Whiteflies can cover new houseplant growth before you notice what is happening. The small insects gather under leaves and around stems, feeding on plant sap. Shake an affected plant and adults may fly from the foliage.
The infestation shown here has whiteflies packed around new growth and leaf bases. A trap made from yellow cardstock and Vaseline can catch adults as they move around the plant.
Yellow Cardstock Draws Adult Whiteflies
Adult whiteflies are attracted to yellow, the same reason many commercial sticky traps use yellow cards. Cut a piece of yellow cardstock and place it close to the affected plant.
Attach the card to a wooden craft stick if you want to position it in the pot. Keep it close to the foliage without letting the sticky surface rest against the leaves.
Color gets the insects onto the card. Vaseline keeps them there.
Coat the Card With Vaseline
Spread Vaseline across the yellow cardstock to create a sticky surface. Vaseline is a brand of petroleum jelly made from mineral oils and waxes, giving the card enough tack to capture small flying insects.
Whiteflies fly toward the yellow card and become stuck when they land on the Vaseline. Coat both sides if the card is exposed from several directions.
Replace the card when insects, dust, or debris cover much of the Vaseline.
Check Under the Leaves for More Whiteflies
Trapped adults represent only part of an infestation. Whiteflies lay eggs on leaves, while immature stages remain attached to the plant. A Vaseline trap won’t remove those stages.
Turn leaves over and inspect the undersides, new growth, and areas close to the stems. Whiteflies can remain hidden there even when fewer adults appear around the room.
Moving an affected plant away from other houseplants can also reduce the chance of adults reaching another host.
Keep Using the Trap While Whiteflies Remain
Yellow cardstock coated with Vaseline works as an adult trap, not a complete treatment for an established infestation. Continue checking the plant while replacing cards that fill with insects.
If Vaseline is running low, a mixture of petroleum jelly and dish soap can also create a sticky coating. The same yellow-card principle remains: attract flying adults to the color, then prevent them from leaving once they land.
The trap also gives you a visible way to track activity. Fewer whiteflies on each replacement card can show whether the adult population around the plant is dropping.
