Axion Lady Beetle / Home and Landscape / UC Statewide IPM Program (UC IPM)

Hosts or Prey

Aphids, phylloxera, scale insects and other plant-sucking insects formerly called Homoptera

Identification

The adult is shiny black with a red to yellowish orange spot on the front sides of each wing cover. In some individuals each spot is more than one-half the width of each wing cover while in others the spot is smaller. The adult is about 1/4 inch (6 mm) long. It is round when viewed from above and dome shaped (convex) when viewed from the sides.

The larva is spiny and when mature about 5/16 inch (7 mm) long. Older instars are mostly blackish with brown to orange on the thorax and whitish on the abdomen. The puparium (pupal covering) is black and whitish and spiny because it is the skin of the last instar. As the pupa ages the covering splits open to reveal the initially orangish pupa that changes to black and reddish before the adult emerges.

Lookalikes

Adults of A. plagiatum resemble those of several other lady beetles in California. These include Chilocorus cacti, C. fraternus, C. kuwanae, twicestabbed lady beetle (C. orbus), and the black and red form of ashy gray lady beetle (Olla v-nigrum). The ashy gray lady beetle has gray to whitish on top both the head and thorax, which the Axion and Chilocorus species lack. Ashy gray lady beetle also lacks the slightly flared (ridged) margin on the wing covers found on A. plagiatum and the Chilocorus species.

In comparison with the Chilocorus species the orange to red spots on A. plagiatum are more to the front and sides of the wing covers. The spots on the Chilocorus species are more toward the middle or slightly behind the middle of the wing covers. Expert dissection and examination of male genitalia may be needed to reliably distinguish A. plagiatum from the Chilocorus species.

Life Cycle

Lady beetles develop through four life stages: egg, larva, pupa, and adult. All stages occur openly on bark, leaves, and stems. After hatching from an egg the larvae develop through four increasingly larger instars. Axion plagiatum has several generations per year.

Habitat

Axion plagiatum occurs from at least Oregon through the Southwestern United States to Louisiana. It can be found wherever any of its various insect prey occur. To improve biological control

Control ants because they attack lady beetles and other natural enemies.
Grow flowering insectary plants to provide nectar and pollen to feed adult natural enemies.
Reduce dustiness that disrupts the activities of natural enemies (e.g., periodically hose off small plants).
Avoid the application of broad-spectrum, persistent insecticides for all pests because they are toxic to natural enemies.

See Protecting Natural Enemies and Pollinators for more information.

Species

At least 191 species of lady beetles occur in California. Another Axion species (A. tripustulatum) occurs in the eastern United States but A. plagiatum is the only reported California species in its genus. Axion plagiatum is sometimes called the twicestabbed, twice-stabbed, or twice-struck lady beetle, names also sometimes given to look-alike species named above.