scholarly journals Influence of Abiotic Factors on Population of Aphid Complex and Its Coexisting Natural Enemies in Mustard Agroecosystem

2021 ◽  
pp. 150-154
Author(s):  
Somala Karthik ◽  
U. Mukherjee
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Natural Enemies ◽  
Abiotic Factors ◽  
Maximum Temperature ◽  
Peak Activity ◽  
Rabi Season ◽  
Mustard Aphid ◽  
Positive Correlation ◽  
Syrphid Larvae

A field experiment was conducted to determine the population build-up of mustard aphid and their natural enemies in relation to abiotic factors at TCA, Dholi during the Rabi season of 2018-19 and 2019-20 respectively. The incidence of mustard aphid started in the 2nd and 3rd SMW of 2019 and 2020 respectively and reached maximum in 8th SMW in both the years. However, the predatory activity of coccinellids, syrphid larvae and spiders were started from 3rd SW with their peak activity at 3rd and 4th week of February in both the years. Mustard aphid population exhibited positive correlation with maximum temperature (0.347 & 0.543), minimum temperature (0.317 & 0.152) and negative correlation with relative humidity (-0.083 & -0.479) during 2019 & 2020 respectively and rainfall (-0.35) during 2020. However, natural enemies viz., coccinellids, syrphid larvae and spiders exhibited positive correlation with Tmax, Tmin, rainfall and negative correlation with RH in both the years.

scholarly journals Reproductive performance of spiralling whitefly on guava and impact of weather parameters on its immature stages

2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Reproductive Performance ◽  
Significant Positive Correlation ◽  
Instar Nymph ◽  
Maximum Temperature ◽  
Immature Stages ◽  
Positive Correlation ◽  
Aleurodicus Dispersus ◽  
Weather Parameters

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)

scholarly journals Population dynamics of exotic rugose spiralling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) on coconut as influenced by weather factors and natural enemies

2020 ◽  
pp. 120-125
Author(s):  
K. Elango ◽  
S. Jeyarajan Nelson
Keyword(s):  
Population Dynamics ◽  
Negative Correlation ◽  
Natural Enemies ◽  
Tamil Nadu ◽  
Abiotic Factors ◽  
Climatic Conditions ◽  
Weekly Interval ◽  
Maximum Temperature ◽  
Weather Factors ◽  
Extent Of Damage

The rugose spiralling whitefly, Aleurodicus rugioperculatus Martin is a new exotic pest occurring in several crops including coconut since 2016 in India. Due to variation in the agro-climatic conditions of different regions, arthropods show varying trends in their incidence also in nature and extent of damage to the crop. Besides, abiotic factors also play a key role in determining the incidence and dominance of a particular pest and their natural enemies in a crop ecosystem. The population dynamics of new exotic whitefly species, A. rugioperculatus and their associated natural enemies was assessed on five-year-old Chowghat Orange Dwarf coconut trees at Coconut Farm of Tamil Nadu Agricultural University. The study indicated that RSW was found throughout the year on coconut and the observation recorded on weekly interval basis shows that A. rugioperculatus population escalated from the first week of July 2018 (130.8 nymphs/leaf/frond) reaching the maximum during the first week of October (161.0 nymphs/leaf/frond) which subsequently dwindled to a minimum during April. The parasitisation by E. guadeloupae on RSW ranged from 31.60 percent in Aug. 2018 to 57.60 percent in December 2018. The association of biotic and abiotic factors with A. rugioperculatus population showed a negative correlation with E. guadeloupae and C. montrouzieri. There was a significant positive correlation between maximum temperature and minimum temperature as well as relative humidity. However, rainfall showed a negative correlation with A. rugioperculatus population.

scholarly journals Abundance, damage severity and management of guava mealybug, ferrisia virgata ckll

2019 ◽  
Vol 16 (2) ◽  
pp. 73-82
Author(s):  
MMH Khan
Keyword(s):  
Relative Humidity ◽  
Leaf Area ◽  
Negative Correlation ◽  
Untreated Control ◽  
Soap Solution ◽  
Maximum Temperature ◽  
Water Spray ◽  
Positive Correlation ◽  
Middle Leaf ◽  
Percent Mortality

