Publications

divergence in the enchenopa binotata say complex (homoptera: membracidae) effected by host plant adaptation.		1980	28563201
genetic differentiation along host plant lines in the sympatric enchenopa binotata say complex (homoptera: membracidae).		1981	28563378
ecological and behavioral basis for reproductive isolation in the sympatric enchenopa binotata complex (homoptera. membracidae).		1982	28563159
enchenopa binotata complex: sympatric speciation?	enchenopa binotata is a complex of six treehopper species that have diverged along host plant lines. when females were forced to oviposit on "adopted" host plants, few eggs were deposited. fewer eggs hatched on "adopted" hosts and those that did hatch did so in response to the phenology of the "adopted" host. mortality of nymphs on "adopted" hosts was substantially higher than on native hosts. these and other data support a sympatric model of speciation through shifts in host plants.	1983	17732919
insect phenology mediated by host-plant water relations.	water relations of host plants modify enchenopa binotata life histories by mediating the termination of egg dormancy, thereby promoting synchronization of egg hatch. dormant eggs must undergo dehydration and subsequent hydration to begin development. dehydration of eggs is brought about in the field by declining water levels in branches during the fall and by prolonged cold. hydration of eggs occurs when sap begins to rise in early spring. since the ascent of sap occurs at different times in the ...	1990	28567982
vibrational communication and reproductive isolation in the enchenopa binotata species complex of treehoppers (hemiptera: membracidae).	sexual communication can contribute to population divergence and speciation because of its effect on assortative mating. we examined the role of communication in assortative mating in the enchenopa binotata species complex of treehoppers. these plant-feeding insects are a well studied case of sympatric speciation resulting from shifts to novel host-plant species. shifting to hosts with different phenologies causes changes in life-history timing. in concert with high host fidelity, these changes ...	2004	15119440
evidence that female preferences have shaped male signal evolution in a clade of specialized plant-feeding insects.	mate choice is considered an important influence in the evolution of mating signals and other sexual traits, and--since divergence in sexual traits causes reproductive isolation--it can be an agent of population divergence. the importance of mate choice in signal evolution can be evaluated by comparing male signal traits with female preference functions, taking into account the shape and strength of preferences. specifically, when preferences are closed (favouring intermediate values), there sho ...	2006	17002943
host shifts and the beginning of signal divergence.	divergence between populations adapting to different environments may be facilitated when the populations differ in their sexual traits. we tested whether colonizing a novel environment may, through phenotypic plasticity, change sexual traits in a way that could alter the dynamics of sexual selection. this hypothesis has two components: changes in mean phenotypes across environments, and changes in the genetic background of the phenotypes that are produced -- or genotype x environment interactio ...	2008	18005157
the importance of female choice, male-male competition, and signal transmission as causes of selection on male mating signals.	selection on advertisement signals arises from interacting sources including female choice, male-male competition, and the communication channel (i.e., the signaling environment). to identify the contribution of individual sources of selection, we used previously quantified relationships between signal traits and each putative source to predict relationships between signal variation and fitness in enchenopa binotata treehoppers (hemiptera: membracidae). we then measured phenotypic selection on s ...	2010	20624180
genotype × environment interaction is weaker in genitalia than in mating signals and body traits in enchenopa treehoppers (hemiptera: membracidae).	theory predicts that selection acting across environments should erode genetic variation in reaction norms; i.e., selection should weaken genotype × environment interaction (g × e). in spite of this expectation, g × e is often detected in fitness-related traits. it thus appears that g × e is at least sometimes sustained under selection, a possibility that highlights the need for theory that can account for variation in the presence and strength of g × e. we tested the hypothesis that trait diffe ...	2011	21695477
experience-mediated plasticity in mate preferences: mating assurance in a variable environment.	an individual's prior experience of sexual signals can result in variation in mate preferences, with important consequences for the course of sexual selection. we test two hypotheses about the evolution of experience-mediated plasticity in mate preferences: mating assurance and mismating avoidance. we exposed female enchenopa binotata treehoppers (hemiptera: membracidae) to treatments that varied their experience of signal frequency, the most divergent sexual signal trait in the e. binotata spec ...	2012	22276541
genetic variation in social influence on mate preferences.	patterns of phenotypic variation arise in part from plasticity owing to social interactions, and these patterns contribute, in turn, to the form of selection that shapes the variation we observe in natural populations. this proximate-ultimate dynamic brings genetic variation in social environments to the forefront of evolutionary theory. however, the extent of this variation remains largely unknown. here, we use a member of the enchenopa binotata species complex of treehoppers (hemiptera: membra ...	2013	23698010
male enchenopa treehoppers (hemiptera: membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk.	finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. to decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. the specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. for example, sit-and- ...	2014	24487912
trees to treehoppers: genetic variation in host plants contributes to variation in the mating signals of a plant-feeding insect.	community genetics research has demonstrated 'bottom-up' effects of genetic variation within a plant species in shaping the larger community with which it interacts, such as compositions of arthropod faunas. we demonstrate that such cross-trophic interactions also influence sexually selected traits. we used a member of the enchenopa binotata species complex of treehoppers (hemiptera: membracidae) to ask whether male mating signals are influenced by host plant genetic variation. we reared a rando ...	2014	24350855
variation in signal-preference genetic correlations in enchenopa treehoppers (hemiptera: membracidae).	fisherian selection is a within-population process that promotes signal-preference coevolution and speciation due to signal-preference genetic correlations. the importance of the contribution of fisherian selection to speciation depends in part on the answer to two outstanding questions: what explains differences in the strength of signal-preference genetic correlations? and, how does the magnitude of within-species signal-preference covariation compare to species differences in signals and pref ...	2015	26306166
insect mating signal and mate preference phenotypes covary among host plant genotypes.	sexual selection acting on small initial differences in mating signals and mate preferences can enhance signal-preference codivergence and reproductive isolation during speciation. however, the origin of initial differences in sexual traits remains unclear. we asked whether biotic environments, a source of variation in sexual traits, may provide a general solution to this problem. specifically, we asked whether genetic variation in biotic environments provided by host plants can result in signal ...	2015	25611556
males adjust their signalling behaviour according to experience of male signals and male-female signal duets.	sexual signals are conspicuous sources of information about neighbouring competitors, and species in which males and females signal during pair formation provide various sources of public information to which individuals can adjust their behaviour. we performed two experiments with a duetting vibrational insect, enchenopa binotata treehoppers (hemiptera: membracidae), to ask whether males adjust their signalling behaviour according to (1a) their own experience of competitors' signals, (1b) how f ...	2016	26749493
local population density and group composition influence the signal-preference relationship in enchenopa treehoppers (hemiptera: membracidae).	many animals exhibit social plasticity - changes in phenotype or behaviour in response to experience with conspecifics that change how evolutionary processes like sexual selection play out. here, we asked whether social plasticity arising from variation in local population density in male advertisement signals and female mate preferences influences the form of sexual selection. we manipulated local density and determined whether this changed how the distribution of male signals overlapped with f ...	2017	27749022