Professor of Biological Sciences
PhD, 1998 Cornell University
Insect communication, behavioral ecology and evolution
Research descriptionWe study the evolution of communication and its role in divergence, speciation and social behavior. Our study animals are plant-feeding insects. Social and ecological interactions among herbivorous insects often involve substrate-borne vibrations, so we also investigate the important features of this widespread but under-studied form of communication. Furthermore, because mechanical vibrations provide information about the activity of plant-dwelling arthropods, we have recently begun investigating the plant’s ability to perceive herbivore-generated vibrations and respond adaptively to them.
Current research areas
Plant perception of herbivore vibrations:
Plant-feeding insects are among the most abundant and diverse organisms on earth, with a major impact on both natural ecosystems and agriculture. An insect on a plant gains much of its information about the environment from the mechanical vibrations produced by predators, competitors, or potential mates on the same plant. In collaboration with Dr. Heidi Appel (MU Bond Life Sciences Center), we are investigating plants’ ability to respond adaptively to vibrational cues of herbivory.
Communication is central to collective behavior in many 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.
Signals and speciation:
What role do communication systems play in assortative mating between diverging populations? And how do the ecological changes that accompany diversification shape the communication systems used in mating and other social interactions? The Enchenopa binotata species complex of treehoppers is one of the most widely cited examples of sympatric speciation in plant-feeding insects. The eleven species in this clade are host plant specialists that may have diversified as a consequence of changes in host use. We have been investigating the patterns and processes of divergence in mating signals in the E. binotata complex, focusing on the consequences of signal evolution for assortative mating and sympatric divergence.
For vibrationally-communicating species, many interactions involve locating the source of a substrate-borne vibration. In the insects we primarily work with (membracid treehoppers), mating involves duets between mobile males that home in on the signals of stationary females; maternal care involves locating a predator based on information provided by offspring signals; and recruitment to a new feeding site in group-living species involves signaling by scouts that find a new site, followed by convergence on that site by the rest of the group. Given the centrality of localization to membracid social behavior (and that of many other vibrationally-communicating organisms), we study the mechanisms by which individuals find the source of a substrate vibration.
Gibson, J.S., Cocroft, R.B. Vibration-guided mate searching in treehoppers: Directional accuracy and sampling strategies in a complex sensory environment (2018) Journal of Experimental Biology, 221 (6), art. no. jeb.175083, DOI: 10.1242/jeb.175083
Hsu, Y.-H., Cocroft, R.B., Snyder, R.L., Lin, C.-P. You stay, but I Hop: Host shifting near and far co-dominated the evolution of Enchenopa treehoppers (2018) Ecology and Evolution, 8 (4), pp. 1954-1965. DOI: 10.1002/ece3.3815
Appel HM & Cocroft RB. 2014. Plants respond to leaf vibrations caused by insect herbivore chewing. Oecogia 175(4): 1257-1266.
Cocroft, RB, Gogala M, Hill, P, Wessel, A. 2014. Studying vibrational communication. Springer, Berlin.
Cocroft, RB, Gogala,M, Hill, PSM & Wessel, A. 2014. Fostering research progress in a rapidly growing field. In: Cocroft RB, et al. (eds), Studying Vibrational Communication (pp. 3-12), Springer, Berlin.
Cocroft, RB, Hamel, JA, Su, Q & Gibson, JS. 2014. Vibrational playback experiments: challenges and solutions. In: Cocroft RB, et al. (Eds), Studying Vibrational Communication (pp. 249-274), Springer, Berlin.
Cocroft, RB & Appel, HM. 2013. Comments on "green symphonies." Behavioral Ecology 24(4):800.
Horisk, CS & Cocroft, RB. 2013. Animal signals: always influence, sometimes information. In: Stegmann, U. (ed.), Animal Communication Theory: Information and Influence (pp. 259-280). Oxford: Oxford University Press.
Cocroft, RB & Sullivan-Beckers, LE. 2012. Female preference functions provide a window into cognition, the evolution of communication, and speciation in plant-feeding insects. In J. Vonk & T. Shackleford (eds.), Oxford Handbook of Comparative Evolutionary Psychology (pp. 339-355). Oxford: Oxford University Press.
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.
Rodríguez, RL, Haen, C, Cocroft, RB & Fowler-Finn, KD. 2012. Males adjust signaling effort based on female mate preference cues. Behavioral Ecology 23: 1218-1225.
Legendre, F, Marting, PR & Cocroft, RB. 2012. Competitive masking of vibrational signals during mate searching in a treehopper. Animal Behavior 83:361-368.
