What kinds of Two-spotted mite are there in Australia?

The two-spotted mite, also known as the red spider mite or Tetranychus urticae, is a common pest in Australian gardens. This mite species is not only found in Australia but is also a widespread pest worldwide. It primarily affects various vegetables, fruit trees, and ornamental plants. Here is a visual description of the two-spotted mite:

1. Appearance: Adult two-spotted mites are very small, measuring about 0.5 mm in length. They have an oval-shaped body with a slightly flattened appearance. The colour of these mites can vary depending on the host plant, temperature, and other environmental factors. They can be green, yellow, or orange with two dark spots on either side of the body. These dark spots are the accumulation of body waste and give the mite its name.

2. Feeding behaviour: The two-spotted mite feeds on plant sap, piercing the cells on the underside of leaves with its mouthparts. This feeding behaviour can cause leaves to develop a characteristic stippled or mottled appearance, eventually turning yellow or bronze and dropping off the plant. Severe infestations can lead to defoliation and reduced plant vigour.

3. Webbing: As they feed and reproduce, two-spotted mites produce fine webbing, which can be seen covering the infested parts of the plant. The webbing provides protection for the mites and their eggs, making control more difficult.

Control measures for two-spotted mites:

1. Monitoring: Regularly inspect your plants for signs of two-spotted mite infestations, such as stippled leaves, webbing, or the presence of mites themselves. Use a magnifying glass or hand lens to get a closer look at these tiny pests.

2. Cultural control: Ensure your plants are healthy and well-watered, as stressed plants are more susceptible to mite infestations. Avoid over-fertilising, as excessive nitrogen can encourage mite reproduction.

3. Biological control: Introduce natural predators, such as predatory mites (Phytoseiulus persimilis or Neoseiulus californicus), lacewings, or ladybirds, which can help control two-spotted mite populations.

4. Physical control: Spray your plants with a strong jet of water to dislodge mites and their webbing. Be sure to target the underside of leaves where the mites tend to congregate.

5. Chemical control: If mite populations are high and causing significant damage, you can use horticultural oil or miticides labelled for two-spotted mite control. Always follow the label instructions and consider the potential impact on non-target insects and pollinators.

By understanding the characteristics and behaviours of the two-spotted mite, you can better target your pest control efforts and maintain a healthy garden.