Biocontrol of Maize Stem Borer (Chilo partellus) Using Entomopathogenic Nematodes
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Date
2006
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Publisher
MPUAT, Udaipur
Abstract
A total of 80 soil samples were collected from the rhizosphere of maize crop
in and around Udaipur during kharif 2005. Out of these soil samples only 3 samples
collected from C8 block and A3 block (RCA farm) yielded entomopathogenic
nematodes belonging to genera S. carpocapsae and H. bacteriophora. Soil samples
were isolated using late instar larvae of rice moth Corcyra cephalonica (Stainton). H.
bacteriophora isolated in 2 samples and S. carpocapsae in one sample EPNs culture
was maintained in BOD at 21-26ºC. The containers were aerated twice a week using
aerator and by changing water frequently. These entomopathogenic nematodes were
mass multiplied (in vivo) on the larvae of rice moth, Corcyra cephalonica (Stainton).
The IJs of S. carpocapsae harvested were 36860.0, 44697.5 and 54347.0 from small,
medium and large sized larvae, respectively. Similarly, IJs of H. bacteriophora
harvested were 63765.0, 76300.0 and 85980.0 from small, medium and large sized
larvae, respectively. The number of IJs harvested increased with an increase in size
and body weight of larvae. The EPNs were also mass multiplied (in vitro) on different
artificial media i.e. wout’s medium, modified nutrient broth medium, wheat flour
medium and wheat bran medium. The highest number of IJs of S. carpocapsae (2.305
x 105) were harvested from wheat bran medium followed by wheat flour medium
(0.297 x 105). Similarly, in H. bacteriophora IJs harvested were (4.05 x 105) and
(0.516 x 105) from wheat bran and wheat flour medium, respectively. The IJs of H. bacteriophora were multiplied better on artificial media as
compared to S. carpocapsae. The pathogenicity test of EPNs was done on Chilo
partellus larvae in laboratory as well as in pot conditions. After 120 hrs. of exposure
the mean per cent mortality of Chilo partellus larvae against S. carpocapsae and was
45.0-95.0 and of H. bacteriophora was 50.0-95.0 per cent, respectively. In pot
conditions the pathogenicity was tested on the basis of per cent mortality of test
insect. The per cent mortality of Chilo partellus was observed better when H.
bacteriophora were sprayed @ 2500 IJs/plant. The per cent morality of Chilo
partellus larvae further, increased after 120 hrs. The per cent mortality of Chilo
partellus larvae increased with an increase in the inoculum level and period of
exposure.
Description
Biocontrol of Maize Stem Borer (Chilo partellus) Using Entomopathogenic Nematodes
Keywords
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Citation
Dhaliwal and Prihar, 2006