The research was carried out to know the abundance and damage severity of mealybug on sarupkathi variety of guava and to evaluate the efficacy of jet powder and Fighter 2.5EC for suppressing populations of mealybug during January to October 2014. Results revealed that the highest number of guava mealybug was observed on middle leaf (42/leaf) while the lowest number was on lower leaf (13/leaf). The highest percent leaf area covered by mealybug was found on middle leaf (78%) while the lowest was on fruit (18%). Maximum temperature and relative humidity had a positive correlation on the mealybug population while the rainfall showed a negative correlation. The highest percent mortality was observed in T2 treatment (Jet powder applied @ 5.0 g L-1 of water) at 24 HAT (hours after treatment) (86.05%) and 48 HAT (93.83%), respectively. At 72 HAT, the highest percent mortality was observed T3 treatment (Jet powder applied @ 7.5 g L-1 of water). In case of insecticidal control, the highest percent mortality was observed in T2 (100%) and T3 (100%) treatments, respectively followed by T1 (98.03%) at 24 HAT. Similar trends were also observed among all treatments at 48 HAT and 72 HAT, respectively. No significant differences were found among three doses of Fighter 2.5EC. The lowest percent mortality of mealybug population was found in T4 (Water spray forcibly) at 24 HAT, 48 HAT and 72 HAT, respectively. No mortality was recorded in untreated control at different HAT in both application of soap solution and insecticides. SAARC J. Agri., 16(2): 73-82 (2018)

Impact of abiotic factors on seasonal incidence of insect pests of soybean

2016 ◽  
Author(s):  
R. K. Kalyan ◽  
O. P. Ameta
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Positive Impact ◽  
Significant Negative Correlation ◽  
Maximum Temperature ◽  
Larval Population ◽  
Positive Correlation ◽  
Pod Borer ◽  
Rain Fall ◽  
Tobacco Caterpillar

The study was carried out at Agricultural Research Station- Banswara during kharif-2012 and 2013. During the years 2012 and 2013, the peak population of white fly was observed in the 35th SMW and 37th SMW, respectively. The population of whitefly had a positive correlation with the maximum temperature and sunshine (hours) while, negative correlation with rain fall and morning and evening relative humidity during both the years but significant only during 2013. The maximum population of semilooper was recorded in the 36th SMW and 39th SMW, respectively. The semilooper exhibited a significant and positive correlation with minimum temperature, morning evening humidity and rain fall during both the years. The highest girdle beetle damage was recorded in the 35th SMW and 37th SMW, respectively; whereas the maximum incidence of gram pod borer was recorded in the 36th SMW and 39th SMW, respectively. The larval population of gram pod borer exhibited a significant negative correlation with sun shine and minimum temperature during experimental period; whereas, it exhibited a significant and positive correlation with rainfall and relative humidity during both the years. The maximum incidence of tobacco caterpillar in soybean crop was recorded during 41st SMW and 42nd SMW, respectively. The maximum temperature and sun shine hours showed a significant positive correlation with the larval population of tobacco caterpillar while, significant negative correlation with rainfall during both the years. The regression equation indicated that rainfall had significant negative and positive impact on population of white fly and semilooper, respectively. Whereas, maximum temperature had significant positive impact on population of tobacco caterpillar while rainfall had significant negative effect.

scholarly journals Seasonal Incidence and Effect of Abiotic Factors on Population Dynamics of Sucking Insect Pest Complex of Groundnut

2021 ◽  
pp. 10-17
Author(s):  
K. Shamili Dhatri ◽  
M. S. V. Chalam ◽  
A. Rajesh ◽  
B. Ramana Murthy ◽  
N. C. Venkateswartlu
Keyword(s):  
Negative Correlation ◽  
Minimum Temperature ◽  
Significant Positive Correlation ◽  
Insect Pests ◽  
Abiotic Factors ◽  
Insect Pest ◽  
Significant Negative Correlation ◽  
Maximum Temperature ◽  
Seasonal Incidence ◽  
Positive Correlation

