Browsing by Author "Dale, D"

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    Chemical 'control of the red spider mite, Tetranychus telarius L. (Tetranychidae)
    (Kerala Agricultural University, 1972) Saradamma, K; Dale, D; Das, N M
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    Clovia bipunctata kirby (cercopidae : hemiptera) as a pest of lemongrass
    (Kerala Agricultural University, 1983) Saradamma, K; Dale, D
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    Composting efficency of indigenous and introduced earthworms
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1997) Jiji, T; Dale, D
    Eight species of earthworm belonging to three families were identified from five different soil types of southern Kerala. The identified species were Megascolex cochinensis, M.konkanensis, M.trivandranus, M.trilobatus, Perionyx, sansibaricus, Pheretima heterochaeta (Megascolecidae), Pontoscolex corethrurus (Glossoscolecidae) and Drawida sp. (Moniligastridae). M.cochinenses and corethrurus were ubiquitous. P. sansibaricus was confined to forest soil and red soil. Forest soil with high water holding capacity, organic carbon content and acidic pH had the highest total count of worms and the highest species diversity. The exotic species Eudrilus eugeniae was more efficient for composting in terms of duration for composting and biomass production. However, the multiplication rate of the indigenous P. sansibaricus was more than that of E.eugeniae. In field conditions, when the same weight of worms was used, the time taken for composting was found equal for E. eugeniae and P. sansibaricus. However, the biomass recovery of earthworm was more in E. eugeniae. Both species performed well in the rainy season, compared to hot summer months. The breeding potential, time required for composting and decomposition rate were significantly superior from june to September. There was posititve correlation between juvenile count and rainfall and negative correlation with maximum temperature with respect to E.eugeniae. In P. sansibaricus adult and juvenile counts expressed positive correlation with rainfall and humidity and negative correlation with maximum temperature. Space was found to be a determining factor in the growth and multiplication earthworms. The cocoons of E.eugeniae required 29+ 1.10 days for hatching. The hatching rate was only 56.25 + 1.19 percent in laboratory condition. The mean number of juvenile hatched /cocoon was 2.88+0.35. The period required to attain reproductive stage was 43.38 + 0.56 days. Cocoons of P.. sansibaricus was elongate and slender. The time required for hatching of cocoon was 16+0.43 days. The hatching rate was 64.06+3.44 percent in laboratory conditions. The juveniles required 38.25 + 0.70 days to become adults. The number of cocoon laid / week was also significantly superior, as compared to E. eugeniae. Vermicompost along with full inorganic fertilizer increased the yield by 21.4 per cent and 19.0 percent in bittergourd and cowpea, respectively. In cowpea, application of vermicompost without inorganic fertilizer was equally effective as that of the recommended manorial schedule. There was significant yield increase when vermicompost was used as a potting mixture in bhindi. However, no significant difference in the biometric characters of plants was observed. Vermicompost along with full inorganic fertilizer increased the yield of bhindi by 15 percent. The effect of in situ vermiculture (250 worms of p. sansibaricus /plot) was on par with that of package of practices recommendations. Neemcake was found beneficial for supporting growth and multiplication of E.eugeniae. Neem cake recorded 102 percent increase in juvenile worm production. Neem leaves and thevetia leaves were equally effective. Mahua cake was not supportive for growth and multiplication. Neem cake was effective in supporting growth and multiplication of P.sansibaricus. Neem cake recorded 52 percent increase in juvenile worm production. Leaves of neem, clerodendron and glyricidia were equally effective in supporting juvenile worm production as that of the control. Calotropis leaves and mahua cake caused significant reduction in adult, juvenile and cocoon production. In a pot culture study, among the treatments, carbofuran, phorate and quinalphos, quinalphos(0.5 kg and 1.0kg ai/ha) was found the least toxic to earthworm and there was total survival after an interval of seven days. The treatments involving earthworms for composting evolved significantly higher Co2 during the period of composting, compared to the control treatment of banana: cowdung mixture without worms. The Co2 evolved by the treatments involving E.eugeniae and P.sansibaricus were on par. Maximum Co2 evolution was observed on the 21st day which was significantly superior to the Co2 evolution estimated at various other intervals. From the 21st day onwards a decline in the CO2 evolution was recorded. The treatment involving earthworms had a significantly higher bacterial, fungal and actinomycetes counts, as against the treatment without worms. The highest fungal count for E.eugeniae was found on the 28th day. Towards compost maturity the fungal counts were more or less steady; however, a slight increase in the count was observed on the 56th day. There was no definite trend with respect to actinomycetes count during the period of composting.
