Factors affecting the cocoa pod borer, Conopomorpha cramerella (Snellen) (Lepidoptera:
General Material Designation
[Thesis]
First Statement of Responsibility
A. B. Ismail
Title Proper by Another Author
Gracillariidae), and its egg parasitoid, Trichogrammatoidea bactrae fumata Nagaraja (Hymenoptera: Trichogrammatidae), in Malaysian cocoa
Subsequent Statement of Responsibility
G. E. Long
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
Washington State University
Date of Publication, Distribution, etc.
1992
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
146
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
Washington State University
Text preceding or following the note
1992
SUMMARY OR ABSTRACT
Text of Note
This thesis describes aspects of the behavior of the cocoa pod borer (CPB), Conopomorpha cramerella (Snellen) and of a potential biological control agent, Trichogrammatoidea bactrae fumata Nagaraja (TBF), in the cocoa agroecosystem of Malaysia. The results showed that oviposition by female moths was not influenced by pod shape, color, or height in the tree. More pods and more eggs per pod were recorded on fan branches than on the main chupon. Survival of CPB eggs and mortality from parasitism by TBF were not significantly affected by pod height, shape or color. Older pods, those of ages 7 wk before ripening (WBR) or less were preferred for oviposition by CPB. No eggs were recorded on pods greater than 17 WBR. The proportion of eggs parasitized by TBF, egg loss and the degree of survival to larval emergence from the pod were independent of pod age. Egg parasitism and losses were low. Larval survival outside the sclerotic layer (SCL) was high and independent of pod age. Mortality of larvae at the SCL was higher in older pods. High larval density lowered the survival of larvae inside the pod. The dispersal behavior of TBF released in a cocoa field was investigated using traps of different colors and shapes. More TBF were caught on green traps than on yellow and more were caught on square than on cylindrical traps. Dispersal of TBF was initially limited around the release site but gradually distributed uniformly as time increased. Chemical field trials were conducted to determine the effects of cypermethrin and deltamethrin on parasitism of CPB by TBF. Cypermethrin resulted in higher TBF mortality (94.9 1.1%) than deltamethrin (88.3 1.7%). Older parasitized eggs were slightly tolerant to insecticides but TBF mortality was relatively high (>70%) regardless of the age of parasitized eggs. Cypermethrin reduced oviposition by both CPB and TBF and emergence of TBF up to twice as much as did deltamethrin.