Seasonal Incidence of Spotted Pod Borer Maruca Vitrata Geyer on Rice Fallow Blackgram in North Coastalandhra Pradesh

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K. SWATHI*, P. SEETHA RAMU1, S. DHURUA2 AND M. SURESH3

Department of Entomology, Agricultural College, ANGRAU, Naira 532 185, Andhra Pradesh

ABSTRACT

A field experiment was conducted at Agricultural College Farm, Naira, on seasonal incidence of spotted pod borer on rice fallow blackgram in North Coastal Andhra Pradesh during rabi 2017-2018. The incidence of M. vitrata revealed that the initial occurrence was observed on 52nd standard week i.e., at 31DAS with a mean population of four larvae per 50 plants and reached a peak by 64 DAS (5th standard week) i.e., at pod development stage with 329 larvae per 50 plants. Thereafter the larval population declined gradually with rise in maximum and minimum temperatures and reached minimum by 80 DAS (7th standard week) with a mean of 100 larvae per 50 plants. The larval population showed negative and non significant association with minimum temperature (r = – 0.493), evening relative humidity (r= -0.218) and wind velocity (r= -0.015) while maximum temperature (r= 0.083) and mean sunshine hours (r= 0.181) has positive and non-significant while positive and significant correlation with morning relative humidity (r=0.657).

KEY WORDS: Blackgram, seasonal incidence, spotted pod borer (M. vitrata), weather parameters,

INTRODUCTION

Pulses are wonderful gifts of nature. They are well known as cheap and excellent source of dietary pro- teins to humans and animals and also soil fertility restor- ers. India is the major country for the pulse production and consumption with a relative share of 25-28 per cent of the total global production. In most parts of the country it is grown traditionally as kharif (wet season) crop, but in Andhra Pradesh it is being cultivated mostly in rabi (dry) season both in uplands and in rice fallow conditions. In Andhra Pradesh, rabi blackgram is cultivated in an area of 2.96 lakh hectares with a production of 244 thousand tonnes and productivity of 936 kg ha-1 ( Indiastat, 2014- 15).

In North coastal districts of Andhra Pradesh rice fallow blackgram is cultivtaed in an area of 76,113 hectares of which Srikakulam district alone contributing an area of 42,117 hectares in rice fallow situations with a production of 331 thousand tonnes, but the productivity is 705 kg ha- 1 , which is far below the state average, the major reason being the biotic causes including insect pest damage.

*Corresponding author, E-mail: ramsento@gmail.com

On an average, 2.5 to 3.0 MT of pulses are lost anually due to pest problems in India (Rabindra et al., 2004). Among them, legume pod borer, Maruca vitrata (Geyer) is a major constraint for the production of blackgram at critical stages such as flowering and pod formation stages in the Southern zone of Andhra Pradesh (Chandrayudu et al., 2008). Because of its extensive host range and destructiveness, it became a persistent pest in pulses, being available throughout the year in different seasons / situations.
The Studies on the seasonal occurrence of blackgram pests, their natural enemy fauna in the pest prone area highly essential towards effective management of these pests.

MATERIALS AND METHODS

A bulk plot of 100 m2 of with popularly growing cultivar of blackgram in North Coastal Andhra Pradesh i.e., LBG-752 in rice fallows was raised and maintained without any insecticidal application to study the seasonal incidence of spotted pod borer (M. vitrata) in relation to biotic and abotic factors viz., spiders, cocccinellids, maxi-
mum and minimum temperature, morning and evening

Swathi et al.,

relative humidities and rainfall. The crop was sown on 27.11.2017 and complete germination is observed seven days after sowing. Inter cultivation operations like thinning and gap filling were taken 15 days after sowing. The first incidence of spotted pod borer was noticed at 31 days after sowing and the data was recorded as per the standard procedures

The incidence of spotted pod borer (M. vitrata) was recorded twice in a week on 50 randomly tagged plants at five different locations @ ten plants per location from the bulk plot of 100 m2 from the inception of flowering and continued up to the crop maturity. The observations were taken by counting the number of larvae per plan on tagged plants.

