Browsing by Author "Amritha, V S"

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Augmentation of pollination in culinary melon (Cucumis melo var. acidulus L. Naudin) with Indian bee (Apis cerana indica Fab.)
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2019) Aneetta, M R; Amritha, V S
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; Amritha, V S
Bioecology of small hive beetles and assessment of their damage in stingless bee colonies
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Gayathri P Bose; Amritha, V S
Characterization and evaluation of aanticancerous property of stingless bee (Tetragonula trvancorica) honey on breast and cervical cancer cell lines
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2022-01-25) Nahala Maheen, N M; Amritha, V S
The research work entitled “Characterization and evaluation of anticancerous property of stingless bee (Tetragonula travancorica) honey on breast and cervical cancer cell lines” was carried out at College of Agriculture, Vellayani, Thiruvananthapuram, during the year 2020 to 2021. The objective of the study was to characterize stingless bee (T. travancorica) honey and to identify its anticancerous property on breast and cervical cancer cell lines. In the current study, characterization of stingless bee honey (SBH) and Indian bee honey (IBH) was done using liquid chromatography-mass spectrometry (LCMS) and ultraviolet visible (UV-VIS) spectrum analysis. Total phenol and flavonoid content in honeys were determined using folin–ciocalteau colorimetric reagent (FCR) method and aluminium chloride method respectively. The antioxidant activity was measured using DPPH (1, 1, -diphenyl-2- picrylhydrazyl), ABTS (2,2'-azino bis(3-ethylbenzothiazoline-6-sulphonic acid)and SOD (superoxide dismutase) radical scavenging assays. The anti-proliferative properties were assessed on different cancer and normal cell lines by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide) assay and trypan blue dye exclusion method. Proteins from honey treated cells were isolated and estimated by Lowry’s method and were run on sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE). The binding effect of different components identified in SBH was examined on estrogen receptor (ER) α and β using Schrodinger Maestro software. LCMS analysis revealed the presence of 2-hydroxy cinnamic acid, methyl syringate and fumaric acid in SBH, whereas these compounds were absent in IBH. The UV-VIS spectrum profile showed highest peak at 284nm, recognized as hydroxymethylfurfural (HMF) and its amount was seen more in SBH. The total phenol and flavonoid content was also seen more in SBH than IBH. 93 Studies on antioxidant assays showed effective scavenging of free radicals by stingless bee honey. The DPPH, ABTS and SOD free radicals were scavenged by SBH with IC50 values of36.15, 22 and 79.85 v/v respectively whereas the IBH scavenged DPPH and ABTS with IC50values of 72.75 and 57.89 v/v respectively. Stingless bee honeyshowed anti-proliferative activity on cervical cancer cell line, HeLa and breast cancer cell line, MCF-7 with IC50 value of 66.68 and58.11 v/v respectively. No toxicity was found on the in vitro safety evaluation done in Vero and IEC-6 cell lines up to the concentration of 100 v/v. For trypan blue dye exclusion method, the SBH shown considerable cytotoxic activity towards murine tumour cells such as DLA (Dalton Lymphoma ascites) and EAC (Ehrlich Ascites Carcinoma) cell lines in a dose dependant manner with IC50 values of 48.02 and 37.41 v/v respectively. In protein profiling study, the total amount of intracellular and membrane bound proteins isolated did not show much variation and in SDS PAGE, the proteins from cancer cell lines and normal cell lines revealed bands between 97 to 116 KDa. The docking studies of compounds present in SBH such as 2-hydroxy cinnamic acid, methyl syringate and fumaric acid with estrogen receptor β shows more binding, than with estrogen receptor α. The 2-hydroxy cinnamic acid docks deep well into the binding pockets of estrogen receptor β with docking score of 6.146 and binding energy -35.607 kcal/mol. Thus, the characterization of honeys revealed that SBH contain certain phenolic compounds (2-hydroxy cinnamic acid, methyl syringate and fumaric acid), whereas these compounds were not identified in IBH. SBH exhibited higher antioxidant activity against DPPH, ABTS and SOD free radicals and significant anti-proliferative activity against reproductive cancers such as breast and cervical cancer cell lines
