A FIELD STUDY OF POPULATION DYNAMICS OF MAJOR INSECT PESTS AND THEIR NATURAL ENEMIES ON CAULIFLOWER OF AJMER DISTRICT

PUJA DEWANDA¹*, SABIHA KHAN^2
1Department of Zoology, S.D. Govt. College, Beawar, Rajasthan, India
²Department of Zoology, Govt. College, Ajmer , Rajathan, India
* Corresponding Author : puja.chandra16@gmail.com

Received : 06-08-2016     Accepted : 20-09-2016     Published : 01-11-2016
Volume : 8     Issue : 53       Pages : 2642 - 2645
Int J Agr Sci 8.53 (2016):2642-2645

Keywords : Population dynamics, Pest, Natural enemies
Academic Editor : Dr Dalip Kumar
Conflict of Interest : None declared
Acknowledgements/Funding : We thank S.P.C., Govt. College, Ajmer, India, for providing facilities in the Department of Zoology, during this study. We gratefully acknowledge Research Fellowship provided by the University Grants Commission for this work.
Author Contribution : None declared

Cauliflower, Brassica oleracea var. botrytis is among one of the most cultivated vegetable crop of Ajmer. A field study was conducted at an experimental research farm, situated in Pal-Bichla, Ajmer. Observations were recorded to study the incidence and population dynamics of major insect pests and their natural enemies on cauliflower. Experiment was laid out in randomized block design (RBD) with three replications. Twenty-four days’ old cauliflower seedlings were transplanted in the plot of 10 m2 area with 40cm x 40cm spacing on 1st August 2014 to study the population dynamics of the major pest and its natural enemies during the monsoon season. The study continued from August 2014 – November 2014. The second study was conducted from January 2015– April 2015. In Aug.-Nov. crop season larval population of Plutella xylostella, DBM ranged from 0 to 17.60 larvae/ plant and DBM was first noticed in the field on 5th September, 2014 (2.76 larvae /plant) with gradual increase in its population and reached its peak on 7th November, 2014 (17.90 larvae/plant). Whereas, in Jan.-Apr. 2015 crop season, larval population of DBM ranged from 0 larvae per plant to 22.30 larvae per plant. The Spodoptera larva was first spotted on 29th of August 2014 (2.0 larvae /plant) with gradual increase in its population and reached its peak by the end of September (8.60 larvae/plant). Severity of aphid incidence was found to be higher in winter season as compared to monsoon season. Highest larval parasitization by Cotesia plutella was recorded on 14th Nov. (9.66%) for the year 2014 and on 05th April (14.16%) for the year of 2015.