What Types of Ants Eat Orchids?

Insects That Attract Ants

• Aphids, mealybugs and scale are insects that bite into orchid leaves and suck juice out of them. These insects excrete honeydew as they feed. Honeydew is a clear sticky substance that you can see as a sheen on the leaves. Ants eat the honeydew excreted by these insects. Ants can also spread scale insects from plant to plant. If there are ants on an orchid, check for the other insects. Aphids are small soft-bodied insects that are commonly black, brown, green or orange. Mealybugs are small oval bugs that look like bits of fluffy cotton. Scale insects move around on the orchid for their first day or so, then settle down and quickly cover themselves with a waxy or cottony secretion. They tend to settle beneath the sheath at the leaf base. Often the first sign of a scale infestation is yellow leaves.

Leaf-Cutter Ants

• Leaf-cutter ants slice out pieces of an orchid's leaves, stems and flowers, but they do not eat them. The ants use the plant pieces to feed and grow a fungus they eat. Orchids are not the only plants leaf-cutter ants use; these ants attack many plants and trees. Leaf-cutter ants would be a likely culprit when orchids grown outdoors are missing pieces that seem to have been cut from the plant.

Other Sucking Insects

• Spider mites feed on orchids by sucking the plant juices out. False spider mites are extremely tiny. You can identify them by the silver stippling they leave on both sides of the orchid leaves. Red spider mites, also extremely tiny, create a very fine web-type film on the underneath of orchid leaves; it will cause the leaves to yellow and eventually die. Leaf hoppers are small white flying insects; you'll find them most commonly underneath the leaves and flowers.

Chewing Pests

• Caterpillars, slugs, snails, thrips and weevils are chewing orchid pests. Caterpillars and weevils, a type of beetle, eat the leaves of orchids. Slugs and snails prefer young orchids and tender leaves. Slugs and snails are nocturnal and are most commonly detected when their slimy trails are discovered. Thrips are tiny gray flying insects that you can commonly find underneath leaves. They cause small scars on the orchid leaves by scraping the leaf surfaces.

Ant-Loving Orchids

• Coryanthes orchids are native to Mexico and Brazil where they are commonly found growing near ant colonies. The ants consume nectar produced by the orchids and in turn protect the plants by making eating the orchids unpleasant for animals to eat. Ants live in the pseudobulbs of Schomburgkia and Catasetum orchids without causing any damage.