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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 Biotic agents for the management of American serpentine leaf miner, Liriomyza trifolii(Burgess) (Diptera:Agromyzidae)(Department of agricultural entomology, College of horticulture, Vellanikkara, 2014) Jyothi Sara, Jacob; KAU; Maicykutty P, MathewA study on “Biotic agents for the management of American serpentine leaf miner, Liriomyza trifolii (Burgess) (Diptera: Agromyzidae)” was carried out at the Department of Agricultural Entomology, College of Horticulture, K.A.U., Vellanikkara during 2011-2013 with the objectives of collection and identification of indigenous natural enemies and to assess the pathogenicity of the entomopathogens to explore the feasibility of utilizing them for its management. Surveys were conducted in the vegetable fields for the collection and identification of natural enemies associated with L. trifolii in three districts, namely, Thrissur, Ernakulam and Kottayam from January to March, 2011. The surveys revealed the occurrence of nine species of hymenopteran parasitoids. The per cent parasitism varied from 10.96 to 58.99 per cent among the crops surveyed. Three species of eulophids, namely, Cirrospilus acadius Narendran, C. brevicorpus Shafee & Rizvi and Aprostocetus sp. as well as the braconid, Toxares sp. are new reports for India. Among the parasitoids, Closterocerus spp. were the dominant group followed by Chrysonotomyia sp. All parasitoids were solitary, larval endoparasitoids except Toxares sp. which was larval-pupal in nature. One species each of small ants (Formicidae) and a dipteran fly (Dolichopodidae) were observed as predators on L. trifolii. In the study, no entomopathogens were observed from L. trifolii. Considering the level of pesticide consumption in vegetable crops that undermine the potential of insect parasitoids and also that no entomopathogens could be observed during the survey, it was decided to evaluate entomopathogenic nematodes (EPNs) as biocontrol agents against L. trifolii. Isolation of EPNs from 72 soil samples from Thrissur, Ernakulam and Kottayam districts yielded four isolates of Steinernema carpocapsae. Bioefficacy studies carried out on these four isolates along with Steinernema bicornutum and Heterorhabditis indica showed that S. carpocapsae Isolate - 1 had the lowest LC 50 , LC 90 and LT values indicating their higher effectiveness against the maggots of the pest. 50 Pot culture study conducted to compare the potential of S. carpocapsae Isolate - 1 with other treatments showed that azadirachtin 1 EC at 0.005% was the most effective causing 84.51 per cent mortality to the maggots of L. trifolii. This was followed by the foliar application of H. indica at 32 infective juveniles (IJs)/ maggot which caused 18.98 per cent mortality. Application of Beauveria bassiana at 1×10 7 spores/ ml was not effective. In the field evaluation, fipronil 5 SC at 0.002% was found to be the most effective treatment for controlling L. trifolii followed by azadirachtin 1 EC at 0.005%. Compatibility of the IJs of the S. carpocapsae Isolate - 1, S. bicornutum and H. indica was studied with ten commonly used insecticides in the laboratory by direct exposure method. Chlorantraniliprole 18.5 SC at 0.005% was found to be the most compatible insecticide with S. carpocapsae isolate - 1 causing only 0.17 per cent mortality to IJs at 72 hours after treatment (HAT). Quinalphos 25 EC at 0.05% and chlorpyriphos20 EC at 0.05% were highly incompatible, causing 96.17 and 92.87 per cent mortality of the nematodes. Dimethoate 30 EC at 0.04% was the most compatible insecticide with S. bicornutum and caused only 0.60 per cent mortality at 72 HAT and was followed by azadirachtin 1 EC at 0.005% with 0.78 per cent mortality to the IJs. Quinalphos 25 EC at 0.05% caused 99.93 per cent mortality at 72 HAT. Heterorhabditis indica was compatible with all insecticides except quinalphos 25 EC at 0.05% which was moderately toxic resulting in 39.6 per cent mortality. The virulence, pathogenicity and multiplication of the survived IJs were not affected by the insecticide treatments. Parasitoids and EPNs were observed as potential candidates for the management of L. trifolii. Hence future studies on the bio-ecology and mass production of dominant parasitoids and standardization of methods to improve the efficacy of EPNs are suggested for the successful control of L. trifolii in polyhouses as well as in the field.ThesisItem Open Access Bio-ecology and management of papaya mealybug on mulberry(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2014) Rajan, V P; KAU; Krishnakumar, RThe experiment entitled “Bio-ecology and management of papaya mealybug on mulberry” was carried out at College of Agriculture, Vellayani, Kerala Agricultural University and in farmers’ fields at Agali, Sholayur and Puthur panchayats during October 2009 to July 2012. The main objectives of the study were to identify and assess the extent of infestation of papaya mealybug on mulberry, its role in disease transmission and population dynamics and to evolve an Integrated Pest Management (IPM) strategy to contain the pest. Preliminary survey conducted in sericulture practising districts of Kerala revealed heavy infestation of the pest in three panchayats of Palakkad district in Kerala. The mealybugs identified in the survey were papaya mealybug, Paracoccus marginatus Williams and Granara de Willink, pink hibiscus mealybug, Maconellicoccus hirsutus (Green) and breadfruit mealybug, Icerya aegyptiaca (Douglas). The occurrence of papaya mealybug and its egg masses were found to be high during the period of May to August. The competition between these three mealybugs and also the influence of weather parameters on the population of the papaya mealybug was studied. The mealybug population showed positive correlation with maximum temperature, sunshine and wind speed and negative correlation with minimum temperature, rainfall and humidity. The different plants belonging to families Asteraceae, Euphorbiaceae, Malvaceae and Solanaceae were observed to be the most preferred hosts for papaya mealybug. The highest number of all life stages of papaya mealybug was observed on