02707nas a2200409   4500008004100000245015100041210006900192260000800261300001200269490000700281520158800288653002401876653001301900653001601913653001101929653001101940653001801951653001201969653001601981653001001997653001102007653001202018653001302030653001802043653003102061653001602092653002302108653001302131653001302144100001802157700001502175700002002190700001602210700002002226700001602246856003502262       2005                        eng d00aSeasonal activity and species composition of dung beetles (Coleoptera : Scarabaeidae and Geotrupidae) inhabiting cattle pastures in North Carolina0 aSeasonal activity and species composition of dung beetles Coleop  cMay  a309-3210 v983 aSpecies composition and seasonal distribution of dung beetles were studied on dairy and beef cattle pastures in North Carolina. Study sites included a dairy located in the piedmont region (North Carolina Department of Agriculture Piedmont Research Station, Salisbury, NC) and a combined dairy/beef facility in the coastal plain (North Carolina Department of Agriculture Center for Environmental Farming Systems, Goldsboro, NC). Dung beetles were trapped in cattle pastures from March 2002 through September 2003 by using dung-baited pitfall traps. Trapping yielded 4,111 beetles representing 14 species from the piedmont dairy, including Aphodius prodromus Brahm, a new record for North Carolina. Totals of 57,026 beetles representing 28 species and 28,857 beetles representing 26 species were trapped from the dairy unit and beef unit in the coastal plain site, respectively. Onthophagus gazella (F.), a second new record for North Carolina, was collected from the coastal plain. Beetles common to all collection sites include Aphodius erraticus (L.), Aphodius fimetarius (L.), Aphodius granarius (L.), Aphodius pseudolividus Balthasar, Onthophagus tattrus Scbreber, Onthophagus hecate hecate Panzer, and Onthophagus pennsylvanicus Harold. The introduced beetle O. taurus dominated the dung beetle population, accounting for &GT; 50% of the total beetles caught at either site. Beetle activity was greatest from March until November, with activity declining during the winter. Nine exotic species in the genera Onthophagus and Aphodius represented nearly 95% of the beetles trapped.10aAfrican buffalo fly10aaphodius10abovine dung10acanada10acattle10acoastal-plain10adiptera10adung beetle10aflies10agrowth10ahabitat10amuscidae10anorth america10anorth carolina dung beetle10aOnthophagus10aonthophagus-taurus10apiedmont10aSURVIVAL1 aBertone, Matt1 aGreen, Jim1 aWashburn, Steve1 aPoore, Matt1 aSorenson, Clyde1 aWatson, Wes  u<Go to ISI>://000228963400009 00955nas a2200205   4500008004100000245011700041210006900158300000800227490000700235520023100242653001400473653001100487653001600498653001600514653001700530100002200547700002500569700002300594856013200617       2006                        eng d00aOnthophagus yucatanus, a new species of the Clypeatus group from Mexico and Guatemala (Coleoptera: Scarabaeidae)0 aOnthophagus yucatanus a new species of the Clypeatus group from   a6-90 v893 aA new Mexican and Guatemalan species, Onthophagus yucatanus , belonging to the Clypeatus group is described and illustrated. The distinctive characters of this species, its geographical distribution, and habits are described. 10aGuatemala10aMexico10anew species10aOnthophagus10aScarabaeidae1 aDelgado, Leonardo1 aPeraza, Lizandro, N.1 aDeLoya, Cuauhtemoc  uhttps://scarabnet.myspecies.info/onthophagus-yucatanus-new-species-clypeatus-group-mexico-and-guatemala-coleoptera-scarabaeidae00721nas a2200181   4500008004100000245012700041210006900168260000800237300001200245490000700257653003800264653001900302653002100321653002000342653001600362100002300378856013800401       1997                        eng d00aAlternative reproductive tactics and male-dimorphism in the horne beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)0 aAlternative reproductive tactics and maledimorphism in the horne  cAug  a335-3410 v4110aalternative reproductive behavior10ahorned beetles10amale competition10amale dimorphism10aOnthophagus1 aEmlen, Douglas, J.  uhttps://scarabnet.myspecies.info/alternative-reproductive-tactics-and-male-dimorphism-horne-beetle-onthophagus-acuminatus-coleoptera-02222nas a2200265   4500008004100000245012400041210006900165260000800234300001400242490000700256520131700263653002301580653001701603653002501620653002101645653001601666653001401682653002101696653001301717100002301730700002401753700001801777700002501795856013601820       2005                        eng d00aDiversity in the weapons of sexual selection: horn evolution in the beetle genus Onthophagus (Coleoptera: Scarabaeidae)0 aDiversity in the weapons of sexual selection horn evolution in t  cJan  a1060-10840 v593 aBoth ornaments and weapons of sexual