Seasonal Incidence of Mealy Bug Species and their Major Parasitoids on Cotton (Gossypium sp. L.) in Coimbatore, Tamil Nadu
S. Thangavel*
Department of Agricultural Entomology, B.A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, India – 388 110
N. Ganapathy
Department of Entomology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India - 641 003
DOI: NIL
Keywords: Seasonal incidence, Mealy bug, Parasitoids, Cotton, Coimbatore, Tamil Nadu
Abstract
Field experiment on seasonal incidence of mealy bug species of cotton was conducted in Coimbatore, Tamil Nadu Agricultural University during 2016-2017. Results showed four mealy bug species such as Phenacoccus solenopsis (Tinsley), Maconellicoccus hirsutus (Green), Ferrisia virgata (Cockerell) and Paracoccus marginatus (Williams & Granara de Willink). Among them, peak population of Phenacoccus solenopsis (400.75 insects/plant) was recorded in October, that decreased slowly during January (100.6 insects/plant) and there was least population during February - March. Correlation analysis between weather parameters and mealy bug activity indicated positive correlation with maximum temperature, minimum temperature, relative humidity and negative correlation with rainy days. The major parasitoids found attacking mealybugs in the experimental field were; Aenasius arizonensis Girault, Promuscidea unfasciati Girault and Acerophagus papayae Noyes & Schauff. The assessment of mealybug population and the level of parasitization of the three parasitoids were carried out based on the adult emergence from the sampled parasitized mealybugs. The parasitism of mealy bug by Aenasius arizonensis was the highest in October which decreased gradually during January with the decrease in mealy bug population.
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Reference
Gupta, G.P. 2001. Alternate strategies for IPM in major crops. ICAR - IARI, New Delhi, June 11 – July 5: 232-236.
Gomez, R.A. and A.A., Gomez, 1984. Statistical Procedures for Agricultural Research. Inter Science Publications, John Wiley and Sons, IRRI, The Philippines. 680p.
Suresh, S. and P. Chandrakavitha. 2008. Seasonal incidence of economically important coccid pests in Tamil Nadu. In: Proceedings of the XI International Symposium on Scale Insect Studies, Oeiras, Portugal, 24-27th Sept. 2007.