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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 Origin and composition of stingless bee propolis(Department of Agricultural Entomology, college of Agriculture , Vellayani, 2023-05-03) Abhijith,R L; KAU; Vijayasree VThe present investigation entitled “Origin and composition of stingless bee propolis” was conducted at the Department of Agricultural Entomology, College of Agriculture, Vellayani during 2020-2022. The objective of the study was to assess the resin-foraging behaviour of stingless bees, the origin of the resin, and the characterization of bee propolis. Four locations viz., AICRP on Honey Bees and Pollinators, Vellayani, and apiaries in Nedumangad, Mariapuram, and Navaikulam were selected for the study. Resin sources, foraging rate, physical characteristics, and major components of propolis were studied. The trees and plants were observed within up to a 100m radius of the bee hive for identifying the resin source. Plants identified were Mango tree (Mangifera indica L.), Jack tree (Artocarpus heterophyllus Lam.), Breadfruit tree (Artocarpus altilis Parkinson), Cashew tree (Anacardium occidentale L.), Cambodge tree (Garcinia cambogia Syn.), False mangosteen (Garcinia xanthochymus Hook.), Monkey puzzle tree (Araucaria araucana Molina). Based on the resin flow and wounds present, plants were grouped into 4 grades from 1-4. The number of bees visiting the wound was also counted. M. indica (4) and G. cambogia (3) were recorded with maximum stingless bees foraging per day. A. araucana and G. xanthochymus came under grade 2 with minimum stingless bees foraging per day. Resin foraging activity was found high from 0900h to 1600h in all the locations throughout the observation. Peak foraging activity was noticed from 1100h to 1200h at Vellayani, Mariapuram, and Nedumangad, Navaikulam. There was no significant correlation between weather parameters and resin foraging rate when correlation studies were conducted. Propolis from all the locations possess pleasant aromatic smells and was sticky in texture at normal temperatures and hard at cold temperatures. The colour of propolis from Vellayani and Navaikulam was moderate brown. It was dark grayish-reddish brown and moderate olive brown in Nedumangad and Mariapuram respectively. LC-HRMS and GC-HRMS analysis revealed that the main chemical classes present in the propolis were acids, fatty acids, steroids, alcohols, amines, amino acids, flavonoids, terpenoids, chalcones, aldehydes, ketones, benzene, coumarin, pterocarpan, ether, and ester. The predominant components identified in the propolis of Vellayani and Nedumangad were 20S, 24S-dihydroxy dammer-25-en-3-one, whereas it was Glycyrrhizic acid in Mariapuram and Navaikulam. The various components found common throughout the locations were syringic acid, and ellagic acid (acids), punicic acid, 9,10-dihydroxystearic acid, and phloionolic acid (steroids and fatty acids), thevetiaflavone, luteolin, and quercetin (flavonoids), octadecanamine and oleamide (amines), ursolic acid and oleanolic acid (terpenoids), 5-[(z)-pentadec-8-enyl] benzene1,3-diol (alcohols), dihydrocordoin and orotinichalcone (chalcones). Thus, this study identified different botanical resin sources and found M. indica and G. cambogia with maximum stingless bees foraging. High foraging activity was observed from 0900h to 1600h in all the locations throughout the year. Several components were identified with functional groups like acids, fatty acids, steroids, alcohols, flavonoids, terpenoids, etc. from the propolis when the chemical characterization studies were carried out.ThesisItem Open Access Bioefficacy of Aloe vera (L.) in managing pests of brinjal, Solanum melongena L.(Department of Agricultural Entomology, College of Agriculture,Vellayani, 2023-04-25) Ajay P Kumar; KAU; Malini NilamudeenThe research programme, entitled “Bioefficacy of Aloe vera (L.) in managing pests of brinjal, Solanum melongena L.” was undertaken at the Department of Agricultural Entomology, College of Agriculture, Vellayani during the period 2020 to 2022. The objective of the study was to evaluate the biopesticidal efficacy of A. vera in managing pests of brinjal. Laboratory screenings were conducted to find out the repellent, antifeedant, insecticidal and the effect on fecundity and egg hatchability of aloe leaf extracts viz., crude aloe gel solution, aloe leaf peel aqueous extract and aloe leaf peel powder aqueous extract at three different concentrations (2.50 %, 5.00% and 10.00%) against second instar grubs and adults of Henosepilachna vignitioctopunctata (F.). The highest per cent repellence recorded