Hosts: Junipers and Arizona cypress
Effects: Several roundheaded and flatheaded
wood borers are aggressive pests in drought-stressed junipers and
cypress. Damage can be extensive before symptoms are apparent. Usually
a large portion of the tree or the entire tree dies before the insects’
exit holes are noticed.
Biology: Callidium spp. larvae
bore beneath the bark making very wide tracks that distinctively
score the outer sapwood much like a router. Older larvae excavate
oval tunnels deep in the wood and overwinter. Adults emerge throughout
the warm months of the year. There is one generation per year. Adult
beetles are rather short-horned for cerambycids and dark blue or
black. These roundheaded borers leave an oval or rectangular exit
Atimia spp. are small roundheaded borers about 6.5 mm long and generally
have a 1-year life cycle. These longhorned beetles attack thin bark
portions of seriously weakened and dead juniper and cypress.
blondeli, the western cedar borer, is 11 to 17 mm long and
attacks juniper and Arizona cypress. Females lay eggs under bark
scales and branches of living trees. Flatheaded larvae bore from
the branches into the main bole. They feed primarily in the heartwood
for several years. Adults emerge in the spring, leaving oval or
rectangular exit holes.
Chrysobothris spp. are flatheaded borers of junipers and
Arizona cypress. They are medium-sized beetles about 11.5 mm long.
Larvae bore into the bark and outer wood of weakened trees.
juniper twig pruner, Styloxus bicolor, is a small roundheaded
borer that mines the small branches and causes twig dieback during
Similar Insects and Diseases: See cedar