Standard Week Research Articles

Pest management practices impact Helicoverpa armigera infestation and foraging behaviour of pollinators in sunflower

Field experiments for two consecutive years (2020 and 2021) were conducted to record population dynamics of Helicoverpa armigera Hubner and foraging behaviour of pollinators in sunflower before and after undertaking pest management practices. The study disclosed that H. armigera (larvae) crossed ETL (Economic Threshold Level) from 10th SW (Standard Week), warranting application of pest management measures. Many pollinator species were observed foraging on sunflowers during the same time. The least foraging by pollinators was recorded in early morning and late evening hours, depicting avoidance of insecticide application when pollinator foraging activity is maximum. A combination of synthetic and bio-insecticides (Chlorantraniliprole, Bt-kurstaki, Emamectin-benzoate, Spinosad, Lambda-cyhalothrin, Novaluron, and Neem-oil) were tested for their efficacy against H. armigera and impact on foraging behaviour of pollinators. Bio-insecticide-treated plots recorded significantly higher number of foraging pollinators as compared to synthetic-insecticide-treated plots. Of the insecticides used, Chlorantraniliprole showed highest efficacy against H. armigera but recorded lowest foraging activity of pollinators in both the years of study. In contrast, neem-oil and Bt-kurstaki treated plots showed maximum foraging by pollinators while successfully managing H. armigera.

Management of Insect Pests of Bottle Gourd in Polyhouse

This study on the insect pests of bottle gourd Lagenaria siceraria grown in polyhouse revealed the incidence of whitefly Trialeurodes vaporariorum and melon aphid Aphis gossipii from 26th to 38th standard week (SW). The peaks in incidence were observed in 34th SW (T. vaporariorum - 12.99 ± 1.18/leaf and A. gossypii- 52.5 ± 9.60/leaf. The incidence of these exhibited a positive correlation with temperature and a negative one with relative humidity. When insecticides were evaluated against these in polyhouse, after two sprays, imidacloprid 17.8SL (0.45 ml) was superior. Imidacloprid 17.8SL (0.3 ml) and dimethoate 30EC (1 ml) provided efficient control.

Population Dynamics of Fall Army Worm <i>Spodoptera Frugiperda</i> (J E Smith) on Maize

Population dynamics of the fall army worm (FAW) Spodoptera frugiperdaon maize was carried out at the research field of Tamil Nadu Agricultural University, Coimbatore (kharif and rabi, 2018 and 2019). The results revealed that maximum FAW trap catches were obtained during 34th(7.6 moths/ trap) and 5th(7.8 moths/ trap) standard weeks (SW) of kharif and rabi seasons of 2018, respectively. During 2019, a more or less similar trend was observed with a maximum during 31st(7.2 moth/ trap) and 48th (8.2 moth/ trap) SW of kharif and rabi seasons, respectively. Correlation with weather factors indicated a significant negative correlation with evening relative humidity (RH) and significant positive correlation with morning RH during 2019-20. No significant effect of weather factors was observed during 2018-19 except for a significant positive correlation with evening RH and rainfall. The correlation between larval counts and pheromone trap catches were significantly positive with r-value of 0.55 and an R2value of 0.907 during 2018-19.