was 73.33 and 83.33 in aloe leaf peel powder aqueous extract 10 % at 8 h after treatment against the second instar grubs and adults, respectively. Crude aloe gel solution 10 % recorded a per cent repellence of 53.33 against both grubs and adults whereas, aloe leaf peel aqueous extract 10 % recorded 53.33, 30.00 per cent repellence against second instar grubs and adults, respectively. Aloe leaf peel powder aqueous extract 10 % recorded a potential Antifeedant Index (AI), of 99.47 per cent and 100 per cent against the grubs and adults, respectively. Crude aloe gel solution 10 % recorded AI of 88.49 per cent and 99.95 per cent against grubs and adults, respectively whereas, aloe leaf peel aqueous extract 10 % exhibited AI of 70.93 per cent and 90.33 per cent against grubs and adults, respectively. The fecundity of the beetles which were fed on leaves treated with aqueous extract of 10 % leaf peel powder of aloe was reduced to 57.00 per cent and the percentage emergence of grubs was only 82.52. Crude aloe gel solution 10 % recorded a reduction of 45.16 per cent in fecundity and the per cent emergence of grubs was 92.17. Aloe leaf peel aqueous extract 10 % reported only 29.03 per cent reduction in fecundity and 100 per cent emergence of grubs. None of the treatments recorded any mortality on grubs and adults even after eight days of treatment. Based on the results under in vitro experiments, field efficacy of crude aloe gel solution, aloe leaf peel aqueous extract and aloe leaf peel powder aqueous extract at 10.00 % concentrations were evaluated at the Instructional Farm, College of Agriculture, Vellayani in managing the population of Aphis gossypii, Amrasca bigutulla bigutulla, Coccidohystrix insolita, H. vigintioctopunctata and fruit damage caused byLeucinoides orbonalis. At 14 days after treatment, aloe leaf peel powder aqueous extract 10 % recorded a reduction of 56.29, 84.74, 65.18 and 73.50 per cent reduction in the population of aphids, leafhoppers, mealybug and epilachna beetles, respectively. Two weeks after the treatment, aloe leaf peel powder aqueous extract 10 per cent was statistically on par with talc-based formulation of B. bassiana NBAIR Bb5 @ 20 g L-1 in reducing the population of, both aphids and leafhoppers. And it was on par with neem garlic soap formulation-KAU Raksha @ 10 g L-1 in reducing the population of aphids, mealybugs and epilachna beetles. Fifteen days after the treatment, the plots treated with aloe leaf peel powder aqueous extract 10 % recorded a reduction of 39.13 per cent in fruit damage caused by L. orbonalis. At 30 days after treatment, all aloe extract treated plots were on par with talcbased formulation of B. bassiana NBAIR Bb5 @ 20 g L -1 and neem garlic soap formulation-KAU Raksha @ 10 g L -1 in reducing the fruit damage caused by the shoot and fruit borer. All the aloe extracts were found safe to natural enemies, in comparison with the chemical check. Fruit yield from aloe leaf peel powder aqueous extract 10 %, aloe leaf peel aqueous extract 10 % and crude aloe gel solution 10 % treated plots were 0.77, 0.54 and 0.49 kg plant -1 . From the present study, it was clear that the aloe extracts viz., crude aloe gel solution, aloe leaf peel aqueous extract and aloe leaf peel powder aqueous extract at different concentrations exhibited repellent and antifeedant activity in addition to its effect on fecundity and egg hatchability of epilachna beetles. Aloe leaf peel powder aqueous extract 10 % was found more effective compared to 10 % concentrations of crude aloe gel solution and aloe leaf peel aqueous extract in field conditions. Further research to isolate and elucidate the chemical constituents responsible for the effectiveness of aloe leaf peel powder aqueous extract, can pave way for the development of a novel biopesticide.ThesisItem Open Access Susceptibility of Tetranychus okinawanus Ehara (Prostigmata: Tetranychidae) infesting ornamental plants to novel acaricides(Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Sreshma, M; KAU; Haseena, BhaskarSpider mites of the family Tetranychidae are well-known agricultural and horticultural pests that feed on a wide variety of plants, including vegetables, fruit trees, and ornamentals. Many traditional insecticides and acaricides have been used to manage mite pests for several decades. The widespread usage of acaricides around the world has facilitated development of resistance in different mite species, making mite management challenging. As a result, many novel acaricides with distinct chemical structures and modes of action have been developed and marketed for mite control. However, after a few years of use, mite