Studies on seasonal incidence of sucking insect pests carried out with three dates of sowing viz., early (July 15th), normal (July 30th) and late (August 15th) revealed that the incidence of leafhoppers, aphids and thrips started from 5 to 14 DAS (days after sowing) and continued till harvesting. In early sown crop, the incidence of leafhoppers started from 31 SW and incidence of aphids and thrips started from 30 SW and continued up to 42 and 43 SW for leafhoppers and aphids, respectively and 41 SW for thrips. In normal sown crop, incidence of leafhoppers and aphids started from 32 SW and incidence of thrips started from 31 SW and continued till the end of 45 SW for all the three pests. In late sown crop, the incidence of leafhoppers started from 35 SW and incidence of aphids and thrips started from 34 SW and continued up to 46 and 47 SW for leafhoppers and aphids, respectively and 46 SW for thrips. Correlation studies revealed that incidence of leafhoppers exhibited significant negative correlation with maximum temperature (r = -0.467, -0.442 and -0.464) and rainfall (r = -0.518, -0.529 and -0.742) during all the three dates of sowing (early, normal and late, respectively) and significant negative correlation with minimum temperature in late sown crop (r = -0.448). Aphids exhibited significant negative correlation with maximum temperature (r = -0.469, -0.521 and -0.472) and rainfall (r = -0.443, -0.450 and  -0.721) in all the three dates of sowing (early, normal and late, respectively) while significant negative correlation with minimum temperature in early and late sown crop with r values -0.519 and -0.324.  Thrips exhibited significant positive correlation with maximum temperature (r = 0.522, 0.459 and 0.447), significant negative correlation with rainfall (r = -0.458, -0.465 and -0.451) during three dates of sowing (early, normal and late, respectively) while significant negative correlation with relative humidity in early sown crop (r = -0.616) and significant positive correlation with minimum temperature in early sown crop (r = 0.463).

scholarly journals Population Dynamics of Fall Armyworm, Spodoptera frugiperda (J. E. Smith) on Sorghum

2021 ◽  
pp. 222-229
Author(s):  
S. V. L. Sunitha ◽  
M. Swathi ◽  
T. Madhumathi ◽  
P. Anil Kumar ◽  
C. H. Chiranjeevi
Keyword(s):  
Relative Humidity ◽  
Natural Enemies ◽  
Significant Positive Correlation ◽  
Fall Armyworm ◽  
Leaf Damage ◽  
Maximum Temperature ◽  
Larval Population ◽  
Seasonal Incidence ◽  
Positive Correlation ◽  
Severity Rating

The study on seasonal incidence of fall armyworm was carried out during kharif, 2019 at Agricultural college farm, Bapatla.  The oviposition of fall armyworm was observed from 34th SMW (Standard Meterological Week) and reached its peak during 40th SMW (0.03 egg masses plant-1). The larval population of fall armyworm was commenced during 35th SMW and increased gradually to a peak of 1.67 larvae plant-1 during 41st SMW. The maximum plant infestation (60.00%) and leaf damage severity rating (3.13) of fall armyworm was observed during 41st SMW. The peak activity of natural enemies was observed during 41st SMW which coincides with the larval population of fall armyworm. The correlation analysis indicated that eggmasses of fall armyworm was positively correlated with minimum temperature(r= 0.668) and wind speed (r= 0.529) while, the larval population showed significant positive correlation with maximum temperature (r= 0.029). The plant infestation caused by fall armyworm had shown significant negative correlation with maximum temperature (r= -0.633) and positive correlation with morning relative humidity (r= 0.678) and evening relative humidity (r= 0.664) whereas, the leaf damage severity rating exhibited significant positive correlation with evening relative humidity (r= 0.691). The multiple regression analysis revealed that the influence of weather parameters on the incidence of fall armyworm and natural enemies in sorghum ecosystem was more than 65% and 40%, respectively.

scholarly journals Population Dynamics of Natural Enemies in Okra Agro-ecosystem in Relation to Abiotic Factors

2021 ◽  
pp. 61-69
Author(s):  
Ram Kumar ◽  
P. P. Singh
Keyword(s):  
Relative Humidity ◽  
Natural Enemies ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Maximum Temperature ◽  
College Of Agriculture ◽  
Pooled Data ◽  
Weather Parameters ◽  
The Relationship ◽  
Positive Effect

