The tiny white flies in your garden are most likely whiteflies, which are tiny, sap-sucking insects that may become abundant in vegetable and ornamental plantings, especially during warm weather. Despite their name, whiteflies are not true flies (in the insect order Diptera) but are in the order Hemiptera, related to aphids, scales, and mealybugs. They derive their name from the mealy white wax covering the adult’s wings and body. Adults are tiny insects with yellowish bodies and four whitish wings. Although adults of some species have distinctive wing markings, many species are most readily distinguished in the last nymphal (immature) stage, which is wingless and lacks visible legs. Whiteflies develop rapidly in warm weather, and populations can build up quickly in situations where natural enemies are ineffective and when weather and host plants favor outbreaks. Large colonies often develop on the undersides of leaves.
To control whiteflies in your garden, you can try the following methods:
- Yellow sticky traps: These can be posted around the garden to trap adults. Such traps won’t eliminate damaging populations but may reduce them somewhat as a component of an integrated management program relying on multiple tactics. Whiteflies do not fly very far, so many traps may be needed.
- Washing off plants with a forceful stream of water: This can be effective in controlling whiteflies if infestations are caught early. Make sure to get the undersides of the leaves, as this is where eggs and nymphs hang out.
- Beneficial insects: One tiny black ladybug Delphastus is a voracious feeder and can consume up to 150 whitefly eggs in a day. Lacewings or parasitic wasps can also be effective in controlling whiteflies. These can be purchased at your local nursery or ordered online in containers of 1,000, and sprinkled on the infested plants.
- Insecticidal soap: This can be used to knock down heavy infestations. Insecticidal soaps coat the eggs and larvae with a coating that makes it difficult for them to breathe. It’ll also kill off adult whiteflies.
- Garlic spray: A homemade garlic spray can be a good home remedy for whiteflies on plants. Garlic can be a particularly pungent aroma, so it is recommended only for outdoor use.