populations developed resistance to these newly introduced compounds too. The spider mite species, Tetranychus okinawanus, recently recorded on an ornamental plant Adenium in Thrissur district, for the first time in India, has now emerged as the predominant species of mite infesting ornamental plants in Kerala. Recently, several growers reported inefficacy of the commonly used novel acaricides against mite pests in many ornamental crops, suggesting that the mite populations might have developed resistance to acaricides. Hence a study was carried out to investigate the status of acaricide resistance in Tetranychus okinawanus infesting Adenium in horticultural nurseries and also to elucidate the biochemical mechanism involved in development of resistance. Purposive surveys were conducted in six commercial horticultural nurseries in Thrissur district viz., National Rose Garden, Mangadan Botanical Garden, Ayyappa Nursery, Saranamayyappa Nursery, Pooja Gardens and Nursery, and Manalur Adenium Garden and samples of spider mite infesting Adenium were collected. Mites were maintained as separate isoline cultures assigning unique accession numbers as NrAd1, MgAd2, AyAd3, SyAd4, PjAd5 and MnAd6. Morphological characterisation of the slide mounted mite specimens from the isoline cultures was carried out to confirm the species identity as T. okinawanus. Susceptibility of the six field populations to three acaricides viz., spiromesifen, fenazaquin and dicofol was evaluated in the laboratory, in comparison with the reference susceptible population maintained without exposure to any acaricides in the laboratory, following toxicological bioassay. Susceptibility studies with fenazaquin revealed that the accession NrAd1 recorded the highest LC50 value (27.85 ppm) and has developed moderate level of resistance (14.38-fold) to fenazaquin. This was followed by PjAd5 (9.70-fold), AyAd3 (4.06-fold), MnAd6 (3.78-fold), and SyAd4 (3.23-fold). The lowest resistance ratio was recorded by the accession MgAd2 (1.66). The toxicity studies of spiromesifen also recorded low to moderate levels of resistance in different populations of T. okinawanus. The accession NrAd1 recorded highest resistance ratio of 27.31 followed by PjAd5 (7.18), MnAd6 (3.94), AyAd3 (1.78), MgAd2 (1.42) and SyAd4 (1.06). However, the mite populations showed only low level of resistance to dicofol, recording resistance ratios in the range of 3.65 to 1.22. Biochemical basis of acaricide resistance in different populations of T. okinawanus was investigated by estimating the activity of detoxifying enzymes such as carboxyl-esterase, cytochrome P450 and glutathione S- transferase. Carboxyl-esterase enzyme showed an enhanced activity of 1.03 to 3.52-fold, while cytochrome P450 monooxygenases recorded 1.01 to 2.08-fold higher activity in the field collected populations, compared to the susceptible population. The level of these detoxifying enzymes was found to be higher in the accession NrAd1, which also recorded the highest resistance ratio in the study. However, the activity of glutathione S-transferase (GST) did not differ significantly among the field populations and also with susceptible population, indicating that GST is not a contributing factor in the development of resistance in T. okinawanus against spiromesifen, fenazaquin and dicofol. The study recorded development of resistance in the spider mite, T. okinawanus on Adenium to spiromesifen and fenazaquin, in the horticultural nurseries in Thrissur district, Kerala for the first time in the world. The significant role of the detoxifying enzymes, carboxyl-esterases and cytochrome P450 monooxygenases in imparting resistance in T. okinawanus to the two novel acaricides, fenazaquin and spiromesifen was also confirmed in the study. The study demands formulation of a suitable resistance management strategy in horticultural nurseries in the state for suppressing or delaying resistance development in mite populations.ThesisItem Open Access Microbial diversity in hive-stored pollen of indian honey bee, Apis cerana indica (Fabricius)(Department of Agricultural Entomology, College of Agriculture, Vellanikkara, 2021) Abhishek, V; KAU; Mani ChellappanHoney bees are eusocial flying insects. Among all insects that pollinate, honeybees are considered to be one of the crucial pollinators. Honey bees represent only a small fraction of the roughly 20,000 known species of bees. Honey bees obtain all of their nutritional requirements from a diverse combination of pollen and nectar. Pollen grains referred to as 'bee bread' or 'bee meat' are the natural sources of proteins, vitamins, fats, lipids and minerals, of which proteins are