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    Effect of chitin synthesis inhibitors on rice swarming caterpillar spodoptera mauritia and rice moth corcyra cephalonica and a larval parasitoid bracon brevicornis
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1991) Prathapan, K D; Dale, D
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    Estimation of nucleic acids in the Indian honey bee Apis indica F.
    (Kerala Agricultural University, 1970) Dale, D; Kulkarni, A P
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    Evaluation of some antifeedants against larvae of Papilio demoleus Linn. (Papilioimidae: Lepidoptera) and Plusia peponis F (Noctuidae:Lepidoptera)
    (Kerala Agricultural University, 1980) Saraswathi Ammal, L; Dale, D
    The antifeedant action of fentin acetate, fentin chloride anJ AC-24055 was evaluated on the caterpillars of Papilla demoleus and Plusia peponis, Fentin chloride ranked first both in the antifeedant action and field persistence on plants, followed by fentin acetate and AC-24055 for both P. demoleus and P. peponis, The slight phytotoxicity on citrus and snakegourd did in no way affect the vigour of the crops.
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    Evaluation of three antifeedants against caterpillars of Spodoptera litura Boisd and Achoea janata Linn
    (Kerala Agricultural University, 1974) Saraswathi Ammal, L; Dale, D
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    Food preference of the rice meal moth Corcyra Cephalonica Stainton (Lepidoptera : Pyralidae)
    (Kerala Agricultural University, 1981) Ambika, B; Abraham, C C; Dale, D
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    Influence of food plants on the consumption of folfage and pupal characters of Pericallia Ricini Fab. (Arctiidae: Lepidoptera)
    (Kerala Agricultural University, 1985) Ranjith, A M; Dale, D
    The influence of different food plants on the growth of the arctiid caterpillar Pericallia ricini is discussed. DJe to differences in the quality of the nutrients and the nutrient balance in the different food plants, the pupal periods of caterpillars feeding on the varied food plants differed significantly. The pupal weights and the mortality of larvae and pupae differed batween the insects feeding on the different food plants. An increased consumption of food by larvae of the later instars and by females than males was also observed.
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    Laboratory evaluation of three antifeedants against the grubs of Epilachna vigintioctopunctata
    (Kerala Agricultural University, 1973) Dale, D; Saradamma, K
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    On the use of neem seed kernel powder as a protectant for storid paddy
    (Kerala Agricultural University, 1977) Saradamma, K; Dale, D; Nair, M R G K
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    Performance of mulberry silkworm races and hybrids in Kerala
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1995) George Thomas; Dale, D
    Silkworm rearing experiment was conducted in the rearing house of the sericulture section in the Department of Agricultural Entomology, College of Agriculture, Vellayani in 93 – 94 to identify a pure race and crose breed suitable for rearing in the southern districts of Kerala, with reference of productivity and commercial quality of cocoons. The trial was conducted with completely randomized design and the treatments were replicated thrice. Four replications were used for studying the fecundities and female pupal weight of pure races. The experiment was repeated in three seasons viz. cold season during December – January, summer season February – March and rainy season during May – June. The percentage of missing larvae during early instars was least in the cross breeds which were on par and pure races suffered heavy loss. Cross breed PM X NB 4 D2 was superior to others in case of total larval duration disease incidence, percentage of spinning and cocoons yield. Among the bivoltines NB4 D2 performed best with shortest larval period, less disease incidence, higher percentage of spinning and higher cocoon yield. It was superior to other bivoltines during most seasons. It consumed maximum food had highest growth index and larval weight in all seasons. Cocoon characters viz. shell weight, shell ratio, cocoon size and reelability of cocoons were also higher. Single cocoon weight, fecundity and female pupal weight were higher in KA. NB7 was heavily infected with diseases in stock rearing it self. Of the cross breeds, PM x NB4D2 was superior to other cross breeds in respect of all parameters during the different seasons except in single cocoon weight. In this case PM x KA performed well. Leaf consumption, weight, length and growth index of fifth instar larva, percentage of spinning and yield of cocoons, size of cocoons, single cocoon weight, shell weight, shell ratio, fecundity and female pupal weight were reduced in summer season. But disease incidence was increased and missing percentage of larvae during early instars, total larval duration, and reelability were not affected by climate.
