Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid

Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid

Studies were conducted to determine the seasonal trends of the cotton aphid Aphis gossypii Glover (Homoptera: Aphididae), its natural enemies (Coccinellidae, Chrysopidae and Araneae) and virus disease incidences on chilli variety MC4 in seven cropping periods. Sampling of alate A. gossypii was done...

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Main Author: Khalid, Fairuz
Format: Thesis
Language:English
Published: 2007
Subjects:
Biology
Online Access:http://ir.uitm.edu.my/id/eprint/27424/
http://ir.uitm.edu.my/id/eprint/27424/1/TM_FAIRUZ%20KHALID%20AS%2007_5.pdf
id uitm-27424
recordtype eprints
spelling uitm-274242020-01-17T08:37:06Z http://ir.uitm.edu.my/id/eprint/27424/ Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid Khalid, Fairuz Biology Studies were conducted to determine the seasonal trends of the cotton aphid Aphis gossypii Glover (Homoptera: Aphididae), its natural enemies (Coccinellidae, Chrysopidae and Araneae) and virus disease incidences on chilli variety MC4 in seven cropping periods. Sampling of alate A. gossypii was done using yellow pan trap while the apterous, natural enemies and virus disease incidence were counted in situ. The spatial distribution of arthropods within each cropping period was analyzed using variance-to-mean ratio, Morisita's Index and Lloyd Index of Patchiness model. The spatial distribution of arthropods between cropping periods was analyzed using Taylor's Power Law and Patchiness Regression model while virus incidences were analyzed using logistic model. Results of the study showed that apterous aphids were found in abundance at the bottom stratum. The populations of apterous aphids on chilli were found to be low in the first 4 cropping periods but high in the fifth, sixth and seventh cropping period. Alate aphid population were found significantly higher in the early mornir'f1, 0800 and 1000 hr and significantly lower in the evening, 1400 and 1600 hr. The population of natural enemies, coccinellidae, chrysopidae and araneae were found low throughout the seven cropping period where the coccinellidae, chrysopidae and araneae preferred the upper, bottom and middle stratum, respectively. Generally, the cumulative data showed a sigmoidal trends. The vertical distribution of apterous A. gossypii and its natural enemies seems to be influenced with climatic condition and phenology of chilli plant along the vertical gradient of chilli plants. Analysis of virus disease incidence showed a slow development of virus disease during the early and late growth period while rapid development was observed in the middle growth period of each cropping. The fifth cropping period demonstrated the most rapid development of virus infection compared to other cropping periods. The Vin IS Apparent Infection Rate (VAIR) analysis revealed that average increasing rate of virus disease in all cropping periods was from 0.077 to 0.32 unit. The analysis also revealed that, the disease took 46.9 to 67.0 days to spread 50% in all cropping periods and 50.2 to 70.1 days to infect 90% of the plot. The Area Under Disease Progress Curve (AUDPC) analysis showed that the chilli plant was highly infected with viruses in the flowering stage followed by fruiting stage. The within field spatial distribution of virus count data were illustrated by the 'red-blue' plots which were analyzed using SADiE (Spatial Analysis by Distance Indices), showed a ephemeral spatial pattern of virus incidences in each sampling date of every cropping periods. 2007 Thesis NonPeerReviewed text en http://ir.uitm.edu.my/id/eprint/27424/1/TM_FAIRUZ%20KHALID%20AS%2007_5.pdf Khalid, Fairuz (2007) Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid. Masters thesis, Universiti Teknologi MARA.
repository_type Digital Repository
institution_category Local University
institution Universiti Teknologi MARA
building UiTM Institutional Repository
collection Online Access
language English
topic Biology
spellingShingle Biology
Khalid, Fairuz
Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
description Studies were conducted to determine the seasonal trends of the cotton aphid Aphis gossypii Glover (Homoptera: Aphididae), its natural enemies (Coccinellidae, Chrysopidae and Araneae) and virus disease incidences on chilli variety MC4 in seven cropping periods. Sampling of alate A. gossypii was done using yellow pan trap while the apterous, natural enemies and virus disease incidence were counted in situ. The spatial distribution of arthropods within each cropping period was analyzed using variance-to-mean ratio, Morisita's Index and Lloyd Index of Patchiness model. The spatial distribution of arthropods between cropping periods was analyzed using Taylor's Power Law and Patchiness Regression model while virus incidences were analyzed using logistic model. Results of the study showed that apterous aphids were found in abundance at the bottom stratum. The populations of apterous aphids on chilli were found to be low in the first 4 cropping periods but high in the fifth, sixth and seventh cropping period. Alate aphid population were found significantly higher in the early mornir'f1, 0800 and 1000 hr and significantly lower in the evening, 1400 and 1600 hr. The population of natural enemies, coccinellidae, chrysopidae and araneae were found low throughout the seven cropping period where the coccinellidae, chrysopidae and araneae preferred the upper, bottom and middle stratum, respectively. Generally, the cumulative data showed a sigmoidal trends. The vertical distribution of apterous A. gossypii and its natural enemies seems to be influenced with climatic condition and phenology of chilli plant along the vertical gradient of chilli plants. Analysis of virus disease incidence showed a slow development of virus disease during the early and late growth period while rapid development was observed in the middle growth period of each cropping. The fifth cropping period demonstrated the most rapid development of virus infection compared to other cropping periods. The Vin IS Apparent Infection Rate (VAIR) analysis revealed that average increasing rate of virus disease in all cropping periods was from 0.077 to 0.32 unit. The analysis also revealed that, the disease took 46.9 to 67.0 days to spread 50% in all cropping periods and 50.2 to 70.1 days to infect 90% of the plot. The Area Under Disease Progress Curve (AUDPC) analysis showed that the chilli plant was highly infected with viruses in the flowering stage followed by fruiting stage. The within field spatial distribution of virus count data were illustrated by the 'red-blue' plots which were analyzed using SADiE (Spatial Analysis by Distance Indices), showed a ephemeral spatial pattern of virus incidences in each sampling date of every cropping periods.
format Thesis
author Khalid, Fairuz
author_facet Khalid, Fairuz
author_sort Khalid, Fairuz
title Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
title_short Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
title_full Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
title_fullStr Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
title_full_unstemmed Ecological studies of aphid (Aphis gossypii Glover), vector of virus disease of chilli (Capsicum annuum L.) and its predators / Fairuz Khalid
title_sort ecological studies of aphid (aphis gossypii glover), vector of virus disease of chilli (capsicum annuum l.) and its predators / fairuz khalid
publishDate 2007
url http://ir.uitm.edu.my/id/eprint/27424/
http://ir.uitm.edu.my/id/eprint/27424/1/TM_FAIRUZ%20KHALID%20AS%2007_5.pdf
first_indexed 2023-09-18T23:18:26Z
last_indexed 2023-09-18T23:18:26Z
_version_ 1777419269009571840

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