About Cydalima perspectalis (Walker, 1859)
This species, Cydalima perspectalis, has eggs 1 mm in diameter that are pale yellow. Eggs are laid on the underside of green leaves where there is no existing herbivory. Newly hatched first-instar larvae measure approximately 1–2 mm in length. Over four weeks of development, larvae reach a maximum final length of 35–40 mm. Larvae shrink slightly at the start of pupation; pupae are 25–30 mm long. Pupae start out green with brown longitudinal lines, and gradually become more uniformly brown over development. Adult Cydalima perspectalis have a wingspan of 40–45 mm. Two distinct adult variants exist: the most common variant is mostly white, while the second variant is almost entirely light brown. As of current records, the light brown variant with white streaked wings has not been observed in North America. This species produces two or three generations per year, with active flying adults present from April or May through September. In the warmest parts of its introduced European range, where cold weather arrives late in the year, up to four generations may sometimes occur per year. The species overwinters as a young, cocooned larva that is around 5–10 mm long. The overwintering larva is protected inside a hibernarium made of two attached living Buxus leaves, bound tightly together with silk.
