Whiteflies, despite their name, are not actually flies but rather, belong to the Hemiptera order of insects. They are close relatives of aphids, scales, and mealybugs. These tiny, white, moth-like creatures are only about 1-2 millimetres in size, making them challenging to spot with the naked eye. Whiteflies are common greenhouse and garden pests, attracted to a wide range of plants, including chilli plants.

These insects are notorious for their rapid reproduction rate, with females laying up to 200 eggs in a single lifetime. Whiteflies have multiple overlapping generations throughout the year, making them a persistent problem for many New Zealand gardeners. Moreover, whiteflies are known carriers of viral diseases, which can further compromise the health and vitality of your chilli plants.

Preventing whiteflies from invading your chilli plants is far more effective than attempting to eliminate an established infestation. Here are some prevention strategies to implement in your New Zealand garden:

1. Choose resistant chilli varieties: Some chilli cultivars are more resistant to whiteflies and other pests. Research and select varieties known for their resilience.
2. Practice good garden hygiene: Remove plant debris and weeds, which can serve as breeding grounds for whiteflies.
3. Monitor plants regularly: Inspect your chilli plants frequently, particularly the undersides of leaves, for signs of whitefly infestations.
4. Encourage beneficial insects: Attract natural predators of whiteflies, such as ladybirds, lacewings, and parasitic wasps, by planting a diverse range of flowers and herbs in your garden.
5. Employ physical barriers: Use fine mesh netting or insect-proof screens to protect your chilli plants from whiteflies.

If whiteflies have invaded your chilli plants, take action immediately to minimise the damage. Here are some natural methods to eliminate whiteflies:

1. Manual removal: Use a handheld vacuum ora soft brush to remove adult whiteflies and eggs from the undersides of leaves.
2. Pruning: If an infestation is localized to specific parts of your chilli plants, prune away the affected leaves and branches. Dispose of them securely to prevent the spread of whiteflies.
3. Neem oil: Apply neem oil, a natural pesticide, to your chilli plants. Neem oil can disrupt the feeding and reproduction of whiteflies, ultimately reducing their population.
4. Insecticidal soap: Insecticidal soaps containing potassium salts of fatty acids can be an effective treatment against whiteflies. Be sure to follow the product instructions and apply the soap directly to the whiteflies for optimal results.
5. Biological control: Introduce natural predators of whiteflies, such as ladybirds, lacewings, and parasitic wasps, to your garden to help control the infestation.

When natural solutions fail to control a persistent whitefly infestation, you may need to resort to synthetic pesticides. However, exercise caution when using chemicals, as they can harm beneficial insects and pollinators.

1. Systemic insecticides: These chemicals are absorbed by the plant and transferred to the sap, making them toxic to whiteflies. Examples include imidacloprid and acetamiprid. Follow the product instructions carefully and avoid overuse, as whiteflies can develop resistance to these chemicals.
2. Contact insecticides: Contact insecticides, such as pyrethroids, kill whiteflies upon direct contact. Apply these products when whiteflies are most active, typically in the early morning or late evening. Be aware that these chemicals can also harm beneficial insects.