02242nas 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>://00017950430001102835nas 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>://000174361200008