Beneficial Insect — Damselflies

Common Name: Damsel Fly

Genus: Calopterygidae, Lestidae and Coenagrionidae

  Three Families of Damsel Flies

The three families of damselflies in Wisconsin are the Broad-winged Damselflies (Calopterygidae), Spreadwings (Lestidae), and Pond Damsels (Coenagrionidae). Damsels come in most colors of the rainbow, and some have striking color patterns.

  Description:

Damsel Bugs are ¼ to ⅓-inch long and usually yellow to tan-colored although there are also black ones. Their legs are stilt-like and the front legs are slightly larger than the other legs to facilitate grasping their prey. Their narrow heads have large bulbous eyes, long antennae and a flexible, needle-like mouth part that is tucked under the head and body when not feeding. They have two pairs of functional wings and some species are excellent fliers.

  Diet:

The nymph stages of damsel bugs feed on smaller prey including mites, aphids, and eggs. Adult damsel bugs feed on both large and small prey including spider mites, caterpillars, potato beetles, cabbage worms, corn earworms, and leaf hoppers. Damsel bugs can live up to two weeks without feeding on prey, but if left longer without food they will start eating each other. They tend to eat pest insects, but will also eat other beneficial insects, including big-eyed bugs and minute pirate bugs.

  Life Cycle:

Adult damsel bugs overwinter and emerge in the late spring. Their favorite over-wintering spots are winter grain and alfalfa fields. When temperatures warm the female damsel bug lays eggs in the plant tissue of host plants. Nymph damsel bugs resemble their adult counterparts but lack wings and go through five stages of growth in about two months before attaining adulthood. There are usually several generations spread throughout the summer months.

The nymph stages of damsel bugs feed on smaller prey including mites, aphids, and eggs. Adult damsel bugs feed on both large and small prey including spider mites, caterpillars, potato beetles, cabbage worms, corn earworms, and leaf hoppers.

Damsel bugs can live up to two weeks without feeding on prey, but if left longer without food they will start eating each other. They tend to eat pest insects, but will also eat other beneficial insects, including big-eyed bugs and minute pirate bugs.

  Gardening With Damsel Flies:

While damsel bugs play a substantial role in eliminating pests in crops and home gardens, they are not commercially available. Damsel bugs need cover for resting and over-wintering, plants for egg-laying, and plenty of other insects for food. They can be found in field crops such as alfalfa, soybeans and other legumes, grassy fields, and gardens.

To encourage damsel bugs in a garden, select a large variety of plants that will attract many kinds of insects for their food supply. Especially good choices include caraway, Cosmos bipinnatus, fennel, spearmint, golden rod and marigold. Incorporating ground covers, grasses and low shrubs into the planting scheme provides shelter and is especially beneficial.