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Journal of Entomology and Zoology Studies 2017; 5(2): 185-188
E-ISSN: 2320-7078
P-ISSN: 2349-6800
JEZS 2017; 5(2): 185-188
© 2017 JEZS
Received: 25-01-2017
Accepted: 26-02-2017
Sarwan Kumar
Department of Plant Breeding
and Genetics, Punjab
Agricultural University,
Ludhiana, Punjab, India
Jaswinder Kaur
Department of Entomology,
Punjab Agricultural University,
Ludhiana, Punjab, India
Correspondence
Sarwan Kumar
Department of Plant Breeding
and Genetics, Punjab
Agricultural University,
Ludhiana, Punjab, India
Efficacy of Beauveria bassiana and Bacillus
thuringiensis as ecosafe alternatives to chemical
insecticides against sunflower capitulum borer,
Helicoverpa armigera (Hübner)
Sarwan Kumar and Jaswinder Kaur
Abstract
During spring 2012, three biopesticides including DOR Beauveria bassiana SC (200, 250 and 300 mg l
-1
)
(developed by ICAR-Directorate of Oilseeds Research, Hyderabad, India), commercial B. bassiana
formulation Daman 1 WP (5g l
-1
) and DOR Bt-5 (Bacillus thuringiensis formulation) (2.5 g l
-1
) along
with synthetic insecticide profenophos 50 EC (0.05%) were evaluated under field conditions against
sunflower capitulum/ head borer, Helicoverpa armigera (Hübner). All the biopesticides were effective in
suppressing the larval population of H. armigera and were safe to natural enemies found in sunflower
agro-ecosystem. The seed yield was also significantly higher in all the treatments as compared to control.
It was concluded from the study that DOR B. bassiana @ 200 mg l
-1
and DOR Bt-5 @ 2.5 g l
-1
are the
potential candidates that can be used for early season suppression of H. armigera on sunflower and are
safe to natural enemies as well. These entomopathogens may be useful components of H. armigera
Integrated Pest Management (IPM) strategy.
Keywords: Biopesticides, capitulum borer, Entomopathogenic fungus, Head borer
1. Introduction
Sunflower (Helianthus annus L.) is an important oilseed crop in India after groundnut, mustard
and soybean. The crop has gained much popularity due to some characters such as short
duration, photo-insensitivity and wider adaptability to different agro-climatic conditions
[10]
and has great potential for diversification of major cropping systems in the country. In
southern states of the country (Karnataka, Maharashtra, Andhra Pradesh and Gujarat), it is
principally grown as monsoon, late monsoon and rabi crop, while in northern states (Punjab,
Haryana, Uttar Pradesh and Rajasthan), it is grown as spring season crop. During the year
2013-14, it was cultivated on an area of 6.91 lakh ha in the country with production and
productivity of 5.47 lakh tones and 791 kg ha
-1
, respectively
[18]
.
The crop is attacked by a number of insect-pests and as many as 251 insect species are known
to attack this crop the world over
[21]
. In India, major insect-pests associated with this crop are
capitulum borer Helicoverpa armigera (Hübner), green semilooper Thysanoplusia orichalcea
Fab., Bihar hairy caterpillar Spilosoma obliqua (Walker), tobacco caterpillar Spodoptera litura
(Fab.), cutworm Agrotis sp. and green leaf hopper Amrasca biguttula biguttula
[4]
. The loss in
seed yield due to these pests is estimated to be around 24.9 per cent
[2]
. Among these,
capitulum/head borer (H. armigera) is the most important one inflicting annual crop damage in
India worth US $ 1 billion
[15]
. It is a major pest of many economically important crops in
India
[11, 14]
and remains active throughout the year on one or the other crop. A wide host range
[7, 23, 31]
, high fecundity
[22]
, a capacity to migrate
[6]
and the ability to develop high resistance to
insecticides
[3]
have enabled this insect to attain key pest status among various major crop
pests. The problem of this pest is further magnified due to its high preference for fruiting
bodies, voracious feeding habit
[12]
, high mobility and overlapping generations with ability to
enter facultative pupal diapause both in winter and summer seasons
[13]
.
The present methods of pest management largely rely on the use of toxic synthetic insecticides
which have their own adverse effects such as development of insecticide resistance, pest
resurgence, secondary pest outbreaks besides environmental pollution and residues in oil and
cake. This necessitates the development of alternate pest management strategies.