Thrips is one of the most common pests of domestic and agricultural plants. Probably, it is unlikely that it will be possible to name a single plant on which these or other types of these insects would not feed.
- Symptoms and Diagnosis
- Life cycle
- Integrated pest management strategies
Symptoms and Diagnosis
Thrips are very small insects (3-4 mm), the wings of which are covered with hair fringes along the edges. Therefore, their name is defined as fringed. They are usually pale in color. As a rule, these pests are responsible for minor problems in indoor plants, but representatives of indoor greenery such as the Gesneriaceae family (African violet) and the Commeline family (Ahasfer) are prone to attack from them.
Thrips can hardly be seen due to their small size. These insects feed by piercing the surface of different parts of plants with their one large lower jaw. After that, they suck on the plant juices that ooze from such a wound. Silvery streaks may form on flowers and leaves.
Severely infested leaves turn brownish or silvery. Also, infection can cause changes in the direction of plant growth. Some types of thrips leave blackish spots with faeces on the leaves.
If we talk about this pest in the garden, then often they can lead to damage to fruits, leaves, shoots, and their effect is very noticeable and has a strong cosmetic effect. However, thrips rarely kill or threaten the survival of trees and shrubs.
Herbaceous ornamental crops and some vegetables are more susceptible to serious injury from eating thrips. This is especially pronounced when the plants are young. Thrips is very often the cause of indoor plant disease. To diagnose these parasites, blue cards are used, covered with a thin film of oil, suspended half a meter above houseplants. This is how you create indicator traps. If they come across small winged insects, this is a sure indicator of the presence of an adult thrips in the plant.
The females of thrips lay their eggs in tiny slits they cut into the surface of leaves, flowers and stems. Eggs can be laid at any time of the year and mature for several days in warm indoor conditions.
Young individuals, the so-called nymphs, from cream to pale green shade are practically invisible to the naked eye. They feed for 7-14 days.
Grown nymphs, in most species, go into the soil, where they hide, in order to pupate. Adult winged individuals are already emerging from the pupae, which complete the cycle.
Integrated pest management strategies
- Keep plants moist. Plants that are kept too dry are more likely to be attacked by thrips. To significantly limit the damage from such attacks and reduce re-infestations, it is imperative that plants be kept humid after using other initial control measures.
- Insecticidal soap. Insecticidal soaps, which are considered non-toxic to humans and pets, work well against these pests. Be sure the flowers and growing shoots are well watered from the spray bottle. Frequent spraying may be necessary as long as the infestation is not well controlled.
- Use improved horticultural oil sprays. There are so-called improved horticultural oils. The oil suffocates insects. These oils are highly refined and under appropriate conditions, can be applied to plant foliage without any damage. Follow the directions on the labels and instructions to avoid the negative effects of misuse of these oils. Some plants can be very sensitive to them. Improved oils are also considered non-toxic and less likely to harm beneficial insects. When spraying indoors, care must be taken to protect surfaces that could be damaged by oil residues.
- Use chemical insecticides. There are a large number of insecticides registered for indoor use. So you can select Sprays containing pyrethrins of plant origin. These insecticides are more effective and milder than other chemical pesticides. Follow label directions and instructions, and spray outdoors if possible. For example, in the garage, or if the weather permits outside.
To limit recurrences of infestations and future problems, check the plants regularly. With regular inspection, pest problems can be avoided very quickly at the initial stage, and the control process itself is much easier than in advanced cases.
It is also recommended to isolate newly acquired plants for 2-3 weeks from the main space to limit accidental migration of pests. Without knowing it, we can sometimes bring these insect pests into the room.
Thrips are difficult to control during their mass reproduction. It is recommended to start early control of them and use a comprehensive program that will combine the use of good cultural practices, natural enemies, the most selective and least toxic insecticides that are effective in a particular situation.
Tips for fighting thrips on video: