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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Population dynamics and management of aphids in vegetable ecosystem(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2009) Thamilvel, D; KAU; Hebsy, BaiEight species of aphids viz., A. gossypii, A. craccivora, A. spiraecola, A. fabae, A. nerii, H. setariae, M. persicae and L. erysimi were recorded from 32 vegetables in a survey conducted in the four taluks of Thiruvananthapuram district of Kerala. Occurrence of A. gossypii on C. grandis, M. oleifera and P. tetragonolobus; A. craccivora on C. gladiata, P. tetragonolobus and S. grandiflora ; A. spiraecola on A. tricolor, C. sativus, C. tetragonoloba, M. oleifera, M. charantia, M. koeingii, P. tetragonolobus and S. androgynus ; M. persicae on A. tricolor and R. sativu; A. nerii on C. annuum and C. frutescens was recorded for the first time from the State and H. setariae on A. tricolor and A. dubius from South India. One hundred and twenty two other plants were identified as host plants of the different aphids. A. gossypii was the dominant species noted, closely followed by A. craccivora, and A. spiraecola. Maximum species of aphids were recorded on amaranthus followed by winged bean. Among the vegetables surveyed, chilli and coccinia were highly susceptible to A. gossypii and winged bean and cowpea to A. craccivora. Mosaic disease incidence was noted in 10 vegetables. Predators were the predominant group of natural enemies associated with the aphids with the coccinellids constituting the major predatory fauna. Twenty species of coccinellids were recorded from different species of aphids on various host plants of which 13 species were new records from Kerala. M. sexmaculatus was the dominant species followed by C. transversalis, S. latemaculatus and C. septempunctata, Four species of syrphids were recorded of which I. scutellaris was predominant. P. yerburiensis and D. aegrota were recorded for the first time from Kerala. Leucopis sp. was the only Chamaemyiid species recorded from the vegetable fields. The chrysopids, C. carneae and A. octopunctata and the hemerobiid, Micromus sp. were the Neuropteran predators of the aphids recorded of which Micromus sp. was dominant. A. octopunctata was recorded for the first time from Kerala. Eleven species of spiders were observed in the vegetable fields among which, O. javanus, T.mandibulata, O. quadridentatus, O. shweta and Phidippus sp. were the frequently encountered species. Aphidius sp. was the most dominant parasitoid in the vegetable ecosystem. Aphelinus sp. and D. rapae were the other parasitoids recorded. Seven species of ants were observed attending the aphids. Studies on the population fluctuation of A. gossypii in chilli and A. craccivora in winged bean during a cropping season indicated that high population was seen during November and December. Correlation studies revealed a significant and positive correlation between the population of both the aphids with the insect predators, spiders and parasitoids. None of the climatic parameters had any significant influence on the aphid population. Excepting, maximum temperature which had a positive influence, all the other weather parameters viz., minimum temperature, relative humidity, rainfall and wind velocity had a negative influence on the population of the predators and parasitoids. Among the botanicals screened in the laboratory, only neem oil- garlic emulsion 2% and NeemAzal T/S 4 ml/l recorded more than 50 per cent mortality of A. gossypii and A. craccivora. Among the insecticides, the neonicotinoids viz., acetamiprid 0.002% imidacloprid, 0.003%, and dimethoate 0.05% proved superior to all other treatments. Dimethoate 0.05% was highly toxic to the coccinellids, syrphids and a hemerobiid (Micromus sp.) predator under laboratory condition. Between the two neonicotinods, acetamiprid 0.002% registered higher mortality than imidacloprid 0.003% whereas NeemAzal T/S 4 ml/l and neem oil + garlic emulsion 2% were safe to the predators. Foliar application of dimethoate 0.05%, acetamiprid 0.002% and imidacloprid 0.003% gave good control of A. gossypii, A. biguttula biguttula, S. dorsalis and A. dispersus in chilli and A. craccivora, A. dispersus, R. pedestris and M. vitrata in winged bean. NeemAzal T/S 4ml/l and neem oil garlic emulsion 2% too checked the population of the pests appreciably. Dimethoate 0.05% was highly toxic to the predators and parasitoids followed by acetamiprid 0.002% both in the chilli and winged bean fields. Comparatively, imidacloprid 0.003% was less toxic. The botanicals were safer to the natural enemies. Dimethoate 0.05% was highly toxic to soil fauna and flora whereas acetamiprid and imidacloprid were less toxic while NeemAzal T/S 4ml/l and neem oil + garlic emulsion 2% were non toxic. In both the trials, significantly higher yield was obtained from all the treatments. However, no significant difference was noted in the yields obtained from acetamiprid 0.002%, imidacloprid 0.003% and dimethoate 0.05% treated plots. Residues of imidacloprid were detected in chilli and winged bean fruits five days after spraying. While on the tenth day after spraying, residues of acetamiprid, and dimethoate were detected in chilli fruits, only residue of acetamiprid was recorded from winged bean pods. Imidacloprid was below detectable level (BDL). Residues of all the three insecticides were below detectable level when estimated fifteen days after spraying. Based on the results of the study, early detection of aphids on weeds and other host through regular monitoring, proper weed and ant management, conservation of the beneficials, application of neem oil + garlic emulsion 2% or NeemAzal T/S 4ml/l during the early stage of infestation and use of imidacloprid 0.003% when needed are suggested for aphid management in vegetables.ThesisItem Open Access Population dynamics and management of erythrina gall wasp quardrastichus erythrinae kim.