Rosemary is an aromatic herb with blue-hued flowers and narrow leaves. Small bugs on rosemary plants may be aphids, whiteflies or spittlebugs, each a pest in its way. Rosemary also attracts beneficial insects, however, including natural enemies of aphids and whiteflies.
Small bugs rarely damage rosemary. The woody stems and natural plant oils resist insect incursions. Aphids in small numbers cause little damage. Large infestations of the small, pear-shaped insects yield to a blast of water or application of insecticidal soap.
Small, white, flying insects are usually whiteflies. A vacuum or a blast of water removes them. Rosemary branches repeatedly harbouring whiteflies may require trimming.
Spittlebugs are small, green or brown insects identifiable by their distinctive foamy discharge. They rarely harm rosemary plants, but they are unsightly. Hosing the plant removes spittlebugs and their discharge. They typically live on weeds or other plants near rosemary. Removal of the nearby host plant is the most effective control.
Small bugs on rosemary plants may be beneficial insects. These predatory insects are drawn to rosemary flowers. They feed on pesky insects such as aphids and whiteflies. Among the beneficial insects that rosemary attracts are ladybirds and small parasitic wasps.