Brown planthopper (rice)
Sap-suckers that crowd the base of rice tillers and dry the crop in circular "hopper burn" patches — worst in dense, over-fertilised fields.
- Pest type
- Sap-sucking hopper
- Attacks
- Base of tillers (water line)
- Worst in
- Dense, high-N, humid crops
- Main risk
- Hopper burn; spray-induced resurgence
Overview
The brown planthopper (BPH) is a small brown sap-sucking hopper that lives low down at the base of rice tillers, near the water line, rather than on the leaves. Both adults and nymphs suck sap in large numbers, draining the plant.
Heavy feeding causes "hopper burn": the plants yellow, then dry and collapse in roughly circular patches that spread outward, and a severe attack can flatten large areas. BPH is very much a man-made problem — it explodes in dense, over-fertilised (high-nitrogen), closely-spaced crops with a humid, closed canopy, and above all after broad-spectrum insecticide sprays kill the spiders and other predators that normally keep it down. It can also transmit rice viruses.
How to identify it
- Part the canopy and look at the base of the tillers near the water — clusters of small brown hoppers and their nymphs, not on the upper leaves.
- Circular patches of plants that yellow, dry and lodge ("hopper burn"), spreading outward from a focus.
- Sticky honeydew and sooty mould at the plant base, and a sudden population surge after a broad-spectrum spray.
- Worst in the densest, most heavily-fertilised parts of the field.
The damage it does
- Hopper burn — yellowing, drying and collapse of plants in circular patches that can flatten large areas.
- Direct sap loss that shrivels grain and cuts yield sharply in a heavy attack.
- Transmission of rice viruses (e.g. grassy stunt / ragged stunt) in some situations.
- Explosive resurgence after ill-timed broad-spectrum sprays, often worse than the original attack.
When to act
- Monitor the tiller base weekly from maximum tillering — part the hills and count hoppers at the base, not on the leaves.
- Act on the recommended threshold (numbers of hoppers per hill), draining the field first, rather than spraying prophylactically.
- Never spray a broad-spectrum insecticide early "to be safe" — it removes predators and invites a BPH outbreak.
Organic & cultural control
- Avoid excess nitrogen and dense planting; keep alleys/rogue spaces and use recommended spacing so the canopy is not a closed, humid hopper haven.
- Drain the field for a few days at the first sign of BPH — alternate wetting and drying disrupts the hopper and exposes it.
- Grow resistant/tolerant rice varieties and conserve natural enemies (spiders, mirid bugs) by avoiding early broad-spectrum sprays.
- Use light traps to monitor migration, and never spray synthetic pyrethroids, which are notorious for triggering BPH resurgence.
Chemical control
- Spray only on threshold, direct the spray to the base of the plants where BPH lives, and drain the field first for better reach.
- CIB&RC-registered options include pymetrozine 50% WG, dinotefuran, buprofezin 25% SC (for nymphs) and flonicamid — chosen for rice and rotated.
- Strictly avoid synthetic pyrethroids and unnecessary broad-spectrum insecticides, which kill predators and cause BPH to resurge worse.
- Confirm the current recommendation and dose for your area with your local KVK.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My rice is drying and collapsing in circular patches. What is it?
That is "hopper burn" caused by the brown planthopper. The hoppers crowd the base of the tillers near the water and suck sap until the plants yellow, dry and lodge in circular patches that spread outward. Part the canopy at the base — not the leaves — and you will see the brown hoppers. Drain the field and treat on threshold.
Why did spraying make the brown planthopper worse?
Because broad-spectrum insecticides — especially synthetic pyrethroids — kill the spiders and other predators that keep BPH in check, so the hopper resurges explosively, often worse than before. This is the classic BPH resurgence. Avoid those sprays, conserve predators, manage nitrogen and spacing, and use a selective registered insecticide only on threshold.
How does over-fertilising cause brown planthopper?
Heavy nitrogen and dense planting produce a lush, closed, humid canopy — exactly the sheltered, sappy conditions in which BPH multiplies fastest. Using the recommended nitrogen and spacing, keeping the canopy open, and draining the field periodically all make the crop far less hospitable to the hopper.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.