selection frequently exhibit prolific interspecific diversity of form. Yet, most studies of this diversity have focused on ornaments involved with female mate choice, rather than on the weapons of male competition. With few exceptions, the mechanisms of divergence in weapon morphology remain largely unexplored. Here, we characterize the evolutionary radiation of one type of weapon: beetle horns. We use partial sequences from four nuclear and three mitochondrial genes to develop a phylogenetic hypothesis for a worldwide sample of 48 species from the dung beetle genus Onthophagus (Coleoptera: Scarabaeidae). We then use these data to test for multiple evolutionary origins of horns and to characterize the evolutionary radiation of horns. Although our limited sampling of one of the world’s most species-rich genera almost certainly underestimates the number of evolutionary events, our phylogeny reveals prolific evolutionary lability of these exaggerated sexually selected weapons (more than 25 separate gains and losses of five different horn types). We discuss these results in the context of the natural history of these beetles and explore ways that sexual selection and ecology may have interacted to generate this extraordinary diversity of weapon morphology. 10aAdaptive radiation10abeetle horns10acharacter divergence10amale competition10aOnthophagus10aphylogeny10asexual selection10aweapons.1 aEmlen, Douglas, J.1 aMarangelo, Jennifer1 aBall, Bernard1 aCunningham, Clifford  uhttps://scarabnet.myspecies.info/diversity-weapons-sexual-selection-horn-evolution-beetle-genus-onthophagus-coleoptera-scarabaeidae01966nas a2200193   4500008004100000245013500041210006900176300001200245490000800257520123000265653001901495653001601514653001401530653002101544653002201565100002401587700002301611856013801634       2003                        eng d00aGenital morphology and fertilization success in the dung beetle Onthophagus taurus: an example of sexually selected male genitalia0 aGenital morphology and fertilization success in the dung beetle   a447-4550 v2703 aIn animals with internal fertilization and promiscuous mating, male genitalia show rapid and divergent evolution. Three hypotheses have been suggested to explain the evolutionary processes responsible for genital evolution: the lock-and-key hypothesis, the pleiotropy hypothesis and the sexual-selection hypoth- esis. Here, we determine whether variation in male genital morphology influences fertilization success in the dung beetle Onthophagus taurus, as predicted by the sexual-selection hypothesis. Variation in four out of five genital sclerites of the endophallus influenced a male’s fertilization success, supporting the general hypothesis that male genitalia can evolve under sexual selection. Furthermore, different genital sclerites were found to enhance first versus second male paternity, indicating that different sclerites serve offensive and defensive roles. Genital-trait variability was comparable to that in other species but was less variable than a non-genital sexually selected trait (head horns). We suggest that directional selection for genital elaboration may be countered by natural selection, which should favour genitalia of a size and shape necessary for efficient coupling and sperm transfer. 10amale genitalia10aOnthophagus10apaternity10asexual selection10aSperm competition1 aHouse, Clarissa, M.1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/genital-morphology-and-fertilization-success-dung-beetle-onthophagus-taurus-example-sexually-selecte02277nas a2200193   4500008004100000245009700041210006900138300001200207490000700219520159100226653001601817653001601833653002301849653002201872653002701894100001901921700002301940856012001963       2008                        eng d00aOptimal investment in sons and daughters when parents do not know the sex of their offspring0 aOptimal investment in sons and daughters when parents do not kno  a607-6150 v623 aOptimal parental i nvestment usually differs depending on the sex of the offspring. However, parents in most organisms cannot discriminate the sex of their young until those young are energetically independent. In a species with physical male–male competition, males are often larger and usually develop sexual ornaments, so male offspring are often more costly to produce. However, Onthophagus dung beetles (Coleoptera; Scarabaeidae) are highly dimorphic in secondary sexual characters, but sexually monomorphic in body size, despite strong male–male competition for mates. We demonstrate that because parents provide all resources required by their offspring before adulthood, O. atripennis exhibits no sexual size dimorphism irrespective of sexual selection pressure favoring sexual dimorphism. By con- structing a graphic model with three