Cocroft, RB. 2011. The public world of insect vibrational communication. Molecular Ecology 20: 2041-2043.
DeLuca, PD & Cocroft RB. 2011 The influence of age on male mate searching behaviour in thornbug treehoppers. Ethology 117: 1-11.
Sullivan Beckers, LE & Cocroft, RB. 2010. The importance of female choice, male-male competition and signal transmission as causes of selection on male mating signals. Evolution 64:3158-3171.
McNett GD, Luan L & Cocroft RB. 2010. Wind-induced noise alters signaler and receiver behavior in vibrational communication. Behavioral Ecology and Sociobiology 64:2043–2051.
Hamilton, KGA & Cocroft, RB. 2010. North American species of Enchenopa (Hemiptera: Membracidae): taxonomic assessment based on adults. Entomological News 20:554-565.
Cocroft, RB, Rodriguez, RL & Hunt, RE. 2010. Host shifts and signal divergence: mating signals covary with host use in a complex of specialized plant-feeding insects. Biological Journal of the Linnean Society. 99: 60–72.
Holan, SH, Wikle, CK, Sullivan Beckers, LE & Cocroft, RB. 2010. Modeling complex phenotypes: Generalized linear models using spectrogram predictors of animal communication signals. Biometrics 66: 914-924
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.
Cocroft, RB. 2010. Vibrational Communication. In: Breed, M & Moore, J Encyclopedia of Animal Behavior (Elsevier, online).
Ramaswamy, K & Cocroft, RB. 2009. Collective signals in treehopper broods provide predator localization cues to the defending mother. Animal Behaviour 78: 697-704.
De Luca, PA & Cocroft, RB. 2009. Age-related changes in an insect mating signal have no effect on female choice. Behavioral Ecology and Sociobiology 63:1787-1798.
Cocroft, RB. 2009. An ecologist marvels at animals that learn to eavesdrop. Nature 460: 439.
De Luca, PA & Cocroft, RB. 2008. The effects of age and relatedness on mating patterns in thornbug treehoppers: inbreeding avoidance or inbreeding tolerance? Behavioral Ecology and Sociobiology, 62:1869-1875.
McNett, GD & Cocroft, RB. 2008. Host shifts favor vibrational signal divergence in Enchenopa binotata treehoppers. Behavioral Ecology 19:650-656.
Rodriguez, RL, Sullivan LM, Snyder RL & Cocroft, RB. 2008. Host shifts and the beginning of signal divergence. Evolution 62:12-20.
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, Rodriguez, RL & Hunt, RE. 2008. Host shifts, the evolution of communication and speciation in the Enchenopa binotata species complex of treehoppers. Pp. 88-100 in: Tilmon, KJ (ed.), Specialization, Speciation and Radiation: The Evolutionary Biology of Herbivorous Insects. University of California Press, Berkeley, CA.
Rodriguez, RL & Cocroft, RB. 2006. Divergence in female duetting signals in the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae). Ethology 112:1231–1238.
McNett, GD, Miles, RN, Homentcovschi, D & Cocroft, RB. 2006. A method for two-dimensional characterization of animal vibrational signals transmitted along plant stems. Journal of Comparative Physiology A 192:1245-1251.
Rodríguez, RL, Ramaswamy, K & Cocroft, RB. 2006. Evidence that female preferences have shaped male signal evolution in a clade of specialized plant-feeding insects. Proceedings of the Royal Society B 273:2585-2593.
Cocroft, RB, Shugart, HJ, Konrad, KT & Tibbs, K. 2006. Variation in plant substrates and its consequences for insect vibrational communication. Ethology 112:779-789.
Cocroft, RB & De Luca, PA. 2006. Size-frequency relationships in insect vibrational signals. Pp. 99-110 in Insect Sounds and Communication: Physiology, Ecology and Evolution (eds. Claridge, MF & Drosopoulos, S). Taylor & Francis, Boca Raton, FL.
Cocroft, RB & McNett, GD. 2006. Vibrational communication in treehoppers (Hemiptera: Membracidae). Pp. 305-317 in Insect Sounds and Communication: Physiology, Ecology and Evolution (eds. Claridge, MF & Drosopoulos, S). Taylor & Francis, Boca Raton, FL.
Rodriguez, RL, Schul, J, Cocroft, RB & Greenfield, MD. 2005. The contribution of tympanic transmission to fine temporal signal evaluation in an ultrasonic moth. Journal of Experimental Biology 208:4159-4165.
Cocroft, RB & Rodríguez, RL. 2005. The behavioral ecology of insect vibrational communication. BioScience 55:323-334.