Effect of insect mediated pollination in culinary melon, Cucumis melo var. acidulus Naudin
(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2025) Vismaya, S A; Amritha, V S
The present study entitled “Effect of insect mediated pollination in culinary melon Cucumis melo var. acidulus Naudin” was conducted at Department of Agricultural Entomology, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2022 to 2024. The objectives of the study were to assess the foraging behaviour of insect visitors, major pollinator-flower interaction and effect of pollination in culinary melon. The popular culinary melon variety, KAU Vishal was used in this study, and the crop was raised both under open field conditions and augmented (bee hive installed) condition. Observations on floral structures viz., flower spread, stamen characters, pistil characters etc., were taken after 10 percentage bloom. Insects visiting culinary melon were documented and the foraging behavior of major pollinator was assessed at weekly intervals for two months. The developmental changes in culinary melon (flower, fruit and seed development) due to bee visits were assessed by installing an Indian bee hive with six frame bee strength among the treatments; augmented, open- pollinated, hand pollinated and in pollinator excluded conditions. Studies on the floral biology of culinary melon revealed that flower bud initiation and anthesis was earlier in male flowers (31.30 days and 32.10 days) when compared to female flowers (38.70 and 49.80 days). Variation in the time of anthesis was also observed among the male (7:45 am) and female flowers (8:04 am). The count as well as the viability of pollen grains on anther and number of pollen grains deposited on the stigma was highest during 1100 -1300 h, which coincided almost with that of the stigma receptivity. A total of 19 insect visitors belonging to 18 genera, 8 families, and 4 orders were recorded, of which 15 species were identified as pollinators in terms of their foraging behaviour. Among them, six were nectar foragers and nine were both nectar and pollen foragers. Based on Shannon-Wiener diversity index, peak pollinator diversity was recorded during 0900-1100 h. Of these pollinators, Apis cerana indica Fab., Nomia 70 strigata Fab. and Ceratina binghami Cockerell recorded highest relative abundance (7.68, 3.70 and 3.04 bees mֿ ² 5 min ⁻¹) and number of loose pollen grains (60,000, 22,000 and 12,500). Thus, A. c. indica was ranked as the efficient pollinator of culinary melon in terms of the pollination efficiency index. Foraging behaviour of A. c. indica exhibited significant temporal variation throughout the day. Peak visitation rates were recorded during 1100-1300 h (11.83 ± 0.68 flowers min⁻¹) when compared to early morning (0700-0900 h: 7.79 ± 0.31 flowers min⁻¹) and late evening (1700-1900 h: 6.16 ± 0.68 flowers min ⁻¹). The number of bees visiting a single bloom was highest during 1100-1300 h (1.92 ± 0.05 bees 5 min⁻¹), followed by 0900 -1100 h (1.76 ± 0.13 bees5 min ⁻¹) and 1300-1500 h (1.62 ± 0.08 bees 5 min ⁻¹). The average time spent by bees on anthers as well as on the stigma was significantly high in the morning hours (0900-1100 h: 11.34 ± 0.84 sec and 0900-1100 h: 65.05 ± 29.65 sec), while, the number of returning foragers was highest during 1300- 1500 h (10.83 ± 0.83 bees 5 min ⁻¹). These findings highlight mid-morning to early afternoon as the optimal period for pollination activity in culinary melon. The impact of bee visits on flower, fruit and seed development under augmented (1-12 visits), open-pollinated, hand pollinated and in pollinator excluded conditions was assessed. Studies on the quantification of endogenous hormone levels such as Auxin (IAA) and Gibberellin (GA₃) revealed that open-pollinated flowers exhibited the highest auxin concentration (19.50 ± 0.20 ppb) which was followed by flowers with seven bee visits (6.32 ± 1.53 ppb). GA₃ was not detected in any treatment, indicating either its negligible role at anthesis in pollination response or due to the concentrations below detection limits. The quantitative and qualitative yield parameters of culinary melon as part of the fruit and seed development among the treatments were also observed. The fruit set percentage (0 to 100%) in culinary melon varied with the number of bee visits, with 100 per cent fruit set both in nine bee visits and open