Narcissus eelworm

Symptoms

Although the pest cannot be seen, the plant will suffer from stunted growth and may show yellowish foliage. Eventually, the bulbs die off leaving bare patches in planting swathes. This problem will get worse in successive years. If you suspect Narcissus eelworm, dig up and cut open a bulb. You will see rings of brown dead tissue.

Spot them

These pests are not visible to naked eye.