Parthenium, Parthenium hysterophorus L., which augmented the perpetuation of papaya mealybug in the absence of other crop hosts. Sprouted potatoes were the host material used for studying the biology of the papaya mealybug, pink hibiscus mealybug and breadfruit mealybug. The average number of eggs laid by an adult papaya, pink hibiscus and breadfruit mealybug were 361.50, 281.30 and 141.30 respectively. The mean larval period of papaya, pink hibiscus and bread fruit mealybugs were found to be 16.7, 21.2 and 47.1 days respectively. DAC-ELISA was performed with infected mulberry plants using antibodies of SCBMV and BSV showed the absence of virus in the infected samples collected from the mealybug infested mulberry gardens. The phenol content was also assessed in the infested samples to get an indication of the level of resistance showed by the host plant against mealybug. The level of resistance of the plant found to be increasing with the increase in the per cent damage. The fifth instar larvae of the predator, Spalgis epius was found as the most active feeder with a feeding potential of 21.69, 118.88, 40.88 and 20.49 of ovisacs and first, second and third instars of papaya mealybug respectively. Third instar larvae of green lacewing, Chrysoperla carnea (Stephens) and fourth instar grubs of ladybird predator, Cryptolaemus montrouzieri (Mulsant) were the most voracious feeders and they consumed significantly higher number of ovisacs, first, second and third instar nymphs of papaya mealybug as compared with first and second instar larvae of the predators. Among the different insecticides evaluated in the laboratory against the first instar and adult papaya mealybugs, dimethoate 0.1% was superior followed by imidacloprid 0.01%. Among the combinations, dimethoate 0.05% + econeem plus 2 ml L-1 was found to be superior with the highest per cent mortality of 93.33% and 96.67% for adult and first instar papaya mealybugs respectively. The silkworm larvae fed with the leaves after 15 days of treatment with the combination of dimethoate 0.05% + econeem plus 2 ml L-1 gave the highest yield of (91 /100 larva reared) cocoons with a total larval duration of 576 hours. Single cocoon weight was found to be high (1.56 g) with the highest shell ratio (22.09). The mean larval weight of different instars were 0.54, 0.87, 1.16, 8.80 and 36.61 gram respectively in first, second, third, fourth and fifth. In the above treatment, effective rearing rate (ERR) by number and weight were 9050.00 and 13744.69 g respectively. Field evaluation with the combination of pruning and weeding along with application of dimethoate (0.05%) 1.7 ml + econeem plus 2 ml L-1 and also providing a second spraying with dichlorvos (0.05%) 2 ml + econeem plus 2 ml L-1 was observed to be superior among all the treatments with minimum leaf damage, shoot damage and highest leaf yield per plant. B: C ratio worked out also confirmed the superiority of this treatment. Hence this treatment can be recommended as an IPM strategy for the management of papaya mealybug on mulberry.ThesisItem Open Access Management of banana pseudostem weevil, Odoiporus longicollis (Olivier), using safe chemicals and bio-rational methods(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Sivakumar, T; KAU; Jiji, TA study on ‘Management of banana pseudostem weevil, Odoiporus longicollis (Olivier), using safe chemicals and bio-rational methods’ was conducted at the College of Agriculture, Vellayani and in farmer’s field during 2012-2015. The main objective was to evolve strategies for managing the pest using safe chemicals and bio-rational methods. The study involved documentation of the pest status and farmers’ management practices, evaluation of the efficacy of different insecticides, botanicals and bio-agents under laboratory and field conditions and determination of harvest time insecticide residues in edible parts. Status of pests in banana was documented from Alappuzha, Pathanamthitta, Kollam and Thiruvananthapuram districts during 2013. O. longicollis incidence in banana cv. Nendran varied from 5.36 per cent in Kollam to 7.64 per cent in Pathanamthitta. Erionota sp., Bactrocera dorsalis (Hendel), Polytus mellerborgi (Boheman), Coccus hesperidum L. were observed as the emerging pests from the area. Pest management practices adopted by banana farmers, documented from the above districts, revealed the use of sixteen types of pesticides, including organic preparations. No specific parasite or predator was recorded from field except earwigs and red ants. Efficacy of insecticides, botanicals and bio-agents for the management of O. longicollis was evaluated under laboratory conditions. Thiamethoxam (0.01%), emamectin benzoate (0.002%) and cartap hydrochloride (0.1%) caused 100 per cent mortality of adults and grubs of the pest within 36 h after treatment. Among the botanicals, cassava leaf distillate based formulation, ‘Nanma’ (5%) caused 36.67 per cent mortality of adults and grubs, whereas neem soap caused 36.67 and 16.67 per cent mortality of adults and grubs, respectively. Among the bio agents tested, Metarhizium majus Bisch, Rehner and Humber (ICAR-CPCRI) 2% caused 80 per cent mortality of grubs on the seventh day of inoculation. Compatibility of insecticides, fungicides and botanicals with M. majus was tested using poisoned media technique. The fungicides viz., propiconazole (0.1%), tebuconazole (0.1%), mancozeb (0.3%) and carbendazim (0.1%) resulted in total growth inhibition of M. majus, while thiamethoxam (0.01% and 0.03%), cartap hydrochloride (0.05%) and neem soap (1.0%) were found compatible. Application methods of insecticides, botanicals and bio-agents were standardised through field experiment at the Instructional Farm, College of Agriculture, Vellayani during 2013-2014. Among the application methods, leaf axil filling (LAF) and injection of thiamethoxam (0.01% and 0.03%) recorded a yield of 10.98 and 10.88 kg plant-1, respectively. In the case of biopesticides, the highest yield (6.43 kg plant-1) was recorded with swabbing + LAF application of M. majus (20g l-1), whereas among botanicals, spraying +LAF gave the highest yield (8.8 kg plant-1) for neem soap (1.0%) application. Prophylactic and curative methods