INTERACTION OF PINK BOLLWORM (LEPIDOPTERA: GELECHIIDAE) POPULATION LEVELS IN PHEROMONE TRAPS AND WEATHER FACTORS

Pink bollworm (Pectinophora gossypiella) is a destructive pest of agricultural crops especially cotton crop in Pakistan. It has ability to form rosette flowers, bolls and makes them unable to open. Thus it deteriorates cotton seed quality which has significant impact on yield reduction. Increasing trend of insecticides has resulted in insecticide resistance, environmental pollution and risks of human health. Integrated pest management has key role to reduce negative impacts. Besides of several other components, pheromone traps are best monitoring and mass capturing tool for bollworms in agricultural crops. The study was conducted to check relation of pink bollworm mass trapping in pheromone traps relating to environmental factors during three years study 2018 to 2020. Results indicated that pink bollworm has two peak activity periods during study years. Standard weeks (SW) 11 to 15 and 31-35 were highly active while SW 20 to 26 was inactive periods of pink bollworm. Adult moth population captures in pheromone traps was 3.14, 4.41 and 6.75/ trap during 2018, 2019 and 2020, respectively. Highest peaks were 11.12, 11.85, 15.94 /trap with maximum, minimum, average temperatures, relative humidity and rainfall of 29.43: 36.59: 35.28°C, 11.31: 21.36: 22.80°C, 20.37: 28.96: 29.04°C, 54.66: 61.23:58. 36% and 0.00, 0.00, 0.00 mm, during 2018, 2019 and 2020, respectively. Temperature 20- 30°C had significant impacts to speed activities of pink bollworm. Minimum (r= -0.165, -0.144, -0.582) and maximum (r= -0.078, -0.045, -0.192) temperatures had negative and non- significant correlation with population in pheromone traps while average temperature had positive and significant correlation (r= 0.112, 0.290, 0.486) during study years. Average temperature had maximum impact of 20.9 (0.01), 20.7 (0.03) and 9.3 (0.07) % on population variability during 2018, 2019 and 2020, respectively. Population trends of pink bollworm had shown increasing trends during the subsequent years. Pheromone traps proved best monitoring tool of pink bollworm to integrate into integrated pest management strategy.

Population Dynamics of Rice Black Beetle Heteronychus lioderes Redtenbacher Under Mid Hill Conditions of Himachal Pradesh

Population dynamics of rice black beetle Heteronychus lioderes Redtenbacher was studied deploying light trap, pit method and assessment of tiller infestation. The pest was observed to be active from 29th to 42nd standard week (SW) with peak being in 35th SW as shown with light trap catches. The incidence started from 29th SW and reached a peak during 31st SW (3.8 adults in five pits and 48.4% tiller infestation). The weather factors when correlated with incidence revealed significant positive correlation with rainfall, minimum and maximum temperature, whereas it was non-significant positive one with relative humidity.

Life-history and life-table parameters of fall armyworm (Spodoptera frugiperda) for maize (Zea mays) in tropical Indian condition

Fall armyworm (Spodoptera frugiperda (J. E. Smith)) is an invasive pest reported in 2018 from India which principally attacks maize during vegetative and reproductive stages. Investigations were carried out to understand biologyof the pest in new tropical and sub-tropical environment for devising effective management strategies in maize. Thebiological aspects included morphometrics and life cycle of fall armyworm reared on maize under laboratory conditions at 26–31ºC and 50–65% relative humidity during August-September, 2018 to January-February, 2019 i.e. 34th to 6th standard weeks (SDW). Life table parameters including stage specific and age specific fecundity, population growth attributes and life expectancy of fall armyworm were computed. The diameter of eggs, length and width of body and their head capsules of different larval instars, pre-pupa, pupa, male and female adults were also measured.

Population dynamics of defoliator and sucking pests in black gram

Population dynamics of black gram defoliators viz., leaf folder, Omiodes indicata (Fabricus), striped flea beetle, Phyllotreta striolata (Fabricus) and the sucking pest, bean aphids, Aphis craccivora (Koch) were studied in the entire crop growth period during Kharif 2020 and Rabi 2020 - 2021. The results exhibited the high peak of population of defoliator’s population at 43rd Standard Week (SW) (91 larvae/ 50 plants) and 14th SW (76 larvae/ 50 plants), 43rd SW (210 beetles/ 50 plants) and 14th SW (197 beetles/ 50 plants) during Kharif 2020 and Rabi 2020 – 2021, respectively. The sucking pest reached a high peak at 45th SW (325 aphids/ 50 plant) and 16th SW (305 aphids/ 50 plant) during Kharif 2020 and Rabi 2020 – 2021. Impact of meteorological parameters on the population dynamics of black gram pests were studied and interpreted.

Population dynamics of cut worm <i>Agrotis ipsilon</i> Hufnagel on maize in Kashmir

The status of cut worm Agrotis ipsilon Hufnagel was studied in district Baramulla and its incidence was monitored in maize crop at the field of Faculty of Agriculture, Wadura, SKUAST-Kashmir during 2018. The incidence was observed at weekly intervals and was found to be infesting maize starting from germination to maturity. The results revealed maximum incidence and damage (74.24± 0.89%) at low altitude followed by medium (58.07± 1.87%); while the least was at high altitude (36.27± 0.78%). The larvae started occurring from 20th standard week (SW), reached its peak on 25th SW and then started decreasing from 26th SW. Incidence revealed a positive and significant correlation (r=0.634) with maximum temperature.