The present experiment was carried out to access the relationship between population fluctuation of natural enemies and abiotic factors in okra agro-ecosystem at the Research Farm, Tirhut College of Agriculture, Dholi, Muzaffarpur (Bihar). From pooled data of two consecutive Kharif seasons i.e. 2018 and 2019 it was inferred that the highest coccinellids population was registered during 35th standard week (4.56 coccinellids/ 5 plant). Thereafter, the population gradually decreases and reached to 1.19 coccinellids/ 5 plant during 41st standard week i.e. end of the crop. Correlation studies of coccinellids population with abiotic factors indicated that the maximum temperature had positive and highly significant effect on coccinellids. While, minimum temperature and relative humidity at 7 hrs showed positive but non-significant effect on coccinellids. The relative humidity at 14 hrs and rainfall had negative and non-significant correlation with coccinellids population. All the weather parameters together governed 49.90 per cent to the coccinellids population build up (R2 = 0.4990). In case of spider, incidence commenced in 27th standard week however, the maximum population (3.94 spiders/ 5 plant) was observed in 35th standard week. Correlation analysis of spider population with abiotic factors exhibited that the maximum temperature had highly significant and positive effect on spider population. Unlike it, minimum temperature and relative humidity at 7 hrs indicated positive and non-significant effect on spider population. However, the effect of relative humidity at 14 hrs and rainfall on spider population was found negative and non-significant. However, all the prevailing weather parameters together contributed 48.23 per cent towards spider incidence (R2 = 0.4823).

scholarly journals Study of seasonal incidence and impact of abiotic factors on sucking pests of brinjal

2017 ◽  
Vol 9 (1) ◽  
pp. 51-54
Author(s):  
Shaik Javed ◽  
K. Vijaya Lakshmi ◽  
C. Narendra Reddy ◽  
B. VidyaSagar ◽  
M. Shanthi
Keyword(s):  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Abiotic Factors ◽  
Significant Negative Correlation ◽  
Aphid Population ◽  
Maximum Temperature ◽  
Seasonal Incidence ◽  
Positive Correlation ◽  
Leaf Hopper ◽  
The Impact

The present investigation was undertaken to find the impact of abiotic factors on seasonal incidence and sucking pest complex of brinjal under field conditions during kharif 2015-2016. The incidence of leaf hopper population (2.80 Lh/L i.e., Leaf hopper mean population/leaf) was noticed during 34th standard week and reached peak by 40th standard week (5.00 Lh/L) (October) whereas the aphid population was noticed during the 34th standard week (3.00 Lh/L) and peak population observed during the 40th standard week (4.60 Lh/L) (October). Correlation studies showed that among the various abiotic factors, maximum temperature showed highly significant positive correlation (r= 0.77) and sunshine hours (r = 0.61) showed significant positive correlation with the leaf hopper population. In case of aphid population, maximum temperature showed significant positive correlation (r = 0.70), rainfall showed highly significant negative correlation (r = -0.74) and relative humidity evening (r = -0.59) showed significant negative correlation with aphid population. The present investigations will give a brief idea about how the abiotic factors influencing the sucking pests of brinjal.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

Distribution and Abundance of a New Pest “Root and Bulb Parasitic Nematode” at Different Elevation Levels and Soil Abiotic Factors in Garlic Growing Centres in Central Java

2020 ◽  
Vol 840 ◽  
pp. 124-130
Author(s):  
Ayu Suci Wulandari ◽  
Siwi Indarti
Keyword(s):  
Negative Correlation ◽  
Parasitic Nematode ◽  
Abiotic Factors ◽  
Nematode Population ◽  
Positive Correlation ◽  
Central Java ◽  
Production Area ◽  
Different Populations ◽  
Ditylenchus Dipsaci ◽  
New Pest

The distribution of root and bulb parasitic nematode in garlic crops at various elevation and the effect of abiotic factors on their distribution were investigated. The survey was done at the centers of garlic production area in Central Java, Indonesia. Soil abiotic factors such as temperature, pH, and C-Organic were measured in each location of sampling. Nematodes were analyzed using incubation and white head tray technique modification. Correlation and regression were used to determine the effect of abiotic factors. The results showed that the five locations with different elevations were positive for Ditylenchus dipsaci distribution. These nematodes were found in various elevation with different populations in the range of 8.00-16.67 nematodes per 100 g of soil and 14.34 to 26.67 nematodes per 2 g of bulb. The highest density of the nematode population both in bulb and soil was in Tegal at elevation <1000 m a.s.l. while the lowest nematode population both in soil and root were found in Temanggung at an elevation of 1000-1200 m a.s.l. Abiotic factors, such as temperature has a positive correlation with D.dipsaci nematode populations in bulb and soil, while pH has a negative correlation with nematode populations. C-organic has a positive correlation in abundance of nematode populations in the soil and negative in abundance of nematode populations in bulb.

Sign in / Sign up

Export Citation Format

Share Document