(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2008) Beena, M P; KAU; Thomas Biju, Mathew. Studies were conducted to understand the population dynamics and management of Erythrina Gall Wasp (EGW)Quadrastichus erythrinae. An abstract of the work done and the results are given below. Population dynamics of Q.erythrinae was studied by observing weekly emergence of male and female insects from leaflets and petioles collected from field during the period from January 2006 to June 2007. The results showed that population was high in the months of July 2006, January 2007, April 2007 and June 2007.The present study indicated that the emergence od adult EGW was the highest from petioles. The increase in weight due to EGW infestation and gall production was the highest in the left lateral leaflets. Weekly mean population of EGW emerged during the period of study showed that the total number of male EGW (1096.36) was higher than the female insects emerged (763.13). Weekly mean population of the male and female emerged from the leaflets and petioles was correlated with weather parameters viz. maximum and minimum temperature. Maximum and minimum relative humidity and rainfall prevailed during the time of sampling, previous one week, previous 14 days,week 21 days before and week 28 days before. The results showed significant and positive correlation between population of male EGW and the minimum temperature, while no correlation existed between female population and other parameters studied. Comparison of biometric observation of uninfested and infested plant parts indicated that the weight of the leaflets and petioles increased significantly due to an increase in biomass. Due galling by EGW, the girth of the petioles was shortened to about one third of uninfested petioles. The emergence of EGW was maximum from petioled scored in the damage category ‘9’. Among the four groups of Erythrina stricta Roxb..stricta trees studied, based on the height of the trees, no group turned out to withstand the damage by EGW. Thiomethoxam, imidacloprid, carbaryl and acephate proved superior among the chemical tested insecticides tried against female and male EGW in the laboratory . Neem oil 2 per cent and neem oil-garlic 2 per cent proved superior among the botanical insecticides tried for protecting the newly formed side shoots. Among the systemic /translaminar insecticides applied on the galled plant parts, triazophos 0.05 per cent and imidacloprid .002 per cent were significantly superior in controlling the EGW emergence. In the field experiment conducted to evaluate insecticide-fungicide combination for EGW infestation and protection of the new side shoots, carbaryl 0.1 per cent and combination of imidacloprid 0.002 per cent and carbendazim 0.2 per cent effectively protected the side shoots up to 8 weeks after spraying. Residue analysis of dry pepper berries collected from pepper vines trailed, on the insecticide sprayed crythrina standards showed that residues at the time of harvest from trees sprayed with acephate 0.05 per cent dimethoate 0.05 per cent were below detectable limit. Where as the residues in pepper collected from lamda cyhalothrin 0.05 per cent and triazophos 0.05 percent treated trees was 1.38 ppm and 1.16ppm respectively. An overall analysis and interpretation of the data on population in relation to phenology to E.stricta foliar growth showed that there existed a six monthly cycle of damage by gall wasp resulting in complete defoliation of the trees by about six month followed by the next cycle of regrowth and re infestation .ThesisItem Open Access Bio-efficacy and molecular characterization of the native isolates of Bacillus thuringiensis Berliner(Department of Agricultural Entomology , College of Horticulture, Vellanikkara, 2008) Jyothi Sara, Jacob; KAU; Maicykutty, P MathewBacillus thuringiensis Berliner shortly known as B.t., is a gram-positive, spore forming bacterium that produces proteinaceous crystal containing insecticidal toxins. The host range of B.t. has expanded considerably due to extensive screening programmes. By virtue of its lack of toxicity towards other species of animals and human beings, B.t. has emerged as a safe candidate in the IPM programmes of various agroecosystems. Frequent exposure to one type of B. thuringiensis toxins can develop resistance in insects. Isolation of novel strains is important to overcome the onset of insect resistance. The present study on “Bio-efficacy and molecular characterization of native isolates of Bacillus thuringiensis Berliner” was conducted at the Department of Agricultural Entomology and CPBMB, College of Horticulture, Vellanikkara during the period from 2006 to 2008 with an objective to study the pathogenicity of 20 B. thuringiensis isolates collected from the Western Ghats of Kerala, one of the well known hot spots of biodiversity. The tobacco caterpillar, Spodoptera litura Fb. which was used as the test insect was reared in semi-synthetic diet (Ballal, 2004) and also in natural diet on castor leaves. The preliminary screening was performed for lepidopteran specificity with the ideal dose of 1 x 109 spores per ml showed that three isolates were toxic to S. litura. The per cent mortality caused by the lepidopteran effective isolates, namely, KAU-11, KAU-51, KAU-166 and the reference strain, HD-1 were 76.7 per cent, 80.0 per cent, 86.7 percent, 96.7 per cent respectively. A standardized bioassay was carried out with five different