UC IPM Home > Homes, Gardens, Landscapes, and Turf > Fruits and Nuts > Invertebrate
Pests
How to Manage Pests
Pests in Gardens and Landscapes
Pest identification
and confirmation—Borers
The four major boring insects that damage trunks and limbs of deciduous fruit or nut trees are the Pacific
flatheaded borer, the peachtree borer, the shothole borer, and the American plum borer. The adult Pacific
flatheaded borer is a hard, dark, mottled beetle with a bronzy cast. Larvae have a distinctive flattened
enlargement just behind the head. Shothole borers are tiny black beetles; larvae are tiny grubs that curl
into a C shape. Both beetles attack trees that have been previously injured or weakened by sunburn or
other causes. Peachtree borers bore into undamaged trunks of young trees.They are a problem on stone fruits
but not other fruit or nut trees. Damage may be primarily in the crown area or lower part of the trunk
or just below the soil line. The adult is a steel blue to black moth. Larvae are light brown or pinkish
with a darker head. American plum borer larvae are white with a darker head. Adults are gray moths with
brown and black markings. Larvae bore into the tree leaving reddish orange frass.
|
Flatheaded
larva
|
Flatheaded
adult
|
Peachtree
borer larva
|
Peachtree
borer adult
|
Amer.
plum larva
|
Amer.
plum adult
|
Shothole
borer adult
|
|
|