Pollu beetle
A blue-black flea beetle whose grubs bore into pepper berries and hollow them out — the most serious insect pest of the crop, worst under dense shade.
- Pest
- Flea beetle (Longitarsus nigripennis)
- Damage stage
- Grubs bore into developing berries; adults on leaves & spikes
- Favoured by
- Dense shade, humid canopy, low elevation
- Main risk
- Hollow "pollu" berries; downgraded lot; spike loss
Overview
The pollu beetle (Longitarsus nigripennis) is the most serious insect pest of black pepper. The adults are small, shiny, blue-black flea beetles that bite small holes in tender leaves, growing shoots and young spikes. The grubs bore into the developing berries and feed inside, so the berry turns black and hollow — "pollu" is the local word for a hollow, chaffy, worthless berry. Heavy spike and shoot boring also checks the vine.
Damage is highest in heavily shaded, low-elevation gardens where the canopy is dense and humid, and lowest where shade is regulated and the garden is open and airy. Because bored berries are worthless and downgrade the whole lot, and because the beetle also opens the way for pollu disease (anthracnose), managing shade and timing sprays to spike emergence and berry set are the core of control.
How to identify it
- Small, shiny, blue-black beetles that jump when disturbed, on tender leaves, shoots and young spikes.
- Small round feeding holes in tender leaves and shoots.
- Berries that turn black and, when opened, are hollow with a grub or its tunnel inside — "pollu".
- Worst in a heavily shaded, dense, humid, low-elevation garden.
Life cycle & conditions
- Adults feed on tender growth and lay eggs on the developing spikes; grubs bore into the berries and feed inside before pupating.
- Populations build under a dense, unregulated shade canopy and in low-elevation gardens.
- The beetle's boring also opens the berry to pollu disease (anthracnose), so the two problems often appear together.
Cultural & organic control
- Regulate the standard shade so the canopy is open and airy — the single biggest lever, as the beetle dislikes bright, well-ventilated conditions.
- Prune out and destroy bored spikes and shoots to remove developing grubs.
- Spray neem formulations at spike emergence and again at berry set.
Chemical control
- In gardens with a history of pollu, spray a recommended insecticide at spike emergence and again 3–4 weeks later during berry development, directed at the spikes and tender shoots.
- Time the sprays to the vulnerable spike-and-berry stage rather than spraying routinely.
- Confirm the current product, dose and timing with ICAR-IISR or your KVK, and observe the pre-harvest interval.
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
Many of my pepper berries are black and hollow inside. What causes this?
Hollow, black, chaffy berries — "pollu" — are usually caused by the pollu beetle, whose grubs bore into and feed inside the developing berry. It is the most serious insect pest of black pepper. Regulate the shade so the canopy is open and airy, prune out bored spikes, and spray neem or a recommended insecticide at spike emergence and berry set. Pollu disease (anthracnose) can cause similar hollow berries and often follows the beetle.
Why is pollu beetle worse in shaded gardens?
The beetle favours a dense, humid, poorly lit canopy and low-elevation conditions. A garden where the standard shade is regulated so the canopy is open and airy has far less pollu-beetle damage. Shade regulation before each monsoon is the most cost-effective control, and it also cuts pollu disease, which the beetle helps spread.
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.