fitness curves (for sons, daughters, and expected fitness return for parents), we demonstrate that natural selection favors parents that provide both sons and daughters with the optimal amount of investment for sons, which is far greater than that for daughters. This is because the cost of producing small sons, that are unable to compete for mates, is far greater than the cost of producing daughters that are larger than necessary. This theoretical prediction can explain sexual dimorphism without sexual size dimorphism, widely observed in species with crucial parental care such as dung beetles and leaf- rolling beetles, and may provide an insight into the enigmatic relationship between sexual size dimorphism and sexual dimorphism.10adung beetle10aOnthophagus10aOptimal investment10aSexual dimorphism10aSexual size dimorphism1 aKishi, Shigeki1 aNishida, Takayoshi  uhttps://scarabnet.myspecies.info/optimal-investment-sons-and-daughters-when-parents-do-not-know-sex-their-offspring02242nas a2200313   4500008004100000245010700041210006900148260001200217300001200229490000700241520132400248653002901572653002501601653001801626653001301644653002001657653002401677653000801701653002401709653001901733653001601752653003801768653001401806653002101820653002101841653001201862100002001874856003401894       2002                        eng d00aSexual selection and condition dependence of courtship display in three species of horned dung beetles0 aSexual selection and condition dependence of courtship display i  cNov-Dec  a791-7990 v133 aSexual selection has traditionally been divided into competition over mates and mate choice. Currently, models of sexual selection predict that sexual traits are expressed in proportion to the condition of their bearer. In horned beetles, male contest competition is well established, but studies on female preferences are scarce. Here I present data on male mating success and condition dependence of courtship rate in three species of horn-dimorphic thing beetles, Onthaphagus taurus, Onthophagus binodis, and Onthophagus australis. I found that in the absence of male contest competition, mating success of O. taurus and O. australis was unrelated to their horn length and body size, whereas in O. binodis horn size had a negative effect but body size had a positive effect on male mating success. Overall, in O. binodis major morph males had greater mating success than minor morph males. In all three species male mating success was affected by courtship rate, and the Courtship rate was condition dependent such that when males were manipulated to be in poor condition they had lower courtship rates than males that were manipulated to be in good condition. My findings provide new insight into the mating systems of horned dung beetles and support an important assumption in indicator models of sexual selection.10aalternative reproductive10acondition dependence10aFEMALE CHOICE10agradient10ahorn dimorphism10ahorned dung beetles10alek10alogistic regression10amating success10aOnthophagus10aonthophagus-acuminatus coleoptera10aSELECTION10asexual selection10astalk-eyed flies10atactics1 aKotiaho, J., S.  u<Go to ISI>://00017950430001100709nas a2200181   4500008004500000245014000045210006900185300000800254490000700262653000600269653002900275653001000304653001600314653001700330100002000347700002200367856013800389       1994                        spandsh  00aRelaciones entre escarabajos (Coleoptera: Scarabaeidae) y nidos de tuza (Rodentia: Geomydae): implicaciones biologicas y biogeograficas0 aRelaciones entre escarabajos Coleoptera Scarabaeidae y nidos de   a1-90 v6210a'10aassociation with rodents10anests10aOnthophagus10aScarabaeinae1 aLobo, Jorge, M.1 aHalffter, Gonzalo  uhttps://scarabnet.myspecies.info/relaciones-entre-escarabajos-coleoptera-scarabaeidae-y-nidos-de-tuza-rodentia-geomydae-implicaciones02310nas a2200325   4500008004100000245012600041210006900167260000800236300000900244490000700253520140400260653001401664653001301678653001501691653001601706653001501722653001701737653001801754653001601772653001601788653001301804653002501817653001701842653001801859653002101877653001601898100001701914700001901931856003401950       2002                        eng d00aExperimental investigations of colonisation by north temperate dung beetles of different types of domestic herbivore dung0 aExperimental investigations of colonisation by north temperate d  cApr  a1-130 v203 aField experiments investigated the colonisation by a north temperate dung beetle community (Aphodius, Geotrupes and Sphaeridium species) of artificial, standardised (11) dung pats from native herbivore species (cow, horse and sheep). An additional experiment compared the colonisation by dung beetles of five different types of cow dung. These experiments did not examine naturally