Wireworms can spoil potato crops and you won't know about it until you harvest the crop. We supply microscopic beneficial nematodes (eel worms) which are watered into the soil.
What are wireworms?
They are click beetle larvae, there are around 70 species of click beetle but only a very small number have larvae that feed on tubour. Wireworms are yellow in color and are long and thin (up to approx 25mm)
Is it wireworms or slug eating your potatoes?
It is wireworms if the holes go all the way through. Slugs will not do this but they will leave cavities in the surface.
When to treat for wireworm
The larval stage of wireworm can last for up to 4 years so treatment is only reliant on the temperature of the soil.
Biological control with parasitic nematodes, either Heterorhabditis bacteriophora or the mix sold as Fruit & Veg nematodes. Microscopic beneficial nematodes (eel worms) are watered into the soil. They enter the larvae and poison them so that they will die within a few days. The soil needs to be above 10°C for the nematodes to survive so people tend to use them at harvest time when they find they have a problem or in the spring before the growing season starts.
Instructions for use
The nematodes arrive in a paste. Mix them vigorously with water and apply to the soil following the instructions on the pack. The grass should be moist before the application and should be irrigated directly afterwards to wash the nematodes into the soil. It should be kept from drying out over the next 2 or 3 weeks, or the nematodes will dry out too. They do not harm any humans, birds or animals.
The single species product is sold in packs of 100 or 500 SQM but you can also use the mixed species pack (Fruit and Veg Nematodes) which is available in the the 60 SQM pack.