George Herbert Carpenter

“ The fore wings have at least a single longitudinal nervure—often two—reaching from base to tip of the wing. The maxillary palps have usually three, the labial either two or four segments. There are two families of Terebrantia: (a) the Aeolothripidae, whose feelers have nine segments; whose wings, relatively broad and rounded at the tip, have a few cross nervules, and whose ovipositor is curved backwards; and (b) the Thripidae, whose feelers have six to eight segments, whose narrow acuminate wings have no cross nervules, and whose ovipositor (fig. 4) is curved downwards. ”

“ Characters.—The Thysanoptera, small insects with firmly chitinized cuticle, are recognized by the combination of imperfectly suctorial jaws—the mandibles acting as piercers and maxillae retaining their palps (see fig. 2) —with the presence of two pairs of excessively narrow wings (fig. 1) , which are partly or completely surrounded by elongate delicate bristles forming a fringe. ”

“ The paired piercers, connected by muscles with the base of the maxillae, but attached directly to the head skeleton, into which they can be withdrawn, are regarded by Börner as true mandibles.
Turning to the thorax we find that the first segment (prothorax) is distinct and free, with a wide dorsal sclerite. The mesothorax and metathorax are rather intimately fused together. Most remarkable in this order is the structure of the feet; there are never more than two tarsal segments, and the claws, usually so conspicuous in insect feet, are reduced (fig. 3 a) or absent. ”

“ A fair number of species are wingless (fig. 5) , either in one or both sexes, and the occurrence of winged females with wingless males is noteworthy.
Ten segments are recognizable in the abdomen, which is elongated and tapers at the hinder end. In two of the three families of Thysanoptera the female has a conspicuous ovipositor (fig. 4) with serrate processes, projecting from the ventral surface of the abdomen between the eighth and ninth segments. The number of spiracles is greatly reduced ”

“ The palps, both maxillary and labial, have two segments. There is no ovipositor, and the wings are either without nervures or have only a single degraded longitudinal nervure which does not reach to the tip. While the Terebrantia are often rapid in their movements, the Tubulifera are slow and deliberate. According to Hinds, “they never run or spring.”
Bibliography.—The number of important writings on the Thysanoptera is not large. A. H. Haliday's papers in Entom. Mag., 1836—1837, vols. iii. and iv., are still valuable and contain nearly all that is known of the fifty British species. ”

“ They shelter in crevices of the bark of trees, in the dried stems of herbaceous plants, or among moss and fallen leaves on the ground. Hinds states that the hibernating individuals live for more than six months. During summer there may be eight or nine successive generations when conditions are favourable and food abundant. ”