occurring dung pats, but used experimental dung pats to examine the ability of north temperate dung beetles to discriminate among different dung types. A small number of laboratory experiments investigated pat residence times (PRT) and larval production across different dung types. There were significant differences in the biomass and abundance of dung beetle colonisation across different dung types. Sheep dung tended to have highest abundances of beetles, but there was evidence of species-specific differences in dung beetle colonisation of the different kinds of dung. In two out of three comparisons, laboratory experiments provided evidence that adult PRT were significantly different among different kinds of dung. In each of three laboratory experiments, larval production was significantly higher in sheep than cow dung pats of the same size. The relevance of these findings to the interpretation of what constitutes a dung type preference is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.10aabundance10aaphodius10aassemblage10acattle dung10aCOLEOPTERA10acolonisation10adisappearance10adung beetle10aOnthophagus10aresource10aresource utilization10aScarabaeidae10aScarabaeoidea10aseasonal-changes10autilisation1 aFinn, J., A.1 aGiller, P., S.  u<Go to ISI>://00017712390000100743nas a2200169   4500008004100000245016400041210006900205300001200274490000600286653002700292653003600319653001600355653002600371653001600397100002200413856013800435       1998                        eng d00aHorn polyphenism in the beetle Onthophagus taurus: larval diet quality and plasticity in parental investment determine adult body size and male horn morphology0 aHorn polyphenism in the beetle Onthophagus taurus larval diet qu  a636-6410 v910aalternative phenotypes10afacultative parental investment10aOnthophagus10aphenotypic plasticity10aPolyphenism1 aMoczek, Armin, P.  uhttps://scarabnet.myspecies.info/horn-polyphenism-beetle-onthophagus-taurus-larval-diet-quality-and-plasticity-parental-investment-de00760nas a2200193   4500008004100000245012800041210006900169300001200238490000700250653001200257653003600269653002200305653001600327653002600343653001600369653002100385100002200406856013800428       1999                        eng d00aFacultative paternal investment in the polyphenic beetle Onthophagus taurus; the role of male morphology and social context0 aFacultative paternal investment in the polyphenic beetle Onthoph  a641-6470 v1010abeetles10afacultative parental investment10ahonest indicators10aOnthophagus10aphenotypic plasticity10aPolyphenism10asexual selection1 aMoczek, Armin, P.  uhttps://scarabnet.myspecies.info/facultative-paternal-investment-polyphenic-beetle-onthophagus-taurus-role-male-morphology-and-social02835nas a2200277   4500008004100000245004900041210004900090260000800139300001000147490000700157520204700164653003502211653002602246653002902272653002402301653002802325653002102353653000902374653001602383653003802399653003102437653001202468653002402480100001902504856003402523       2002                        eng d00aAllometric plasticity in a polyphenic beetle0 aAllometric plasticity in a polyphenic beetle  cFeb  a58-670 v273 a1. Environmental conditions. such as variation in nutrition. commonly contribute to morphological variation among individuals by affecting body size and the expression of certain morphological traits however the scaling relationship between a morphological trait and body size over a range of body sizes is generally assumed not to change in response to environmental fluctuation (allometric plasticity), but instead to be constant and diagnostic for a particular trait and species or Population. The work reported here examined diet- induced allometric plasticity in the polyphenic beetle Onthophagus taurus Schreber (1759) (Coleoptera: Scarabaeidae). 2. Male O. taurus vary in body size depending on larval nutrition, Only males above a critical body size threshold express fully developed horns: males smaller than this threshold develop only rudirrientary horns or no horns at all. 3. Field populations that naturally utilise two different resources for feeding larvae (horse dung vs. cow manure) exhibited significant differences in the average scaling relationship between body size and male horn length over the same range of body sizes. Males collected from cow manure populations expressed consistently longer horns for a given body size than males collected from horse dung Populations. 4. Males reared in the laboratory on horse dung or cow manure also exhibited significant differences in the average scaling relationship between body size and horn length. Differences between laboratory populations reared on horse dung or cow manure were of the same kind and magnitude as differences between field populations that utilise these different resources naturally. 