concentrations of all the selected isolates namely, KAU-11, collected from Thusharagiri (Calicut Dt.), KAU-51 from Kolahalamedu (Idukki Dt.), KAU-166 from Nelliyampathi(Palakkad Dt.) and the reference standard HD-1 (B. thuringiensis subsp. kurstaki). The mortality ranged from 63.3 to 100.0 per cent in various isolates and there was no significant difference between isolates. This indicated the equal effectiveness of the native isolates with the standard strain, HD-1. The LC5o value for the isolates was calculated by Finney’s Method of Probit Analysis. The lowest LC50 was obtained in KAU-51, with 6.3095 x 104 spores per ml and highest in KAU-11, with 1.2589 x 106 spores per ml. The lethal time to cause 50 per cent mortality (LT50) ranged from 44.4 h. to 96.0 h. in different isolates. The lowest LT50 was recorded in HD-1, which shows the ability of the standard to cause mortality slightly earlier compared to other isolates. The molecular characterization of the selected isolates was performed with RAPD-PCR technique. RAPD-PCR is a simple and rapid method for determining genetic diversity in various organisms and is a means of creating a biochemical finger print of an organism. Out of the 20 primers screened, 10 primers which produced more than five bands were selected for RAPD analysis. The RAPD data was used to generate a similarity matrix using the NTSyS programme. Clustering was done and dendrogram was drawn using Unweighted Pair Group Method of Arithematic Averages (UPGMA). The results showed that high variability exists between the selected isolates. Further studies are required to identify the subspecies of the efficient B.t. isolates to evaluate the field effectiveness against S. litura and other major lepidopteran pests for its utilization in pest management programmes. More primers need to be screened to study the genetic diversity of the isolates.ThesisItem Open Access Pests of tropical mushroom and their management(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2008) Princy, John J; KAU; Naseema, Beevi SThe occurrence of mushroom pests and their extent of damage in five different locations in Thiruvananthapuram district were studied in a survey conducted at monthly intervals for a period of one year from April 2006 to March 2007. An experiment was conducted to evaluate the efficacy of various botanicals and synthetic insecticides for the management of major pests of mushroom in the Mushroom house, Instructional Farm, College of Agriculture, Vellayani. The study revealed that the common pests of mushroom were springtails Seira sp., phorid flies Megaselia sp., sciarid flies, cucujoid beetle Cyllodes sp., staphylinid beetles viz., Staphylinus sp. and Scaphisoma nigrofasciatum Champ, noctuid moth, parasitic mite Poecilochirus necrophori Vitzthum, slugs and snails. Of these, the occurrence of Cyllodes sp., P. necrophori, noctuid moth, slugs and snails in oyster mushroom were reported for the fist time from Kerala. The common pests of mushroom namely Seira sp., Megaselia sp., S. nigrofasciatum, Cyllodes sp. were observed throughout the year in all the five locations. Staphylinus sp. was observed in three locations for a period of one year. P. necrophori and slug population were recorded only in one location from September 2006 to March 2007. Correlation studies between the population and extent of damage with weather parameters revealed that Seira sp., P. necrophori and slugs had positive correlation with relative humidity and rainfall, while it showed negative correlation with maximum temperature. Population of Megaselia sp., S. nigrofasciatum, Cyllodes sp., Staphylinus sp. were positively correlated with maximum temperature and negatively correlated with relative humidity and rainfall Efficacy of various botanicals and synthetic insecticides applied at different intervals after bed preparation on the incidence and extent of damage caused by mushroom pests in mushroom beds showed that lindane 0.05 per cent applied as floor treatment before bedding was the most effective. This was followed by dichlorvos 0.02 per cent and chlorpyriphos 0.02 percent applied at fifteenth day after bed preparation, which were at par. Among the various treatments adapted for the control of pests in mushroom, floor treatment with lindane before bedding has been found superior compared to other treatments. Considering a better control of pests and absence of residues, the floor treatment with lindane can be suggested for getting an effective control of pest, which presumed to result in a consequent higher yield.ThesisItem Open Access Insect community analysis in cucurbitaceous vegetables and impact of insecticides on insect pollinators(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2007) Jangaiah, V; KAU; Devanesan, SA study was undertaken to document the various insects associated with cucurbitaceous vegetables in ten locations of Kalliyoor panchayat of Thiruvananthapuram district from March 2006 to February 2007. A field trial was also carried out to assess the impact of insecticides on the insect pollinators, natural enemies and pests. The total number of different species of insects recorded on the cucurbitaceous vegetables was found to be 47. Of these, the important groups of insects observed were Hymenoptera (28 per cent), Coleoptera (21 per cent), Lepidoptera (19 per cent), Hemiptera (17 per cent), Diptera (11 per cent) followed by Orthoptera and Thysanoptera (2 per cent each). Besides the insects, two species of spiders (Araneae) and one species of mite (Acariformes) were observed in three cucurbits. Bees were the predominant insect pollinators identified. Among the four species recorded, Apis cerana indica Fab. was the most abundant in oriental