very much essential for building the body tissues of the bees, especially during the early embryonic growth. Worker bees of Apis cerana indica help in the fermentation of pollen which releases additional nutrients that are used in the production of antibiotics and fatty acids which inhibit spoilage. Pollen analysis of samples provides the information regarding the plants preferred by bees for nectar, as the pollen grains dispersed are mostly collected by bees along with nectar. Honey has two sources of contamination, primary one being the hive stored pollen. Thus, it is very essential to study the microbial diversity of pollen, which may lead to spoilage of pollen and nectar. The present investigation on “Microbial diversity in hive-stored pollen of Indian honey bee, Apis cerana indica (Fabricius)” was conducted at Department of Agricultural Entomology, College of Agriculture, Vellanikkara, Kerala Agricultural University during 2020-2021 in order to study the diversity of hive-stored pollen and associated microbes in A. cerana indica (Fabricius) colonies. Purposive surveys were conducted in six locations at Palakkad and Wayanad district viz., Mannarkkad, Nellipuzha, Nottaamala, Kenichira, Kayakunnu and Cheengode. Hive stored pollen collected were maintained in refrigerated conditions after assigning unique accession numbers as PKD-1, PKD-2, PKD-3, WYD-1, WYD2, WYD-3. Microbial diversity, microbial load of hive stored pollen, identification and characterization of pollen with respect to its nature, size, shape, aperture, exine pattern along with physicochemical properties viz., moisture content, water activity, pH, ash content, total acidity and protein content were studied. Palynological identification plays a crucial role in beekeeping industry. Pollen aids as a food supplement to honeybees for their growth and development. It assists in the identification of geographical and botanical origin of pollen. A total of 21 plants were recorded as pollen sources by bees from the study area (six locations) of two districts. Ten pollen types were identified based on its nature, size, shape, aperture, exine pattern using PalDAT software. Identified plant species were Sphagneticola trilobata (Asteraceae), Caesalpinia pulcherrima (Fabaceae), Zinnia elegans (Asteraceae), Ocimum sanctum (Lamiaceae), Clitoria ternatea (Fabaceae), Biophytum sensitivum (Oxalidaceae), Bauhinia acuminata (Fabaceae), Mimosa pudica (Fabaceae), Tecoma stans (Bignoniaceae), Portulaca grandiflora (Portulacaceae). Characterization of pollen revealed that ten plant species belonging to seven families serve as pollen sources in respective survey locations. Physicochemical properties of hive stored pollen of A. cerana indica collected from six locations were investigated by estimating the moisture content, water activity, pH values, ash content, total acidity and protein content. Moisture content varied from 15.29-15.38 (g/100g). Water activity varied from 0.73 to 0.74 (aw) and the pH varied between 3.77 and 3.83. Ash content varied from 1.87-2.01 (g/100g). Total acidity varied from 9.64-10.13 (mmol/g). Protein content varied from 3.46-3.69 (%). Parameters like moisture content, water activity, protein content were more in the Wayanad sample, it may be because of high humidity and temperature variations. Parameters like pH, total acidity and ash content were more in Palakkad sample, which infers that mineral content might be more. Microbial diversity of hive stored pollen of Apis cerana indica collected from six locations was investigated by identifying the microbes through their morphological, cultural, molecular characterization. Other parameters like microbial diversity, microbial load, microbial load to pollen grain ratio, microbial population were also observed. In total, four bacteria and three fungal species were identified. However, colonies of actinomycetes and yeast were not obtained. Out of four bacteria, B2, B3, B4 – gram positive while B1- gram negative. The shape of all bacterial isolates was rod with change in their colony colour.16s rRNA sequencing of bacterial isolates revealed that B1 as Pseudomonas aeruginosa, B2 as Bacillus megaterium, B3 as Bacillus aryabhattai and B4 as Bacillus megaterium respectively. Out of the three fungi, colony colour of T1 colony colour was green, W1 colony colour was white and A1 colony colour was orange. All isolates have flat elevation with an entire margin. ITS sequencing of fungal isolates revealed that T1 as Trichoderma reesei, W1 as Westerdykella multispora and A1 as Neurospora crassa. Microbial diversity was more in sample collected Wayanad with two fungal and two bacterial colonies