Seasonal incidence of sap feeders and defoliators in black gram [Vigna mungo (L.) Hepper], at Pajancoa and RI, Karaikal, U.T. OF Puducherry

Seasonal incidence of black gram feeder pests viz., bean aphids, Aphis craccivora and flower thrips, Megalurothrips. usitatus and defoliator pests like striped flea beetle, Phyllotreta. striolata, leaf folder Omiodes indicata and tobacco leaf caterpillar, Spodoptera litura were studied in the entire crop period during Kharif 2019 and Rabi 2019 -2020. The results indicated that the population of sap feeders reached a high peak at 38th and 36th standard week (SW); 12th and 11th SW during Kharif 2019 and Rabi 2019 - 2020. Defoliators reached high peak at 37th and 11th SW in both the seasons and Spodoptera infestation was high during 13th SW. The population of sap feeders and defoliators was recoded positive correlation with morning and evening relative humidity (RH) and rainfall and negative correlation with maximum and minimum temperature during Kharif 2019. During Rabi 2019 -2020, positive correlation was recoded with maximum and minimum temperature and rainfall and negative correlation with morning and evening RH.

Population Dynamics of Sucking Pests in Guava Under High Density Planting

The population dynamics of sucking pests of guava under a high-density planting system was studied at the Tamil Nadu Agricultural University, Coimbatore during 2016–2017. The reults revealed that maximum incidence of Aphis gosspii was observed during 13th standard week (SW) (294.40/ top 3 leaves/ tree), and that of Ferrisia virgata (122.00/ 3 leaves/ tree) during 12th SW. The maximum counts of Planococcus citri was during the 16th SW (102.00/ 3 leaves/ tree) and that of Paracoccus marginatus (108/ 3 leaves/ tree) during the 13th SW, while in case of Bemisia tabaci it was 39th SW (84.00/ 3 leaves/ tree). There existed a positive correlation with maximum temperature, solar radiation, and a negative one with minimum temperature, relative humidity and rainfall for the incidence of sucking pests.

Rainy days analysis by using normal, binomial distribution and discrete probability for Navsari district of south Gujarat

The standard weekly rainy days analysis of binomial distribution for monsoon season of Navsari on chi-square test on binomial distribution was found in SW 22 to 31, 33 and SW 35 to 39 and post monsoon in standard week (SW) 41 to 44 shows significant. The result also reveals that the monsoon season SW 32 and 34 and post monsoon season SW 40, 45, 46 and 47 revealed non-significant result. Analysis reveals the rainfall is not equally distributed during SW 32, 34, 40, 45, 16 and 47, so that the test of binomial distribution is a good fit. Monsoon season rainfall data of Navsari reveals that the normal distribution at 10, 20 and 30% probability levels for the month of June, July, August and September shows the possibility of increasing rainy days occurrence. The Navsari districts during post monsoon season rainfall of months of October and November reveals decreasing tendency. The binomial distribution fit only those standard weeks in which rainfall is not equally distributed. From above results observed that the rainfall distribution is not equally distributed so test of binomial distribution at above given standard week is a good fit. The data also shows that, decreasing tendency in rainfall was observed in district.

Population Dynamics of Shoot and Fruit Borer Earias Vitella on Okra

Field experiment to evaluate the population dynamics of okra shoot and fruit borer Earias vitella F., was conducted at the Research Farm, Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar during kharif 2018 and 2019. The observations revealed that its shoot infestation initiated from 29th standard week (SW) (3.84%) and reached its peak (10.09%) during 31st SW. The fruit damage was first noticed during 31st SW (4.91%), continued till 41st SW (6.44%) reaching peak (29.30%) at 34th SW. The larval count on fruit was of a maximum (7.13 larva/ 25 fruit) during 31st SW. The maximum and minimum temperature and relative humidity at 7 hr were found positively correlated with fruit damage (r = 0.512, 0.286 and 0.217, respectively). The larval counts exhibited a positive and significant relationship with maximum temperature (r = 0.549) while that of minimum temperature (r = 0.327) and relative humidity at 7 hr (r = 0.211) were positive and nonsignificant. The weather factors collectively infulenced 64.10, 87.10 and 86.90% of shoot and fruit damage and larval counts, respectively.