pollinated ones. Though percentage fruit set increased with bee visitation, the percentage of malformed fruits were also found increasing in flowers with 10 visits and beyond. Maximum fruit weight (2.43 ± 0.11 kg), fruit length (46.00 ± 1.00 cm), fruit diameter (11.46 ± 0.41 cm), flesh thickness (3.90 ± 0.10 cm), and TSS content (3.03 ± 0.06 °Brix) were recorded from 71 seven bee visit treatment. The seed quality parameters viz., seed set (1265.67 ± 140.10 seeds per fruit), total seed weight (11.02 ± 0.07 g), 100-seed weight (2.37 ± 0.06 g), and seed germination percentage (97.33 ± 0.57 per cent) were also maximum in the seven bee visits treatment. The present study revealed that A. c. indica was the dominant pollinator in terms of the Pollination efficiency index with peak foraging activity during 0900 to 1300 h. The count as well as viability of pollen grains on anther and number of pollen grains deposited on the stigma coincided almost with that of the stigma receptivity. The syngenesious type of anthers in culinary melon flowers with more than half of them inside the corolla cup and the similarity in length of Indian bee proboscis and stamen, signifies the relevance of bee pollination. Developmental changes in flower, fruit and seed among the pollination treatments indicated that both open-pollinated flowers and those receiving seven bee visits exhibited elevated auxin (IAA) levels, while the treatment, seven bee visits exhibited superior fruit and seed traits. These results highlight the critical role of A. c. indica in pollination, yield and quality of fruits in culinary melon.
Etiology of honey bee brood disease in Southern Kerala
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Jyothis, P Joseph; Amritha, V S
Evaluation and characterisation of effective fungal pathogens associated with the coconut eriophyid mite (Aceria guerreronis Keifer)
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2006) Amritha, V S; Pahummal Beevi, S
Outbreak of coconut eriophyid mite has become a serious menace by inflicting heavy damage to coconut plantation both in terms of yield reduction and economic return. The increased awareness of the general public about the repercussions of extensive use of chemical pesticides and also because of the apprehension being expressed by scientists and policy makers on various side effects of chemicals, biocontrol is getting more attention in the management of mite. The present study on “Evaluation and characterisation of effective fungal pathogens associated with coconut eriophyid mite (Aceria guerreronis Keifer)” was carried out in the Department of Agricultural Entomology, College of Horticulture, Vellanikkara. The main objectives of the study were to isolate, identify and confirm the pathogenicity of fungi associated with the eriophyid mite, identification of the potential acarifungal pathogens and molecular characterisation of the selected isolates. Survey conducted at three different locations each from four panchayaths of Thrissur district for one year revealed that there was no significant difference in mite population (live mite, dead mite and egg) among the four panchayaths, but it varied significantly within the three locations of the four panchayaths. A uniform distribution of mite population was followed in the outer perianth, inner perianth and nut surface with maximum live mites and egg count on the nut surface and dead mites on the inner perianth. Live mite and egg count contributed to about 36 per cent while the dead mite formed 28 per cent of the total mite population. Predatory mite population varied significantly both among the four panchayaths as well as among the locations within the four panchayaths. Two types of predatory mites, Amblyseius spp. and Bdella spp. were mainly observed during the study with an average population range from 4.469 to 15.719 per nut. Seasonal variation showed three peaks of live mite population and egg count during the late monsoon (August), winter (January/February) and summer (April/May) months; where as two peaks during winter (January to February) and summer (March to April) for the dead mite population. Predatory mite population followed a normal range which increased with increase in mite population to a certain degree within the limited range of predatory mite population. Correlation analysis showed a positive relationship between population parameters of mite (live mite, dead mite, egg count) and predatory mite population