whereas, one fungal and two bacterial colonies in sample collected from Palakkad. Microbial load was more in samples from Wayanad (6.6x104 cfu/g) when compared with Palakkad sample (3.3x104 cfu/g). Comparison of microbial load to pollen grain ratio revealed that Wayanad sample recorded highest with 6.6x104 cfu/g to Palakkad sample with 3.3x104 cfu/g. Bacterial and fungal populations were observed more in Wayanad sample when compared to Palakkad sample. The study recorded the pollen sources of different localities in and around the Palakkad and Wayanad districts of Kerala. Moisture content plays a significant role which might be the reason for high microbial diversity and microbial load in Wayanad. The present study demands the investigations of other physicochemical properties like EC, starch content, amino acid composition, microbial spores present in pollen which could be useful for the food preservation industry or potentially hazardous in due course of time.ThesisItem Open Access Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Anitha, N; KAU; Mithra, MohanThe study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.ThesisItem Open Access Insecticide resistance management in Rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Neethu, P; KAU; Thania Sara VargheseThe research work entitled "Insecticide resistance management in rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)" was done at College of Agriculture, Vellayani during 2019 to 2021.The objectives of the study were to assess the resistance levels in rice weevil, biochemical basis of resistance and screening of new molecules for the management of S. oryzae. Different sample populations of S. oryzae were collected from the three godowns of Food Corporation of India (FCI) viz., Kollam, Valiyathura, and Thikkodi, as well as a susceptible lab culture of S. oryzae maintained without pesticide exposure, was obtained from the Division of Entomology, Indian Agricultural Research Institute (IARI). Resistance levels of the commonly used insecticides in FCI viz., malathion and deltamethrin were evaluated in the three populations collected from Kollam, Valiyathura and Thikkodi by film method of bioassay and compared it with the susceptible lab population from IARI. Kollam population showed highest resistance to both malathion and deltamethrin with resistance ratios of 14.94 and 9.03 followed by Valiyathura with resistance ratios of 11.39 and 7.79, respectively. Thikkodi population showed the least resistance to malathion and deltamethrin, with resistance ratios of 8.74 and 5.48, respectively. Malathion resistance was higher in all the three populations than the deltamethrin resistance. The most resistant population selected from the previous experiment i.e., the Kollam population was further assayed for its biochemical basis along with the susceptible IARI lab culture. The Kollam population was found significantly higher in total protein (6 mg ml-1 ) and activity of detoxifying enzymes viz., carboxylesterases (0.65 µmol min-1 mg protein-1 ), glutathioneS-transferases (0.41 µmol min-1 mg protein-1 ) and cytochrome P450 (0.74 p mol min-1mg protein-1 ) than the lab sample. The sample population collected from Kollam was again screened for their susceptibility to new generation insecticides like fipronil, indoxacarb and chlorantraniliprole by film method of bioassay. Fipronil was found to be more toxic with LC50 value of 5.86 ppm followed by indoxacarb (90.57 ppm) and chlorantraniliprole (4041.43 ppm). Fipronil and indoxacarb were 619.8- and 40.13-fold toxic to resistant population of S. oryzae with respect to malathion. The newer insecticides in the previous experiment along with malathion and deltamethrin were further screened simulating the conditions of FCI godown. The insecticides were sprayed on jute bags containing 1 kg of rice grains and 50 adult beetles of Kollam population of S. oryzae. The dosages of newer insecticides were taken 10 times more the LC50 value obtained in the laboratory bioassay and FCI recommended dosage was taken for malathion and deltamethrin. Fipronil 5% SC @ 0.006% recorded significantly higher mortality of 86.5 and 89.5 per cent at 24 and 48 h of treatment followed by indoxacarb 14.5% SC @ 0.09% and chlorantraniliprole 18.5% SC @ 4.04%. The persistence of the most effective insecticide fipronil along with malathion and deltamethrin on rice grains were further studied by recording the residue levels at different time intervals after spraying. Dosages were same as the previous experiment. Insecticides were sprayed on jute bags containing rice grains and residues were analysed at 0 (2 h after spray), 1, 3, 5, 7,10, 15, 