THE DEVELOPMENT AND FECUNDITY OF THE ORIENTAL FRUIT MOTH, GRAPHOLITHA (CYDIA) MOLESTA (BUSCK) UNDER CONTROLLED TEMPERATURES AND HUMIDITIES

152 Pages·04.228 MB·English

by  CHAUDHRY, GHULAM-ULLAH

ifWBj
This is to certifq that the
thesis entitled
The Development and Fecundity of the
Oriental Fruit Moth, Grapholltha
(Cydia) Moleata (Busck) Under Controlled
x-^AV:
Temperatures and Humidities.
presented by
Ghulam-Ullah Chaudhry
has been accepted towards fulfillment
of the requirements for
Ph.D. tn Entomology
mmmm
i ajor professor
ssvssm
July 13, 1951
0-169
THE DEVELOPMENT AND FECUNDITY OF THE ORIENTAL
FRUIT MOTH, GRAPHOLITHA (CYDIA) MOLESTA
(BUSCK) UNDER CONTROLLED
TEMPERATURES AND
HUMIDITIES
By
GHULAM-ULLAH CHAUDHRY
A THESIS
Submitted to the School of Graduate Studies of Michigan
State College of Agriculture zmd Applied Science
in partial fulfillment of the requirem ents
for the degree of
DOCTOR OF PHILOSOPHY
Department of Entomology
1951
ACKNOWLEDGMENTS
The w riter wishes o express his sincere appreciation
and thanks to Professor Ray Hutson, Head of the Department
of Entomology for guidance, criticism , help and constant en-
couragement in the conduc of this work.
The author is further indebted to Dr. W. B. Drew, Dr.
C. J. Alexopoulos and Dr. E. S. Beneke for the use of their
incubators; to Professor D. Cation for his assistance in Sup-
plying peach seedlings and for perm ission to remove infested
twigs from his peach nurseries; to Dr. W. D. Baten for help
in analyzing part of the da ;a statistically; to Dr. H. L. King
for reading the m anuscript critically; to the United States
W eather Bureau and the M eteorological Department of Pakistan
for furnishing meteorologic al data; and to the graduate students
in the Entomology Department for cooperation during the course
of these studies.
VITA
Ghulam-Ullah Chaudhry
candidate for the degree of
Doctor of Philosophy
Final examination, Friday, July 13, 1951, 2:00 p.m ., 245
Natural Science Building.
D issertation: The Development and Fecundity of the Oriental
Fruit Moth, Grapholitha (Cydia) m olesta (Busck)
under Controlled Tem peratures and Humidities.
Outline of Studies:
M ajor subject: Entomology.
Minor subjects: Botany, Plant Pathology, Mycology,
Horticulture, Statistics.
Biographical Items:
Born, January 13, 1913, Hoshiarpur, India.
Undergradeate Studies, University of the Panjab, 1929-33.
Graduate Studies, Indian A gricultural Research Institute,
New De1hi, 1936-42 and 1947. Michigan State College,
East Lansing, 1949-51.
Experience i. Locust Research A ssistant, 1933-34.
ii. Field A ssistant (Cotton), 1934-36.
iii. A ssistant to the Im perial Entomologist,
1936-42.
iv. Locust Technical officer, 1942-44.
v. Entomologist, Baluchistan State, 1944-47.
vi. Technical Officer, Bureau of Plant P ro­
tection and Quarantine, India, 1947.
vii. A ssistant Plant Protection Entomologist,
Dept, of Plant Protection and Quar­
antine, Pakistan, 1947-49.
THE DEVELOPMENT AND FECUNDITY OF THE ORIENTAL
FRUIT MOTH, GRAPHOLITHA (CYDIA) MOLESTA
(BUSCK) UNDER CONTROLLED
TEMPERATURES AND
HUMIDITIES
By
GHULAM-ULLAH CHAUDHRY
AN ABSTRACT
Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirem ents
for the degree of
DOCTOR OF PHILOSOPHY
Department of Entomology
Year 1951
Approve d_
GHULAM-ULLAH CHAUDHRY ABSTRACT
The development and fecundity of the oriental fruit moth,
Grapholitha (Cydia) m olesta (Busck) was studied under several
controlled tem peratures of 50. 5° to 95° F. and relative humid­
ities of 35%, 70% and 100%. The optimum range of tem per­
ature for this insect was 75°-85° F. It could develop at 95°
F. under high humidities only. The incubation period was
lowest under 70% relative humidity at tem peratures of 65° to
95° F. At low tem peratures of 50.5° and 60° F. the eggs
developed best under 100% relative humidity. The eggs tol­
erated an exposure of forty hours to 98° F. and twenty-one
