The Collaborative International Dictionary
Cyrtophyllus concavus
Katydid \Ka"ty*did`\, n. (Zo["o]l.) A large, green, arboreal, orthopterous insect ( Cyrtophyllus concavus) of the family Locustid[ae], common in the United States. The males have stridulating organs at the bases of the front wings. During the summer and autumn, in the evening, the males make a peculiar, loud, shrill sound, resembling the combination Katy-did, whence the name.