Browsing by Author "Sreekumar, K M"

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Biology and biometry of Neochetine elchhorniae warner (Curculionidae: Coleptera)and the nature of damage caused by it on Eichhornia crassipes (mart)
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1990) Sreekumar, K M; Joseph, D
The biology, morphology, biometrics and dispersal pattern of the weevil Neochetina eichhorniae Warner and the nature and extent of damage caused by it on water hyacinth (Eichhornia crassipes (Mart.) were studied. An indirect method of estimating the field population was also attempted. The insect laid the eggs beneath the epidermis of plant parts. Incubation period was 6.6 days and the hatching percentage was 93.2. The larvae fed by tunnelling, and the first, second and third larval instars were completed in 8-10, 13-16 and 13-17 days, respectively. The cocoon was attached to the live roots of the plant and the pupation was just below the water surface. The pupal period was 16.6 days. Adult female longevity was 75.3 days while that of the male was 172.3 days. Pre-oviposit iona I period was 49 days and the total number of eggs produced during the whole life period was 462.5. The head capsule width of first, second and third instar larvae were 0.3, 0.488 and 0.693 mm respectively. In adult males, the average distance between the antennal socket and the tip of the rostrum was 0.259 mm and it was 0.487 mm in females. This character helps in the identification of sexes. No microbes or mites were recorded as natural enemies. The predators were the common non-specific aquatic insects like dytiscid beetle, giant water bug, dragon fly naiads and back swimmers.
Diversity and population dynamics of mango fruit fly bactrocera spp (Diptera: Tephritidae)
(Department of entomology, college of agriculture, Padannakkad, 2023-08-21) Anagha, K P.; Sreekumar, K M
The study entitled “Diversity and population dynamics of Bactrocera spp. (Diptera: Tephritidae)” was conducted at the Department of Entomology, College of Agriculture, Padannakkad during 2021-2022. The main objective of the study was the documentation of species complex, varietal preference and population dynamics of Bactrocera spp. infesting mango in the Instructional Farm I, College of Agriculture, Padannakkad. Surveillance of fruit flies for a period of one year from 17-09-2021 to 16-09-2022 was carried out using bottle traps with methyl eugenol as the lure. A total of 10,546 individual fruit flies were trapped during the surveillance period of which major percentage was B. dorsalis. Four species of fruit flies viz. Bactrocera dorsalis, B. zonata, Zeugodacus tau and Z. cucurbitae were identified from the population collected in that order of dominance. Out of 10,546 total fruit flies captured 10,332 adults were identified as B. dorsalis, accounting for 97.97% of the population being the dominant fruit fly in the area, 199 number of fruit flies (1.89%) were identified as Zeugodacus cucurbitae, nine fruit flies (0.09%) were identified as B. zonata, and six fruit flies (0.06%) were identified as Z. tau. The highest weekly population of fruit flies was recorded in the 14th Standard Meteorological Week of 2022 (02-04-2022 to 08-04- 2022), with a population of 793 fruit flies and the lowest population in 50th SMW (10- 12-2021 to 16-12-2021), with only one fruit fly. The average monthly population was recorded highest in May with a population of 667.5 flies per month and lowest in December with a population of 16 flies per month. Population parameters of fruit flies such as species richness was found to be 0.32, Simpson dominance index as 0.04, Shannon Weiner diversity index as 0.11 and evenness index as 0.42. Population of fruit flies during the surveillance period of one year had a significant positive correlation with minimum temperature (+0.354). Population of fruit flies during the fruit availability i.e., from April to June had a significant positive correlation with minimum temperature +(0.805), and a significant negative correlation with soil temperature (-0.512). Maximum temperature (-0.329) and wind speed (-0.192) had a negative correlation with population of fruit flies and a positive correlation with rainfall (0.204). Both field and laboratory evaluations were carried out to determine the varietal preference of Bactrocera dorsalis for ten different mango varieties, viz., Phirangiladuva, Kalapady, Neelum, Bangalora, Bennet Alphonso, Mundappa, Banganappalli, Himayuddin × Neelum, Gomanga, and