Integrated Pest Management IPM Pest Management Pests Red Spider Mite Spider Mites Two-Spotted Spider Mite

Spider Mite Integrated Pest Management

Nov 23, 2023

Spider mites are tiny arachnids that belong to the family Tetranychidae. They are closely related to spiders and ticks. These minuscule pests are known for their ability to damage a wide variety of plants by feeding on plant fluids, specifically the contents of plant cells. There are several species of spider mites, but two of the most common ones that affect crops are the two-spotted spider mite (Tetranychus urticae) and the red spider mite (Tetranychus cinnabarinus).

Spider mites are particularly problematic in warm and dry conditions. They thrive in hot weather and can reproduce rapidly, leading to infestations that can severely impact crop health.

Two-spotted Spider Mite
Scientific name:	Tetranychus urticae		Image of juvenile T. Urticae (next to adult and egg)	Image of adult T. Urticae
Common name:	Two-spotted Spider Mite
Insect order:	Trombidiformes
Family:	Tetranychidae
Host range		Over 200 different plant genera are susceptible to attack by T. urticae including, but not limited to, Capsicum, Cucumis, Solanum, Spinacia, Rubus, Rosa, Citrus, Pyrus.
Metamorphosis		Incomplete metamorphosis.
Life cycle and seasonal behaviour		T. urticae are most active during the hot and dry summer months, mated female mites overwinter amongst ground litter to produce new generations of mites during the warming of spring.
Adult mouthparts		Adult mites feed on the leaves of their host plant, piercing their surface and sucking to feed on their contents.
Juvenile mouthparts		Juvenile mites feed on the leaves of their host plant, piercing their surface and sucking to feed on their contents.
Plant part affected		Two-spotted spider mites puncture the leaf surface of their host plant, which leaves behind a distinct stippling pattern upon the surface. These mites produce a fine webbing upon the surfaces they are feeding on, and also use this webbing to move between areas of the host, or from one host to another. Heavy infestation can result in a thick webbing that covers the entire plant.
Pest management options
Chemical		T. urticae are known for their resilience to chemical controls, and are able to rapidly build resistance to new chemical controls. Chemical controls that are registered for the control of this pest include: Azidirachtin, neem oil, horticultural soap, pyrethrum.
Cultural		Maintain soil moisture levels, drought stressed plants are susceptible to mite attack. Dusty conditions can also be a cause of mite infestations, ensure frequent rinsing off of dusty foliage, pathways and greenhouse benches/surfaces. Spider mites favour hot and dry conditions, so increasing humidity and lowering of temperatures can make the environment less favourable.
Physical		Spraying down the entire plant with water until run-off, focusing on the undersides of leaves and crevices along the stem tissue, can be very effective in removing mite infestations from the affected plant. Mites can be easily transferred from one location to another on shoes and clothing, washing boots and changing of clothes is effective for preventing population spread.
Biological control		Phytoseiulus persimilis, Neoseiulus californicus, Stethorus sp. Ladybird,
Integrated Pest Management (IPM)		Establishment of pest threshold levels, and use of regular observation to monitor plants for the presence of mites. A magnifying glass is extremely helpful, as two-spotted spider mites can be miniscule and easy to miss. Ensure healthy water management to avoid any plants becoming stressed from lack of available water, which attracts mites. Regular misting down of plants can be very effective at controlling rising two-spotted spider mite populations without use of chemicals. Two-spotted spider mites are able to build resistance to pesticides very quickly, and therefore chemicals should be used very sparingly to maintain effectiveness. Spraying of neem oil is effective at controlling mite populations, and while generally considered safe to beneficial insects should not be used if predatory mites have been released to control the two-spotted spider mites, as it will kill any mites on contact. Predatory insects are an excellent method of control for two-spotted spider mite, and are available in differing species each suitable to different environmental conditions.