5. These findings suggest that between- population differences in scaling relationships between horn length and body size can be the product of differences in the quality of resources available to developing larvae. Results are discussed in the context of onthophagine mating systems and recent insights in the developmental and endocrine control of horn polyphenisms.10aadaptive phenotypic plasticity10aallometric plasticity10aalternative reproductive10aalternative tactics10adevelopmental threshold10ahorn polyphenism10amale10aOnthophagus10aonthophagus-acuminatus coleoptera10astatus-dependent selection10atactics10athreshold evolution1 aMoczek, A., P.  u<Go to ISI>://00017436120000803343nas a2200265   4500008004100000245007300041210006900114300001200183490000700195520248900202653003502691653002802726653001902754653001902773653000902792653001602801653001602817653002502833653002402858653003102882653002402913653002402937100002202961856009402983       2003                        eng d00aThe behavioral ecology of threshold evolution in a polyphenic beetle0 abehavioral ecology of threshold evolution in a polyphenic beetle  a841-8540 v143 aFacultative expression of alternative male morphologies is thought to allow individual males to select the phenotype with the highest fitness gain given their competitive status relative to other males with which they compete for females. Choice of, or switching between, morphs commonly relies on developmental threshold responses. Evolutionary changes in developmental threshold responses are thought to provide an important avenue for phenotypic diversification and the evolution of morphological and behavioral novelties. However, the extent to which alternative male phenotypes and their underlying threshold responses actually evolve in natural populations is unclear. Likewise, the ecological factors that shape the evolution of threshold responses in natural populations are unexplored for most organisms, as are the consequences of such modifications for patterns of morphological diversity. I examined the ecological basis of rapid threshold evolution in exotic populations of the horn-polyphenic dung beetle Onthophagus taurus. Male O. taurus vary continuously in body size as a function of larval feeding conditions. Only males that exceed a critical threshold body size develop a pair of long horns on their heads, whereas males below this threshold remain hornless. Populations in two exotic ranges of this species, the eastern United States and western Australia, have diverged in the mean threshold body size, which has resulted in the evolution of highly divergent and novel horn length–body size allometries in these populations. Populations in a third and previously unstudied exotic range of O. taurus in eastern Australia exhibit threshold body sizes roughly intermediate between the eastern U.S. and western Australian populations. I tested three hypothesis to explain how differences in ecological and demographic factors can drive allometric divergences between populations, using data derived from comparative, standardized sampling of a large number of populations in each exotic range. Results suggest that differences in the intensity of both intra- and interspecific competition have contributed to the evolution of divergent thresholds in these populations. My results do not support the hypothesis that shifts in threshold body sizes to larger body sizes are a consequence of increases in the mean body size of competing males. I discuss my results in the context of Onthophagus mating systems and the evolutionary implications of threshold evolution.10aadaptive phenotypic plasticity10adevelopmental threshold10aexotic species10ahorned beetles10amale10aOnthophagus10aPolyphenism10aresource competition10asex ratio evolution10astatus-dependent selection10athreshold evolution10a–male competition1 aMoczek, Armin, P.  uhttps://scarabnet.myspecies.info/behavioral-ecology-threshold-evolution-polyphenic-beetle00673nas a2200193   4500008004100000245009500041210006900136260000800205300001200213490000800225653001400233653001700247653001300264653001600277653002600293653002100319100002200340856011700362       2006                        eng d00aPupal remodeling and the development  and evolution of sexual dimorphism in horned beetles0 aPupal remodeling and the development and evolution of sexual dim  cdec  a711-7290 v16810aallometry10aevolvability10alability10aOnthophagus10aprogrammed cell death10apupal remodeling1 aMoczek, Armin, P.  uhttps://scarabnet.myspecies.info/pupal-remodeling-and-development-and-evolution-sexual-dimorphism-horned-beetles02856nas a2200205   4500008004100000245015400041210006900195300001200264490000700276520206400283653001402347653002902361653002702390653001602417653001202433100002202445700001902467700002602486856013802512       