Agrilus tchitcherini

Agrilus tchitcherini is a species of metallic wood-boring beetle belonging to the Buprestidae family. Like other members of the Agrilus genus, adults are small, slender, and elongated, perfectly adapted for crawling into bark crevices.

The adult beetles exhibit a brilliant metallic sheen, ranging from bronze to green, which serves as camouflage against the foliage and bark of their host plants.

The head of the beetle is relatively large, featuring well-developed compound eyes and serrated antennae, which are essential for navigating and finding suitable mates.

The larvae are typically legless and flattened, specifically adapted to survive in the narrow, high-pressure environment beneath the bark of woody plants.

Identification is primarily achieved through observing adult morphology and the distinct feeding patterns left behind by the larvae within the tree.

This species primarily attacks members of the Rosaceae family, making various orchard fruit trees, such as plums and cherries, highly susceptible to infestation.

Larvae are internal feeders; they create winding galleries beneath the bark, disrupting the cambium layer which is vital for the tree's nutrient transport.

When the galleries encircle the branch or trunk, they effectively cut off the flow of water and nutrients, leading to the rapid dieback of distal sections.

Heavily infested trees show reduced vigor and are often unable to recover, as the damage weakens the structural integrity and physiological state of the host.

Furthermore, the physical wounds serve as entry points for secondary pathogens, such as fungi or bacteria, which can cause cankers and further rot.

Adult beetles typically emerge in late spring or early summer, synchronized with the onset of favorable temperatures and host tree foliage development.

Mating and oviposition occur throughout the summer months, with females carefully placing eggs into cracks or injuries on the bark surface.

The larval stage is the longest part of the life cycle, as they spend the summer and winter feeding and developing within the sapwood.

Overwintering usually takes place in the larval stage, deep within the protective tissues of the wood, allowing the insect to survive harsh conditions.

Pupation occurs in the spring, leading to the emergence of a new generation, thereby completing the annual or biennial cycle of the pest.

The most reliable indicator of an Agrilus infestation is the presence of D-shaped exit holes on the bark, left by emerging adults.

Visible symptoms include the yellowing of leaves, premature defoliation, and the characteristic flagging or dieback of individual branches in the canopy.

In stone fruit trees, excessive gumming (gummosis) around cracks in the bark may indicate a tree's attempt to defend itself against the boring larvae.

Bark may become cracked or exhibit sunken areas where the underlying galleries are most concentrated and the cambium has died off.

Reduced annual growth and overall lack of vitality in the orchard are often early warning signs of a hidden infestation occurring beneath the bark.

Sanitation is the cornerstone of control; all infested branches and trees must be pruned and destroyed, preferably by burning, to kill the larvae inside.

Maintaining optimal tree health through proper irrigation, fertilization, and pruning is essential to prevent trees from becoming stressed and susceptible.

Targeted insecticidal sprays applied to the trunk and main branches during the adult emergence period can help prevent new infestations.

Avoid unnecessary mechanical damage to trunks during agricultural operations, as exposed wood serves as an ideal site for female beetles to lay eggs.

Monitoring for adult activity using traps or visual inspection can help time interventions effectively, reducing the need for broad-spectrum pesticide use.