Quantitative evaluations in biological control

Heong K . L ., . (1986) Quantitative evaluations in biological control. [Proceedings Paper]

Examines of various techniques use in the study of biological control. Each category of techniques had its own limitation and inadequacies. The indirect assessment methods usually involved correlative analyses between numbers of the prey and natural enemy. For such data even when a direct causal relationship was established further work was often required to determine wether the prey numbers were being controlled. More direct assessment techniques were those using experimental manipulations in the field like excluding the natural enemies atificially and measuring the effects. The main weaknesses here were that these exclusion techniques often affect the microclimate and influence the prey behaviour. For parasitoids and pathogens direct observations was made from field collected hosts or by placing known numbers of prey in the field. usually effectiveness was measured as a proportion of the host density. This needed not necessarily represent net production in host numbers. A large value may merely mean replacement of some other mortality factors. Laboratory experiments was used to assess components of the natural enemy's performance. Despite their limitations these techniques was useful for comparative assessments. Models and life tables were often more precise but may not be sufficiently realistic. However principles and conclusions drawn from these such as the importance of hyperparasitism multiple introductions spatial and temporal heterogeneity were of direct use to improve biological control

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Abstract

Examines of various techniques use in the study of biological control. Each category of techniques had its own limitation and inadequacies. The indirect assessment methods usually involved correlative analyses between numbers of the prey and natural enemy. For such data even when a direct causal relationship was established further work was often required to determine wether the prey numbers were being controlled. More direct assessment techniques were those using experimental manipulations in the field like excluding the natural enemies atificially and measuring the effects. The main weaknesses here were that these exclusion techniques often affect the microclimate and influence the prey behaviour. For parasitoids and pathogens direct observations was made from field collected hosts or by placing known numbers of prey in the field. usually effectiveness was measured as a proportion of the host density. This needed not necessarily represent net production in host numbers. A large value may merely mean replacement of some other mortality factors. Laboratory experiments was used to assess components of the natural enemy's performance. Despite their limitations these techniques was useful for comparative assessments. Models and life tables were often more precise but may not be sufficiently realistic. However principles and conclusions drawn from these such as the importance of hyperparasitism multiple introductions spatial and temporal heterogeneity were of direct use to improve biological control

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Item Type:	Proceedings Paper
Additional Information:	Bibliography 66 ref. Summary En
AGROVOC Term:	CONTROL BIOLOGICO
AGROVOC Term:	DEPREDACION
AGROVOC Term:	EVALUACION
AGROVOC Term:	MALASIA/ DEPREDADORES
Geographical Term:	MALAYSIA
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:25
URI:	http://webagris.upm.edu.my/id/eprint/14010

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