for the management of the pest, using thiamethoxam, neem soap, cassava leaf based preparation and M. majus, were tested in farmer’s field at Konni, Pathanamthitta district during 2014-2015. In prophylactic method thiamethoxam injection (0.03%) at 5th and 6th months after planting recorded an yield of 10.67 kg plant-1, followed by thiamethoxam (0.01%) leaf axil filling (10.32 kg plant-1) at 5th and 6th months after planting. Significantly higher value for BC ratio (2.44) was recorded for thiamethoxam (0.03%) injection. The BC ratio was 2.33 for thiamethoxam (0.01%) leaf axil filling. Application of M. majus (2%) at five months after planting, followed by thiamethoxam LAF (0.01%) at 6th month after planting yielded 8.82 kg plant-1. In curative method, plant survival was the highest (80 per cent) for thiamethoxam injection (0.03%). However, a low BC ratio of 0.86 was observed. Thiamethoxam injection (0.03%) and leaf axil filling (0.01%) were on par with chlorpyrifos (0.03%), as curative method. No detectable residue of thiamethoxam on any edible parts of the plant was observed at the time of harvest. To conclude, ‘Nendran’ was found to be the most susceptible banana cultivar to O. longicollis. Thiamethoxam at 0.01 per cent and 0.03 per cent were compatible with the entomopathogen, M. majus. Prophylactic method using thiamethoxam injection @ 0.03% and leaf axil filling @ 0.01%, both at five and six months after planting, were found effective, eco friendly and economical practice for O. longicollis management. The application of entomopathogenic fungi M. majus at five months after planting followed by thiamethoxam (0.03%) injection at six months after planting was also effective for managing the pest.ThesisItem Open Access Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Anju Padmanabhan; KAU; Ambily PaulStudies on “Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower” was conducted in College of Agriculture, Vellayani, Cardamom Research Station, Pampadumpara and farmers field at Kalliyoor during 2015-2018. The present research work was under taken to study the dissipation of select insecticides viz., chlorantraniliprole 18.5 % SC, flubendiamide 39.35 % SC, indoxacarb14.5 % SC, emamectin benzoate 5 % SG, fipronil 5 % SC, quinalphos 25 % EC, cypermethrin 10% EC, acetamiprid 20% SP, thiamethoxam 25 % WG and dimethoate 30 % EC in cabbage and cauliflower, to assess their potential risks to human health, to determine their effect on soil microbial activity, to estimate the residues in cooked samples and to evaluate the efficacy of “Veggie Wash” to eliminate residues. Survey conducted among 25 each of farmers cultivating cabbage and cauliflower in plain (Thiruvananthapuram) and hill (Idukki) representing two agro climatic conditions revealed that pest infestation was more in hills when compared with plains. Accordingly, pesticide usage was higher in Idukki (84 % each) than in Thiruvananthapuram district (12 and 8 %) in cabbage and cauliflower respectively. Dissipation studies of insecticides having label claim for cabbage and cauliflower under CIB & RC in two agroclimatic regions of Kerala viz., Thiruvananthapuram and Idukki showed that the degradation of insecticides varied with crop and chemistry of the insecticides. Insecticides persisted more in cabbage under plain were flubendiamide (20 days) followed by acetamiprid and quinalphos (10 days each), while in hills, higher persistence was observed in flubendiamide, cypermethrin and quinalphos (10 days each). The lowest persistence was observed in fipronil (3 days) in cabbage under plains and acetamiprid (3 days) in hills. In cauliflower higher persistence was observed for flubendiamide, chlorantraniliprole and dimethoate in plains and flubendiamide, quinalphos (20 days each) and cypermethrin (15 days) treated plots in hills. The lowest persistence was observed for emamectin benzoate (3 days) in cauliflower under plains and hills. Risk assessment study was carried out in cabbage and cauliflower using selected insecticides under plains and hills by comparing the values of Theortical Maximum Residue Concentration (TMRC) and Maximum Permissible Intake (MPI). The result revealed that consumption of dimethoate and fipronil treated cabbage and cauliflower were found to be risky to the end users. However, all other insecticides are safe even on the same day of insecticide application. Effect of insecticides on soil microbial activity was studied in cabbage and cauliflower through the activity of urease, phosphatase and dehydrogenase enzymes. Lower reduction in urease activity was observed in flubendiamide, dimethoate and thiamethoxam treated plot and higher reduction was recorded in fipronil and quinalphos treated plots over control both in cabbage and cauliflower. However, lower reduction in phosphatase activity was recorded in flubendiamide, thiamethoxam and cypermethrin and higher reduction was observed in indoxacarb and fipronil treated plots over control. Lower reduction in dehydrogenase activity was recorded in cypermethrin, acetamiprid and thiamethoxam treated plots and higher reduction was recorded in indoxacarb and fipronil treated plots over contol in both cabbage and cauliflower. Study on extent of removal of insecticides through cooking from cabbage and cauliflower was conducted with insecticides which had more persistence revealed that 15 min cooking removed more residues and the highest removal was observed for quinalphos (54.79 %) in cabbage under plains and cypermethrin (66.47 %) in hills. However, in cauliflower the highest per cent removal was observed for chlorantraniliprole (44.78) in plains and cypermethrin (52.32 %) in hills. “Veggie wash” technology was evaluated in the cabbage and cauliflower after application of insecticides at recommended doses revealed that dipping of cabbage and cauliflower in one per cent “Veggie Wash” solution for 10 min. followed by water wash removed 12-40 per cent of treated insecticides while water wash alone removed 9 -35 per cent. The present study revealed that the dissipation pattern of insecticides varied with crop, agro climatic areas, and chemistry of the molecules. Risk assessment study shown that insecticides viz., fipronil and dimethoate posed risk on human health even at recommended dose. Studies on effect of insecticides on soil enzyme revealed that except fipronil and indoxacarb, all other insecticides under present study have less impact on soil enzymes. Decontamination studies showed that cooking at 15 min. removed 50-60 per cent of insecticides and “Veggie Wash” removed 12-40 per cent of treated insecticides. Present study urged the need to evaluate the new insecticides carefully, by considering safety to environment and human health. The risk assessment studies of all insecticides should be done before going for field level recommendations.ThesisItem Open Access Bio-ecology and management of borer pests infesting yard lond bean, Vigna unguiculata subsp. sesquipedalis (L.) verdc.