Kuttiattoor mango during the peak period of infestation i.e., from April to June. Natural infestation showed a significantly lower number of egg laying in fruits of Neelum, maggot development in the pulp of Bennet Alphonso and Neelum and adult emergence from the fruits of Himayuddin X Neelum, Kalapady and Bennet Alphonso respectively. Kuttiattoor mango recorded significantly higher number of eggs laid, maggot developed and adult emergence from natural incidence. A total number of 1934 adults emerged from naturally infested varieties were identified as B. dorsalis. Laboratory evaluation of preference of B. dorsalis showed non preference for egg laying, maggot development and adult emergence from mango varieties like Bennet Alphonso, Kalapady, Neelum, Mundappa, Himayuddin X Neelum, and Kuttiattoor mango. Number of eggs laid, maggots developed and adult emergence was significantly higher in Gomanga, Banganappalli, and Gomanga and Bangalora varieties of mango respectively in laboratory condition. Naturally fallen mangoes of six varieties viz., Banganappalli, Phirangiladuva, Kalapady, Neelum, Bangalora and Mundappa collected from IF 1 recorded significantly lower number of maggot development in the Kalapady variety. Phirangiladuva and Banganappalli varieties recorded significantly higher numbers of maggot development. Screening of mango varieties for fruit fly resistance showed that variety Neelum is highly resistant and variety Kalapady is resistant to fruit fly infestation. Correlation between morphological characters of fruit and number of eggs laid in fruits showed that peel thickness had a significant negative correlation (-0.674). Correlation between biochemical characters and maggot population, adult emergence and percent infestation of fruits showed significant negative correlation with ascorbic acid content (-0.67, -0.77, -0.66) and crude fibre content (-0.86, -0.82, -0.59) and significant positive correlation with total sugar content (0.71, 0.70, 0.84). Total phenol content, flavonoid and titrable acidity had a negative correlation. Varietal preference of B. dorsalis suggested that Neelum and Kalapady varieties showed a significant resistance. Morphological and biochemical characters of fruits are significantly related with resistance of mango varieties against B. dorsalis and therefore, can be used as marker traits in further breeding programmes to select resistant varieties.
Evaluation of pongamia oil soap against major pests of Okra, Abelmoschus esculentus (L). Moench
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2019) Anu Thomas; Sreekumar, K M
Evaluation of pongamia oil soap against major pests of vegetable cowpea, Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2019) Sajay, S; Sreekumar, K M
Evaluation of the effect of mineral nutrition in the management of major pests of cowpea
(Department of Agricultural Entomology, College of Agriculture, padannakkad, 2017) Vishnu Priya, T A; Sreekumar, K M
Horticultural mineral oil for pest management in Brinjal and Chilli
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2026-01-31) Sajay,S; Sreekumar, K M
The research programme entitled ‘Horticultural mineral oil for pest management in brinjal and chilli’ was aimed at elucidate the mode of action, phytotoxicity, safety to natural enemies, compatibility and pest management efficacy of horticultural mineral oil in brinjal and chilli. Safety evaluation of horticultural mineral oil was carried out in the Department of Agricultural Entomology, College of Agriculture, Padannakkad, during 2022-23 to evaluate phytotoxicity, toxicity to natural enemies and compatibility with biocontrol agents. Eleven concentrations of HMO (HMO at 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% and 8%) and a control were applied on one month old seedlings of brinjal and chilli as part of phytotoxicity evaluation. For experimenting on natural enemies and biocontrol agents, six concentrations of HMO (HMO at 2%, 2.5%, 3%, 3.5%, 4% and 4.5%) and a control were evaluated. All the safety evaluation experiments were designed under CRD with three replications. Results showed that HMO up to 6.5% did not show any phytotoxic symptoms in both brinjal and chilli. But HMO at 7%, 7.5% and 8% resulted in phytotoxicity symptoms like necrotic patches, with the severity of these symptoms showing an increasing trend as the concentration increased. HMO at 2% is safest for Trichogramma chilonis, Bracon brevicornis, Cheilomenes sexmaculata and Chrysoperla sp. followed by 2.5% and 