Relationships Between the Anthophiles Abundance and Flower Density of Guava

The plant-pollinator interaction is an important aspect and plant-pollinator relationships are pertinent for biodiversity conservation. This study delineates relationships between flower and flower-visiting insects (anthophiles) in guava Psidium guajava (L.). The anthophiles diversity index calculated by Shannon-Wiener diversity index reveals that there are 13 key anthophiles species observed during day time on the flowers in rainy season. Despite of jhoom cultivation, there exists a rich diversity of anthophiles. Of these, the honey bees are the abundant. Guava blooming commences in 16th standard-week (SW) and cessation is in 22nd SW, with peak observed in 19th SW. The anthophiles abundance and diversity increased with flower density, revealing a positive correlation.

Population dynamics of chilli thrips scirtothrips dorsalis hood and mite polyphagotarsonemus latus banks on chilli

The population dynamics of thrips Scirtothrips dorsalis Hood and mite Polyphagotarsonemus latus Banks on chilli was evaluated in West Bengal during kharif season of 2012–13 and 2013–14. The results revealed that their incidence initiated from 34 and 42 meteorological standard week (SW) during 2012–13 and 2013–14, respectively and continued up to harvest. Thrips incidence reached its peak (3.34 and 3.84/ 3 leaves) in the 51st SW and 10th SW in 2012–13 and 2013–14, respectively. Mite incidence revealed two peaks (3.18 and 4.27/ 3 leaves) in the 49th SW and 1st SW during 2012–13 but with only one peak (3.74/ 3 leaves) in the 10th SW during 2013–14. Correlation coefficients with weather factors revealed significant negative correlation with maximum and minimum temperature, maximum and minimum relative humidity, and total rainfall during 2012–13. No significant impact of weather factors was noticed during 2013–14 except for a significant positive correlation with maximum temperature on mite incidence.

Population Dynamics, Life History and Efficacy of Acaricides Against European Red Mite,Panonychus ulmi(Koch), on Almond and Apple

European red mite (ERM), Panonychus ulmi (Koch) is a major pest of fruit crops (apple and almond) in Kashmir Valley, India. Investigations were carried out at ICAR-Central Institute of Temperate Horticulture, Srinagar,Jammuand Kashmir to study the population dynamics, biology and efficacy of acaricides against P. ulmi on almond and apple. In both the crops highest population (31.56 and 6.46 mites/leaf), respectively, was observed in the 29th standard week (SW) and significantly correlated with the temperature. Biology of ERM was also studied on almond: eggs hatched in 6.50 ± 0.29 days; larval development took 2.00 ± 0.00 days; protonymphal and deutonymphal stages lasted for 1.75±0.25 days each. Longevity of adult males and females was 4.25 ± 0.25 and 8.25 ± 0.48 days, respectively. The efficacies of some of the acaricides were evaluated against ERM on almond. Among these, fenazaquin 10 EC (0.004 %) was found to be excellent with 94.92 % mortality of ERM on almond.

Monitoring of tobacco beetle, Lasioderma serricorne (Fab.) in turmeric store houses

The adult activity of tobacco beetle was monitored using New Serrico Fujitrap from the first week of January till the end of August, 2015 at store houses of Duggirala, Andhra Pradesh. The tobacco beetles were active throughout the study period with their peak activity during 16th standard week (SW) (16th-22nd April) that recorded maximum mean number of adults (37.0). As many as three distinctive peaks (during 10th, 16th and 19th SW) were observed in trap catches which may play a contributory role in population build up during storage. Although adult activity was found throughout the monitoring period, male beetles were trapped in more numbers during summer, between 10th and 20th SW i.e., 5th March to 20th May, 2015. It is evident that the New Serrico traps were effective for monitoring tobacco beetles in turmeric store houses.

Population dynamics of hoppers and thrips on mango

Pest calendar of hoppers and thrips on mango in Gujarat when observed revealed that the mango hopper complex was observed throughout the year. Maximum populations were observed from flower initiation or panicle emergence to the stone-sized fruits stage. A population density of 8.46 hoppers/panicle observed on 14th standard week (SW) coinciding with stone sized fruit stage was found positively influenced by maximum temperature, sunshine and evaporation. There existed a negative correlation with relative humidity (evening and average), wind velocity and rainfall. As regards thrips, maximum population on flower (43.33/panicle) and foliage (29.46/twig) was observed on 15th and 42nd SW coinciding with stone sized fruit and emergence of new flush stages, respectively. The thrips incidence was observed to be positively influenced by maximum temperature, sunshine, and negatively with minimum temperature, relative humidity, wind velocity and rainfall.