pickling melon and snake gourd. Trigona sp. was abundant in bitter gourd. Apis mellifera L. least visited the cucurbit flowers. Among the three cucurbitaceous vegetables, the highest insect pollinators activity was recorded in oriental pickling melon followed by bitter gourd and snake gourd. The peak period of activity of the pollinators was noted to be during 1000 hr to 1100 hr and 1500 hr to 1600 hr. Maximum foraging activity of different insect pollinators was recorded during the seventh week after sowing in bitter gourd and snake gourd and sixth week after sowing in oriental pickling melon. The population of insect pollinators was more in summer than rainy season. The higher activity of insect pollinators was observed under pesticide free condition in the Instructional farm when compared to farmer’s field where insecticides were frequently applied. The dominant insect pests recorded were Bactrocera cucurbitae Coq. and Aulacophora spp. followed by Aphis spp., Henosepilachna sp., Liriomyza trifoli Burgess, Diaphania indica Saunders, Anadevidia peponis Fb. and thirteen other pests. The highest fruit fly infestation was observed in bitter gourd (38.66 per cent) followed by snake gourd and oriental pickling melon. Pumpkin beetles caused up to 28.99 per cent damage in oriental pickling melon and 22.44 per cent in snake gourd. No infestation was observed in bittergourd. Two species of spiders(Oxyopes javanus Thorell and Lycosa pseudoannulata Boes et st.), three coccinellid beetles (Menochilus sexmaculatus Fab., Synharmonia octomaculata Fab. and Micraspis crocea Mulsant) and two parasitoids (Apanteles sp. and Chrysocharis johnsonii Walker) were the major natural enemies recorded. Foliar application of neem oil 2.0 per cent, imidacloprid 0.002 per cent and malathion 0.2 per cent proved to be safer to pollinators than other chemical insecticides. Imidacloprid 0.002 per cent and malathion 0.2 per cent significantly reduced pest infestation. Neem oil 2.0 per cent and imidacloprid 0.002 per cent were also safer to the natural enemies. The highest yield was recorded in imidacloprid 0.002 per cent treatment followed by malathion 0.2 per cent and carbaryl 0.1 per cent treated plot. Evidently, selective use of insecticides like imidacloprid 0.002 per cent and malathion 0.2 per cent could effectively check pest infestation without harming the pollinators and natural enemies in cucurbitaceous vegetable ecosystem.ThesisItem Open Access Potential of entomopathogenic nematodes for the management of weevil pests of banana (musa SP)(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2007) Remya, K R; KAU; Sheela, M SA study was taken up, to isolate native entomopathogenic nematodes from banana rhizosphere, to standardize artificial media for the wax moth Galleria mellonella L., the trap insect of EPN, to identify cheap medium for the mass production of native EPN, to establish the potential of native isolates of EPN in comparison with the standard cultures by screening and to assess the potential of native isolates for the management of two major weevil pests of banana viz. , pseudostem weevil Odoiporus longicollis Oliv. and rhizome weevil Cosmopolites sordidus Ger. in the laboratory of Department of Agricultural Entomology, College of Agriculture, Vellayani during 2005-06. Native isolates of EPN were collected from banana rhizosphere in six blocks of the Instructional Farm, Vellayani covering an area of 75 ha. Out of the hundred samples processed, ten native isolates were obtained. Based on the mortality of grubs of pseudostem weevil in the laboratory, the native isolates N1 and N2 were selected for further studies. The G. mellonella larvae were fed with standard medium along with cheap media viz., M1, M2, M3 and M4. The result revealed that among the cheap media, maximum survival of larvae was recorded in M1 medium. The cost of preparation of standard medium used for the rearing was high as compared to other three media. The percentage reduction of cost of ingredients of M1, M2 and M3 media from the standard medium was 21.29, 34.87 and 21.67 respectively. Among the three media, minimum reduction in cost of ingredient was computed for M2 medium. But considering the number of larvae survived and mass multiplication rate M1 medium was promising. For mass multiplication of native EPN, the rate of multiplication of infective juveniles was assessed in G. mellonella reared in different cheap media along with standard medium. The result showed that all the EPN (H. indica, S. glaseri, N1 and N2) reared in standard medium recorded maximum emergence of infective juveniles. The studies on the rate of multiplication of native isolates along with standards revealed that initial inoculum of 10 infective juveniles per G. mellonella larva recorded maximum emergence of infective juveniles of all EPN except N2. But the native isolate N2 required an initial inoculum level of 25 IJ per G. mellonella larva for maximum emergence of infective juveniles of EPN. The results of the study revealed that maximum emergence of EPN including native isolates were recorded at 20 days after inoculation rather than 15, 10 and 7 DAI. In order to establish the potential of native isolates on the mortality of grubs and adults of pseudostem and rhizome weevil, trials were conducted in vitro condition and using infested pseudostem and banana rhizome in the laboratory condition. Maximum mortality of grubs and adults of the pseudostem and rhizome weevils were recorded at 72 hrs after treatment. Under in vitro conditions the inoculum required for getting maximum mortality of grubs of pseudostem weevil was 100 IJ per grub, while it was 200 IJ per grub in rhizome weevil. In the case of adult weevils, the