The incidence of natural enemies was also recorded on the same plants that were selected for observing the incidence of M. vitrata. The number of coccinellid predators and spiders per plant were recorded at weekly interval from one week after sowing till crop maturity.

Abiotic factors such as maximum and minimum temperatures, morning and evening relative humidities, mean sunshine hours, rainfall and wind velocity were recorded daily to study the relationship with the occurrence of spotted pod borer,(M. vitrata) and natural enemies in rice fallow blackgram.

STATISTICALANALYSIS

The influence of abiotic factors on the occurrence of spotted pod borer (M. vitrata) on blackgram were statistically analyzed by subjecting the data to simple correlation and multiple linear regression (MLR) analysis (Gomez and Gomez, 1984).

RESULTS AND DISCUSSION

During rabi 2017-18, the incidence of M. vitrata on blackgram was recorded and correlated with the cor- responding meteorological data to understand the rela- tionship during the season which varied in different months. The data recorded on the incidence of M. vitrata revealed that the initial occurrence was observed on 52nd standard week i.e., at 31DAS with a mean populpopulation of 4 larvae per 50 plants per five locations in LBG – 752

The average maximum and minimum temperatures prevailed during the initial infestation of M. vitrata were
33.94 and 17.140C, while the average morning and evening relative humidities were 85.875 and 61.5 per cent, respectively. The population of coccinellids and spiders recorded during the initial incidence were 1.8 and 2.2 per 50 plants, respectively. This is in agreement with Hariprasad (2007) who reported that the incidence of M. vitrata started at 32 DAS. Hukte et al. (2014) revealed that the incidence of M. vitrata commenced from the 5th week after sowing.

The larval population increased gradually from 31 DAS and reached a peak by 64 DAS (5th standard week) i.e., at pod development stage with 329 larvae per 50 plants The average maximum and minimum temperatures during the initial level of population were
32.78 and 14.42 0C, respectively and the average morning and evening relative humidities were 91.28 and 35.42 per cent, respectively. The population of coccinellids and spiders during the initial incidence were 92 and 81 per 50 plants respectively. This was in agreement with the findings of Lakshmi (2001), Dillirao (2001) Imosanen and Singh, (2005) who reported that the peak larval incidence of M. vitrata larvae was observed coinciding with the maximum flowering and podding stage of blackgram. Thereafter the larval population declined gradually with rise in maximum and minimum by temperatures and reached minimum by 80DAS (7th standard week), with a mean of 100 larvae per 50 plants. The average maximum and minimum temperatures prevailed were 33.07 and 17.850C, respectively and the average morning and evening relative humidities were 90.85 and 39.14 per cent, respectively. The population of coccinellids and spiders during this period was 36 and 84 per 50 plants respectively (Table 1).

Correlations were worked to find out the relationship between spotted pod borer population and the major weather parameters and natural enemies in LBG- 752. The results indicated negative and non significant association between the spotted pod borer population and the minimum temperature (r = -0.493), evening relative humidity (r= -0.218) and wind velocity (r= -0.015). Relationship between the spotted pod borer population maximum temperature (r= 0.083) and mean sunshine hours (r= 0.181) was positive and non-significant while positive and significant correlation with morning relative humidity (r= 0.657) (Table. 2)

Seasonal incidence of Maruca vitara (Geyer)) on rice fallow blackgram in north coastal Andhra Pradesh

The relationship between the spotted pod borer and coccinellids (r = 0.777), spiders (r = 0.569) was positive and significant correlation which is in contradictory with the finding of Babu (2008) who reported positive but non significant correlation between natural enemies (coccinellids and spdiders) with the larval population of
M. vitrata.