3%. HMO is not compatible with biocontrol agents such as Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii and Trichoderma asperellum. Laboratory evaluation of horticultural mineral oil against selected pests of brinjal and chilli was carried out in the Department of Agricultural Entomology, College of Agriculture, Padannakkad, during 2022-23 to evaluate the toxicity against grubs of epilachna beetle Henosepilachna vigintioctopunctata and caterpillar of shoot and fruit borer Leucinodes orbonalis. A net house experiment was conducted to find the repellency of chilli whitefly, Aleurothrixus trachoides. The test organisms were exposed to seven treatments including T1: HMO at 2%; T2: HMO at 2.5%; T3: HMO at 3%; T4: HMO at 3.5%; T5: HMO at 4%, T6: HMO at 4.5% and T7: control designed under CRD with three replications. From the results, HMO at 4.5% caused the highest significant mortality of Leucinodes orbonalis which was on par with 4% followed by 3.5%, and 3%. HMO at 4.5% caused the highest significant mortality of Henosepilachna vigintioctopunctata, which is on par with 4% followed by 3.5%, and 3%. HMO at 4.5% resulted in the highest significant repellency against Aleurothrixus trachoides, which was on par with 4% followed by 3.5%, and 3%. HMO at 3% was selected as the best concentration based on the results of safety evaluation experiments and laboratory evaluation of selected pests. Field study was carried out using RBD with eight treatments and three replications on brinjal and chilli from November 2023 to April 2024 at the Instructional farm of College of Agriculture, Padannakkad. Treatments applied in brinjal were: T1: HMO at 3 %; T2: HMO at 3 % + azadirachtin formulation at 1 % 1ml/L; T3: azadirachtin formulation at 1 % 2ml/L; T4: HMO at 3 % + thiamethoxam 25WG 0.1g/L, T5: thiamethoxam 25WG 0.2g/L, T6: HMO at 3 % + chlorantraniliprole 18.5SC 0.15ml/L, T7: chlorantraniliprole 18.5SC 0.3ml/L and T8: untreated control and treatments applied in chilli were T1: HMO at 3 %, T2: HMO at 3 % + azadirachtin formulation at 1 % 1ml/L, T3: azadirachtin formulation at 1% 2ml/L, T4: HMO at 3 % + thiamethoxam 25WG 0.2g/L, T5: thiamethoxam 25WG 0.4g/L, T6: HMO at 3 % + fenpyroximate 5EC 0.3ml/L, T7: fenpyroximate 5EC 0.6ml/L and T8: untreated control. Observations on pest population were made a day prior to spraying and post treatment population at 1,3,5,7 and 14 DAT while damage symptoms were observed at 7 and 14 DAT. Results indicated that, HMO at 3% in combination with half the recommended dose of chemical pesticides (azadirachtin formulation 1 % 1ml/L, thiamethoxam 25WG 0.1g/L, and chlorantraniliprole 18.5SC 0.15ml/L) yielded the same significant results when compared with the full recommended dose (azadirachtin formulation 1% 2ml/L, thiamethoxam 25WG 0.2g/L and chlorantraniliprole 18.5SC 0.3ml/L) against epilachna beetle Henosepilachna vigintioctopunctata in brinjal. HMO at 3% in combination with chlorantraniliprole 18.5SC 0.15ml/L (half the recommended dose) and chlorantraniliprole 18.5SC 0.3ml/L (full recommended dose) achieved the highest reduction in the damaged shoots and fruits caused by the attack of shoot and fruit borer Leucinodes orbonalis in brinjal. HMO at 3 % in combination with thiamethoxam 25WG 0.1g/L (half the recommended dose) was superior among all other treatments against leaf hopper Amrasca biguttula biguttula in brinjal, which was on par with treatment thiamethoxam 25WG 0.2g/L (full recommended dose). HMO at 3% in combination with chlorantraniliprole 18.5SC 0.15ml/L recorded the highest marketable yield of brinjal, which was followed by chlorantraniliprole 18.5SC 0.3ml/L and HMO 3% in combination with azadirachtin formulation 1% 1ml/L. HMO at 3% in combination with fenpyroximate 5EC 0.3ml/L (half the recommended dose) achieved the best result, which was on par with fenpyroximate 5EC 0.6ml/L (full recommended dose) against chilli mite Polyphagotarsonemus latus in chilli. HMO 3% in combination with fenpyroximate 5EC 0.3ml/L and thiamethoxam 25WG 0.2g/L (half the recommended dose) resulted in highest success rate in controllling the thrips Thrips parvispinus population in chilli which was on par with fenpyroximate 5EC 0.6ml/L and thiamethoxam 25WG 0.4g/L (full recommended dose). HMO at 3 % in combination with thiamethoxam 25WG 0.2g/L (half the recommended dose) combination gave the best results among all other treatments against whitefly Aleurodicus disperses in chilli, which was on par with treatment thiamethoxam 25WG 0.4g/L (full recommended