Sexual and Male Horn Dimorphism in Copris ochus (Coleoptera: Scarabaeidae)

  title={Sexual and Male Horn Dimorphism in Copris ochus (Coleoptera: Scarabaeidae)},
  author={Shinji Sugiura and Yuichi Yamaura and Hiroshi Makihara},
  booktitle={Zoological science},
Abstract Copris ochus (Coleoptera: Scarabaeidae), an endangered species, is the largest dung beetle in Japan. In C. ochus, males have a long head horn, while females lack this long horn (sexual dimorphism). Very large males of C. ochus have disproportionately longer head horns than small males, suggesting male horn dimorphism, although the dimorphism has not been investigated quantitatively. To clarify sexual and male horn dimorphism in C. ochus quantitatively, we examined the scaling… 

Evidence for Male Horn Dimorphism and Related Pronotal Shape Variation in Copris lunaris (Linnaeus, 1758) (Coleoptera: Scarabaeidae, Coprini)

Analysis of shape showed that the three morphs had similar heads, but different pronota, major males showing a more expanded, rounded pronotum than minor males and females, which can ultimately have important functional consequences in the ecology of this species.

Size-dependent seasonal activity for males of the dung beetle Copris acutidens (Coleoptera: Scarabaeidae)

Long horns may directly confer a competitive advantage to males, enabling them to stay in nests with females, whereas early activity of minor males does not always indicate the effect of horn length directly, regardless of whether the morphs differ in body size or horn length.

Dimorphism of both head and prothoracic horn morphologies in male Copris acutidens (Coleoptera: Scarabaeoidea)

Both the head and prothoracic horns were dimorphic, and this characteristic was not found in the scarabaeoid beetle Onthophagus, which suggests that the dimorphism of the two kinds of horns may result from the same developmental threshold mechanism.

Horn polyphenism and related head shape variation in a single-horned dung beetle: Onthophagus (Palaeonthophagus) fracticornis (Coleoptera: Scarabaeidae)

It is proposed that such a developmental process giving rise to it may be evolutionarily ancient as well and underlies the expression of both plesiomorphic and apomorphic horn shapes in the genus.

Size- and context-dependent nest-staying behaviour of males of the Japanese dung beetle, Copris acutidens (Coleoptera: Scarabaeidae)

The present study revealed an alternative behaviour during the post-copulatory stage associated with horn dimorphism and the presence or absence of a rival male, which indicates that because of the risk of sperm competition, major males stay longer in nests if a rival males is present.

The First Morphometric Study of the Horn Morphological Pattern in a Geotrupidae: The Case of the Dor Beetle Ceratophyus rossii Jekel, 1865

This paper describes for the first time the horn expression pattern in a dor beetle and identifies and modeled shape and size horn patterns combining traditional and geometric morphometric approaches.

Allometry and Fighting Behaviour of a Dimorphic Stag Beetle Cyclommatus mniszechi (Coleoptera: Lucanidae)

The allometric relationship between mandible and body size in males of the stag beetle Cyclommatus mniszechi is investigated to uncover distinct morphs, suggesting that major males may compete more aggressively than minor males in contests.

Dung beetle distress signals may be correlated with sex and male morph: a case study on Copris lunaris (Coleoptera: Scarabaeidae, Coprini)

This paper provides the very first perspective of the potential role of sex and male polymorphism on sound production in Copris lunaris, and highlights an isometric growth of pars stridens in response to body size, and identifies a wing-pygidium locking structure that assists sound emission.

Are Horn Morphological Patterns Able to Differentiate the Two Closely Related Species Copris klugi Harold and Copris sierrensis Matthews?

Combining traditional and geometric morphometric methods, it is evidenced that male head horn phenotypic pattern is able to clearly differentiate C. klugi from C. sierrensis, supporting the hypothesis that they are two true species.

It takes two to tango : functional roles , sexual selection and allometry of multiple male weapons in the flower beetle

The findings suggest that sexual selection acts on both male weapon traits in D. w.



Alternative reproductive tactics and male-dimorphism in the horned beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)

  • D. Emlen
  • Biology
    Behavioral Ecology and Sociobiology
  • 1997
Both overall body size and relative horn length significantly affected the outcome of fights over tunnel ownership, suggesting that alternative reproductive tactics may favor divergence in male horn morphology, with long horns favored in males large enough to guard tunnels, and hornlessness favored in smaller males that adopt the “sneaking” behavioral alternative.

Diet alters male horn allometry in the beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)

  • D. Emlen
  • Biology, Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1997
B breeding experiments on horned beetles demonstrate that the scaling relationship between male horn length and body size changes when larval nutrition changes, thereby revealing a new mechanism by which males regulate the production of exaggerated secondary sexual traits.

Environmental control of horn length dimorphism in the beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)

  • D. Emlen
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1994
Results from experiments designed to assess the relative importance of genetic and environmental factors as determinants of male horn morphology support recent theories on sexual selection which predict that male ornaments will evolve to be reliable indicators of male quality.

Evolution of Sexual Dimorphism and Male Dimorphism in the Expression of Beetle Horns: Phylogenetic Evidence for Modularity, Evolutionary Lability, and Constraint

It is shown that maleDimorphism and sexual dimorphism map together on the phylogeny; whenever small males have horns, females also have horns (and vice versa), raising the possibility that correlated evolution of these two phenomena results from a shared element in their endocrine regulatory mechanisms rather than a history of common selection pressures.

Developmental Biology and Phenology of a Korean Native Dung Beetle, Copris ochus (Motschulsky) (Coleoptera: Scarabaeidae)

The development and life history of a Korean native dung beetle, Copris ochus (Motschulsky), is described based on laboratory studies of beetles collected from the subtropical island of Je-Ju, which is brood-caring and has an annual life cycle.

Normal and atypical nesting behaviour of Copris lunaris (L.): comparison with related species (Coleoptera, Scarabaeidae)

Abstract. 1. The lifecycle, mating and larval behaviour of Clunaris are described. Adults appeared in the autumn and nested in the following spring. The female beetle remained in the nest with the

Parental behaviour in Copris lunaris (Coleoptera, Scarabaeidae): care and defence of brood balls and nest

Nesting female beetles righted brood balls (so as to replace the egg or larva in the uppermost position) and repaired damaged balls and the shape of the ball was also a righting stimulus since artificial ellipsoids were stood on end.


Analysis of 17 species from six families indicates that male dimorphisms in weapon design may be common, at least in homed beetles, and constitutes evidence against the idea that the forms of these animals' weapons are the result of developmental constraints.

The development and evolution of exaggerated morphologies in insects.

It is argued that scaling relationships are best viewed as reaction norms, and that the evolution of exaggerated morphological traits results from genetic changes in the slope and/or shape of these scaling relationships.

The effects of the antiparasitic drug, ivermectin, on the development and survival of the dung‐breeding fly, Orthelia cornicina (F.) and the scarabaeine dung beetles, Copris hispanus L., Bubas bubalus (Oliver) and Onitis belial F.

No mortality occurred among sexually mature adults of the dung beetle, Bubas bubalus when fed for five weeks on dung collected at intervals ranging from 1–32 days after injection, and substantial mortality was recorded among newly emerged beetles of Onitis belial, following exposure to ivermectin residues.