As adult plants, daffodils are relatively resistant to pests. But daffodil bulbs are susceptible to maggots, mites and a few other insects. The best way to control these pests is to take preventative measures. Do not store or purchase bulbs until you have thoroughly inspected them for signs of insect damage. In most cases, infested bulbs should be discarded so that the insects cannot spread to healthy bulbs.
Handle Bulbs with Care
Pests often target bulbs that are cut, nicked or otherwise broken. Do not store or plant bulbs that are physically damaged.
Control Bulb Mites
Bulb mites are slow-moving, tiny, yellow-white or transparent insects. Bulbs that they have been feeding on develop mushy, rotten areas and they often fail to grow. If you spot mites or mite damage on cured bulbs, dip them in 120-degree F water for 2 minutes. Uncured bulbs should be discarded.
Lesser Bulb Flies
Lesser bulb fly maggots are less than 3/8 of an inch long and white, gray or yellow in color. As they feed, they tunnel through the bulbs which begin to rot and become mushy. Severely damaged, soft and mushy bulbs must be discarded. Lightly damaged bulbs can be soaked in 110 degree F water for 3 hours.
Narcissus Bulb Fly
Narcissus bulb fly maggots are small (1/16 to 3/4 of an inch long) and gray-white or yellow in color. These maggots are often found when daffodils are pulled out of the ground for winter storage. As they feed, they tunnel through the bulb and leave portions of it hollow. Severely damaged bulbs will feel soft and sponge-like, and some may even have begun to rot. To control the narcissus bulb fly, mow the daffodils' leaves right after they dry out in the spring. Then till the soil a few inches deep and spread 2 inches of organic mulch to cover soil openings that narcissus bulb flies use to lay their eggs. If your bulbs are only slightly infested, soak them in 110 degree F water for 40 minutes before storing them. Severely damaged or rotten bulbs must be discarded.