2004                        eng d00aLinear and threshold-dependent expression of secondary sexual traits in the same individual: insights from a horned beetle (Coleoptera: Scarabaeidae)0 aLinear and thresholddependent expression of secondary sexual tra  a473-4800 v833 aElaborate horns or horn-like structures in male scarab beetles commonly scale with body size either (a) in a linear fashion with horn size increasing relatively faster than body size or (b) in a threshold-dependent, sigmoid fashion; that is, males smaller than a certain critical body size develop no or only rudimentary horns, whereas males larger than the threshold size express fully developed horns. The development of linear vs. sigmoid scaling relationships is thought to require fundamentally different regulatory mechanisms. Here we show that such disparate regulatory mechanisms may co-occur in the same individual. Large males of the south-east Asian Onthophagus  ( Proagoderus ) watanabei  (Ochi & Kon) (Scarabaeidae, Onthophagini) develop a pair of long, curved head horns as well as a single thoracic horn. We show that unlike paired head horns in a large number of Onthophagus  species, in O. watanabei  the relationship between head horns and body size is best explained by a linear model. Large males develop dispropor- tionately longer horns than small males, but the difference in relative horn sizes across the range of body sizes is small compared to other Onthophagus  species. However, the scaling relationship between the thoracic horn and body size is best explained by a strongly sigmoid model. Only males above a certain body size threshold express a thoracic horn and males smaller than this threshold express no horn at all. We found a significant positive correlation between head and thoracic horn length residuals, contrary to what would be expected if a resource allocation tradeoff during larval development would influence the length of both horn types. Our results suggest that the scaling rela- tionship between body size and horn length, and the developmental regulation underlying these scaling relation- ships, may be quite different for different horns, even though these horns may develop in the same individual. We discuss our results in the context of the developmental biology of secondary sexual traits in beetles.10aallometry10adevelopmental constraint10adevelopmental tradeoff10aOnthophagus10ascaling1 aMoczek, Armin, P.1 aBruhl, Carsten1 aKrell, Frank-Thorsten  uhttps://scarabnet.myspecies.info/linear-and-threshold-dependent-expression-secondary-sexual-traits-same-individual-insights-horned-be02616nas a2200253   4500008004100000245006900041210006900110300001200179490000600191520178900197653003501986653002402021653002802045653001902073653002102092653001602113653003102129653002502160100002202185700001502207700002302222700002302245856009402268       2002                        eng d00aThreshold evolution in exotic populations of a polyphenic beetle0 aThreshold evolution in exotic populations of a polyphenic beetle  a587-6010 v43 aPolyphenic development is thought to play an important role in the evolution of phenotypic diversity and morphological novelties, yet the evolution of polyphenisms has rarely been docu- mented in natural populations. Here we compare the morphologies of male dung beetles (Onthophagus ttaurus; Coleoptera: Scarabaeidae) from populations introduced to Australia and the eastern United States. Males in this species express two alternative morphologies in response to larval feeding conditions. Males encountering favourable conditions grow larger than a threshold body size and develop a pair of horns on their heads, whereas males that encounter poor conditions do not reach this threshold size and remain hornless. Australian and US populations did not differ in overall body size ranges, but exhibited significant differences in the location of the critical body size threshold that separates alternative male morphs. Australian males remained hornless at much larger body sizes than males in US populations, resulting in substantial and significant differences in the average body size–horn length allometry between exotic populations, as well as significant differences in morph ratios. The phenotypic divergence observed between field populations was maintained in laboratory populations after two generations under identical environmental conditions, suggesting a genetic basis to allometric divergence in these populations. Divergence between exotic O. taurus populations was of a magnitude and kind typically observed between species. We use our results to examine potential causes of allometric divergence in onthophagine beetles, and discuss the evolutionary potential of threshold traits