common willow calligrapha

not listed

NNR - Unranked

not listed

Common willow calligrapha, also called common willow calligrapher beetle, is a small, broad-bodied leaf beetle. It occurs throughout the United States and southern Canada. It is common in Minnesota.

Adults are active from April to September. Most calligrapher beetles are specialist feeders, feeding on a single species or a small group of species. The preferred host for common willow calligrapha is Bebb’s willow (Salix bebbiana).

Adults are ¼″ to 5⁄16″ (6.5 to 8.5 mm) in length. The body is elongated-oval when viewed from above and very convex when viewed from the side. The head, exoskeletal plate covering the first segment of the thorax (pronotum), and dark markings on the hardened wing covers (elytra) are black without a metallic green sheen.

The head is inserted into the first segment of the thorax and is only partly visible from above. The mouthparts are directed downward. The antennae are black and have 11 segments. They are weakly expanded beyond the fifth segment, gradually enlarged as they approach the tip. The eyes are not notched.

The pronotum is rectangular and wider than the head. It is dark reddish brown with a broad pale band around the front and lateral margins and a black spot of variable size in the middle. The black spot is usually very large, completely or almost completely obscuring the reddish-brown area. The sides of the thorax are not thickened.

The elytra are creamy white. Each elytron has three longitudinal lines, a large, boot-shaped spot near the base in the shoulder area, and numerous small spots. The spots are all black. The markings are variable, and they have been named as an aid to identification of the species in this genus. The stripes include: a complete stripe on the inner margin (sutural stripe); a complete stripe near the inner margin (subsutural stripe); and a short, curved stripe (arcuate stripe). The three stripes are clearly separated from each other. The subsutural stripe and usually the sutural stripe is as dark as the other markings. The arcuate stripe is sometimes interrupted, sometimes partly broken into small spots. The lateral margins are completely pale and free of dark spots.

The legs are dark reddish brown. The last part of each leg (tarsus), corresponding to the foot, has five segments. The fourth segment is very short and is concealed within the broadened tip of the third segment, making the tarsus appear to have only four segments. There is a pair of claws at the tip of the tarsus on each leg. The claws are well separated at the base.

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The above description refers to Calligrapha multipunctata multipunctata.

Total length: ¼″ to 5⁄16″ (6.5 to 8.5 mm)

Dogwood calligrapha (Calligrapha philadelphica) dark markings have a metallic green sheen. The pronotum is entirely dark.

May to September

Bebb’s willow (Salix bebbiana)

Sources

7, 27, 29, 30, 82, 83.

Common

Common willow calligrapha on willow