and maximum temperature. A non-uniform correlation was observed between mite population and other weather parameters. Natural occurrence of the mite specific pathogen, Hirsutella thompsonii isolates at monthly intervals for 12 months contributed to 4.90 per cent. Maximum number of Hirsutella isolates was obtained during winter season followed by the monsoon season. Isolates belonging to the genus Fusarium spp., Acremonium spp. and Paecilomyces spp. were mostly isolated during the monsoon season while the isolates of actinomycetes during summer period over the entire four panchayaths. The fungal species which proved pathogenicity to coconut eriophyid mite were two species coming under the genus Hirsutella, viz., H. thompsonii and H. kirchnerii and the other fungal species coming under the genus Acremonium viz., A. strictum and A. incoloratum, Fusarium viz., F. lateritium and F. verticillioides, Paecilomyces, P. fumosoroseus and P. lilacinus. Based on the presence or absence of synnemata, two different varieties of Hirsutella were found to occur, namely, H. thompsonii var. thompsonii and H. thompsonii var. synnematosa. Cultural and morphological observations revealed that among the eight isolates coming under the two varieties H. thompsonii var. synnematosa isolate, Madakkathara-I recorded maximal fungal growth (4.167 cm) and biomass (2.660 g) while the H. thompsonii var. thompsonii isolate, Chirakkekodu-I possessed maximum mean sporulation (3.33 x 106 spores ml-1). Among the other fungal pathogens, maximum growth and sporulation was observed on Acremonium spp., A. strictum (7.99 cm) and A. incoloratum with a mean value of 43.11 x 106 spores ml-1. Mortality assessment of the Hirsutella isolates along with other fungi at their respective doses of sporulation revealed that the fungal pathogen, P. fumosoroseus recorded the maximum mortality of 83.65 per cent which was closely followed by H. thompsonii var. thompsonii (Chirakkekodu-I) with a mortality of 80.63 per cent. Molecular characterisation of the seven isolates of Hirsutella using the five primers comprising of the OPE and OPAH series exhibited a maximum genetic similarity of 74 per cent between the Hirsutella isolates, Madakkathara-I and Konnakuzhy-I. Fifty per cent genetic similarity was obtained between two clusters with the Hirsutella isolate, Marakkal-I in one cluster and all the other Hirsutella isolates and H. kirchnerii in the other cluster. The isolates coming under two varieties of H. thompsonii, H. t. var. thompsonii, Chirakkekodu–I with maximum sporulation and H. t. var. synnematosa Madakkathara-I with maximum growth rate and biomass came under the same subcluster.
Field toxicity of new generation insecticides to bee pollinators
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Raeesa, P; Amritha, V S
Histomorphology of Indian bee (Apis cerana indica Fab.) supplemented with probiotics
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2019) Akhila Pahee; Amritha, V S
Management of coconut eriophyid mite Aceria guerreronis Keifer using ecofriendly methods
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2001) Amritha, V S; Saradamma, K
Experiments were conducted in the Department of Agricultural Entomology and in the Instructional Farm, College of Agriculture, Vellayani during 2000-2001, to generate eco-friendly components in developing a sustainable long term strategy of pest management against coconut eriophyid mite. The treatments included the laboratory screerung of various oils, botanicals and synthetic acaricides. The promising treatments and innovative farmer practices were evaluated in a field experiment. The results of laboratory screening revealed that Neem oil three per cent followed by Neemazal 0.4 per cent and castor oil three per cent were promising among the botanicals while fenazaquin 0.05 per cent followed by sulphur W.P 0.4 per cent were found to be effective among the synthetic acaricides. The field evaluation using promising natural products and synthetic acaricides, showed that fenazaquin 0.05 per cent was effective followed by sulphur W.P 0.4 per cent. Maximum protection was observed after the third round of spraying. Sprays applied at the critical stage of infestation afforded maximum protection to the bunches. Results of the field evaluation experiment using natural products and innovative farmer practices revealed that starch solution five per cent was the most effective among the various treatments.
