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 Influence of prevailing weather parameters on population dynamics of fruit borer, Helicoverpa armigera (Hübner) on tomato in Haryana

2021 ◽  
Vol 21 (2) ◽  
pp. 193-196
Author(s):  
SHIVANI KHOKHAR ◽  
KRISHNA ROLANIA ◽  
GAURAV SINGH ◽  
ANIL KUMAR
Keyword(s):  
Relative Humidity ◽  
Helicoverpa Armigera ◽  
Significant Positive Correlation ◽  
Linear Regression Analysis ◽  
Maximum Temperature ◽  
Population Fluctuations ◽  
Larval Population ◽  
Positive Correlation ◽  
Helicoverpa Armígera ◽  
Weather Parameters

A field experiment was conducted for two years (2016-17 and 2017-18) at Entomological Research Area, Department of Entomology, CCS Haryana Agricultural University, Hisar to ascertain the influence of various meteorological parameters on population fluctuations of Helicoverpa armigera on tomato. The maximum oviposition (4.60 eggs/ plant) was recorded during 15th standard meteorologicalweek (SMW) whereas larval population was at peak (4.91 larvae/ plant) during 16th SMW. The larval population showed significant positive correlation with maximum temperature (r=0.617*) and highly significant negative correlation with morning (r=-0.784**) as well as evening relative humidity (r=-0.814**). Maximum eggs parasitization (12.85 %) by Trichogramma sp. was recorded during 16th SMW. These trichogrammatid parasitoids exhibited non-significant correlation with weather parameters and highly significant positive correlation (r=0.976**) with egg counts of H. armigera. Multiple linear regression analysis showed that 77 per cent (R2=0.77) variability in larval population was accounted by weather parameters particularly maximum temperature, morning and evening relative humidity. 

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 Relationship between Weather Parameters and Incidence of Gram Pod Borer, Helicoverpa armigera on Chickpea

2021 ◽  
Author(s):  
Keshav Mehra ◽  
Veer Singh
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Significant Negative Correlation ◽  
Larval Population ◽  
Positive Correlation ◽  
Minimum Relative Humidity ◽  
Pod Borer ◽  
Sunshine Hours ◽  
Weather Parameters

Background: Chickpea, Cicer arietinum which is considered as a “King of pulses” get adversely affected by several biotic and abiotic stresses, out of which gram pod borer, Helicoverpa armigera (Hübner) is the major one. The damage caused by H. armigera starts from vegetative growth and continues till maturity of the crop. This pest is causes 25 to 70 per cent pod damage in chickpea but in favorable conditions pod damage goes upto 95 per cent. Methods: Present study was carried out during, rabi, 2014-15 and 2015-16 at Research Farm, College of Agriculture, Bikaner (Rajasthan). Correlation coefficient was worked out with weather parameters such as temperature (maximum and minimum), relative humidity (maximum and minimum), rainfall and sunshine hours. Multiple linear forms of regression model were also used to assess the effect of the weather parameters on the incidence of pod borer. Result: The studies revealed that peak larval population of gram pod borer was recorded in the second fortnight of February thereafter, population declined abruptly. The larval population of pod borer on chickpea occurred low at vegetative and flowering stages and high at pod formation as well as at grain developmental stages. The temperature (maximum and minimum) and sunshine hours had significant positive correlation with larval population during rabi, 2015-16. The maximum relative humidity showed significant negative correlation during rabi, 2015-16 whereas, minimum relative humidity showed significant negative correlation with larval population during both the seasons. The rainfall showed significant positive correlation during rabi, 2014-15.

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.

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 Spatial variation of important mulberry pests and their natural enemies

2017 ◽  
Vol 49 (1) ◽  
Author(s):  
A. Mohan ◽  
J. Ravikumar ◽  
D. Senthilkumar
Keyword(s):  
Relative Humidity ◽  
Spatial Variation ◽  
Natural Enemies ◽  
Significant Positive Correlation ◽  
Insect Pests ◽  
Food Plant ◽  
Positive Correlation ◽  
Ladybird Beetles ◽  
Unidentified Species

Mulberry is a silkworm food plant (<em>Bombyxmori</em>. L) that is seriously affected by many insect pests. The incidence of <em>Diaphania</em> <em>pulverulentalis</em> (Hampson), <em>Maconellicoccus</em> <em>hirsutus</em> (Green), <em>Paracoccus marginatus</em> (Williams and Granara de Willink), <em>Aleurodiscus</em> <em>dispersus</em> (Russels) and <em>Pseudodendrothrips</em> <em>mori</em> (Niwa) and their natural enemies, <em>viz</em>. coccinellids and spiders (/100 plants), were observed through survey and surveillance for 3 months. In February 2013, the incidence of insect pests in Vaikkalpattarai and Reddipudur villages (India) was: <em>D. pulverulentalis,</em> 1.20 and 0.85%; <em>P. marginatus</em>, 6.80 and 33.10%; <em>P. mori</em> 42.98 and 45.50%, respectively. Further, the infestation of <em>M</em>. <em>hirsutus</em> (1.40%) and <em>A. dispersus</em> (59.72%) was also observed in February at Vaikkalpattarai. The population of coccinellids was high in December (1.02 and 0.84/100 plants), but the spider population was even higher in February and January (1.04 and 1.81/100 plants). Population of pests had a significant positive correlation with relative humidity. The population of coccinellids and spiders have positive correlation with temperature and mulberry pests infestation. The natural enemies observed in the study were mostly the ladybird beetles, <em>Psyllobora</em> <em>bisoctonotata</em> and unidentified species of spiders.

scholarly journals Influence of prevailing weather parameters on population dynamics of spotted stem borer, Chilo partellus (Swinhoe) and its natural enemies on maize in Haryana

2021 ◽  
Vol 22 (3) ◽  
pp. 295-304
Author(s):  
GAURAV SINGH ◽  
MAHA SINGH JAGLAN ◽  
TARUN VERMA ◽  
SHIVANI KHOKHAR
Keyword(s):  
Population Dynamics ◽  
Chilo Partellus ◽  
Natural Enemies ◽  
Minimum Temperature ◽  
Significant Positive Correlation ◽  
Maximum Temperature ◽  
Positive Correlation ◽  
Average Maximum ◽  
Weather Parameters ◽  
Average Minimum Temperature

The experiment was conducted at CCS Haryana Agricultural University Regional Research Station, Karnal to ascertain the influence of prevailing meteorological parameters on population dynamics of Chilo partellus and its natural enemies on maize during Kharif, 2017. Maximum oviposition (0.75 egg masses per plant) was recorded during 28th standard meteorological week (SMW) whereas larval population was at peak during 31st SMW (3.8 larvae per plant). Cumulative (47.5%) and fresh plant infestation (11.5%) were maximum during 34th and 28th SMW, respectively. Maximum egg parasitisation (6.53%) by Trichogramma sp. and larval parasitisation (31.64%) by Cotesia flavipes was recorded during 28th and 33rd SMW, respectively. Changes in pest population were correlated and regressed with weather parameters. Egg and larval populations of C. partellus and parasitisation by Trichogramma sp. exhibited significant positive correlation with average minimum temperature whereas C. flavipes exhibited significant negative correlation with average maximum temperature (r = -0.741) and highly significant positive correlation with evening relative humidity (r = 0.695). Plant infestation and dead heart formation were significantly correlated with average minimum temperature and non-significantly correlated with all other weather parameters. The multiple linear regression analysis explained the variability due to various weather parameters. This information can be utilised while formulating integrated management tactics against this pest.

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 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 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)

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