(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Sontakke Pritin, Pramod; KAU; Amritha, V SA study on ‘Bio-ecology and management of borer pests infesting yard long bean, Vigna unguiculata subsp. sesquipedalis (L.) Verdc.’ was conducted at the College of Agriculture, Vellayani during 2014-17. The main objective was to study the biology and population dynamics of borer pest complex infesting yard long bean, Vigna unguiculata subsp. sesquipedalis (L.) Verdc. and to evolve suitable management measures. A survey was conducted in six major yard long bean growing tracts of Thiruvananthapuram district during 2015-16 to document the infestation of important borer pests and their natural enemies. The biology of major borer pests were studied under laboratory conditions and population dynamics through competitive exclusion was studied by releasing the adults of two major pod borers simultaneously on to the netted yard long bean plants. Ten varieties of yard long bean were collected and evaluated for pod borer resistance, if any as per the field screening technique of Jackai (1982). The in-vitro efficacy of microbial insecticides and field evaluation of selected new generation insecticides and their combinations were conducted in managing the borer pest complex of yard long bean. Stem fly, Ophiomyia phaseoli (Tryon), girdle beetle, Nupserha bicolour (Thoms.), blue butterfly, Lampides boeticus (L.) and spotted pod borer, Maruca vitrata (G.) were the major borer pests which infested yard long bean at their different growth stages. The infestation of O. phaseoli was recorded during seedling stage while N. bicolour infestation occurred during vegetative stage of the crop. Among the six panchayats/location, significantly highest number of girdles as well as plant infestation were recorded from Balarampuram and the maximum intensity of infestation was recorded during fourth week and it was found decreasing with increasing crop age. The occurrence of L. boeticus was recorded from all the panchayats/location with the highest pod infestation in Balarampuram panchayat, while the incidence of M. vitrata was recorded only from two panchayats (Athiyannoor and Venganoor). Correlation studies between the weather parameters and population dynamics of pests revealed that per cent pod damage by M. vitrata showed significant positive correlation with wind speed and negative correlation with rainfall, whereas, O. phaseoli showed a significant negative correlation with the sunshine hours. With regard to the biology studies, female girdle beetle was found to lay eggs (0.54 mm x 0.13 mm) inside the growing stem by making punctures and girdles for oviposition. The mean incubation period was 2.66 days. The larva is yellowish white, soft-bodied with a dark head capsule which possesses an average larval period of 31.99 days and the pupation within the stem. The life cycle was completed in 67.63±7.75 days on yard long bean. On biochemical analysis, the phenol content in the upper part of the girdle infested stem was higher than lower part. The eggs of L. boeticus were disc-shaped, finely sculptured and pale green colour with an incubation period of 3.20±0.20 days. There were four larval instars and last instar was slug like, pea green in colour. Its life cycle completes in 20-22 days. In case of M. vitrata, the mean longevity of the adult was 6.00±0.57 days. There were five larval instars which took 12.25±1.43 days to enter into pupal stage. Pupation took place in the webbed flowers/pods and the pupal period lasted for about 8.25±0.75 days. The life cycle was completed in 28.00±3.03 days. From the population dynamics studies, it was revealed that L. boeticus was dominant over M. vitrata based on the per cent pod and flower infestation. In the varietal screening of yard long bean against borer pests, the cultivar VS- 13 was found resistant against O. phaseoli with significant variation in branches infested per plant, while no significant variation was observed with respect to number of girdles per plant and percentage plant infestation in the case of N. bicolour. The cultivars VS-13 and VS-05 were found resistant against L. boeticus. The resistant cultivar, VS-13 recorded less sugar content, high phenol and maximum pod length and breadth when compared to other cultivars. Efficacy of five microbial insecticides against pod borers viz., L. boeticus and M. vitrata under laboratory conditions showed that Bt. var. kurstaki @ 1 g l-1 on 5 days after treatment (DAT) recorded the highest mortality followed by B. bassiana and M. anisopliae @ 107 spores ml-1. Foliar application of chlorantraniliprole 18.5 SC @ 30 g a.i.ha-1 was effective against O, phaseoli with the least feeding punctures per leaf (4.85) and adults per plant (0.35) followed by seed treatment with acetamiprid 20 SP @ 20 g a.i.ha-1 in field condition. Field evaluation of insecticides against L. boeticus showed that indoxacarb 14.5 SC @ 75 g a.i.ha-1 recorded lowest pod infestation (11.98 per cent) which was followed by flubendiamide 39.35 SC @ 48 g a.i.ha-1 (12.33 per cent) and thiacloprid 21.7 SC @ 120 g a.i.ha-1 (12.40 per cent). In case of percentage flower damage, chlorantraniliprole 18.5 SC @ 30 g a.i.ha-1 followed by flubendiamide 39.35 SC @ 48 g a.i.ha-1 and thiacloprid 21.7 SC @ 120 g a.i.ha-1 recorded low flower damage (5.68, 6.77 and 6.95 per cent) when compared to control (31.98 per cent). Maximum crop yield was recorded from plots treated with emamectin benzoate 