SHOT HOLE BORER

Scientific Name: Xyleborus perforans (Wollastan)
Family: Scolytidae
Order: Coleoptera
Common Name : bark beetle

Shot hole borer becoming a major pest now a days on pomegranate in many parts of Karnataka.They are non-native species in our region, introduced from Europe in the early 1900’s.  SHB attacks many different tree and shrub species,but tends to be attracted to weak or dying trees, or trees suffering from water or nutrient deficiencies

Appearance:

Shot hole Borer eggs are oval or round, shiny and iridescent white. The larvae are white and legless, and can be up to 4 mm long. The adult is about 2-3 mm long, black to reddish-brown, and cigar shaped. They have a short, stubbed head capsule, with chewing mouthparts. Male adults do not fly. Two generations per year.

Adult         

Life cycle:

Each female will lay up to 50 eggs along the walls of the tunnel, from which the newly hatched larvae will excavate new mines at right angles from the central tunnel. The larvae continue to feed and widen their tunnels for 6-8 weeks,when they construct pupal cells at the end of the tunnels. Second generation adults emerge in mid August and the larvae from this generation overwinter and complete development in late winter or early spring.

Nature of damage: Adult females bore into the basal part of the stem and roots

Damage symptoms:Causes Small shot holes on roots, main trunk, wilting and finally leads to death of the tree

Shot hole borer damage