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 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 Prediction of Helicoverpa armigera (Hubner) larval population using weather based forewarning model in soybean

2021 ◽  
Vol 21 (4) ◽  
pp. 494-498
Author(s):  
RAM MANOHAR PATEL ◽  
A.N. Sharma ◽  
PURUSHOTTAM SHARMA
Keyword(s):  
Helicoverpa Armigera ◽  
Training Dataset ◽  
Maximum Temperature ◽  
Validation Dataset ◽  
Larval Population ◽  
Pod Borer ◽  
Significant Difference ◽  
Helicoverpa Armígera ◽  
Predicted Values ◽  
Helicoverpa Armigera Hubner

Weekly larval populations of pod borer, Helicoverpa armigera (Hubner) collected from 20 districts of Maharashtra under Crop Pest Surveillance and Advisory Project (CROPSAP) during 2010-2015 were analyzed to work out the effect of weather variables on the incidence of this insect on soybean. The appearance of larva was observed throughout the soybean growing season, and the peak incidence was observed during third week of August to first week of September (34-35 SMW). The correlation analysis of the data revealed that larval population was significantly and positively influenced by the minimum temperature and rainfall of current week as well as previous two weeks. For the development of forewarning model, data for the period from 2010 to 2013 were used as training dataset and two year (2014-2015) data as validation dataset. The mean model used for forewarning the incidence of pod borer larval population was developed by using step-wise multiple regression analysis in polynomial form. The results of mean model revealed that the significant variables affecting the pod borer larval population in soybean were maximum temperature (current and 1st lag week), and rainfall (current week) and the model explained 48.93% variation. The pre-disposing conditions for the incidence of larvae have been worked out as maximum temperature ranging from 26.1 to 31.47 ºC and rainfall ranging from 6.63 to 141.46 mm with low or medium rainfall in previous weeks followed by high in current week. The model was validated with 2014-15 independent dataset with predicted R2 (R2 ) value 28.13%. Two sample t-test showed no Pred significant difference between observed and predicted values (p = 0.3691 > 0.05).

scholarly journals Effects of weather on the abundance and infestation of major insect pests of sweet gourd in Gazipur

2019 ◽  
Vol 47 (2) ◽  
pp. 285-291
Author(s):  
Mansura Afroz ◽  
Md Ruhul Amin ◽  
Md Ramiz Uddin Miah ◽  
M Mofazzal Hossain
Keyword(s):  
Relative Humidity ◽  
Significant Positive Correlation ◽  
Insect Pests ◽  
Fruit Fly ◽  
Combined Effect ◽  
Cucurbita Moschata ◽  
Individual Effect ◽  
Positive Correlation ◽  
Weather Parameters ◽  
The Individual

The study was to assess the infestation of red pumpkin beetle, epilachna beetle and fruit fly on 12 germplasm of sweet gourd Cucurbita moschata. The study also investigated the effect of weather parameters on the abundance of the insects. Red pumpkin beetle, epilachna beetle and fruit fly showed the highest level of infestation during 3rd week of December, 3rd week of January and 4th week of February, respectively. All the insects revealed the lowest level of infestation on BD274 and BD277 germplasm. Relative humidity had insignificant positive correlation with all the insects. Red pumpkin beetle showed significant positive correlation with temperature. Epilachna beetle exerted significant positive correlation with rainfall. The weather parameters jointly contributed 35.2% abundance of red pumpkin beetle and temperature individually depicted the highest effect (18.9%). Rainfall revealed the highest contribution (44.4%) on the abundance of epilachna beetle and the combined effect of the weather parameters was 66.5%. Temperature, relative humidity and rainfall showed 43.2% contribution on fruit fly abundance and the individual effect of relative humidity was the highest (27.0%). Bangladesh J. Zool. 47(2): 285-291, 2019

Influence of Weather Parameters on the Seasonal Abundance of Legume Pod Borer Maruca vitrata (Crambidae: Lepidoptera) on Dolichos Bean (Lablab purpureus var. typicus)

