A variety of animals and insects eat tulip bulbs. Some animals dig the bulbs up, others attack them from below the surface of the soil, and larval insects often burrow into the bulbs to feed.
Chipmunks frequently seek out tulip bulbs for food, even though the plants may be buried deep below the soil. These adept diggers will expend any amount of effort to get to the bulbs. Deter chipmunks by covering the planting area with chicken wire, hardware cloth or landscaping fabric.
Skunks often dig up tulip bulbs in search of insects. They are particularly attracted to organic fertilisers, such as bone or fish meal. Avoid attracting skunks by using decomposed and well-mixed fertilisers that contain a variety of ingredients.
Squirrels are the most common culprit when it comes to eaten tulip bulbs. They often dig up tulip bulbs, partially eat them, and then bury the rest of the bulb for later consumption. Squirrels can be deterred using the same techniques utilised against chipmunks.
Gophers and moles may take a bite out of tulip bulbs to find embedded insects. They usually just unearth bulbs while digging, making the plant easily accessible to other pests. Discourage these burrowing animals by planting bulbs in gravel beds.
Mice are the most frequent offenders when bulbs are attacked from underground. Field mice often follow mole holes to reach the bulbs. Prevent mouse damage by trapping them or discouraging them with a cat or dog.
Vole-damaged bulbs look very similar to those attacked by mice. These small rodents also burrow their way through the soil in search of food. Voles can be deterred by using the same methods that work for mice.
Tulip bulb aphids and bulb mites often bore into tulip bulbs. These small insects even attack stored bulbs, and can also spread fungal diseases. Aphids must be controlled above ground by spraying infested plants with water. Severe infestation may require pesticides, such as malathion, rotenone or nicotine sulphate.
Wireworms, the larval form of black or click beetles, burrow into bulbs. They feed their way out through the top, which causes blooming tulips to flop over. Spread diazinon or chlordane throughout your planting bed to rid the soil of wireworms.
Slugs often get blamed for causing holes in tulip leaves, but they also attack the base of bulbs. They feed on the new shoots, usually resulting in a lack of flowers and bulb rot. Control slugs by setting traps (use beer in a cup) or sprinkling sharp diatomaceous earth around your plantings.