Meeting Abstract

21.5  Monday, Jan. 4  Receivers, functions, and costs of parent-offspring signaling in treehoppers (Hemiptera: Membracidae) HAMEL, Jennifer A.*; COCROFT, Reginald B.; University of Missouri jahtf7@mail.missouri.edu

In species in which parents defend offspring against predators, communication between parents and offspring may facilitate defense. Understanding signal function in this context is challenging, because signals may have evolved to influence the behavior of family members or of predators. Platycotis vittata are oak-feeding treehoppers in which mothers defend offspring from invertebrate predators. During predator encounters, offspring produce repetitive, synchronized vibrational signals. Mothers also produce vibrational signals during and after the predator encounter, in addition to actively defending their offspring. For offspring signals in Platycotis, one function is to elicit the mother’s defense, but it is also possible that they influence predator behavior. For maternal signals, we hypothesize that they function to ‘reset the alarm’ after a predator encounter by inhibiting offspring signals. However, it is also possible that maternal signals are directed toward the predator. We used playback experiments to test these hypotheses with a generalist walking predator in the laboratory and with naturally occurring treehopper families in the field. Predators moved less during offspring signals, suggesting that predators may be attracted to signaling offspring. Predators oriented away from maternal signals, suggesting they may be deterred by signaling females. Nymphs did not stop signaling in response to maternal signals. Offspring signals, then, appear to have evolved to influence the mother’s behavior, at the cost of attracting vibration-sensitive predators. Maternal signals may have evolved to influence predators rather than offspring.