fifteen-spotted lady beetle

not listed

NNR - Unranked

not listed

Fifteen-spotted lady beetle is a large “giant lady beetle.” It occurs in North America east of the Great Plains. It is most common in the United States from Maine to Minnesota in the north to Virginia and Missouri in the south.

The body is almost round, very convex, ¼″ to ⅜″ (7.2 to 9.5 mm) long, and 3 ⁄16″ to 5 ⁄16″ (5.5 to 8.0 mm) wide.

The head is shallowly inserted into the thorax, but is visible from above.

The upper thoracic plate (pronotum) is convex and wider than long. It is white with a large black spot in the center and a small black spot on each lateral margin. The central black spot has two white spots at the base and looks vaguely like a W or M, depending on if it is viewed from the front (W) or from behind (M).

The thick, hardened, shell-like forewings (elytra) are strongly convex and very narrowly flattened at the margins. They completely cover the abdomen. The background color is variable but the pattern is not. They may be gray, yellowish-orange, or dark brownish-red, but they always have fifteen black spots. Each elytron has eight spots in a 2-3-3 pattern. The spot in the middle at the base merges with one on the opposite elytron and is counted as a single spot, giving a total count of fifteen. The spots are never ringed with white or yellow. As the beetle ages, the elytra become darker. Older individuals are very dark reddish-brown to almost black, making the spot pattern difficult to see.

The legs are yellowish-brown. The fourth segment (tibia) on the middle and hind legs have two spurs at the tip. The last part of each leg (tarsus), corresponding to the foot, has four segments, but the third segment is very short and tucked within the extended lobes of the second segment, making the leg appear to have only three segments. The tip of the last tarsal segment on the middle and hind legs has a pair of claws. Each claw has a large tooth at the base.

Total Length: ¼″ to ⅜″ (7.2 to 9.5 mm)

Forests and woodlands

April to July

Aphids on coniferous and deciduous trees

Sources

24, 27, 29, 30.

Location: Woodbury, Minnesota