The present investigation results are in conformity with Reddy et al. (2001), Lakshmi (2001), Sivaramakrishna et al. (2004), Rao (2010) and Babu et al. (2009) who reported that significant positive correlation between the morning relative humidity and larval population of M. vitrata. Hukte et al. (2014), Dabhade et al. (2014) and Sravani et al. (2015) observed non significant negative correlation between evening relative humidity larval population of M. vitrata. Sahoo and Behra (2001), Banker et al. (2015) and Bairawa et al. (2017) reported positive non significant correlation between maximum temperature and larval population of M. vitrata. Srinivas (2003) confirmed negative non significant correlation with minimum temperature and larval population of M. vitrata in groundnut. Reddy et al. (2001) reported that wind velocity has negative non significant correlation with the larval population of M. vitrata in pigeonpea. Hukte et al. (2014) and Bairawa and Singh (2017) concluded a positive non significant correlation bright sunshine hours and larval population of M. vitrata.

REFRENCES

Babu, G.C. 2008. Seasonal incidence and pest manage- ment strategies against spotted pod borer (Ma-
-ruca vitrata Geyer) in rice fallow blackgram. M.Sc. (Ag.) Thesis. Submitted to Acharya N.G. Ranga Agricutural University, Rajendranagar, Hyderabad.

Babu, G.C., Madhumathi, T., Rao, A.P and Rao, V.S.
2009. Seasonal incidence of spotted pod borer- (Maruca vitrata (Geyer); Pyralidae; Lepidop-
-tera) on blackgram. The Andhra Agricultural Journal. 56(2):206-209.

Bairawa, B and Singh, S.P. 2017. Population dynamics of major insect pests of mung bean (Vigna radi-
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Bankar, S.P., Galande, S.M and Sinde, Y.A. 2015.Sea-
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infesting cowpea. Pestology. 39(3): 40-45.

Chandrayadu, E., Srinivasan, S and Venugopala Rao,
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Dillirao, S. 2001. Bio-ecology and management of spo-
-tted pod borer, Maruca vitrata (Geyer) on blackgram. M. Sc.(Ag.) Thesis. submitted to Acharya N. G. Ranga Agricultural University, Rajendranagar, Hyderabad.

Dabhade, P.L., Bapodra, J.G and Jethva, M. 2014. Seasonal incidence of major insect pests of groundnut. Pestology. 38(6): 44-47.

Hariprasad, A. 2007. Incidence and management of pest complex on cowpea (Vigna unguiculata (L.) Walp). M.Sc.(Ag.) Thesis. submitted to Acharya
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Gomez, K.A and Gomez, A.A. 1984. Statistical procedure for Agricultural Research, John Wiley Sons, New York: 68.

Hukte, S.S., Virani, V.R., Jethva, D.M and Klasariya, R.L. 2014. Seasonal incidence of pod borer complex of cowpea. Pestology. 38(9): 51-54.

Indiastat, 2015. http://www.indiastat.com. Ministry of Agriculture, Government of India, 2014-15.

Imosanen and Singh, H.K.B. 2005. Incidence of Helicoverpa armigera (Hub.) and Maruca vitrata (Geyer) on pigeonpea under Medzephema conditions of Nagaland. Journal of Applied Zoological Research. 16 (1): 85-86.

Lakshmi, P. S. R. 2001.Seasonal incidence and management of spotted pod borer, Maruca vitrata (Geyer) on Blackgram. M.Sc. (Ag.). Thesis submitted to Acharya N. G. Ranga Agricultural University, Rajendranagar,

Hyderabad. 3

Swathi et al.,
Table 1: Influence of abiotic and biotic factors on the seasonal incidence of pest complex on blackgram cultivar LBG-752 during rabi, 2017– 18

The data on spotted pod borer incidence when subjected to multiple linear regression analysis in LBG- 752 (Table 4), the following equation were arrived.

