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Theses

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1981 - 19875
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Subject: Agricultural Entomology × End date: 1987 × Start date: 1980 × Type: Thesis × Thesis Type: Ph.D ×
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Now showing 1 - 5 of 5
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    ThesisItemOpen Access
    Persistence and metabolism of phorate in rice plants and in different soil types of Kerala and its effect on non target organisms
    (Division of Agricultural Entomology, College of Agriculture, Vellayani, 1987) Naseema Beevi, S; KAU; Visalakshi, A
    The uptake, persistence and metabolism of phorate in rice plants and in different types of soil, viz., alluvial, sandy and lateritic loam when applied at 3 doses and 3 growth stages of the crop were studied by conducting field experiments. In these studies, the insecticides was applied as granules at 3 doses of 1.0, 1.25 and 1.5 kg ai/ha at 20, 40 and 60 days after planting. The residues were estimated colorimetrically and by bioassay. The metabolites in plants and soil were separated by T.L.C and further estimated colorimetrically at intervals of 2,7 and 14 days after application. The ultimate residues of the insecticide in grain and straw also were determined.
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    ThesisItemOpen Access
    Nuclear polyhedrosis of Opisina arenosella WLK. (= Nephantis serinopa Meyr;) (Cryptophasidae: Lepidoptera) and its utility for the control of the pest
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1985) Babu, M Philip; KAU; Mohandas, N
    The black headed caterpillar, Opising arenosella Hlk. (= Nephantis serinopa Meyrick) is a serious pest of coconut. The slender caterpillars found under the leaves in galleries made of silk and foreign matter feed on the chlorophyll tissues . Philip et al., (1982) reported the occurrence of a nuclear polyhedrosis virus in the larvae of O. arenosella. Basic information for judging the suitability of this pathogen for the control of the pest were lacking. Hence detailed studies were made on the symptamatology, morphology of the pathogen, histopathology, mode of transmission of the virus to the progeny, cross infectivity to other species of lepidoptera, bioassay of the virus , persistence of the virus on coconut foliage , effect of physical factors on the persistence of the virus, safety of the pathogen to non target organisms and the efficacy of the virusin controlling the pest in field.
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    ThesisItemOpen Access
    Biology, Bionomics and control of coconut cockchafer Leucopholis coneophora Burm.
    (Division of Agricultural Entomology, College of Agriculture, Vellayani, 1983) Abraham, V A; KAU; Mohan Das, M
    The biology of the coconut cockchafer Leucopholic coneophora Burm. was studied in detail for the first time. Techniques for rearing the pests from egg to adult in potted palnts kept in field were standardized. The egg laying behaviour of adults was observed. The morphological changes off eggs, different instars of grubs and pupae during development were studied in detail. The changes in immature stages of male and female insects were traced separately. The general morphology of different instars of the grubs was studied in full with a view to finding distinct identifying characters for each.
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    ThesisItemOpen Access
    Host resistance in brinjal varieties to the fruits and shoot borer Leucinodes orbonalis Guen ( Lepidoptera: pyralidae)
    (Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1983) Madhavan, Nair G; Abraham, C C
    In studies on the host plant resistance in brinjal (Solanum melongena L.) against the shoot and fruit borer, Leucinodes orbonalis Guen. (Lepidoptera : Pyralidae), germplasm materials were screened to identify sources of resistance and an attempt was made to investigate the mechanisms of resistance involved. Forty accessions of brinjal and related species were initially screened in a field trial conducted during the monsoon season of 1982 and these were classified into highly susceptible, moderately susceptible, moderately resistant and resistant classes. The accessions SM-6, SM-56, SM-72 and SM-74 from the highly susceptible group; SM-1, SM-45, SM-48 and SM-71 from in moderately susceptible group; SM-65, SM-68, SM-97 and SM-105 from the moderately resistant group and SM-67, SM-88, S.indicum and S.incanum from the resistant group were further field tested during the summer season, 1982-83 and were evaluated for the levels of resistance. Under artificial infestation of caged single plants of the accessions by the first instar larvae of L. orbonalis, the susceptibility spectrum was found to be similar to the trend noticed in the field trials. In the resistant types, the infestation by L. orbonalis occurred for a relatively shorter duration than in the susceptible ones. In studies on the antibiosis, it was found that the resistant accessions gave rise to larvae and pupae of reduced weights which took longer durations as compared to the highly susceptible accessions. The larval survival was lower in the resistant types. The highly susceptible accessions produced more females than did the resistant line. There was no significant variation in the fecundity of second generation females. In multiple-choice and no-choice tests, the females of L.orbonalis showed a clear preference for the highly susceptible and moderately susceptible accessions for oviposition. Correlation studies revealed that the density of trichomes on the shoot apex, lower leaf surface and lower surface of midribs exerted considerable influence on the ovipositional response of the female moth, the relationship between oviposition and trichome density being of a negative nature. Among the biophysical characters, the higher density of trichomes on shoot apex and lower midrid; lower pith area, lingnified selerenchymatous hypodermis and compact vascular bundles in shoot apex and tight or semi-tight calyx in fruit were found to impart resistance to borer infestation. Positive correlations were detected between the mean percentages of total sugars, crude protein, total ash, nitrogen, potassium and calcium in the fruit on the one hand and fruit infestation on the other. The contents of total ash, calcium, magnesium and iron in shoots on the one hand and shoot infestation on the other were also found to be positively correlated, while silica, zinc, copper and crude fibre contents were negatively correlated with shoot infestation.The implications of the findings have been discussed.
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    ThesisItemOpen Access
    Use of insecticides as granules for protecting paddy crop against pests
    (Division of Agricultural Entomology, College of Agriculture, Vellayani, 1981) Sasidharan, Pillai K; KAU; Gopalakrishnan, Nair N R