20 and 30days intervals using the methods validated prior to residue estimation. Fipronil residues were below the limit of quantification at 2 h after spraying. The residues of deltamethrin and malathion persisted up to 3 and 5 days after spraying with a half-life of 2.48 and 2.71 days, respectively. From the present study it is revealed that S. oryzae collected from Kollam, Valiyathura and Thikkodi were resistant to the commonly used insecticides viz., malathion and deltamethrin and it is confirmed here by the presence of higher levels of detoxifying enzymes in the resistant population. Further screening of newer insecticide molecules against the resistant population of S. oryzae suggested that fipronil 5% SC @ 0.006% is highly effective and less persistent on grains when compared to malathion and deltamethrin.ThesisItem Open Access Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Mithra, Mohan; KAU; Anitha, NThe study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.ThesisItem Open Access Eumolpinae (Coleoptera: Chrysomelidae) of southern India(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2021) Amritha Kumari, S; KAU; Prathapan, K DThe present study entitled “The Eumolpinae (Coleoptera: Chrysomelidae) of southern India” was carried out at Collage of Agriculture, Vellayani from October 2015 to March 2020. The study was designed with the objectives of collection and identification of the eumolpine leaf beetles of south India, preparation of illustrated keys to genera and species with emphasis on the characters of male and female genitalia and documentation of host plants in all possible cases. One thousand five hundred and two specimens from various ecosystems in south India were studied. Hand picking, aspiration, sweep netting and light traps were used to collect eumolpines. Specimens were also procured on loan basis from different institutions in India and abroad. Collected specimens were mounted and labelled. Available ecological and biological information was gathered in all cases. Genitalia was dissected as per standard procedures. Inflation and eversion of endophallus follow Yamasako & Obhayashi (2011). Specimens were identified tentatively based on the available literature and then confirmed by comparing with type specimens or consulting with experts. Measurements were made with a calibrated ocular micrometer and pertinent ratios were worked out. Illustrated keys, descriptions and diagnosis are provided. Male genitalia, including endophallus and female genitalia are described and illustrated. The Afrotropical genus Microeurydemus is newly reported from the Oriental Region. Malegia and Scelolanka are new reports to India. Pagria ingibbosa, P. ceylonica and P. pseudograta are new species records for India. Range of distribution of Basilepta subcostata and Trichochrysea are extended to south India. Tricliona Lefèvre, 1885 new snynonym is a new junior synonym of Bathseba Motschulsky, 1866. Neofidia Strother new name, is proposed as the replacement name for Fidia Baly, 1863, a junior homonym of Fidia Motschulsky, 1861. Bathseba syzygium n. sp. and Pseudostonopa palynophaga n. sp. are described as new to science. Eleven putative new species in the genera Mesocolaspis, Malegia, Microeurydemus, Basilepta, Cleoporus, Dermorhytis, Edistus, Pagria, Scelolanka and Trichochrysea were described. New host plant records include Anacardium occidentale L. (for Fidia kanaraensis), Ixora (for Eurypelta modesta), Aegle marmelos (for Colasposoma downesi), Mallotus atrovirens (for Cleoporus inornatus), Antidesma acidum (for Edistus sp.), Milletia pinnata (for Scelolanka). Bathseba syzygium n. sp. has been reported on Syzygium cumini and Pseudostonopa palynophaga n. sp. has been reported as a pollen feeder of Poaceae. Pagria signata species group warrants further investigations, due to inconsistencies in morphological, genetalic and molecular characters. The eumolpine leaf beetle fauna of south India comprises 146 species placed in 35 genera. Checklist of Eumolpinae of south India is provided. The study treated 53 species under 20 genera. Two new species, 11 putative new species in 10 genera, 12 new host plant records, several new distributional records and new characters of taxonomic value are reported. Nomenclature of many economically important eumolpines are updated.ThesisItem Open Access Field tolerance of chilli varieties against sucking pest complex(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2022) Haritha, N K; KAU; Vijayasree, VThe study on the “Field tolerance of chilli varieties against sucking pest complex”was conducted at Department of Agricultural Entomology, College of