Y = -499.50 – 16.02 X1 + 2.38 X2 + 11.79 X3 – 1.22 X4 + 7.21 X5 + 17.75 X6 + 4.86 X7 – 2.177X8

The multiple linear regression analysis data (Table 3 & Fig 1) revealed that all the biotic abiotic factors togetherwere responsible for a total influence of 81.7 per cent (R2 = 0.81.7) and in spotted pod borer population which was significant in LBG-752 which is in proximity to the findings of Babu (2008) who reported that all the weather factors together put forth 94.40 per cent of total variation in M.vitrata population in blackgram.

Seasonal incidence of Maruca vitara (Geyer)) on rice fallow blackgram in north coastal Andhra Pradesh

Table 2: Correlation between abiotic and biotic factors and M. vitrata on Blackgram during rabi, 2017 – 18

Abiotic & biotic factors (Weather parameters and natural enemies) Correlation coefficient (r) in LBG – 752
X1 – Maximum temperature (0C) 0.083
X2 – Minimum temperature (0C) -0.493
X3 – Morning relative humidity (%) 0.657**
X4 – Evening relative humidity (%) -0.218
X5 – Mean Sunshine Hours 0.181
X6 – Wind Velocity -0.015
X7 – Coccinellids 0.777**
X8 – Spiders 0.569**
** Significant at 5% level

Pred(maruca)/ maruca

a c ru a

0
-6 200 400 600 800 1000 1200

-600

Pred(maruca)

Fig 1. Relationship between the predatory population and larval population of M. vitrata logistic
multiple linear regression

Swathi et al.,

Table 3: Multiple linear regression between abiotic and biotic factors and M. vitrata on blackgram during rabi, 2017- 18

Variable LBG-752
Partial regression coefficient Standard error
t-value
X1 – Maximum temperature (0C) 0.615 29.465 -0.544
X2 – Minimum temperature (0C) 0.959 43.460 0.055
X3 – Morning relative humidity (%) 0.261 8.975 1.307
X4 – Evening relative humidity (%) 0.805 4.644 -0.264
X5 – Mean Sunshine Hours 0.752 21.324 0.338
X6 – Wind Velocity 0.904 138.404 0.128
X7 – Coccinellids 0.203 3.198 1.521
X8 – Spiders 0.384 2.229 -0.977
Intercept -499.5

Regression equation Y = – 499.50 – 16.02 X1 + 2.38 X2 + 11.79 X3 – 1.22 X4 + 7.21 X5 + 17.75 X6 + 4.86 X7 – 2.177X8
R2 82.6
** Significant at 5% level

Rabindra, R.J., Ballal, C.R and Ramanujan, B. 2004. Biological options for insect pests and nematode management in Kalyani Publishers, New Delhi, India. 487Pp.

Rao, D.G. 2010. Seasonal incidence and pest manage-
-ment strategies against spotted pod borer, Ma-
-ruca vitrata (Geyer) in rice fallow blackgram.
M.Sc.(Ag.) Thesis.

Reddy, C.N., Singh,Y and Singh, V.S. 2001. Influence of abiotic factors on the major insect pests of pigeonpea. Indian Journal of Entomology.63 (3): 211- 214.

Sahoo, B.K and Behera, U.K. 2001. Influence of abio-
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Seasonal incidence of Maruca vitara (Geyer)) on rice fallow blackgram in north coastal Andhra Pradesh

Sivaramakrishna, J., Rajasekhar, P and Ramachandrarao,
G. 2004. Influence of weather parameters on the occurrence of major Lepidopteran pests on blackgram. The Andhra Agricultural Journal. 51 (1&2): 86-89.

Sravani, D., Mahalakshmi, M.S., Sandhyarani, C and Kumari, V.P. 2015. Seasonal incidence of spotted pod borer, Maruca vitrata (Fabricius) (Crambidae, Lepidoptera) on greengram under unsprayed conditions. International Journal of Pure and Applied Bioscience. 3(5): 152-158.

Srinivas, S.M. 2003. Ecology and microbial control of lepidopteran pests in rabi groundnut. M.Sc (Ag.). Thesis.Acharya N.G. Ranga Agricultural University, Hyderabad.

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