Mass queen rearig and royal jelly characterization in Indian bee, Apis cerana indica fab
(Department of Entomology, College of Agriculture , Vellayani, 2023-12-20) Anjali, J S.; Amritha, V S
The study entitled “Mass queen rearing and royal jelly characterisation in Indian bee Apis cerana indica Fab.” was carried out at Department of Entomology, College of Agriculture, Vellayani during 2021-2023. The objectives of the study were standardisation of mass queen rearing and characterization of the royal jelly in Indian bee, A. c. indica. Ten good Indian bee colonies (C1 to C10) maintained at AICRP on Honey bees and Pollinators were selected based on the previous record. The colonies were screened for their economic traits (honey and pollen area in the brood), colony development traits (brood area, number of brood cells, number of combs containing brood, brood survival rate ie., number of eggs hatched and bee population), hygienic traits (number of pin-killed pupae removed, brood pattern continuity and cleanliness of the bottom board) and foraging behaviour (number of incoming bees and outcoming bees per min during different times of a day). Observations were taken during the honey flow season (March-April), dearth season (May-July) and brood rearing season (Aug-Oct). A non-uniform trend was found among colonies in different parameters. Significant difference was observed in traits like honey area, brood population and brood survival rate during the honey flow season, where the colony C7 had the highest honey area (168.25cm2) and brood area (620cm2) while the colony, C1 exhibited highest brood survival rate (97.75%), number of combs occupied by brood (4.00) and foraging activity (57.50 bees/min). C1 was found to be the best colony in terms of honey area (67.00cm2), brood survival rate (96.50%), brood area (576.36cm2), number of brood cells (2305.45), pin killed pupae removed (100%), brood pattern (1.67), number of combs occupied by brood (3.77) and foraging activity (40.50bees/min) during the dearth season. The performance of the colonies varied during the brood rearing season. The parameters (honey, pollen and brood area) which exhibited significant variation among the colonies were further analysed to assess their monthly variation throughout the seasons. It was found that highest honey storage was recorded during March (90.50cm2) followed by April (78.05cm2), while the pollen area was at its peak during May to June which ranged from 32cm2 to 33 cm2. Brood area was found highest during August (525cm2) followed by March (482.50 cm2) Correlation analysis of traits which had prominent role on colony development viz., honey area, pollen area, brood area, bee population and foraging activities with the weather parameters revealed a significant negative correlation with rainfall and relative humidity whereas a positive correlation was found with sunshine hours. Pollen area had a significant positive correlation with the temperature. With regard to the foraging activity, it showed a significant positive relation with temperature and sunshine hours. Based on the selection index, the colonies were ranked and the first five colonies which showed good performance (C1, C7, C4, C6 and C8) were selected for raising the next generation by the Doolittle method of grafting. Comparative analysis of traits between the parent and daughter colonies revealed that no significant difference exists among the colonies, thus they exhibited a similar performance. An exception was found in case of pollen area where daughter colonies had more pollen area than the parent colonies. The number of queens which can be reared at a time was assessed by Doolittle method of grafting. For this, queen less colonies with population levels of six frame in the brood chamber was utilized. Percentage acceptance of queen cells was found to be higher in colonies provided with 10 grafts when compared to five and 20 grafts. Monthwise queen cell acceptance showed highest percentage (66.66) in August. The royal jelly which has a major role in mass queen rearing was analysed for the major constituents based as per standard protocols. Analysis of major components in royal jelly revealed protein (35.70%) as the major component followed by lipid (20.00%). Among vitamins, vitamin B2 (15.30%) was found in significant proportion. Thus, the present study concludes that the quality traits of Indian bee mother colonies can be transferred to the daughter colonies through Doolittle method of grafting. The optimum number of grafted queen cells for mass queen rearing was standardised as ten with the peak queen cell acceptance during August. The analysis of major components in Indian bee royal jelly revealed the presence of protein (35.70%), lipid (20.00%) and vitamins (20.61%).