5 SG @ 10 g a.i.ha-1 (160.77 g plant-1) followed by chlorantraniliprole 18.5 SC @ 30 g a.i. ha-1 (159.83 g plant-1) and flubendiamide 39.35 SC @ 48 g a.i.ha-1 (152.66 g plant-1) while in untreated plot the yield was 93.11 g plant-1. In the case of insecticide combinations against pod borer complex, seed treatment with acetamiprid 20 SP @ 20 g a.i.ha-1 and foliar application of insecticide combination (chlorantraniliprole 18.5 SC + flubendiamide 39.35 SC) at flowering stage followed by foliar application of chlorantraniliprole 18.5 SC @ seedling stage and combination (chlorantraniliprole 18.5 SC + flubendiamide 39.35 SC) at flowering stage and seed treatment with acetamiprid 20 SP @ 20 g a.i.ha-1 at seedling stage and foliar application of flubendiamide 39.35 SC @ g a.i.ha-1 were effective in reducing the flower and pod damage with less larval population and maximum crop yield. Among the borer pests of yard long bean, L. boeticus is the dominant pest based on their infestation and occurrence, whereby its incidence is more closely associated with crop stage rather than the weather parameters. From the biology studies, the vine borer, N. bicolour is found to possess maximum longevity on yard long bean than other borer pests. The resistant cultivars VS-13 and VS-54 could be utilized in future breeding programme. With regard to management of borer pests, foliar application of chlorantraniliprole 18.5 SC @ 30 g a.i.ha-1 was found effective in terms of percentage reduction in the flower and pod damage, reduced larval population and increased crop yield.ThesisItem Open Access Systematics of the tribes scymnini and stethorini (coleoptera: coccinellidae) from South India(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2018) Vidya, C V; KAU; Haseena BhaskarFamily Coccinellidae, the lady beetles, belong to the superfamily Coccinelloidea of the order Coleoptera and comprises approximately 6000 described species worldwide. Tribes Scymnini and Stethorini of the subfamily Scymninae of Coccinellidae are economically important predators successfully used in the biological control programmes of sucking pests of crops. Members of Scymnini are mainly predators of aphids, mealybugs, whiteflies and scales, whereas Stethorini are specific to mites. Though the fauna of Scymnini and Stethorini in India is species rich, it is poorly studied. The present investigation on “Systematics of the tribes Scymnini and Stethorini (Coleoptera: Coccinellidae) from south India” was carried out during 2015-17. The objectives include the following: (1) taxonomy of the tribes Scymnini and Stethorini associated with sucking pests in different agricultural ecosystems of south India, (2) prepare a key to the species of Scymnini and Stethorini and (3) generate DNA barcode for different species of Stethorini. Purposive surveys were undertaken across different districts of Kerala, Karnataka and Tamil Nadu covering 47 locations and 64 crops under different agricultural ecosystems. Beetles and immature stages of Scymnini and Stethorini were collected along with the associated prey. Immature stages of Scymnini and Stethorini were reared to adults. The specimens were then mounted, labeled and preserved as per standard procedures. The beetles were dissected and the taxonomic characters viz., antenna, mouth parts, prosternum, tarsus, post coxal line, male and female genitalia were studied and illustrated. The specimens were identified up to species level. Descriptions, illustrations and key to genera and species of Scymnini and Stethorini of southern India were prepared. The study encompasses 28 species of Scymnini of which six are putative new species. Two species are recorded for the first time in India and two species each from south India and Kerala are new records. Scymnini include Axinoscymnus, The genera treated under Cryptolaemus, Horniolus, Nephus, Sasajiscymnus and Scymnus. The genus Scymnus, represented by 20 species, of which 18 species are placed in three subgenera viz., Scymnus, Neopullus and Pullus. Two species are treated separately, as these differ distinctly from the known subgenera. The genus Nephus is represented by three species, Axinoscymnus with two species and Cryptolaemus, Horniolus and Sasajiscymnus with one species each. Stethorini are represented by 10 species in two genera: Stethorus and Parastethorus. Two putative new species of the tribe are described. Six species of Stethorini are new reports for Kerala. Two subgenera recognized under the genus Stethorus are Stethorus and Allostethorus. represented by four species each. Stethorus keralicus, one of the most common species, has been treated separately in this study, as its characters are not in agreement with the known subgenera. The genus Parastethorus is represented by only one species. The prey ranges of Scymnini and Stethorini were documented. Species distribution map were prepared for the species studied. Twenty one species of prey in four families viz., Aphididae, Pseudococcidae, Aleyrodidae and Diaspididae were recorded in association with the tribe Scymnini. Two new prey records for Scymnini are Toxoptera odinae for Scymnus pyrocheilus and Saccharicoccus sacchari for Nephus tagiapatus. Among Scymnini, Scymnus coccivora and S. saciformis are widely distributed with wider host range of six species as prey, while species of Axinoscymnus, though widely distributed, is specific to whiteflies. Among Stethorini, Stethorus pauperculus was found to be the predominant species with wider host range, while Stethorus keralicus was specific to Raoiella indica. New prey records for Stethorini includes Tetranychus okinawanus and T. truncatus for Stethorus forficatus; T. macfarlanei for S. pauperculus and Eutetranychus orientalis for Parastethorus indira. For barcoding the species of Stethorini, DNA was isolated using Qiagen DNeasy blood and tissue kit and the COI locus was amplified and sequenced. The sequences were aligned and characteristic barcode gaps were identified for Parastethorus indira, Stethorus forficatus, S. pauperculus, S. rani, S. keralicus, S. (Allostethorus) sp. 1 and S. (Stethorus) sp.1. Pairwise distances between the sequences were analysed which showed that intraspecific divergence ranged between 