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Elm Calligrapha – Caligrapha scalaris

Written by Amisha on .

Elm Calligrapha – Calligrapha scalaris   Common Name: Elm Calligrapha Latin Name: Calligrapha scalaris Appearance:
  • Elm calligrapha is a medium-sized calligrapher beetle that was previously common but is now in decline. It has traditionally been a species specialist, eating nearly entirely on American elm. As Dutch elm disease decimates that species, the beetle migrates to other hosts, including slippery elm, willow, and potentially dogwood and paper birch.
  • Adults range in size from (7.5 to 9.5 mm). When viewed from above, the body is elongated-oval but highly convex when viewed from the side. It is primarily white with black patterns. The head, pronotum and dark marks on the hardened wing coverings (elytra) are completely black with a metallic green sheen.
  • The head is black and partially visible from above, although it may retreat into the body. The antennae are short, measuring less than half the length of the body. They are slightly clubbed (clavate), progressively expanding towards the tip. The pupils are not dilated.
  • The pronotum is black and without markings. It is three times as long as it is wide, almost as wide as the base of the elytra. The tiny triangular plate between the elytra bases (scutellum) is black.
  • The elytra are white with black patterns on them. The markings are erratic. There are 10 to 14 little isolated spots, a boot-shaped patch towards the base, and a centre stripe on each elytrum.
Host plant: A dogwood species has been reported to be affected on a few occasions. Territory: It is found in North America Damages caused by Elm Calligrapha: The adults use their teeth to eat oval or circular holes in the leaves. Except for the veins, the larvae consume the entire leaf. Both can be powerful enough to defoliate American elms in Oklahoma. Damage is more prevalent in the centre part of the state and less common in the fareast and west.   Life history and Habits: Adults spend the winter in bark cracks, protected areas around the tree’s base, or in the topsoil. They emerge in late March or early April and deposit their eggs in April. During late April and early May, the larvae feed. From mid-June to late July, first-generation adults are active and produce a second generation of larvae. During July and August, these larvae eat. Second-generation adults are involved in September and October before looking for overwintering habitats.