Agriculture, Vellayani during 2019-2021 with the objective to evaluate chilli genotypes for field tolerance to sucking pest complex viz; Aphis gossypii Glover, Polyphagotarsonemus latus Banks and Scirtothrips dorsalis Hood. A total of 30 genotypes were screened for the field tolerance to the sucking pests, including indigenous genotypes of Kerala, KAU released varieties and accessions from NBPGR. The mean population count of A. gossypii, P. latus and S. dorsalis on 20, 35, 50 and 65 days after transplanting was recorded and significantly lower mean number of A. gossypii was recorded in L3 (2.83 leaf-1), L9 (4.61 leaf-1) and L14 (5.75 leaf-1). The population of P. latus was observed least in the genotype L5 with a mean number of 1.47 mites leaf-1 which was followed by L14 (2.36 leaf-1) and L3 (2.49 leaf-1). The minimum incidence of S. dorsalis was recorded in the genotype L5 which showed a mean population of 2.25 thrips leaf-1 and it was followed by L14 (3.94 leaf-1) and L3 (4.03 leaf-1). The genotype L11 was found most susceptible with the highest number of A. gossypii (23.72 leaf-1), P. latus (6.30 leaf-1) and S. dorsalis (6.75 leaf-1). The damage assessment was done by observing the leaf damage caused by mites and thrips. When the mean leaf damage was recorded on 20, 35, 50 and 65 days after transplanting, P. latus showed least preference to the genotype L5 with a per cent leaf damage of 14.92 and this was followed by L14 (16.92) and L3 (20.92). The minimum damage by S. dorsalis was observed in the genotype L5 with a leaf damage of 15.08 per cent and was followed by L3 and L14 with a leaf damage of 18.33 and 21.08 per cent respectively. The genotype L11 was severely damaged by P. latus and S. dorsalis with a per cent leaf damage of 76.33 and 74.08 respectively. The Per cent Leaf Curl Index (PLI) was calculated based on the leaf damage, for grouping the chilli genotypes into resistant, moderately resistant, susceptible and highly susceptible categories. Based on the mean PLI due to damage by P. latus the genotypes, L5 and L14 were grouped under moderately resistant category. The genotypes L5 and L3 were grouped as moderately resistant based on mean PLI due to damage by S. dorsalis. The genotypes L11, L4, CF1 and IC284628 were coming under the highly susceptible category due to infestation of P. latus and S. dorsalis. Principal Component Analysis (PCA) was carried out based on the mean population of A. gossypii, P. latus and S. dorsalis to find out the tolerant and susceptible genotypes against the sucking pest complex. The genotypes L5, L3 and L14 were found as the tolerant and L11 as the susceptible genotype for which the analysis of morphological traits, biochemicals and nutrients were carried out. Different morphological traits like plant height, total number of leaves plant-1 and leaf area were highest in L3. The number of branches plant-1 and trichome density was highest in L5 and the length-width ratio of leaves in the genotype L14. However, all these morphological characters were found lowest in the genotype L11. Analysis of biochemicals revealed that the total phenol content and capsaicin content was highest in the genotype L5 (0.290 mg g-1 and 0.016mg g-1 respectively) and lowest in the genotype L11. Total protein and total sugar were highest in L11 (6.169 mg g-1 and 0.216 mg g-1 respectively) and lowest in L14. Total nitrogen and total phosphorus were highest in L11 (0.18% and 0.63% respectively) and lowest in L3. Total potassium was highest in L14 (1.08%) and lowest in L11 (0.46%). Correlation studies were done to find out the relationship between the different traits in chilli genotypes and infestation of A. gossypii, P. latus and S. dorsalis. Among the morphological characters, plant height and leaf area had a significant negative correlation with the population of A. gossypii while number of branches plant-1 had a significant negative correlation with the incidence of all the three sucking pests. The total protein and total sugar had a significant positive correlation with the population of A. gossypii, whereas total phenol had a significant negative correlation with the incidence of P. latus and S. dorsalis. Total nitrogen had a significant positive correlation with the population of A. gossypii whereas total phosphorus had a significant positive correlation with the population of S. dorsalis. Based on the mean population of A. gossypii, P. latus and S. dorsalis and the leaf damage caused by them, the genotypes L5, L3 and L14 were observed as the tolerant whereas the L11 was found as the susceptible genotype to these sucking pest complex.
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