inoculum level required to get maximum mortality was 200 IJ per adult in both the cases. But inside the pseudostem and banana rhizome both the grubs of pseudostem and rhizome weevils recorded maximum mortality with 100 IJ per grub. From this investigation it was evident that native EPN strains are available in different agro ecosystems and are more virulent than the standard ones. The rearing media for trap insect, G. mellonella was modified with cheap ingredients and there by reducing the cost of production to 21.29 per cent with out affecting the nutritional status and survival of different instars. Comparative efficacy of native isolates (N1 and N2) and standards were worked out for the management of grubs and adults of weevil pests of banana. An inoculum level of 100 IJ per insect recorded a mortality of above 80 per cent in vitro condition in rhizome and pseudostem weevils but it was reduced to 52 to 56 per cent inside the rhizome and pseudostem. Thus from these studies, mortality of grubs and adults of the weevils inside the banana pseudostem and rhizome required a minimum inoculum level of 200 IJ per insect.ThesisItem Open Access Bioecology, population dynamics and integrated management of rice blue beetle, Leptispa pygmaea Baly (Chrysomelidae:Coleoptera)(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2007) Karthikeyan, K; KAU; Sosamma JacobThe Rice Blue Beetle Leptispa pygmaea Baly (Chrysomelidae : Coleoptera), hitherto reported as a minor pest of rice, has recently assumed a serious status by causing severe outbreaks in different northern districts viz., Palakkad, Kannur and Kasaragod of Kerala.This pest is reported to inflict extensive damage to rice in both kharif and rabi seasons. Since the rice blue beetle has been considered as a pest of minor importance, very scanty information is available on the pest. In this context, the present investigation on the “Bioecology, population dynamics and integrated management of Rice Blue Beetle Leptispa pygmaea Baly” was carried out at the Regional Agricultural Research Station, Pattambi, Kerala Agricultural University during 2004-06. The study has helped to generate information on the biology, population dynamics and management methods of rice blue beetle by which an IPM strategy could be formulated against this pest. The biology of rice blue beetle, L. pygmaea was worked out on a short duration (Jyothi) and a medium duration (Aiswarya) variety of rice under nethouse conditions. The female beetle laid eggs either singly or in groups in a straight line either on the dorsal or ventral surface of mature or tender rice leaves of Jyothi and Aiswarya. There was no marked difference in the biology of the blue beetle between the two rice varieties. Eggs were seen glued to the leaf surface. The fecundity ranged from 10 to19 eggs during an oviposition period of six days. A pre oviposition period of 14 to 16 hours was also observed. The eggs hatched into grubs within 3 to 4 days. The grub period lasted for 6 to 11 days with five instars, each with duration of 1 to 2 days. The grub pupated for 2 to 4 days and the adult beetle emerged out. The total life cycle from egg to adult stage was completed within 12 to 19 days. The longevity of adult varied with the sex of blue beetle. Males lived longer than females. The male life span was 37 to 41 days, while the females lived for 25 days. Among the duration of different stages viz., egg, larva, pupa and adult of L. pygmaea, the period of adult stage was found to be longest (39 days) followed by larva (8 days), egg (3 days) and pupa (3 days). The emergence of adult beetle was highest during morning period between 0800 to 0900 hours and then it was reduced as the day temperature increased. No emergence was observed between 1300 and 1500 hours when the temperature was high at the noon. The number of male beetles in the field was more, compared to the females with a sex ratio of 1.5: 1.3. Study on the morphology and morphometrics of different stages of blue beetle showed that the size of egg measured 0.39 mm in length and 0.19 mm in width. Freshly laid eggs were light green and changed to yellow towards hatching. The grub was light green in colour with brown head. It showed a small head capsule, long body and a tail like projection at the posterior end of the body. The newly emerged first instar grub was light green coloured with a brown head and changed to dirty white towards pupation. The head capsule measured a width of 0.17 to 0.26 mm from 1st to 5th instar, while the body measured an average length and width of 4.56 and 0.90 mm respectively. The tail length increased from 0.1 to 0.2 mm from first to fifth instar. Freshly formed pupa was white in colour and later it changed to brown and was seen loosely attached to the leaf by its distal end. It measured a maximum length of 3.89 mm and minimum length of 3.73 mm. Newly emerged adult beetle was metallic bluish green in colour dorsally and white coloured on the ventral side of the body. The male and female beeles could be differentiated based on the body size. The males were bigger in size than the females. The male had a longer antenna (1.1mm) than the female (0.08mm).The basal two segments were larger than the rest. In case of females, the basal scape was the largest (truncated) with 0.15 mm in width. In both sexes, the 3rd, 4th, 5th and 6th antennal segments were small and uniform, while the 7th to 11th segments were larger than the middle four segments. Dissection of the reproductive systems revealed that male reproductive system consisted of tegmen and sipho. The aedeagus showed an average length of 1.36 mm and width of 0.09mm. The female reproductive system consisted of spermatheca and two lateral