Narcissus Grubs

Grubs

• Grubs are small larvae of various insects that do a great deal of damage to plants like the narcissus flower. Narcissus bulb fly and the lesser bulb fly are both grub-producing pests that target flowers grown from bulbs, like the daffodil. Identifying the damage done by grubs requires examination of the whole plant, because the grubs tunnel into the bulbs and kill the plant from there. The presence of Narcissus bulb flies damages entire gardens.

Damage Caused by Grubs

• Narcissus bulb flies lay their eggs near the base of Narcissus flowers and the grubs burrow into the ground, overwintering in the bulbs and causing them to become weakened or rotted. Narcissus bulbs infested with grubs produce weak, spindly growth in the spring and fail to put out flowers. Lesser bulb flies damage the bulbs much faster, but tend to attack bulbs that are already damaged or dying, leading to bulbs that don't produce growth at all.

Fusarium Wilt

• Narcissus damage from grubs, including poor growth, wilt and unproductive foliage, is similar in appearance to Fusarium wilt, as well as problems caused by cankers, drought and Verticillium and bacterial wilts. The similarity of symptoms makes proper identification of the problem essential; Narcissus plants that show signs of grub damage may not have grubs at all and require a wholly different kind of care. Examine the bulbs for signs of grubs to determine whether or not grubs are the problem.

Control

• Grubs are a controllable pest, although early detection and treatment are key to keeping Narcissus plants healthy and growing. Once spring rolls around, it's too late to stop the damage done by grubs and replacing the Narcissus bulbs is the only way to ensure a garden filled with daffodils. According to the Purdue Department of Horticulture, pesticides containing the chemical dylox are effective for controlling Narcissus bulb flies and lesser bulb flies. Follow all directions when using chemicals.