2021 ◽  
Author(s):  
T.D. Jayabal ◽  
J.S. Kennedy
Keyword(s):  
Linear Regression Analysis ◽  
Maruca Vitrata ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Larval Abundance ◽  
Lablab Purpureus ◽  
Larval Population ◽  
Pod Borer ◽  
Legume Pod Borer ◽  
Weather Parameters

Background: Legume pod borer, Maruca vitrata (Fabricius), infests the Dolichos bean throughout the cropping season. However, there is no information on the seasonal abundance of M. vitrata over different seasons on Dolichos bean, which is an essential tool for forecasting and developing integrated pest management strategies. Methods: The seasonal abundance of M. vitrata on Dolichos bean were studied during three consecutive cropping seasons of 2019 Summer, Kharif and Rabi. The larval population in flowers and pods and the number of larval webbings and weather parameters were recorded and subjected to correlation and multiple linear regression analysis. Result: The overall larval abundance was observed to be higher in flowers than in pods. The highest larval abundance in flowers and pods was 14.60 and 13.40 during the 48th and 50th standard meteorological week (SMW) of Rabi 2019 respectively, which corresponds to 8 to 10 weeks after sowing (WAS) in flowers and 10 to 12 WAS in the case of pods. The number of larval webbings was higher, with 18.76 during the 49th SMW of Rabi 2019. The maximum temperature had a significant negative correlation with the larval abundance in flowers (r= -0.570), pods (r= -0.523) and the number of active webbings (r= -0.477). At the same time, the regression coefficient shows that rainfall had a significant negative influence on the larval abundance in pods (B= -1.26).

scholarly journals Role of weather parameters on seasonal abundance of insects in a mangobased agroforestry in Bangladesh, with particular reference to mango hopper

2017 ◽  
Vol 42 (2) ◽  
pp. 197-205
Author(s):  
S Namni ◽  
MR Amin ◽  
MRU Miah ◽  
MF Rahman ◽  
SJ Suh
Keyword(s):  
Relative Humidity ◽  
Significant Positive Correlation ◽  
Fruit Set ◽  
Species Abundance ◽  
Significant Negative Correlation ◽  
Seasonal Abundance ◽  
Insect Species ◽  
Positive Correlation ◽  
Weather Parameters

Weekly sweeping was done by sweep net in order to collect insects to study the effect of weather parameters on the seasonal abundance of total insect species as well as mango hopper population in a mango-based agroforestry in Bangladesh during January to June 2013. The total insect species abundance was the highest during April to May, following the flushing of inflorescence and fruit set. At that time temperature and relative humidity were comparatively higher and there was rainfall. Mango hopper population was the highest in May and synchronized to fruit set. The abundance of total insect species and mango hopper population showed significant positive correlation with temperature, and relative humidity, while significant negative correlation with light intensity and non-significant positive correlation with rainfall. Multiple linear regression equation based on weather parameters revealed 59.2% and 61.7% role on population build up of total insect species and mango hopper, respectively. Temperature was found to be the most important effect which individually contributed 31.3% on population abundance of total insect species and 29.9% on mango hopper.Bangladesh J. Agril. Res. 42(2): 197-205, June 2017

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 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 Effect of weather parameters on the incidence of thrips, Thrips tabaci Lindeman and its predator, Coccinella septumpunctata Linn. on garlic crop

2021 ◽  
Vol 2 (1) ◽  
pp. 134-136
Author(s):  
Ramgopal Dudwal ◽  
◽  
B.L. Jat ◽  
Alka Kataria ◽  
◽  
...  
Keyword(s):  
Relative Humidity ◽  
Significant Positive Correlation ◽  
Thrips Tabaci ◽  
Rabi Season ◽  
College Of Agriculture ◽  
Positive Correlation ◽  
Weather Parameters

The incidence of thrips was studied at Horticulture Farm, S.K.N. College of Agriculture, Jobner (Rajasthan) on garlic crop during Rabi season. The incidence of thrips on garlic crops was commenced in the first week of February and reached its peak in the second week of March. The predator, Coccinella septumpunctata Linn. was commenced in the second week of February and reached the maximum in the second week of March. The weather parameters viz., temperature, relative humidity, and sunshine (hrs) had a non-significant correlation with thrips incidence on garlic crop, whereas, predator, C. septumpunctata possess significant positive correlation.

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