and polyphenic development in the origin of morphological and behavioural diversity.10aadaptive phenotypic plasticity10aalternative tactics10adevelopmental threshold10aexotic species10ahorn polyphenism10aOnthophagus10astatus-dependent selection10athreshold evolution.1 aMoczek, Armin, P.1 aHunt, John1 aEmlen, Douglas, J.1 aSimmons, Leigh, W.  uhttps://scarabnet.myspecies.info/threshold-evolution-exotic-populations-polyphenic-beetle02565nas a2200217   4500008004100000245009600041210006900137300001200206490000800218520181500226653001702041653002502058653001402083653001802097653002102115653001602136653003402152100002202186700002202208856011702230       2004                        eng d00aTrade-offs during the development of primary and secondary sexual traits in a horned beetle0 aTradeoffs during the development of primary and secondary sexual  a184-1910 v1633 a Resource allocation trade-offs during development affect the final sizes of adult structures and have the potential to constrain the types and magnitude of evolutionary change that developmental processes can accommodate. Such trade-offs can arise when two or more body parts compete for a limited pool of resources to sustain their growth and differentiation. Recent studies on several holo- metabolous insects suggest that resource allocation trade-offs may be most pronounced in tissues that grow physically close to each other. Here we examine the nature and magnitude of developmental trade-offs between two very distant body parts: head horns and geni- talia of males of the horned scarab beetle Onthophagus taurus. Both structures develop from imaginal disklike tissues that undergo ex- plosive growth during late larval development but differ in exactly when they initiate their growth. We experimentally ablated the pre- cursor cells that normally give rise to male genitalia at several time points during late larval development and examined the degree of horn development in these males compared to that of untreated and sham-operated control males. We found that experimental males developed disproportionately larger horns. Horn overexpression was weakest in response to early ablation and most pronounced in males whose genital disks were ablated just before larvae entered the pre- pupal stage. Our results suggest that even distant body parts may rely on a common resource pool to sustain their growth and that the relative timing of growth may play an important role in deter- mining whether, and how severely, growing organs will affect each other during development. We use our findings to discuss the phys- iological causes and evolutionary consequences of resource allocation trade-offs. 10abeetle horns10adevelopmental timing10agenitalia10aimaginal disk10aJuvenile hormone10aOnthophagus10aresource allocation trade-off1 aMoczek, Armin, P.1 aNijhout, Frederik  uhttps://scarabnet.myspecies.info/trade-offs-during-development-primary-and-secondary-sexual-traits-horned-beetle03256nas a2200325   4500008004100000245009200041210006900133300001200202490000800214520225500222653002602477653003702503653001102540653001402551653001502565653001702580653001702597653001502614653002502629653002002654653001602674653001302690653001702703653001702720653002202737653002102759100001902780700001602799856011502815       2001                        eng d00aBody size and paternal invest ment in the genus Onthophagus (Coleoptera, Scarabaeoidea)0 aBody size and paternal invest ment in the genus Onthophagus Cole  a405-4120 v2553 aDuring reproduction, dung beetles of the genus Onthophagus typically bury portions of dung removed from the dung pad. Even though females are capable of successfully constructing and provisioning nests when unaccompanied by males, extensive levels of co-operation between sexes have been reported. In some species, males show a clear dimorphism in body plan and only large horned males are known to assist females. In O. taurus this form of paternal investment is facultative and depends on social context (namely the presence of other males). We studied relationships between body size and paternal investment in five Onthophagus species (i.e. O. coenobita, O. fracticornis, O. illyricus, O. taurus and O. vacca). Two types of tests were established. In test A, a large and a small male were placed with a single, medium-size female, in test B, a large and a small female were placed with a single large male. In controls one male was placed with one female. Individuals were maintained for 10 days. Then the enclosures were opened to assess the position of each beetle. When two mates were found in close vicinity or in the same tunnel provisioning dung, a co-operative behaviour was assumed. In competitive tests, small males and small females never cooperated with their potential mates whilst large and