Farmers have been advised to adopt biological or mechanical methods or spray chemicals to control the black bug menace on paddy crop noticed in certain parts of the delta.
In a press release, V.Ambethgar, director, Tamil Nadu Rice Research Institute, Aduthurai, said that the institute received information that the presence of Scotinophara lurida (Burmeister), known as rice black bug (RBB) or psunami vandu in local parlance, was noticed on the paddy crop particularly in the coastal areas and it was multiplying rapidly.
The pest attacks the rice plant at almost all the stages of growth and results in severe to complete crop loss during heavy infestation.
If a rice plant was infested with about 10 to 15 RBB per hill, then it could cause a yield loss of around 25 per cent.
Pointing out that the study of RBB carried out for about a decade has revealed that these insects were noticed in the fields during or after a full moon period, he said that it was ascertained that the full moon cycle affects the RBB’s flight activity. Farmers were advised to adopt light trapping technology since the RBBs are highly attracted to the high intensity of light.
Light trapping of bugs could be adopted two days before or until three days after full moon period from 8 p.m. to midnight for better and effective results, he added.
As these bugs are susceptible to biological control agents like Bevariana basiana and Metarhizium anisopliae and counter checked by the presence of parasitoids such as coccinellids, trichogramma, telenomus and spiders it was suggested to adopt these biological control methods also.
In case if humid weather condition prevails in the late season of the crop, insecticides can be used on the need basis, he said. For effective results, the spraying of 100 ml of monocrotophos per hectare or 625 grams of acephate per hectare or need seed kernel extract at the bottom portion of the hill should be carried out. If further details required, the farmers could contact the Institutes’s Assistant Professor (Agriculture Entomology), P.Anandhi (0435 – 2472108).