0.00 to 0.03, while the interspecific distance ranged between 0.14 to 0.24. A phylogenetic tree was constructed with 21 sequences in MEGA 7 using the maximum likelihood tree method. The sequences were submitted to GenBank (NCBI) and to BOLD for the generation of species specific barcodes. The study identified 38 species of predatory coccinellids in the tribe Scymnini and Stethorini in association with aphids, mealybugs, whiteflies, scales and mites, which are serious pests of crops. Knowledge on the taxonomy of these predators and their prey range throws light on the potential of the above groups in biocontrol of sucking pests.ThesisItem Open Access Characterization of Bemisia tabaci (Gennadius) (hemiptera: aleyrodidae), for genetic variability, endosymbionts and vector-virus interactions in cassava(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2018) Harish, E R; KAU; Mani ChellappanCassava is one of the important tuber crops cultivated all over the World. Cassava Mosaic Disease (CMD) is the most important limiting factor in its production. Silverleaf whitefly, Bemisia tabaci (Gennadius) is the vector responsible for the transmission of Cassava mosaic virus in cassava, which causes CMD. Genetic variation among the members of B. tabaci, makes them very difficult to manage. Endosymbionts present in the whitefly system could be a factor responsible for making them a successful sucking pest. There are various kinds of interactions existing between whitefly and the CMV. Studying these interactions precisely will help to understand the behavioural and physiological variations in whiteflies. In this background the present study, “Characterization of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), for genetic variability, endosymbionts and vector-virus interactions in cassava” was proposed and carried out at the Department of Agricultural Entomology, College of Horticulture, Vellanikkara, during Mrch 2014 to April 2016, with the objectives to analyse the genetic variability in cassava whitefly, characterization of its endosymbionts and elucidation of cassava whitefly - cassava mosaic virus interactions. Various life stages of B. tabaci were collected from different cassava growing agro ecological zones of Kerala and reared in laboratory as well as in polyhouse at optimum conditions. Genetic variability study was conducted with 10 selected ISSR primers which had shown polymorphism in their banding pattern; with amplicon size ranged between 200bp to 2900bp. Phylogenetic analysis using NTsys software revealed the presence of two major clusters with Sultan Bathery population as out group. Similarity matrix had shown up to 49 per cent variation between the samples. Polymerase chain reaction using mitochondrial cytochrome oxidase1 primers, C1-J2195 and L2-N-3014 had given amplicon of 850bp. Nucleotide sequences had shown variation up to 16.5 per cent and dendrogram generated out of the sequences using MEGA-6 (Neighbor Joining Method) gave two clusters and one out group. Sequence similarity check using reference sequences from NCBI data base indicated the presence of two biotypes, AsiaI and AsiaII5 in cassava plants of Kerala. Morphometric studies were conducted to assess the variations in different pupal and adult characters of thirteen whitefly populations. Significant variations were found in pupal length and pupal width of the biotypes. Pupal length varied between 0.746 mm to 0.668 mm and pupal width varied between 0.539 mm to 0.468 mm in female pupa. Out of 14 characters of pupa studied, variations in length and width were found to be significant. Among seven characters of adults studied, variations in wing, antennal length, body length and width were significant. AsiaI biotype was found to have lesser body length, but more width compared to AsiaII5. AsiaII5 was found to be an important biotype of B. tabaci infesting cassava in 12 out of the 13 locations surveyed. Endosymbiont characterization from whitefly using Next Generation Sequencing (NGS) - Illumina platform revealed the variations in microbiota. At phylum level, Proteobacteria was found at 87.57 per cent in whitefly populations collected from plains. The populations from high ranges contained Firmicutes at 82.67 per cent. Arsenophonus, an ‘indirect helper’ for virus spread by protecting viral coat protein from degradation in insect system with their GroEL chaperones were found at 24. 69 per cent in B. tabaci populations collected from plains. Behavioural and life cycle variation study of B. tabaci using six cassava genotypes had shown that virus infection in B. tabaci altered the dispersal and settling. Speed of movement observed to be maximum at 16.25 cm/s in non- virulent female whiteflies on the genotype CMR-9. Life cycle of virulent and non-virulent whiteflies was found to vary between 19.57 days to 30.77 days. A thorough understanding of genetic variations, endosymbiont diversity and behavioural response to virus could help the researchers in planning proper management strategies for B. tabaci. In future, information generated of such kinds could also help the researchers and policy makers to foresee and manage any possible outbreak of the pest and avoid any havoc caused by them.ThesisItem Open Access Microbial consortium for the management of insect pests of bitter gourd (Momordica charantia L.)