). Fig. 13. Cremaster
o f 0 . nubilalis.
Ant = antenna; Cr = cremaster; FI = prothoracic
femur; LI = prothoracic leg; L2 = mesothoracic
leg; L3 *= metathoracic leg; M = maxilla;
W »» wings.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE VI
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate VII. Variations in venation of fore wings of
D. saccharalis. Fig. 1. Normal. Fig. 2.
Two cross-veins between 10 and 8+9. F ig . 3.
Vein 10 located very close to 8+9. F ig . 4.
Isla n d between veins 10 and 8+9. F ig . 5.
Vein 10 almost joined with 8+9. F ig . 6.
Several islands between veins 10 and 8+9.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. N
the c°Py«(
Pr°hib,i0 0 w«h,out Perhits,‘Von Plate VIII. Setal map of C. plejadellus larva. Fig. 1.
Thorax with abdominal segments 1-2. Fig. 2.
Abdominal segments 7-9.
DA *= dorsal-anterior; DP = dorsal-posterior;
LA = lateral-anterior; MVM = mid-ventral-
median; MW = mid-ventral-ventral.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 78
PLATE V I I I
V0
o
0 I
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate IX. Setal maps of larvae of Chilo sp. and
D. crambidoides. Fig. 1. Thorax and
abdominal segments 1-2 of Chilo sp. Fig. 2.
Abdominal segments 7-9 of Chilo sp. Fig. 3.
Abdominal segments 1-2 of D. crambidoides.
DA = dorsal-anterior; DP = dorsal-posterior;
LA = lateral-anterior; MVM = mid-ventral-median
MW * mid-ventral-median; V *» ventral.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ■?LATE IX Chilo Chilo sp
with permission of the copyright owner. Further reproduction prohibited without permission. Plate X. Setal maps of larvae of D. evanescens and
JE. dense!la; Fig. 1- Abdominal segments 1-2
of D. evanescens. Fig. 2. Thorax and abdominal
segments 1-2 of E. densella. Fig. 3. Abdominal
segments 8-9 of E. densella.
DA = dorsal-anterior; DP = dorsal-posterior;
LA = lateral-anterior; MVM « mid-ventral-median
MW = mid-ventral-ventral.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ) 80
PLATE X
(
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate XI. Setal map of thorax and abdominal segments
1-2 of 0. nubilalls.
DA = dorsal-anterior; DP = dorsal-posterior;
LA = lateral-anterior; MW = mid-ventral-ventral.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 'WQ
\\
0 ^ n u b lla lis
\
of the copyright owner. Further reproduction prohibited without permission. Plate XII. Setal map of thorax and abdominal segments
1-2 of 55. grandiosella.
DA « dorsal-anterior; DP « dorsal-posterior;
LA e lateral-anterior; MVM «= mid-ventral-median
MW = mid-ventral-ventral.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 82
PLATE XII " " H
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate XIII. Mouthparts of adults of different Pyralid
species. Fig. 1. D. saccharalis. Fig. 2.
D. evanescens. Fig. 3. D. venosalis.
Fig. 4. Z. grandiosella. Fig. 5. C.
p le ja d e llu s . F ig . 6. Chilo sp . F ig . 7.
E. d e n s e lla . F ig . 8 . D. lisetta. Fig. 9.
0. nubilalis. Fig. 10. Abnormal labial
palp of D. saccharalis.
a = labial palp; b ** maxillary palp;
c = fro n s.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE X III
a b c a b a b c Fig. 1 Fig. 2 Fig. 3
a a Fig. 6 Fig. 4 Fig. 5
a b ci Fig. 7
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate XIV, Wing venation of different Pyralid species.
Fig. 1. D. saccharalis. Fig. 2. C.
plejadellus. Fig. 3. D. lisetta.
Fig. 4. E. densella. Fig. 5. 0. nubilalis.
a “ forewing; b = hindwing.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE X IV
l ( r
It- 1C
1
1C,
I t r S
Fig. 3 Fig. 4
s
ft. Fig. 5
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate XV. Male genitalia of different Pyralid species.
Fig. 1. C. pleiadellus. Fig. 2. Chilo sp.
Fig. 3. D. evanescens. Fig. 4. D.
saccharalis. Fig. 5. D. venosalis.
F ig . 6. E. densella. Fig. 7. D. lisetta.
F ig . 8. 0. nubilalis. Fig. 9. Z. grandiosella.
a = vinculum, anellus and harpes;
b = aedeagus; c =» lateral lobes, uncus and
gnathos.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. IPLATE XV
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Plate XVI. Female genitalia of different Pyralid species.
Fig. 1. C.plejadellus. Fig. 2. Chilo sp.
Fig. 3. D. evanescens. Fig. 4. D. saccharalis.
Fig. 5. D. venosalis. Fig. 6. E. d e n s e lla .
Fig. 7. B. lisetta. Fig. 8 . 0. nubilalis.
Fig. 9. Z. grandiosella.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PLATE X V I
( M ilt
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. BIOGRAPHY
Ram Autar Agarwal was born on December 11, 1925 in Sambhal,
district of Moradabad, Uttar Pradesh (India). After finishing his
early education at the Government College at Moradabad, he obtained
thie degree of Bachelor of Science in Agriculture specializing in
Entomology in 1944. He entered the Uttar Pradesh State service on
January 5, 1945 to operate the Trichogramma colonization program at
Muzaffarnagar centre. He further obtained the Associateship of
I.A .R.I., New Delhi in Entomology in 1952.
Mr. Agarwal worked as Entomologist and Head of the Entomology
Section at the Sugarcane Breeding Institute, Coimbatore, under the
Ministry of Food and Agriculture for the Government of India from
1.955 to 1960.
He left for the United States on August 29, 1960 to pursue
graduate studies in Entomology at Louisiana State University, Baton
Rouge.
8 7
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. EXAMINATION AND THESIS REPORT
Candidate: Ram A utar Agarwal
Major Field: Entomology
Title of Thesis: D iatraea s a c c h a ra lis (F ab r.) and Some R elated P y ra lid Stem
Borers in Louisiana. Approved:
J.
Major Professor and Chairma^j/
Dean of the Graduate School
EXAMINING COMMITTEE:
f t i / f y '
Date of Examination:
February 8, 1963
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