Oxythrips divisus

Oxythrips divisus is a species of thrips belonging to the family Thripidae, order Thysanoptera. This insect is recognized as a pest that primarily targets coniferous species, particularly those in the genera Picea (spruce) and Abies (fir). It poses a particular risk to seedlings in forest nurseries and young landscape plantings.

The primary hosts for this pest are coniferous trees. Both adults and nymphs feed on the plant tissues, specifically targeting the needles and developing buds. By piercing the surface cells and sucking the sap, the insect disrupts the plant’s normal development, leading to metabolic stress and stunted growth of the affected shoots.

The life cycle of Oxythrips divisus is synchronized with the bud burst and shoot elongation of its host trees. Adult insects overwinter in sheltered locations such as bark crevices or needle litter. As temperatures rise in spring, they emerge and migrate to the new growth, where they lay eggs and initiate the life cycle, which typically consists of two larval stages, a prepupal stage, and a pupal stage.

Damage symptoms include chlorosis (yellowing), twisting, and premature shedding of needles. Affected buds may fail to develop correctly, resulting in curled or stunted shoot tips. This physiological damage significantly reduces the aesthetic and commercial value of the trees and weakens the overall vigor of the host plant, making it more susceptible to environmental stress.

Management strategies for this thrips species focus on prevention and integrated pest management (IPM). Key tactics include:

• Regular monitoring using sticky traps to detect initial migrations.
• Application of appropriate systemic insecticides during the peak activity of larvae.
• Maintaining tree health through adequate irrigation and nutrient management.
• Sanitation, which involves removing heavily infested plant debris to reduce the overwintering population.