medium-size individuals often co- operated with mates inside the same tunnels. No differences in frequencies of co-operation were found between large and medium-size females. Small females and small males scarcely co- operated with large or medium-size mates in controls. These results suggest that large individuals outcompete the small ones. They also suggest that paternal investment depends on body size of both mates. Large males of all species assist medium-size and large females, whereas small males do not. However, large males do not invest much parental effort on small females that, in fact, are poorly, assisted. We assume that large individuals of both sexes are reproductively superior to small ones. The propensity of both small females and small males to excavate was lower than that of larger individuals, accordingly, digging capacity could be a proximate factor explaining facultative paternal investment in these species.10aACUMINATUS COLEOPTERA10aALTERNATIVE REPRODUCTIVE TACTICS10abeetle10abody size10aBROOD CARE10aco-operation10aDung beetles10ainvestment10aMALE HORN DIMORPHISM10aMALE MORPHOLOGY10aOnthophagus10apaternal10areproduction10aScarabaeidae10aTAURUS COLEOPTERA10aVACCA COLEOPTERA1 aPalestrini, C.1 aRolando, A.  uhttps://scarabnet.myspecies.info/body-size-and-paternal-invest-ment-genus-onthophagus-coleoptera-scarabaeoidea02061nas a2200205   4500008004100000245010100041210006900142260000800211300001400219490000700233520134300240653001301583653001801596653001601614653003401630653001501664100002301679700002201702856013101724       2008                        eng d00aRapid antagonistic coevolution between primary and secondary sexual characters in horned beetles0 aRapid antagonistic coevolution between primary and secondary sex  csep  a2423-24280 v623 aDifferent structures may compete during development for a shared and limited pool of resources to sustain growth and differ- entiation. The resulting resource allocation trade-offs have the potential to alter both ontogenetic outcomes and evolutionary trajectories. However, little is known about the evolutionary causes and consequences of resource allocation trade-offs in natural populations. Here, we explore the significance of resource allocation trade-offs between primary and secondary sexual traits in shaping early morphological divergences between four recently separated populations of the horned beetle Onthophagus taurus as well as macroevolutionary divergence patterns across 10 Onthophagus species. We show that resource allocation trade-offs leave a strong signature in morphological divergence patterns both within and between species. Furthermore, our results suggest that genital divergence may, under certain circumstances, occur as a byproduct of evolutionary changes in secondary sexual traits. Given the importance of copulatory organ morphology for reproductive isolation our findings begin to raise the possibility that secondary sexual trait evolution may promote speciation as a byproduct. We discuss the implications of our results on the causes and consequences of resource allocation trade-offs in insects. 10aAedeagus10aHorned beetle10aOnthophagus10aresource allocation trade-off10aspeciation1 aParzer, Harald, F.1 aMoczek, Armin, P.  uhttps://scarabnet.myspecies.info/rapid-antagonistic-coevolution-between-primary-and-secondary-sexual-characters-horned-beetles00792nas a2200205   4500008004100000245012300041210006900164300001200233490000700245653002300252653001600275653002300291653001600314653002700330653002800357100001900385700002200404700002200426856013800448       2001                        eng d00aFood availability controls the onset of metamorphosis in the dung beetle Onthophagus taurus (Coleoptera: Scarabaeidae)0 aFood availability controls the onset of metamorphosis in the dun  a173-1800 v2610adevelopmental cues10adung beetle10alarval development10aOnthophagus10aregulation of pupation10atiming of metamorphosis1 aShafiei, Majid1 aMoczek, Armin, P.1 aNijhout, Frederik  uhttps://scarabnet.myspecies.info/food-availability-controls-onset-metamorphosis-dung-beetle-onthophagus-taurus-coleoptera-scarabaeida00699nam a2200157   4500008004100000245011900041210007300160260005700233653001600290653002700306653001600333653001700349100001500366700002200381856013800403       1988                        eng d00aAnálisis taxonómico, ecológico y biogeográfico de un grupo americano de Onthophagus (Coleoptera, Scarabaeidae)0 aAnálisis taxonómico ecológico y biogeográfico de un grupo americ  aTorinobTorino : Museo regionale di scienze naturali10adung beetle10afood resources mammals10aOnthophagus10aScarabaeinae1 aZunino, M.1 aHalffter, Gonzalo  uhttps://scarabnet.myspecies.info/lisis-taxon-mico-ecol-gico-y-biogeogr-fico-de-un-grupo-americano-de-onthophagus-coleoptera-scarabaei