Many species of Thysanoptera are known to be habitually parthenogenetic. The eggs are laid on the food-plant, those females possessed of an ovipositor cutting through the epidermis and placing their eggs singly within the plant-tissues; a single female may take five or six weeks to deposit all her eggs.
Thysanoptera are found on the leaves and in the blossoms of plants.
While the majority of the Thysanoptera are thus vegetarian in their diet, and are frequently injurious in farm and garden, some species, at least occasionally, adopt a predaceous habit, killing aphids and small mites (so-called "red-spiders") and sucking their juices.
The usual variations in habit that characterize plant-feeding insects are exhibited by the Thysanoptera some species being found only on one particular food-plant, while others thrive indifferently on a large assortment.
The Thysanoptera are probably world-wide in their range, but they have hardly been studied outside Europe and North America.