Acoustic and Mating Behavior of a Mexican Katydid, Pterophylla Beltrani (Orthoptera: Tettigoniidae)

Abstract

Males of the Mexican katydid, Pterophylla beltrani, sing day and night and form aggregations at the ends of tree branches. Males of other pterophylline species sing only at night and from singing sites which may be 15 m from nearest singing neighbors. When singing alone (solo calling), P. beltrani males produce mostly 2-pulse (range 1-5) phrases (a pulse is the sound produced during the closing phase of a wingstroke cycle). Phrases are produced at a rate of 78-126/min and the pulse rate of 15-20/sec (25-30@*C) is the fastest reported for the Pterophyllini. Acoustic interaction of male pairs (<1 m apart) consists of soloing (singing two or more phrases prior to response of partner), synchronizing (overlapping) phrases, and alternation of single or grouped phrases. During alternation, a katydid's phrase rate is slowed compared to the rate of solo and synchrony, and phrases may be lengthened by one pulse. In contrast, when a katydid solos during acoustic interaction the solo rate is faster than that of solo calling. When antennating, or being antennated by, another male or female, P. beltrani males sing at a rate which is equivalent to that of soloing during acoustic interaction. P. beltrani males and females produce erratic "disturbance" sounds when handled. The nature of acoustic interaction is compared with that of Pterophylla camellifolia males (Shaw 1968) and proximate mechanisms suggested, copulatory behavior is described, and possible mating strategies are discussed.