Collective decisions

An aggregation of Umbonia crassicornis nymphs.

An aggregation of Umbonia crassicornis nymphs.

Communication is central to many collective decisions in animal groups. We are studying collective communication in the thornbug Umbonia crassicornis, in which mothers defend aggregated offspring from predators. The group signals of offspring provide directional information that alerts the mother to both the predator’s arrival and its location, a process we are studying using experimental, observational and modeling approaches.


Hamel, JA & Cocroft, RB. 2012. Negative feedback from maternal signals reduces false alarms by collectively signaling offspring. Proceedings of the Royal Society B 279:3820 – 3826. doi:10.1098/rspb.2012.1181(pdf)

Cocroft, RB &Hamel, JA. 2010. Vibrational communication in the “other” social insects: a diversity of ecology, signals, and signal function. Pp. 47-68 in O’Connell-Rodwell, CE (ed.), Vibrational Communication in Animals. Research Signposts, Trivandrum, India. (pdf)

Ramaswamy, K & Cocroft, RB. 2009. Collective signals in treehopper broods provide predator localization cues to the defending mother. Animal Behaviour 78: 697-704. (pdf)

Borduin R, Ramaswamy K, Mohan A, Cocroft RB & Nair S. 2008. Modeling the rapid transmission of information within a social group of insects: emergent patterns in the antipredator signals.American Society of Mechanical Engineers Dynamic Systems and Control Conference ProceedingsDSCC2008-2298: 1441-1444.

Cocroft, RB. 2005. Vibrational communication facilitates cooperative foraging in a phloem-feeding insect. Proceedings of the Royal Society B272:1023-1029 (pdf).

Cocroft, RB. 2002. Antipredator defense as a limited resource: unequal predation risk in broods of an insect with maternal care. Behavioral Ecology 13:125-133. (pdf)

Cocroft, RB. 2001. Vibrational communication and the ecology of group-living, herbivorous insects. American Zoologist  41:1215-1221. (pdf)

Cocroft, RB. 1999. Offspring-parent communication in a subsocial treehopper (Hemiptera: Membracidae: Umbonia crassicornis). Behaviour 136:1-21. (pdf)

Cocroft, RB. 1999. Parent-offspring communication in response to predators in a subsocial treehopper (Hemiptera: Membracidae: Umbonia crassicornis). Ethology 105:553-568. (pdf)

Cocroft, RB. 1996. Insect vibrational defence signals. Nature 382:679-680 (pdf).



Dr. Satish Nair, Computer & Electrical Engineering, University of Missouri

Dr. Chris Wikle, Statistics, University of Missouri

Dr. Rico Holdo, Biological Sciences, University of Missouri