Population dynamics and management of yellow mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) infesting gerbera under protected cultivation
Soumita Pal and Krishna Karmakar
The present experiment was conducted in an experimental unit, at Horticultural Teaching Farm, of Bidhan Chandra Krishi Viswavidyalaya during August to December in the year 2015 to study the population dynamics of yellow mite and its management on the susceptible cultivar Jaffana. It appears in a devastating form causing curling, twisting and malformed growth of the plants yielding deformed flowers. Mites colonize and feed on the young leaves and flowers and cause distortion. The females lay eggs under surface of leaves and all the active stages viz., larvae and adults were observed to suck cell sap. As a result of continuous feeding, leaf margins to curl, brittle and shriveled. The infested leaves become cupped, curled, dwarfed, and flowers become discoloured and deformed. The mite population is significant and directly correlated with prevalent temperature and relative humidity and also sunshine hours having a positive role to build up the population. Application of sulphur @ 1600gm ai/ha, dicofol @277.5 gm a.i/ha, diafenthiuron @ 800gm a.i/ha, fenazaquin @ 100 gm a.i/ha and spiromesifen @ 500 gm a.i/ha registered highest mite mortality while ethion was least effective to the mite species.