Cocroft, RB. 2005. Vibrational communication facilitates cooperative foraging in a phloem-feeding insect. Proceedings of the Royal Society B272:1023-1029.2004
Rodríguez, RL, Sullivan, L, & Cocroft, RB. 2004. Vibrational communication and reproductive isolation in the Enchenopa binotata species complex of treehoppers. Evolution 58:571-578.
Sattman, DA & Cocroft, RB. 2003. Phenotypic plasticity and repeatability in signals of Enchenopa treehoppers, with implications for gene flow among host-shifted populations. Ethology 109:981-994.
Angulo, A, Cocroft, RB, Reichle, S. 2003. Species identity in the genus Adenomera (Anura: Leptodactylidae) in southeastern Peru. Herpetologica 59:490-504.
Cocroft, RB. 2003. The social environment of an aggregating, ant-attended treehopper. Journal of Insect Behavior 16:79-95.
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.
Cocroft, RB. 2001. Vibrational communication and the ecology of group-living, herbivorous insects. American Zoologist 41:1215-1221.
Miles, RN, Cocroft, RB, Gibbons, C and Batt, D. 2001. A bending wave simulator for investigating directional vibration sensing in insects. Journal of the Acoustical Society of America 110:579-587.
Cocroft, RB, Tieu, T, Hoy, RR & Miles, R. 2000. Mechanical directionality in the response to substrate vibration in a treehopper. Journal of Comparative Physiology 186: 695-705.
Cocroft, RB. 1999. Thornbug to thornbug: the inside story of insect song. Natural History 108:52-57
Cocroft, RB. 1999. Offspring-parent communication in a subsocial treehopper (Hemiptera: Membracidae: Umbonia crassicornis). Behaviour 136:1-21.
Cocroft, RB. 1999. Parent-offspring communication in response to predators in a subsocial treehopper (Hemiptera: Membracidae: Umbonia crassicornis). Ethology 105:553-568.
Barnett, K, Cocroft, RB & Fleishman, L. 1999. Possible communication by substrate vibration in a chameleon. Copeia 1999:225-228.
Cocroft, RB & Pogue, M. 1996. Social behavior and communication in the neotropical cicada Fidicina mannifera. Journal of the Kansas Entomological Society 69(S):85-97.
Cocroft, RB. 1996. Insect vibrational defence signals. Nature 382:679-680.
Schultz, T, Cocroft, RB & Churchill, G. 1996. Reconstruction of ancestral character states. Evolution 50:504-511.
Cocroft, RB & Ryan, MJ. 1995. Patterns of advertisement call evolution in toads and chorus frogs. Animal Behaviour 49:283-303.
Cocroft, RB. 1994. A cladistic analysis of chorus frog phylogeny (Hylidae: Pseudacris). Herpetologica 50:420-437.
deVries, PJ, Cocroft, RB & Thomas, J. 1993. Comparison of acoustical signals in Maculinea butterfly caterpillars and their obligate host Myrmica ants. Zoological Journal of the Linnean Society 49:229-238.
Ryan, MJ, Cocroft, RB & Wilczynski, W. 1990. The role of environmental selection in intraspecific divergence of mate recognition signals in the cricket frog Acris crepitans. Evolution 44:1869-1872.
Cocroft, RB, McDiarmid, WR, Jaslow, A & Ruiz-C, P. 1990. Vocalizations of eight species of Atelopus, with comments on communication in the genus. Copeia 1990:631-643.
Cocroft, RB & Hambler, K. 1989. Observations on a commensal relationship of the microhylid frog Chiasmocleis ventrimaculata and the burrowing theraphosid spider Xenesthis immanis in southeastern Peru. Biotropica 21:2-8.
Cocroft, RB & Heyer, WR. 1988. Notes on the frog genus Thoropa (Amphibia, Leptodactylidae) with a description of a new species (Thoropa saxatilis). Proceedings of the Biological Society of Washington 101:209-220.
Heyer, WR & Cocroft, RB. 1986. Descriptions of two new species of Hylodes from the Atlantic Forests of Brazil (Amphibia, Leptodactylidae). Proceedings of the Biological Society of Washington 99:100-109.
Honors & Awards
Selected honors and awards
Insect Drummer Award for Lifetime Achievement in Vibratory Communication Research 2018
Sept. 24, 2018
Rex Cocroft honored for lifetime achievements
Aug. 27, 2015
July 10, 2014
Professor Cocroft's study on caterpillar vibrations gets national coverage
July 2, 2014
New study from Cocroft lab shows that plants respond to leaf vibrations caused by insect chew
July 1, 2014
July 1, 2014
May 24, 2006
A Journey to the Edge of the Amazon