Population dynamics of pink stem borer, Sesamia inferens (Walker) on maize as influenced by weather conditions

A field study on population dynamics of pink stem borer, Sesamia inferens (Walker) on maize was carried out during rabi, 2015-2016 at the research farm of CCS Haryana Agricultural University, Regional Research Station, Karnal. Studies on population dynamics revealed that the maximum number of egg masses was observed during 46th SW (standard week), 2015. The larval population increased after 45th SW and reached the maximum during the 49th SW, 2015 and then declined till 7th SW, 2016. Maximum plant infestation by larvae was recorded 19.5 per cent in inbred HKI 1128 and 21.0 per cent in hybrid HQPM 1 during the 7th SW, 2016. No larval activity of S. inferens, plant infestation and dead hearts were observed during 2nd SW to 4th SW of 2016 (second week to last week of January). It could be due to the fact that insect might have entered the hibernation. Correlation of S. inferens population with various environmental factors revealed that larval population had a significant negative correlation with maxi-mum temperature (Tmax.) and minimum temperature (Tmin.), rainfall (RF) (r= -0.4992, -0.5183 and -0.5698) on HKI 1128 and (r= -0.4872, -0.4717 and -0.5242) on HQPM 1, respectively. Multiple regression analysis of S. inferens population with weather parameters showed that there was 80 per cent (HQPM1) and 82 per cent (HKI 1128) variability in larval population due to various environmental factors. The population dynamics revealed by this study have far reaching significance in pest management strategy as integrated control measures may be focused only during the period wherein population exceeds economic threshold level (ETL).

Population dynamics of citrus whitefly, Dialeurodes citri (Ashmead) on Citrus reticulate (Mandarin) var. Kinnow as influenced by weather conditions

A field study on population dynamics of citrus whitefly, Dialeurodes citri (Ashmead) on citrus mandarin (var. Kinnow) was carried out during 2014-15 at Centre of Excellence (COE) for Fruits situated in village Mangiana of district Sirsa, Haryana. The population of nymphs and adults of this pest was recorded from March 2014 to February 2015 at weekly interval. The nymphal population of the pest was observed only between 12th to 47th meteorological standard weeks (SW) with two major peaks i.e. one during 16th SW with a population of 83.44 nymphs/ 20 leaves and the second during 40th SW with a population of 133.22 nymphs/20 leaves. The above said population dynamics confirmed that this pest remained inactive in pupal stage during winter i.e. 48th to 11th SW. Similar trend was observed in respect of adult population. Nymphal population showed significant positive correlation with morning relative humidity (r = 0.329) and sunshine hours (r = 0.362), while adult population was found to have positive correlation with sunshine hours only (r = 0.332). Multiple regression analysis of the pest population with environment variables indicated that out of 45 per cent variability in nymphal population, 37 per cent was due to relative humidity and sunshine hours. Out of the total variability of 30 per cent variation in adult population, 20 per cent was due to evening relative humidity, while 10 per cent attributed to sunshine hours. The other weather parameters were found to have no significant correlation with the pest population. Although study of population dynamics of this study were conducted elsewhere but this is first study of its kind in the state of Haryana. The population dynamics revealed by this study have far reaching significance in pest management strategy as integrated control measures may be focused only during the period wherein population exceeds economic threshold level (ETL). The information on population dynamics of any insect pest in a given ecological niche should be considered as starting point for evolving eco - friendly pest management package.

Population dynamics of mango leaf gall midge, Protocontarinia matteiana and its correlation with weather parameters

Highest leaf gall midge damage (60.49 %) was observed on 7th standard week (SW) coinciding with pea cum marble sized fruit stages of the crop. It was positively influenced by sunshine and negatively by temperature (minimum and average), relative humidity, rainfall and wind velocity. The lowest leaf damage (31.69 %) was observed during 36 SW coinciding with emergence of new flush stage.