Booklice

Booklice (lat. Psocus) belong to the order Psocoptera and the family Psocidae. These are tiny insects that often go unnoticed due to their microscopic size. In agronomic practice, they are rarely considered primary pests, but during mass outbreaks, they can cause significant damage to agricultural crops and stored agricultural products.

These insects prefer humid habitats. In open fields, they are most commonly found on the bark of trees, where they feed on lichens, fungal spores, and organic debris. However, in greenhouses or during crop storage, they can move to the vegetative parts of plants, damaging young tissues, or colonize dry plant debris, contaminating them with their excrement.

The biology of booklice includes the egg stage, nymphs (which go through several instars), and adults. Depending on temperature and humidity, the developmental cycle is relatively fast. Females lay eggs in clusters, covering them with a characteristic secretion or silk. High humidity and poor air circulation are critical factors that contribute to a rapid increase in population density in greenhouse environments.

Damage symptoms usually manifest as the scraping of the leaf epidermis or damage to the surface layers of fruit. The primary harmfulness lies not so much in mechanical tissue destruction, but in the transmission of fungal pathogen spores and the contamination of produce, which reduces its marketability and quality. In storage conditions, booklice can contribute to grain spoilage by feeding on mold fungi developing on damp areas.

Control measures for booklice involve a comprehensive approach based on agrotechnical practices.

• Regular ventilation of premises and reduction of relative humidity to below 60%.
• Removal of all plant debris that serves as a food source.
• Sanitation and disinfection of storage facilities and greenhouses before the start of the season.
• In cases of high population density, contact insecticides authorized for use on specific crops may be applied.