Tomato pinworm, techniques and treatments to avoid and cure the disease

Tomato pinworm

Tomato pinworms are native to South America, and appeared in France in 2009 in the Drôme area. Since then, they have invaded all of France and spread to other European countries as well.

This pest spreads far and wide, and is often credited for destroying many tomato crops nowadays.

Its latin name is Tuta absoluta, and it is part of the Lepidoptera order.

Tomato pinworm lifecycle

The tiny pinworm larvae start gnawing at tomato leaf edges, then attack stems and finally attack the fruits themselves.

At that stage, tunnels on leaves and stems can be seen, which then appear on tomatoes, especially green ones. White spots appear on the tomato leaves.

Tomato pinworms infest all plants belonging to the solanaceae or nightshade family such as potato or eggplant.

These pinworm larvae reproduce extremely quickly and up to 10 consecutive generations can breed in a single season.

Growing larvae are the ones responsible for digging new tunnels on plants.

Fighting and treating a tomato pinworm infestation

As of today, there are no authorized organic curative tomato pinworm treatments.

However, it is possible to keep them from attacking your tomato plants by providing adequate protection.

  • Anti-insect nets against tomato pinworms

First and foremost, the most effective protection is an anti-insect net, with a 1/5 inch (5 mm) mesh at most.

  1. Position hoops so that the net does not touch any part of the tomato plant.
  2. Check that there is no single space more than 1/5 inch (5 mm) wide all around the net, even near the ground.
  3. Once risks of pinworm attacks are averted, the net can be removed.
  • Destroy infested tomato plants
  1. Preventive measures also include getting rid of all infested plants.
  2. Don’t place contaminated remains on your compost, because the larvae may reappear and your compost will become unusable.
  3. Ascertain that you have pulled out every single hint of pinworm presence, because a single remaining larvae can lead to a new infestation.
  • Weed around tomato plants on a regular basis.
  • Use beneficial insects such as Nesidiocoris tenuis (Nesibug) and Macrolophus caliginosus (Mirical) which are considered effective against eggs and young larvae.
  • Spraying fermented rhubarb tea preventively also yields good results.

Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Wider as it grows by Nandini Pathania under © CC BY-NC 4.0