(Department of Agricultural Entomology College of Agriculture, Vellayani, 2018) Naveeda, S; KAU; Anitha, NThe study entitled "Microbial consortium for the management of insect pests of bitter gourd" was undertaken in the Department of Agricultural Entomology at College of Agriculture, Vellayani during the period 2013 - 2018 with an objective to isolate and identify microbial pathogens of pests of bitter gourd, develop a microbial consortium, test its compatibility with new pesticide molecules and to evaluate the efficacy of the microbial consortium against major pests of bitter gourd. Important pests of bitter gourd viz. fruit fly, Bactrocera cucurbitae, pumpkin caterpillar Diaphania indica, epilachna beetle Henosepilachna septima and red pumpkin beetle Aulacophora foveicollis were monitored from bitter gourd fields in Thiruvananthapuram and Kollam districts. One entomopathogenic fungi from diseased epilachna grub and pumpkin caterpillar larvae and one phylloplane bacteria were isolated. Kotch's postulates were proved for both the fungi. Upon preliminary screening for pathogenicity to various pests of bitter gourd, the fungi showed infectivity only towards epilachna grubs and pumpkin caterpillar whereas, the bacteria was found to be infective to epilachna grub, pumpkin caterpillar and adults of red pumpkin beetle. The fungus from both the insects was identified as Fusarium verticilloides and the bacteria was identified as Serratia marcescens Pathogenicity studies were conducted using isolates of Metarhizium anisopliae (Ma4) Beauveria bassiana (Bb5) and Lecanicillium lecanii obtained from NBAIR, Paecilomyces lilacinus isolate (rrCC 6064), Beauveria bassiana isolate (rrCC 6063) and the indigenous isolates. The fungi M anisopliae and B. Bassiana were infective to all the test insects selected whereas the P. lilacinus was found infective only to pumpkin caterpillar and fruit flies. Lecanicillium lecanii was not infective to any of the test insects. M anisopliae was more virulent to the test insects compared to B. bassiana and reported a mortality of 93.54%, 82.5%, 45%, 5%, 25%, 61.05% respectively in B. cucurbitae adults, D. indica larvae, grubs and adults of H septima, adults of A. foveicollis and nymphs of L. australis seven days after treatment at a dose of 10 8 spores Lethargic movement followed by cessation of feeding was common symptom of mycosis in all the species. Bioassay was conducted against the adults of B. cucurbitae, H septima and A. foveicollis and the larvae of D. indica and H septima using M anisopliae (Ma4), B. bassiana (Bb5) and P. lilacinus (nCC 6064). The LC 50 values for M anisopliae were 1.55x10, 0.18X10, 1.56X10 and 4.70x10 spores mL- 1 respectively for adults of B. cucurbitae, D. indica larvae, grubs and adults of H septima, adults of A. foveicollis at seven days after treatment. With respect to B. bassiana, LC 50 values were 1.65x10, 1.20x10, 1.05X10, 5.48x10 and 2.94 x 10 spores ml respectiveiy was required for the adults of B. cucurbitae, D. indica larvae, grubs and adults of H septima, adults of A. foveicollis respectively. In vitro compatibility studies were conducted between the different entomopathogenic fungi viz. B. bassiana, M anisopliae, P. lilacinus and L. Iecanii. In dual cultures, colony growth of B. bassiana and M. anisopliae got locked at the point of contact after two weeks of inoculation leaving a space of 3 to 5 mm apart from each other. In dual culture combinations of B. bassiana with P. lilacinus and L. Iecanii and M anisopliae with P. lilacinus and L. Iecanii, the colony growth stopped at two weeks after inoculation and a space of 1.5 cm to 2 cm was observed between different fungi. The interactions between various microbes in-vitro is not necessarily an indicator of their in-vivo interactions. Hence in vivo studies were conducted to assess the effect different microbial combinations viz. M anisopliae with B. Bassiana (consortium 1), M anisopliae with P. lilacinus (Consortium 2) and B. bassiana with P. lilacinus (Consortium 3) on test insects. Laboratory evaluation of the fungal consortium showed that the mixtures of various fungi were more pathogenic to the test insects in comparison with the fungi using individually. The fungal consortium 1 (Ma4 +Bb5) was highly virulent to all the test insects and resulted in per cent mortality of 100, 100, 88.33, 36.67, 36.67 and 100 respectively for adults of B. cucurbitae, D. indica larvae, grubs and adults of H septima, adults of A. foveicollis and nymphs of L. Australis seven days after treatment. Talc based formulations of the consortium maintained the required standards of colony forming units in the formulation and retained bioefficacy against various test insects. Cfu at three months after storage was 0.83 x 10 7 and 7.23 x 10 7cfu g-1 respectively for room temperature and refrigeration. The components of the consortium I, B. bassiana and M anisopliae were tested for the compatibility with five insecticides commonly used for pest management in bitter gourd in order to evaluate the suitability of integrating the product with pesticides in pest management programmes. Compatibility of both the fungi was observed for the insecticide Chlorantraniliprole 18.5 SC 0.006 % . Field experiment was conducted in bitter gourd, variety Preethi to evaluate the talc based formulation of consortium I along with insecticide Chlorantraniliprole 18.5 SC and Malathion as check. The treatments were two application of Consortium I @ 35 g L -1, consortium followed by Chlorantraniliprole 18.5 SC 0.006 %, Chlorantraniliprole 18.5 SC 0.006 % followed by Consortium I @ 35 g L-1, two applications of Chlorantraniliprole 18.5 SC 0.006 % and two applications of Malathion and untreated check. Results showed that the treatment, consortium 1 followed by Chlorantraniliprole 18.5 SC 0.006 % effectively managed populations of D. indica (0.08 larvae /10 leaves) , H septima (0.11 grubs/ 10 leaves) and A. foveicollis (1.5 adults/ plant) at five days after treatment. The percentage infestation of fruits by B. cucurbitae also got reduced from 52.18 % during pre-treatment count to 9.13% after treatment and produced the highest yield of 14.53 t ha-1. To conclude, the fungal isolate which caused natural epizootic in epilachna grub and pumpkin caterpillar larvae was identified as F. verticilloides. A bacterium S. marcescens was obtained from the phylloplane of bitter gourd and found to be pathogenic to larvae of D. indica and grubs of H septima. The fungi B. bassiana and M anisopliae were pathogenic to all the test insects. The combination of both resulted in a higher mortality of the test insects and increased the speed of kill than when treated alone. However, in dual culture studies, the fungi were incompatible. Talc based formulation of the consortium maintained the required standards of cfu in the formulations and efficacy upto three months after storage. Highest mortality of the test insects were noticed at the dose 40 g L -1 of the formulation. In the field study, consortium 1 (Ma4 + Bb5) followed by Chlorantraniliprole 18.5 SC 0.006 % was effective in managing the insect population and resulted in a high yield.ThesisItem Open Access Bioefficacy and safety evaluation of biorational insecticides for the management of sucking pest complex of chilli (capsicum annuum L. )(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2011) Thania, Sara Varghese; KAU; Thomas, Biju MathewThe efficacy and safety of biorational insecticides used for the management of sucking pest complex of chilli, viz. mites (Polyphagotarsonemus latus Banks), thrips (Scirtothrips dorsalis Hood) and aphids (Aphis gossypii Glover) were tested in laboratory and field conditions. The efficacy of eight new generation insecticides viz., spinosad 75 g a.i. ha-1, spiromesifen 100 g a.i. ha-1 , spirotetramat 60 g a.i. ha-1 , indoxacarb 60 g a.i. ha-1 , imidacloprid 20 g a.i. ha-1, thiamethoxam 40 g a.i. ha-1 , flubendiamide 60 g a.i. ha-1 and acetamiprid 20 g a.i. ha-1 was assessed in comparison with propargite 570 g a.i ha-1 and dimethoate 300 g a.i ha-1 as acaricidal and insecticide check, against three sucking pests of chilli viz, mites, thrips and aphids under laboratory conditions. Based on the laboratory evaluation, acetamiprid, spiromesifen, propargite, spinosad and dimethoate were very effective against chilli mite whereas 100 percent mortality of chilli thrips was obtained in spinosad, spiromesifen, imidacloprid, thiamethoxam, acetamiprid, propargite and dimethoate in leaf disc method. The neonicotinoid insecticides viz, acetamiprid, imidacloprid, thiamethoxam and other insecticides viz, spiromesifen and dimethoate were found effective against chilli aphids. Spiromesifen was found as the safest insecticide to coccinellid and hemerobid grubs. Flubendiamide, spirotetramat and indoxacarb were also found safe to coccinellid grubs and hemerobid grubs, but they were not effective against the pest complex of chilli. Dimethoate was found toxic to coccinellid and hemerobid grubs. Among the neonicotinoid insecticides, acetamiprid and thiamethoxam were safer than imidacloprid. In the safety evaluation against the predatory mite Amblyseius spp, acetamiprid, thiamethoxam, spiromesifen and spirotetramat were safer than other insecticides. In the pot culture study, significantly lower population of chilli mites were recorded in spiromesifen, propargite, imidacloprid, acetamiprid, thiamethoxam and dimethoate sprayed chilli plants. Chilli thrips were not recorded in acetamiprid sprayed chilli plants upto seven days after spraying. When the damage caused due to the feeding injury of mites and thrips were indexed, (Leaf curl Index) lower indices were recorded in spiromesifen and propargite sprayed chilli plants. Among the different chemicals evaluated in field viz, spiromesifen, imidacloprid, acetamiprid thiamethoxam, propargite and dimethoate, ethion and oxy demeton methyl, the mite population was significantly lower in propargite, spiromesifen and acetamiprid treated plots. Acetamiprid treated plots recorded the lowest thrips population and lowest average leaf curl index (LCI) was recorded in spiromesifen and propargite treated plants. Spiromesifen and propargite treated plots harboured maximum numbers of natural enemies, where as among the neonicotinoids, acetamiprid and thiamethoxam were comparatively safer than imidacloprid. The yield of chilli was more in spiromesifen treated plants followed by acetamiprid sprayed chilli plants. Considering the waiting period of different insecticides worked out in the present investigation, acetamiprid is having the shortest waiting period of 3.51 days and it is the only insecticide which fits well in to the harvest interval of chilli fruits, whereas the conventional insectides like ethion and dimethoate recorded the maximum waiting period of 27.89 and 13.63 days, respectively. The half-life of acetamiprid, ethion and dimethoate were 2.27, 3.43 and 1.94 days respectively. The insecticide spiromesifen, sprayed on chilli fruits had a waiting period of 7.03 days to reach below the MRL of 0.5 ppm and the time taken for half of the spiromesifen to degrade was 1.71 days. Imidacloprid sprayed on chilli fruits took 2.08 days to degrade its residues to half of the initial deposit and the waiting period was fixed as 6.8 days. Propargite had a waiting period of 5.7 days on chilli fruits and the half life was calculated as 0.63 days. The insecticides selected to study the effect of different processing techniques in removing the insecticide residues on chilli fruits harvested at two hours after spraying and at five days after spraying were spiromesifen, imidacloprid, acetamiprid, propargite, ethion and dimethoate. In the case of spiromesifen, maximum residue removal (90.03%) occurred when the fruits were dipped in tamarind 2% solution followed by washing in water. For imidacloprid, all the treatments were very effective in removing residues, more than eighty percent of the residues were removed in all the treatments which justify its high polarity and the maximum removal was recorded when the fruits were dipped in 2% solution of tamarind (96.83%) followed by washing in water. In the case of acetamiprid, mere water wash removed 97.69% of the residues where as in the case of propargite, maximum removal of residues was obtained by dipping in 2% solution of tamarind (96.69%) for twenty minutes followed by washing in water. The extent of residue removal in the OP insecticides viz, ethion and dimethoate was less when compared to other new generation insecticides. In the case of ethion sprayed chilli fruits, maximum residues were removed when the fruits were dipped in 2% solution of lemon juice (83.13%) followed by washing in water. For dimethoate sprayed chilli fruits, maximum removal of residues occurred when the fruits were dipped in 2% solution of tamarind (53.98%). Out of six insecticides studied, dipping insecticide treated chilli fruits in 2% tamarind solution for twenty minutes followed by washing in water removed maximum amount of residues in the case of spiromesifen, imidacloprid, propargite and dimethoate. In the case of ethion also, tamarind treatment removed fairly good amount (60.88%) of residues. Owing to this majority, tamarind can be recommended as a good option for removing insecticide residues from fruits and vegetables.