hours to 105° F ., but their incubation period increased by
24-40 hours as compared to those kept throughout at an opti­
mum tem perature.
o o
The threshold of development for eggs was 40 and 44
F .; for pupae 46.5° and 52.5° F. under relative humidities
of 100% and 35%, respectively. For larvae it was 43.5° F.
The eggs and pupae can develop at lower tem peratures when
exposed to high humidity than under low humidity.
The larvae of the fruit moth entered into a short dia­
pause for a period of 31 to 60 days and into a long diapause
vi
GHULAM-UL L.AH CHAUDHRY ABSTRACT
1
of over 60 days during September to November, 1950, under
various conditions of tem perature and humidity. A substan­
tially larger number of larvae entered into and completed their
long diapause when the relative humidity to which they were
exposed during the cocoon period was high enough. Generally
out of the total number of moths emerging at various tem pera­
tures about 50%, 33% and 0.0% moths em erged from the long
cycle larvae under relative humidities of 100%, 70% and 35%,
respectively. This adaptation ensures greater survival for
this species in regions where a high humidity of 80-90% pre­
vails in late sum m er and fall.
Photoperiodism did not affect the induction or duration
of larval diapause as the larvae went into hibernation even when
grown in darkness. The real cause which initiates diapause
may be inherent.
The viability of the pupae was usually highest under
saturated atm osphere. The moths laid m ore eggs if their
preim aginal life had been under higher humidities.
The present distribution of the oriental fruit moth in
tem perate regions appears to be governed by relative humidity.
vii
GHULAM-ULLAH CHAUDHRY ABSTRACT
In humid areas the insect is m ore abundant than in dry areas.
This difference is explained here by the influence of relative
humidity on its development and on the successful completion
of larval diapause; higher humidities favouring this insect and
lower hum idities affecting its biotic potential adversely.
TABLE OF CONTENTS
Page
I. IN TRO D U CTIO N .......................................................... 1
II. TECHNIQUE AND M ETHODS................................ 6
III. NOMENCLATURE AND DESCRIPTION
OF S P E C IE S ............................................................... 10
IV. DEVELOPMENT AND VIABILITY OF
GRAPHOLITHA M O L E S T A ................................ 17
•»>
1. Egg S t a g e ........................................................... 18
(a) Effect of tem perature on
d e v elo p m e n t............................................. 18
(i) Incubation p e rio d ................................ 18-
(ii) Threshold of development . . . 20 .
(iii) Upper vital l i m i t ................................ 26
(b) Effect of humidity on development
of e g g s .......................................................... 29
(c) Effect of tem perature and
humidity on v ia b ility .......................... 30
2. Larval S t a g e .................................................... 35
ix
Page
(a) Effect of tem perature on
d e v elo p m e n t............................................. 35
(i) D u ra tio n ................................. 35
(ii) Threshold of development . . . 41
(b) Effect of tem perature on
viability ................................................... 42
3. Pupal S ta g e ........................................ 43
(a) Effect of tem perature on
d e v elo p m e n t........................... 45
(i) D u ratio n ................................... 45
(ii) Threshold of development . . . 55
(iii) Optimum and upper vital
l i m i t s .................................. 56
(b) Effect of humidity on
developm ent............................. 57
(c) Effect of tem perature and
humidity on v ia b ility ........ 59
4. Larval D ia p a u s e ............................ 61
(a) Short Diapause ...................................... 65
(i) Effect of tem perature . . . . 65