Mandevilla Buds & Stems Being Eaten? Look for Night-Feeding Pests

For 15 years, a Michigan gardener has grown mandevilla on a trellis. The last two years, new buds and stems are chewed off within days, but no culprit is visible during the day. Leaves are untouched. Squirrels use the trellis, but the speed suggests an insect. What's eating the plants and how to stop it?

Night-Feeding Culprits: Slugs or Caterpillars

Because damage occurs overnight and no pests are seen by day, Nick points to slugs or nocturnal caterpillars. Both hide in soil or debris during daylight and feed after dark.

Three-Pronged Treatment Plan

1. Apply a systemic insecticide (e.g., Bayer Rose & Flower systemic) to protect new growth from within.
2. Scatter slug bait around the base of the plant.
3. Inspect at night with a flashlight to catch the pests in action and confirm identity.

Prevention

Keep the area clean of fallen leaves and debris where slugs and caterpillars hide. Regular monitoring and early treatment will keep mandevilla blooming all season.