Journal ArticleDOI
Sampling egg batches of Maliarpha separatella RAG. (Lep., Pyralidae) in Madagascan rice fields.
TLDR
Sampling with quadrats of 0.25 m2 in Madagascan rice fields reveals that egg batches of the African White Stem Borer, Maliarpha separatella RAG.Abstract:
Sampling with quadrats of 0.25 m2 in Madagascan rice fields reveals that egg batches of the African White Stem Borer, Maliarpha separatella RAG. are distributed at random. The physical size of the sampling unit is selected because of practical rather than ecological considerations. According to the enumerative sampling plan at least 40 quadrats should be taken per field to satisfy precision requirements. Sequential binomial sampling with constant error rates is more cost efficient and decision making with respect to an action threshold is possible with 12 quadrats or more at a critical time. For regional estimates a stratified random sampling procedure is proposed.read more
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Population models for threshold-based control of Tetranychus urticae in small-scale Kenyan tomato fields and for evaluating weather and host plant species effects.
TL;DR: The spatial distribution of motile life stages of the two-spotted spider mite Tetranychus urticae Koch in Kenyan small-scale tomato fields was described by Taylor’s power law and an enumerative sampling plan was designed, and the exponential model was extended to account for the influence of weather and host plant species.
Journal ArticleDOI
Rice production in Madagascar: Regression analysis with particular reference to pest control
TL;DR: In this paper, a multiple regression model was used to explain the variability in yield of transplanted rice in Madagascar, and to estimate the effects of various production factors, including mechanical and chemical pest control.
Journal ArticleDOI
Noxiousness of the African white stem borer, Maliarpha separatella Rag (Pyralidae: Phycitinae) in irrigated paddy fields at Lake Alaotra (Madagascar).
TL;DR: An explorative analysis of the infestation rate-yield loss relationship, showed that a sigmoid model describes this interdependence appropriately and the proposed economic injury level (EIL) is here considered more the result of an approach, which had as its goal the re-definition of the status of the pest than as an instrument of a chemical control programme with treatments based on an action threshold.
Journal Article
Comments on the dynamics of insect population assemblages and sampling plans for aphids in commercial alpine yarrow fields
TL;DR: The method consisted in stratifying the field and taking random samples of yarrow stems and leaves, aphid numbers, and numbers of adult coccinellids and mummified aphids throughout the growing period, and an enumerative sequential sampling plan appears to be more efficient than the enumerative fixed sample size sampling plan.
References
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Book
Ecological methods: With particular reference to the study of insect populations
TL;DR: Ecological methods : with particular reference to the study of insect populations, Ecological methods for estimating insect populations using probabilistic methods.
Journal ArticleDOI
Ecological Methods, with Particular Reference to the Study of Insect Populations
L. R. Taylor,T. R. E. Southwood +1 more
Journal ArticleDOI
The density-dependence of spatial behaviour and the rarity of randomness
TL;DR: Spatial disposition is thus density-dependent and it is deduced that spatial behaviour is also density- dependent as required by Taylor & Taylor's A-model for intrinsic population control by movement.