Methodology for Baseline Susceptibility Monitoring of leaffolder in rice
1. Leaf preparation
1) Leaf cutting
Obtain cutting of 4-5 cm length from the middle portion of the leaf (at least 5 cm from both ends of the leaf).
2) Leaf dipping
After cutting enough leaves needed for the assay, dip them in the prepared treatment solution for 5 seconds. Use an NIS surfactant (i.e. X-77) to improve coverage.
3) Leaf drying
With the leaf cutting adequately treated, they are air dried for about 2 hours.
4) Larval infestation
Infest one (1) 2nd instar larva per leaf per cell of a HIS tray by allowing the larva to cling and into crawl on and into the treated leaf cutting.
5) Handing the HIS tray
Close the trays using the snap-on plastic lids and keep the trays at 25-27 ๐C for 96 hours.
6) Data collection and Recording
At 96 hours after infestation, check whether there are any larvae in the tray and on the exterior of the leaf.
Record the observations on an appropriate data sheet prepared specifically for this purpose. Evaluate whether larvae in each cell is live (L), moribund (M) or dead (D).
Live
Live larvae are already almost twice the size from the start of the test.
Larvae are very active, moves quickly and are sensitive to probing.
Moribund
Moribund show no growth.
Larvae are sluggish, obviously in a dying state or near death. They are unable to flip over when placed on its back or unable to crawl normally.
Dead
Dead larvae are already shriveled and have dried up.