Thrips are tiny, slender insects that are notorious for causing damage to a wide range of crops. They are easily recognized by their characteristic two pairs of fringed wings and pale yellow to light brown. They have an extensive host range and can complete their entire life cycle on crops like Tomato, pepper, lettuce, and fava beans.
They can also harbor and spread the Tomato spotted wilt virus, which can significantly impact crop production. Weed hosts such as cheeseweed, sowthistle, and prickly lettuce can serve as reservoirs of thrips populations and the spread of the virus. Effective management of thrips is crucial in preventing and controlling infestations and reducing the spread of the Tomato spotted wilt virus in crops.
Thrips management in Tomato
The life cycle of Thrips
The life cycle of thrips can be divided into the following stages:
- Egg: The female lays eggs on or inside the host plant using her ovipositor.
- Larva: The eggs hatch into wingless larvae that feed on the host plant.
- Pre-pupa: The nymph thrips stop feeding and molt into the pre-pupal stage.
- Pupa: The pre-pupa undergoes further molting and transforms into a pupa.
- Adult: The pupa emerges as an adult thrip, characterized by two pairs of fringed wings and a pale yellow to light brown color.
These stages can take a week to a few weeks, depending on the species of thrips and environmental conditions. Understanding the life cycle of thrips is important for developing effective management strategies that target pests at different stages of their development.
Identification of Thrips in Tomato field
- Silver lesions on the leaves that are irregular in shape and size eventually become beige and dotted with tiny black droppings from thrips.
- Chlorination and dulling of the color of affected leaves.
- Flower drop.
- Brown punctate lesions on young fruits surrounded by a large whitish ring or deformed fruits with linear corky lesions. These are the oviposition sites of F. occidentalis thrips.
Damage symptoms of Thrips in Tomato field
- Vectoring of Tomato spotted wilt virus.
- Distorted plant growth
- Deformed flowers
- White-to-silvery patches on emerging leaves
- Tiny black fecal specks on leaves.
Thrips management in Tomato by the cultural method
- Grow plants that are well-adapted to local soil and weather conditions
- Keep plants well-watered and avoid excessive nitrogen application
- Use resistant rose cultivars
- Prune-infested and injured terminals and destroy them
- Use hot caps, row covers, or cages with fine mesh to protect young herbaceous plants
- Apply covers before crops emerge and leave them on while plants are young and vulnerable to damage
- Remove covers as temperatures warm and plants grow larger
- Use hoops, plastic tunnels, or wire frames covered with fine mesh for sensitive plants
- Provide light irrigation when using row covers.