coxites with an average length of 1.60 mm and width of 0.52 mm. Survey on the field population dynamics of blue beetle during Kharif and Rabi, 2005 showed that in Kharif’05, the field incidence of L. pygmaea started from fourth week of June at 10 days after transplanting and there was an increasing trend in the population up to the second week of July’05. The peak population was found coincided with the early tillering stage of the crop. After the second week of July’05, there was a declining trend in the population and reached the lowest during the third week of September’05. The field population of blue beetle was highest during the month of July in Kharif season. The abiotic factors viz., maximum temperature, minimum temperature, relative humidity, rainfall and sunshine during the peak period were 29.8C, 23.7C, 95 %, 50.9 mm and 2.9 hours respectively. In Rabi’05, the beetle population showed an increasing trend from the third week of October at 10 days after transplanting and reached a peak during the first week of November’05, when the crop was in the tillering stage. The population indicated a decreasing trend from the second week of November onwards. Highest population occurred at 24 DAT when the crop was in the early tillering stage during both seasons (Kharif and Rabi). Therefore, stage of the crop is a critical factor for the rapid build up of L. pygmaea. The weather parameters during the peak period were maximum temperature 31.8 C, minimum temperature 23.2 C, relative humidity 95 %, rainfall 70.2 mm and sunshine 4.2 hours. Two abiotic factors viz., minimum temperature of 23 C and relative humidity of 95 % were found to influence the peak population in both the Kharif and Rabi seasons. Correlation analysis of beetle population and per cent leaf damage with the weather parameters revealed a negative correlation with regard to maximum temperature and sunshine hours (respective correlation values -0.281 and -0.400). A positive correlation of blue beetle population with minimum temperature and relative humidity was observed. Rainfall showed no significant effect on beetle population. Damaged leaves by L. pygmaea were found to be positively correlated with minimum temperature and relative humidity while it was negatively correlated with maximum temperature and sunshine hours. However, there was no significant relationship between rainfall and per cent damaged leaves. Thus, it is indicated that minimum temperature and relative humidity were the two important abiotic factors that influence the damage by L. pygmaea. Study on the nature of attack and symptoms of damage of L. pygmaea showed that both the grub and adult feed on the upper surface of rice leaves by scrapping chlorophyll tissueleading to longitudinal white streaks on them. The streaks made by the larvae were shorter and narrower than those by the adults. In case of severe damage, the rice leaves were seen folded longitudinally and ultimately dried up. The plants became very weak or dried up. From a distance, the damaged rice patch showed severe drying. Symptoms of damage by rice blue beetle resembled those caused by leaffolder. Observations on the feeding intensity of different stages of the blue beetle revealed that grubs caused highest damage followed by adult female and adult male in both Jyothi and Aiswarya. The grub caused 69.0-73.7 per cent more damage than males while female caused 48-59 per cent more damage than males. The study on leaf area consumption by different stages also indicated similar results. Leaf area consumption by L. pygmaea was more in Jyothi than in Aiswarya. Early tillering stage was found to be the most susceptible stage for the infestation of blue beetle in both Kharif and Rabi . Damage was found to increase from the seedling stage and reached peak at early tillering and thereafter it gradually declined. The order of susceptibility of growth stages to rice blue beetle damage was early tillering > seedling > maximum tillering > panicle initiation > booting > flowering. Transplanted rice suffered more damage by L. pygmaea than the direct seeded rice in both the rice varieties Jyothi and Aiswarya during Kharif and Rabi’05 seasons. In Kharif the transplanted rice suffered 42.40-83.15 per cent more damage over direct seeding in Jyothi during seedling stage. In early tillering stage, the transplanted rice suffered 34.24 to 58.17 per cent more damage over direct seeding. Studies were also carried out on integrated pest management methods involving screening of resistant lines / varieties, effect of plant spacing and oil cakes, chemical management by nursery treatment with granular insecticides and main field treatment with eco-friendly foliar insecticides against L. pygmaea. Among the 106 varieties / entries screened for their field reaction against L. pygmaea, none of them was found to be completely resistant. No high yielding variety except Hraswa (a short duration Mannuthy variety) showed moderate resistance. But nine traditional Pattambi varieties viz., Ptb.3, Ptb.4, Ptb.7, Ptb.9, Ptb.18, Ptb.19, Ptb.20, Ptb.25, Ptb.26 revealed a damage score of ‘3’ indicating moderate resistance. Therefore, these varieties could be utilized for future breeding programmes for resistance against rice blue beetle. Other KAU varieties showed susceptibility, while three varieties viz., Jyothi (Ptb.39), Rangini (MO10) and Bharathy (Ptb.4) were found to be highly susceptible to L. pygmaea. The most popular rice variety of Kerala, Jyothi,was found to be highly susceptible to rice blue beetle. Search for the alternative hosts for L. pygmaea revealed that among the 10 commonly seen weed plants in rice fields, the beetle was found to oviposit only on two grassy weeds viz., Panicum repens and Isachne miliacea. Though eggs were laid, there was no hatching of eggs on I. miliacea. But on P. repens, the beetle laid 12-15 eggs with cent per cent hatchability and the beetle was able to carry out its normal life cycle on this weed host in 10-13 days. A comparative study on the biology of L. pygmaea on Jyothi, Aiswarya and Panicum repens indicated that the life cycle of rice blue beetle was shortest (11.5 days) on P. repens followed by Aiswarya (14 days) and Jyothi (15 days). The influence of agronomic practice of different spacings on the incidence of L. pygmaea revealed that in closer plant spacings (10x15 cm and 10 x 10 cm), there was reduction on the incidence of blue beetle with reduced leaf damage, hill damage and beetle population. Infestation was significantly higher in the recommended wider spacing (20x15 cm), as compared to closer spacing. The effect of application of neem cake, castor cake and pungam cake in the field against L. pygmaea showed that there was no significant difference between these cakes on the leaf damage, damaged hills and beetle population. No interaction effect of plant spacings and oil cakes was observed. Survey for the natural enemies of blue beetle in the field showed that the beetle eggs were parasitized by Trichogramma sp., Telenomus sp. and Tetrastichus sp. indicating a good scope for biological control of the pest. Laboratory studies to assess the pathogenicity of white muscardine fungus, Beauveria bassiana against L. pygmaea illustrated the effective role of B. bassiana by causing a cumulative mortality of 56.67 to 80.00 per cent at 105 to 109 spores / ml. Its LC50 value was 2.26 x 104 spores / ml. Evaluation of the entomopathogenic nematode (EPN), Heterorhabditis indica under the laboratory conditions indicated its bioefficacy by bringing out mortality against grubs of L. pygmaea. The EPN produced a cumulative mortality of 66.67 to 91.67 per cent at concentrations of 5 IJ’s to 9 IJ’s in the grubs with a LC50 value of 3.83 IJ’s per ml. Biological management studies thus resulted in the identification of three new egg parasitoids in the field. The pathogenicity of white muscardine fungus and the EPN against L. pygmaea were also explored. Studies on the chemical management of L. pygmaea by nursery application of granular insecticides revealed the efficacy of cartap hydrochloride in reducing the leaf damage, hill damage and beetle population of L. pygmaea in both Kharif and Rabi seasons during 2004 and 2005.The leaf damage was reduced by 40.29 and 37.86 per cent (mean = 39.21 per cent) over control during 2004 and 2005 respectively while the beetle population was reduced by 30.73 and 61.13 per cent (mean = 45.9 per cent). Hill damage was reduced by 55.16 and 33.71 per cent (mean = 44.4 per cent) over control during the years. Carbofuran was the next best effective insecticide against L. pygmaea. It produced significant reduction of leaf damage by 30.16 and 23.62 per cent (mean = 26.9 per cent) over control in Kharif and Rabi respectively. Beetle population was reduced by 25.10 and 54.66 per cent (mean = 39.9 per cent) and hill damage by 55.70 and 10.11 per cent (mean = 32.9 per cent) over control. Fipronil was found least effective against L. pygmaea. Persistent toxicity of granular insecticides applied in the nursery against blue beetle showed that carbofuran was the most persistent insecticide with highest PT value followed by carbosulfan, phosphamidon, cartap hydrochloride and fipronil. Evaluation of eco-friendly foliar insecticides for the field toxicity against L. pygmaea indicated the effectiveness of B. bassiana at 107spores/ml. It significantly reduced leaf damage (mean = 46.7 per cent), population of blue beetle (mean = 47.7 per cent), and hill damage (45.9 per cent) over control. The insecticide, chlorpyriphos @ 0.05 % was equally effective against rice blue beetle. It was followed by carbaryl > econeem > paraffin oil > neem oil. The persistent toxicity of foliar insecticides in the field was in the descending order viz., carbaryl > chlorpyriphos > econeem > neem oil > paraffin oil > B. bassiana. It is quite evident that the persistent toxicity of eco-friendly insecticides is low as compared to the chemical insecticides. Though. B. bassiana showed lowest persistence in the field, it was on par with chlorpyriphos in bioefficacy causing highest mortality of blue beetle.ThesisItem Open Access Documentation and predatory potential of spiders in rice ecosystem and impact of insecticides on spiders(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2007) Anis Joseph, R; KAU; Premila, K SThe survey conducted to document the spiders in the paddy fields of Thiruvananthapuram district during the Virippu and Mundakan seasons of 2005-’06, brought out sixty five species of spiders, which fall into two major groups, hunters and web builders and belonged to eleven families and seven foraging guilds. The species composition of hunters was more than the web building spiders, although the latter was numerically dominant. The dominant guild was orb web weavers. Araneidae was the family with more species composition, followed by Tetragnathidae and Salticidae. The predominant genus being Tetragnatha, and species, Tetragnatha mandibulata Walckenaer. The other dominant species were Tetragnatha maxillosa Thorell, Argiope anasuja Thorell, Neoscona rumpfi Tikader & Biswas, Telamonia dimidiata Simon, Bianor carli Reimoser, Oxyopes javanus Thorell, Peucetia viridana Stoliczka, Pardosa pseudoannulata Böesenberg & Strand and Thomisus projectus Tikader. Seventeen species of spiders were reported for the first time from the rice fields of Kerala, and it included the three dominant spiders, viz., N. rumpfi, B. carli