Caterpillar Killer Nematodes


What damage can Caterpillars cause?

Caterpillars develop from the eggs of moths and butterflies, and certain species of caterpillar can cause significant damage to plants. Cabbage White Caterpillars, for example, cause extensive damage to plants such as Brassicas and Nasturtiums. They make holes in the leaves and excrete on the plants, which develops into mould. Cabbage White Caterpillars will also feed on Cabbages and Cauliflowers. Other caterpillars, produced from moths such as the Silver Y Moth and Diamond Back Moth, can also cause significant plant and crop damage.

What are Caterpillar Killer Nematodes and how can they help?

Caterpillar Killer contains Steinernema species nematodes for the effective biological control of caterpillars. The nematodes enter the caterpillars via a natural opening, like the mouth, and feed on the contents of the caterpillar. A natural bacterium is produced by the nematodes inside the caterpillar, which kills it. Infected caterpillars die within a few days turning yellow to light brown and become slimy. The nematodes also reproduce inside the caterpillar, releasing more nematodes into the surrounding area. 

When should I apply my nematodes?

Apply from May - September, as this is peak caterpillar season.

How many nematodes do I need?

Caterpillar Killer nematodes are supplied in two pack sizes:

The standard pack of Caterpillar Killer contains 1 x 25 million nematodes treating up to 35m2.


The large pack containing 2 x 25 million nematodes providing two treatments for area of 35m2 or a single application to total area of 70m2.

When high numbers of caterpillars are present repeat applications of nematodes may be required.

What conditions do the nematodes require?

Choose a humid or wet day to apply your Caterpillar Killer Nematodes. Nematodes are UV-sensitive and will not survive long when exposed to bright, sunny conditions. Apply the nematodes early in the morning or early in the evening in order to utilise the optimum humidity levels. 

How do I apply my nematodes?

1. First open and empty the contents of your 25 million sachet of nematodes into a bucket or container of 2.5 litres of water and mix thoroughly.

2. Next, fill your sprayer (hand held sprayers should suffice, with filters removed - or use our  Nema Super Sprayer or our 8/15 Litre Pump Action Sprayers for optimum nematode application) with the mixed 2.5 litres of nematode concentrate and add another 5.5 litres of water so you are left with 8 litres of nematode solution.

3. Finally, spray your plants and ensure plenty of the spray solution is applied and directed where possible directly onto the caterpillars.

For severe infestations, repeat the process 5 days after first treatment.

Full instructions are provided on delivery.

Can I store my nematodes?

You can store unopened nematode packs in a fridge but it is best to ensure you apply your nematodes as soon as possible for the best results.

Caterpillar Killer nematodes are harmless to humans, and safe to apply to edible plants.