Callidiellum rufipenne (Motschulsky) - Smaller Japanese cedar longhorned beetle

Coleoptera: Cerambycidae

IDENTIFICATION

Adult beetles are 6 to 14 mm long, 3 to 4 mm wide and have a slightly flattened body.⁹¹ The head and thorax are brown with reddish-brown hairs.⁹¹ The 1^st antennal segment is black while the following segments are chestnut brown.⁹¹ Male antennae are slightly longer than the body while those of the female are about two-thirds the body length.⁸ Male elytra are usually black with metallic blue-violet or greenish reflections.^{8, 91} Females typically have brownish-red to red elytra.⁹¹

HOST TREES

Chamaecyparis, Cryptomeria, Cupressus, Juniperus and Thuja.¹ The suitability of Cedrus, Pinus and Abies is still in question.⁹¹ In North America, C. rufipenne has been found in T. occidentalis, J. virginiana and J. communis.^{1, 90, 91, 92}

LOCATION OF INFESTATION WITHIN THE TREE

Larvae feed on inner bark and sapwood where the stem or branch diameter is at least 1 cm.^{8, 90, 91}

HOST CONDITION

Preferentially attacks dying, weakened, stressed or freshly felled trees.^{10, 90}

DISTRIBUTION

China, Japan, Noth Korea, South Korea and Russia (Sakhalin). Introduced into Italy, Spain and North America (Connecticut and North Carolina).^{1, 20, 90, 91, 92}

SIGNS AND SYMPTOMS

Eggs are laid in bark crevices. Newly hatched larvae bore through the bark and construct shallow, flat and irregular shaped galleries (2 to 6 mm wide).^{10, 91} Gentle scraping of the bark may be required to expose the frass-filled galleries.⁹¹ These larval galleries increase in width as the larvae increase in size.⁹⁰ Mature larvae create an "L-shaped" gallery by boring straight into the sapwood, then construct 2.4 to 2.7 cm long pupation chambers parallel to the grain.^{10, 91} The entrance to these pupal chambers is tightly packed with fine, powdery frass.¹⁰ Adults emerge from elliptical exit holes that are 6 to 10 mm or more in diameter.⁹⁰

Other signs of attack include bark depressions resulting from larval mining, light red frass on branches and the trunk, 8 to 15 mm long cracks in the bark, callus tissue (i.e. puckering) forming over the larval galleries and brittle branches that may crack and expose the larval galleries beneath.^{9, 90, 91} Attacks can also hasten the death of the host tree or increase its susceptibility to pathogens or other forest insects.⁹¹

A - Adult C. rufipenne. Head and thorax are brown with reddish-brown hairs.

B - Male C. rufipenne has black to bluish-green elytra and longer antennae. Female has red elytra and shorter antennae.

C - Adult C. rufipenne ready to emerge from the pupal chamber.

D - Frass plug blocking the pupal chamber entrance.

E - Frass filled C. rufipenne larval galleries.

F - Callus tissue surrounding C. rufipenne galleries.

G - Elliptical C. rufipenne exit hole (6-10 mm wide).