Spider mites are small arachnids that feed on various plants and can cause significant damage in gardens and landscapes. They are called web-spinning mites and belong to the Tetranychus genus. The most common species include the Pacific spider mite, two-spotted spider mite, and strawberry spider mite. They are difficult to differentiate, but their biology and control methods are similar.
Spider Mite management in Tomato
The life cycle of Spider Mite
- The life cycle of spider mites in tomato plants is similar to that in other plants. The eggs have fine silk webbing and hatch in about three days. The life cycle includes the stages of egg, larva, protonymph, deutonymph, and adult.
- The time from egg to adult depends on temperature, with faster development at around 80°F, taking five to twenty days.
- There are multiple overlapping generations in a year, and the adult female can live for two to four weeks, laying several hundred eggs during her lifetime.
Factors favoring population increase in Spider Mite in the field
- Two-spotted spider mites favor hot and dry weather, particularly during the summer.
- Overwintering females that can survive in ground litter or under the bark of trees or shrubs, giving them the ability to resume their feeding activities when conditions are favorable.
- Lack of natural predators, such as ladybugs and predatory mites, that can control spider mite populations.
- Widespread use of pesticides that may kill beneficial insects but not spider mites leads to a population explosion.
- Stressed or weakened plants are more vulnerable to spider mite feeding, providing an easier target for the mites to colonize.
- High levels of carbon dioxide, which can increase the rate of spider mite development and reproduction
Identification of Spider Mites in Tomato field
- To identify spider mites in a tomato field, look for small, eight-legged creatures that may range in color from light orange to deep orange or brown.
- It is also important to check for signs of damage to the tomato plants, such as yellow stippling or bronzing of the leaves, indicating that spider mites are present. Webbing, produced by the mites for protection and as a way of moving from plant to plant, is another sign that can be used for identification.
- A magnifying glass may sometimes be needed to see the spider mites.
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Damage symptoms of Spider Mite in Tomato field
The following symptoms can identify the damage caused by red spider mites in a tomato field:
- Yellowish-white and mottled leaves due to the mites feeding on the plant’s sap.
- Webbing, produced by the mites, can cover the leaves’ undersides and, in severe infestations, the entire plant.
- Leaf drop, stunted growth, and plant wilting can occur in severe infestations.
- The mites are found on the undersides of the leaves near the leaf veins and may move to the other side of the leaf.
- In extreme cases, the death of the plant.
Spider Mite management in Tomato by cultural method
- Using shade cloth in greenhouses or indoors reduce