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    Persistence of some systemic insecticides in cowpea when applied as granules in different soil types of Kerala
    (Kerala Agricultural University, 1975) Das, N M; Dale, D; Sasidharan Pillai, K
    A pot trial was conducted to study the persistent toxicity of phorate, car. bofuran, mephosfolan and disulfoton to the pea aphid, Aphis craccivota on cowpea grown in sandy, laterite, red, forest and black soils treated with the above insecticides as granule. The persistent toxicity was highest in plants treated with disulfoton in all types of soils. Mephosfolan was next best in sandy, red and forest soils whereas carbofuran was next to disulfoton in laterite and black soils. The yields obtained from treated plants were significantly higher than those of corresponding controls. But there was no direct correlation between the persistent toxicity of insecticides and the yield. The yield factor appears to be influenced by the impact of the insecticide on some soil factors favouring plant growth.
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    Studies on the consumption, digestion and utilisation of food plants by Pericallia ricini
    (Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1981) Ranjith, A M; Dale, D
    The present investigation was carried out in the Entomology Department of the College of Horticulture, Vellanikkara. It was aimed at working out idices relating to consumption, digestion and utilisation of eight food plants by the larvae of Pericallia ricini F., a polyphagous pest in Kerala. The study was also meant to assess the relative growth of the caterpillars on the different food plants so that a general idea can be obtained on the suitability of the food plants to the larvae. Data on the pupal and adult emergence were also collected with a view to probing further in to the identification of probable insect growth inhibitory substances among the host plants. The most preferred plants with regard to the consumption of foliage were pumpkin, castor and brinjal. Consumption index was calculated on fresh and dry weight bases. It was seen that the consumption of brinjal leaves was the maximum and the index was the least for sweet potato. The other foods did not differ among them significantly. On dry weight basis, banana-fed insects with a C.I. of 3.02 ranked first, followed by larvae fed on cotton. Larval weight gain on brinjal was the maximum followed by those grown on pumpkin. The least weight gain of 0.66 g was exhibited by larvae which were fed on banana leaves. The last instar larvae consumed the largest quantity of food during their larval period. Consumption of food was very low among the third instar larvae. Females were to consume more foliage than the corresponding male counterparts. The differences in consumption by the two sexes were statistically significant. The growth rates were calculated both on fresh and dry weight basis. On fresh weight basis, larvae reared on brinjal had the highest growth rate of 65.7 and the least growth rate of 30.7 was obtained from larvae grown on banana. On dry weight basis, it was seen that pumpkin was superior to all others in supporting larval growth of P. ricini. The approximate digestibility was calculated on the basis of fresh weight of the digestible food and the weight of the ingested food. A.D. was the maximum (91.40 per cent) with sesamum on fresh weight basis, but on dry weight basis, it was castor that the larvae digested most. Indices relating to efficiencies of converting ingested food and digested food to biomass were also calculated both on fresh and dry weight bases. The reasons for the observed values deviating from the expected ones are discussed. Utilisation of nitrogen, both ingested and digested, by the larvae varied among food plants significantly. Colocasia, sesamum and cotton had the higher values of E.C.I. (N). In the descending order. But taking into consideration of the E.C.D. (N) values, the numerical figure was the highest with castor and the least with banana. The present study has clearly indicated that the food plants have a significant effect on the pupal period, pupal weight and pupal length. It is also seen that some host plants cause larval and pupal mortalities at varying degrees. The effect of larval feeding on the sex ratio of emerging adults was also recorded. Insects fed on castor and cotton leaves showed the near best sex ratio of 1: 0.88. In the case of sweet potato and sesamum, the ratio was 1: 2. All other foods led to sex ratios ranging from 1:0.67 to 1: 2.
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    Studies on the relative toxicity of some insecticides to adults of Dacus cucurbitae (Coquillett) when used in bait sprays
    (Division of Entomology, Agricultural College and Research Institute, Vellayani, 1965) Dale, D; Nair, M R G K
    The relative toxicity of six new synthetic insecticides namely DDT, BMC, parathion , malathion, dipterex and sevin to adults of D.cucurbitae was ascertained by exposing the files : (a) to snake gourd leaves sprayed with the bait fluid and : (b) to droplets applied on glass surface. The order of relative toxicity of the different insecticides was Parathion= Dipterex > Malathion > Sevin = BMC > DDT. Coarso spray droplets of the baits were found to be more effective in killing the files than the fine sprays. An explanation for this phenomenon is given. It is concluded that field conditions for practical control, coarser will be better than fine sprays of the liquid bait.
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    Studies on the relative toxicity of some insecticides to adults of Dacus cucurbitae (Coquillett) when used in bait sprays
    (Kerala Agricultural University, Vellanikara, 1966) Dale, D; Nair, M R G K
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    Studies on the residual effect of some insecticides in soil to maggots of the melon fly Dacus cucurbitae Coquillett
    (Kerala Agricultural University, Vellanikara, 1966) Dale, D; Das, M N; Nair, M R G K