and T. projectus. Spiders were also observed in the field bunds and border weeds, and from the webs built among plants, in between the plants and on individual leaves. The seasonal occurrence of spiders during the Virippu and Mundakan seasons did not show any remarkable difference. Among the eleven families, six were more populated viz., Tetragnathidae, Araneidae, Salticidae, Lycosidae, Oxyopidae and Thomisidae. The predominant family was Tetragnathidae. The vegetative and reproductive stages of the crop harboured more spiders and the highest population was recorded during the reproductive stage. The crop growth stages had significant influence over the spider population, where as the weather parameters had no correlation. The ten spiders showed a definite preference for the different hoppers, bugs and lepidopterans when evaluated for their prey preference. The spiders A. anasuja, P. viridana, T. dimidiata and T. projectus broadened their preference to the orthopteran and coleopteran pests. The predatory potential of the spiders showed that the spiders which consumed more number of prey insects per day in a mixed diet took comparatively lower numbers when the prey insects were provided individually. A. anasuja was the most potential predator and P. viridana was the spider with highest rate of hyper predation and the most cross predated insect predator was C. lividipennis. The parasitoids were not consumed by the spiders. The topical application of chemicals recorded higher mortality of spiders than when released on the treated plants. Among the chemicals, imidacloprid 0.005 per cent proved to be safer and triazophos 0.05 per cent more toxic. Azadirachtin 0.004 per cent had more toxicity among the neem formulations. In the field, better recolonization of spiders was noticed in the neem products treated plots than the synthetic pesticides, imidacloprid proved to be the safest chemical for the spiders and all the insect natural enemies and was quite promising for the pests. From the results obtained, it can be concluded that pest management will be effectively executed in the field by these potential predators, which are abundant and had specific adaptations which overpowered the other natural enemies in the rice fields. In a naturally balanced rice ecosystem, in a pesticide free environment, these carnivores can survive and when assembled into groups, they could contribute to significant reductions in pest numbers, which have a positive effect on crop production and is beneficial to farmers. Imidacloprid 0.005 per cent could be utilized for pest control when infestation is severe without harming the spider fauna. Hence, conservation biological control could be practiced along with spider mediated IPM.ThesisItem Open Access Pests of tulsi (Ocimum tenuiflorum L ) and their management(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2007) Malini, Nilamudeen; KAU; Nandakumar, CThe seasonal occurrence and the extent of damage caused by pests of tulsi were assessed in a survey conducted at monthly intervals for one year in five locations viz., Perumpazhuthoor, Parasuvaikkal, Poojapura, Peroorkada and Vellayani of Thiruvananthapuram district. A field trial was carried out in the Instructional Farm, College of Agriculture, Vellayani to evaluate the effect of various botanicals against the pests, the spiders and on herbage yield of tulsi. The five major hemipteran pests recorded on tulsi were Monanthia globulifera W., Aphis gossypii Glover, Cajanus cajani Maskell, Phymatostetha deschampes L. and Icerya spp. The minor pests recorded were Anchon pilosum L., Lygaeus sp., Agonoscelis sp., Leptocorisa acuta (Thunb.), Pseudococcus sp., Cyrtacanthacris sp., Syngamia abruptalis Wlk., Anisephyra ocularia Fab., Lasius sp. and Solenopsis sp. A viral disease and a fungal leaf spot caused by Colletotrichum gloeosporioides Penz. were also recorded. The infestation by A. gossypii., Icerya spp., P. deschampes, A. pilosum Lygaeus sp., Agonoscelis sp., L. acuta, Pseudococcus sp., A .ocularia, Lasius sp. and Solenopsis sp. are being reported for the first time. The diseases are also being reported for the first time from Kerala. All the five major pests were polyphagous in nature. The incidence of the pests and magnitude of damage caused by them varied among the different locations as well as during the different months. Both the density dependent factors like availability of other host plants and density independent factors like temperature, relative humidity and rainfall played a major role in the distribution of pests in various locations. Except P. deschampes, the population and infestation of all the other major pests were high during summer months compared to the rainy months. The population and damage by P. deschampes had positive correlation with rainfall. The natural enemies of the pests included eight species of spiders and a dipteran (syrphid). The spiders were observed in all locations throughout the year. The syrphid Paragus serratus Fabr. was a predator of A.gossypii. An encyrtid pupal parasitoid of P.serratus was also observed. The adults of C.cajani were parasitized by Coccophagus tschirchii (Madhihassan) and the larvae of S. abruptalis were parasitized by Bracon sp. The results of the pest management trial revealed that the botanicals were not only effective in containing the pests but also safe to the spider fauna. The treatments gave higher yield also. Among the botanicals, pongamia oil two per cent or azadirachtin 0.004 per cent or neem cake soil application @ 250 kg ha-1+ NSKE five per cent could be recommended for the control of the pests of tulsi. This would be of use in the protection of tulsi in homesteads as well as in mediculture.