Mellissopalynology of indian honey bee (Apis cerana indica Fab.) apiaries in southern kerala
(Department of Agricultural Entomology, College of Agriculture,Vellayani, 2013) Aswini, S; Amritha, V S
Morphometric variations of stingless bees in Southern Kerala and assessment of honey quality
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2016) Divya, K K; Amritha, V S
Pollination efficiency of stingless bee tetragonula iridipennis (Smith) in cucumber (Cucumis sativus L.) under protected cultivation
(Department of Agricultural Entonology, College of Argiculture, Vellayani, 2020) Lintu, V V; Amritha, V S
The present investigation entitled “Pollination efficiency of stingless bee, Tetragonula iridipennis (Smith) in cucumber (Cucumis sativus L.) under protected cultivation” was conducted in the polyhouse at College of Agriculture, Vellayani from November 2019 to February 2020. The objective was to evaluate the effect of pollination by stingless bee (T. iridipennis) on fruit set, yield and quality of salad cucumber under protected cultivation. The foraging behaviour of T. iridipennis inside the protected environment was observed to evaluate their diurnal variations in resource collection and pollination ability in cucumber flowers. Observations on mode of alighting of bees, foraging behaviour of stingless bees, floral biology of C. sativus and pollination efficiency of stingless bees in terms of the quantitative and qualitative parameters were recorded. Most of the observed bees were side workers (78 %), which landed on the petals and proceeded towards the reproductive part (stamen or stigma) while the rest of the foragers (22 %) were top workers, which landed directly on the top of stamen or stigma. Foraging rate was the highest (6.80 male flowers 5 min-1) during the time of initiation of foraging (0800 – 0900 h), while maximum foraging intensity was recorded as 4.40 bees male flower-1 10 min-1 during 1000 – 1100 h. Maximum time spent by pollen collectors per male flower was recorded as 44.20 sec. during 1200 - 1300 h of the day during which maximum pollen grains were observed from the body of the bees. Irrespective of the time period, stingless bee spent significantly more time on female flowers compared to that of male flowers in respective time intervals. The diurnal activity of a colony assessed in terms of the total number of incoming and outgoing foragers at the hive entrance revealed that their number increased with the ascent of the day, reached a maximum during 1300-1400 h (67.00 and 58.00 number of incoming and outgoing foragers respectively) and then decreased thereafter. Weekly observations showed that the pollen and nectar foraging activity of stingless bees varies in a day with the peak period during 1200-1400 h. A significant positive correlation was recorded between temperature and number of incoming foragers (r = 0.78) while a significant negative correlation was observed between relative humidity and number of incoming foragers (r = -0.68). Studies on the floral biology as well as the morphology of bees has revealed that the individual nectar foraging bee insert its head into the corolla tube of both male and female flowers to reach the nectaries. Significant increase in per cent fruit set was observed in stingless bee pollinated crop (76%) compared to hand pollinated one (54%) whereas the qualitative yield parameters like per cent malformed fruit, length and diameter of fruit were statistically on par. With regard to the quantitative yield parameters significantly higher single fruit weight, number of seeds per fruit and germination per cent (2 DAS) (685.00 g, 344.10 seeds/ fruit and 90.60 %, respectively) was recorded from the stingless bee pollinated crop than that of the control crop (555.00 g, 210.90 seeds/ fruit and 63.00 %, respectively). Higher yield was observed in augmented pollination (5.09 kg m-2) compared to hand pollination (3.16 kg m-2). Apart from this, bee assisted pollination was economically feasible with better B:C ratio (1.23) than that of the hand pollinated one (0.67). The foraging activity of bees varied in a day with the peak period during 1200-1400 h. Stingless bee pollination had a profound influence on the per cent fruit set as well as the quantitative parameters like fruit weight, germination percentage and number of seeds per fruit. Augmentative pollination with stingless bee under protected cultivation resulted in increased yield of 61 per cent in C. sativus.
Quantification and characterization of Indian honey bee (Apis cerana indica Fab.) Venom
(Department of Agricultural Entomology, College of Agriculture,Vellayani, 2022) Alen Joy; Amritha, V S
Seasonal incidence of predatory wasp (Vespa spp.) in Indian bee apiaries and evaluation of bait traps
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Ann Verghese Kolady; Amritha, V S