dose). HMO at 3% in combination with fenpyroximate 5EC 0.3ml/L recorded the highest marketable yield of chilli, which was followed by fenpyroximate 5EC 0.6ml/L. The scanning electron microscope (SEM) study conducted to find out the morphological changes in Myzus persicae and Spodoptera litura treated with HMO 3% indicated that the treatment changed the mouthpart morphology of Myzus persicae. SEM images also revealed that HMO 3% blocked the spiracles and damaged the trichomes, and produced significant changes in the structure of the cuticle of Spodoptera litura. A comparative study of the droplet spreading area of HMO, insecticides, and their combinations was designed under CRD with nine treatments and three replications. Treatments applied were: T1: HMO at 3 %; T2: HMO at 3 % + azadirachtin formulation at 1 % 1ml/L; T3: azadirachtin formulation at 1 % 2ml/L; T4: HMO at 3 % + thiamethoxam 25WG 0.1g/L, T5: thiamethoxam 25WG 0.2g/L, T6: HMO at 3 % + chlorantraniliprole 18.5SC 0.15ml/L, T7: chlorantraniliprole 18.5SC 0.3ml/L, T8: HMO at 3 % + fenpyroximate 5EC 0.3ml/L and T9: fenpyroximate 5EC 0.6ml/L. Results showed that, the droplets of the combinations having HMO at 3% and HMO at 3% alone spread more compared to chemical formulations which used alone. Since oil plus emulsifier in the HMO reduces surface tension and creates more stable dispersed droplets, when sprayed on leaves or other plant surfaces, the chemical combination with HMO can spread more effectively than with the chemical applied alone.
Incidence of pepper pollu beetle in major black pepper growing agro ecological units of Kasaragod district
(Department of Agronomy, College of Agriculture, Padannakkad, 2024-06-04) Mule Siri Chandana; Sreekumar, K M
An investigation entitled ‘Incidence of pepper pollu beetle in major black pepper growing agro ecological units of Kasaragod district’ was conducted during September to November of 2023 to evaluate the infestation of pollu beetle in two agroecological units viz., northern laterites (AEU-11) and high hills (AEU-15). Seven gardens from AEU-11, namely Madikkai, Cheemeni, Badiyadka, Kodom-Bellur, Chengala, Madhur and Periya were chosen. Three gardens were selected from AEU-15, which include East Eleri, Malom and Kallar. Panniyur-1 variety was selected for the study. In AEU-11, Chengala recorded the highest population of pollu beetle adults, whereas Periya, Cheemeni and Badiyadka had the lowest counts. Chengala experienced maximum intensity of leaf and spike damage, whereas Cheemeni and Madikkai had the lowest. Madhur reported the highest larval population and Badiyadka being the lowest. Spike fall was intense in Chengala and lowest in Cheemeni. Berry damage was most severe in Chengala and least in Badiyadka among the locations surveyed. In AEU-15, Kallar recorded the highest adult beetle population, spike damage, spike fall, larval population and berry damage. Conversely, East Eleri witnessed the most intense leaf damage. Malom experienced the lowest damage among all the observed parameters. There was no significant difference between the two agro ecological units when adult beetle population, leaf damage, spike damage, larval population and berry damage were considered. There was significantly high difference between spike fall in AEU-15 when compared to AEU-11. Correlation analysis revealed that pollu beetle adult population (0.53), larval population (0.64) and berry damage (0.57) exhibited the strong positive correlation with shade level of the field. Spike fall, leaf damage and spike damage also correlated positively, although all correlations are statistically non-significant.
Management of pests of cowpea using red ant, oecophylla smaragdina (fab.)
(Department of agricultural entomology, College of agriculture, Padannakkad, 2015) Amida Saparya; Sreekumar, K M
Mass trapping of cowpea pod borer maruca vitrata (F.) (lepidoptera; pyralidae) using sex pheromones
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2018) Eurekha Savadatti; Sreekumar, K M
Pongamia oil soap for the management of major pests of brinjal (Solanum melongena L.)
(Department of Agriculture, College of Agiculture, Padannakkad, 2020) Jeevitha, P; Sreekumar, K M
Population dynamics and management of coconut root grub (Leucopholis coneophora Burm.)
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2014) Jeevan, C H; Sreekumar, K M
Role of mineral nutrition in the management of pests in chilli
(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2018) Shaana, O M; Sreekumar, K M