How to kill small leaf rollers

Leaf rollers can cause rice epidemics in the northern provinces. It is necessary to rely on the announcements of local plant protection stations about the time when small leaf rollers emerge and eggs hatch to determine the time to spray pesticides. However, the specific time when eggs hatch in each field and area is different depending on the planting season and the microclimate of each place.

Method 1:In the morning around 9-10am (start monitoring 2-3 days before the butterfly season as announced by the local plant protection station or the day when butterflies are seen in large numbers in the lights of families near rice fields) use a 1.5-2m long stick to chase butterflies 2-3m from the bank, about every 2 days to chase butterflies once, see the butterfly density gradually increase, when you see the butterfly chasing right after that the butterfly density suddenly decreases, then 2 days later is the appropriate time to spray the pesticide.

Method 2: Check for hatching leaf roller eggs by chasing away butterflies and seeing that the butterfly density has decreased significantly compared to the previous time. Check 2 points in the field 2-3m apart, each point is 1m2. Newly hatched leaf rollers, age 1-2, are located at the tip of the rice leaves with the spathe bent. The size of the worm is the size of a small toothpick, light green, 0.3-0.7cm long and very flexible. When you see >10 insects/m2, it is time to spray.

Using new pesticides for insects that are not familiar with pesticides such as Virtako; Tasodant or common pesticides such as Regent 800WG Regill 800WG; Targo 800WG; Rhironin 800WG...); Patox 95SP; Sattrungdan 95WP; Silsau 3,6WP (Abamectin 36EC; Aremec 36EC; Sherpatin 36EC) also gives good results. However, rice leaf rollers quickly become resistant to pesticides. If one pesticide is used 2-3 times, the next time the dose needs to be increased or the pesticide changed. Mixing two pesticides can be more effective.

Need to spray again after the first time 3-5 days in the cool afternoon if the density of worms is high, eggs hatched scatteredly. From the stage of rice grain filling, the leaf rollers are small and no longer harmful.

According toAgriculture Newspaper