fourteen-spotted lady beetle

not listed

NNR - Unranked

not listed

Fourteen-spotted lady beetle is an exotic, small, black-spotted lady beetle. It is native to Europe, where it is commonly used in greenhouses to control unwanted insects. The first North American reported sighting was near Ste-Foy, Quebec in 1968, but the species appears to have already been well established by that time. It was probably accidentally introduced by European ships in the St. Lawrence Seaway.

In 1968, Propylea quatuordecimpunctata was intentionally released in the United States in the Great Plains states to control greenbugs, but it did not become established. Between 1970 and 1982 it was intentionally introduced into New Jersey, Delaware, Oklahoma, and Washington. None of these introductions became established. Between 1987 and 1992 it was reared and released in 16 western states to control the Russian wheat aphid. These did not become established. During all this time, the Quebec population continued to spread. The first recorded sighting of an established population of Propylea quatuordecimpunctata in the United States was in Grand Isle County, Vermont in 1984. In 1989 and 1990 it was propagated and released in Georgia, Iowa, Indiana, Maryland, Michigan, Minnesota, Missouri, New Jersey, and Pennsylvania. Fourteen-spotted lady beetle now occurs in the United States from Maine to Delaware, west to Minnesota and Iowa. It is common in the northeast, uncommon but increasing in Minnesota.

Adults are active mostly from May to August. They are found in many different habitats, including forests, grasslands, meadows, fields, parks, lawns, and gardens. They feed on aphids, whiteflies, scale insects, and the larvae of beetles and butterflies.

Adults are ⅛″ to 3⁄16″ (3.5 to 5.2 mm) long and ⅛″ (3.0 to 4.0 mm) wide. Males are smaller than females. The body is oval when viewed from above. When viewed from the side it is convex but slightly depressed in the middle. The upper surface is hairless and pale with black spots. The coloration and markings are highly variable, and this has resulted in several varieties being described. The ground color may be cream-colored, yellowish, yellow, or light orange (pale).

The head is deeply inserted into the thorax. It is normally partially visible from above, but it can be retracted beneath the upper thoracic plate (pronotum). It is mostly yellow, but the top of the head (vertex) is black. The eyes are large and black. The antennae are yellow and longer than the head. They have 11 segments. The last three segments are slightly expanded into a weak club. The mouthparts are yellow. The jaws (mandibles) have two teeth at the tip. On the male, the upper part of the face (frons), corresponding to the forehead, is yellow. On the female, the plate on the face (clypeus) has a large black spot on the lower margin.

The pronotum is wider than long and is widest at the rear. The rear angles are rounded and the front angles project forward. The rear margin is rounded. The upper surface is pale with two rectangular spots at the rear margin and four rectangular spots in the middle. The spots usually coalesce into a single large, black patch.

The hardened wing covers (elytra) are pale and shiny, with fourteen rectangular spots, seven on each elytron. This is the feature that gives the beetle its common name and its species epithet. Each elytron also has a black stripe on the inner margin (sutural stripe). Four of the spots on the rear half usually merge into a broad U shape, and two spots in the front half merge into a rectangle. Together with the sutural stripe, this creates an anchor shape. Sometimes all of the spots are separate. Rarely they all coalesce, creating black elytra with pale spots.

The legs are mostly yellow, but there is usually at least some black on the third segment (femur) of each leg.

Total length: ⅛″ to 3⁄16″ (3.5 to 5.2 mm)

Forests, grasslands, meadows, fields, parks, lawns, and gardens

April to September

Aphids, whiteflies, scale insects, and the larvae of beetles and butterflies

Sources

29, 30, 82, 83.

Common in the northeast, uncommon but increasing in Minnesota

Genus
Three spellings on this genus are currently in use. In the past, the most common spelling of this genus was Propylaea. That was a misspelling, and today it is usually corrected to Propylea. At least one source (DiscoverLife) spells it Propyleae, but that is also a misspelling.

Several varieties have been described, but these are usually treated as forms.

Location: Albany, NY

Location: Albany, NY

Location: Albany, NY