Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations
Japanese rhinoceros beetle (<i>Trypoxylus dichotomus</i>) males have exaggerated head horns that they use as weapons in combat over reproductive opportunities. In these contests, there is an advantage to having a longer horn, and there seems to be little cost to horn exaggeration. Howeve...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-10-01
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| Series: | Insects |
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| Online Access: | https://www.mdpi.com/2075-4450/10/10/346 |
| _version_ | 1818489290474127360 |
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| author | Benjamin Buchalski Eric Gutierrez Douglas Emlen Laura Lavine Brook Swanson |
| author_facet | Benjamin Buchalski Eric Gutierrez Douglas Emlen Laura Lavine Brook Swanson |
| author_sort | Benjamin Buchalski |
| collection | DOAJ |
| description | Japanese rhinoceros beetle (<i>Trypoxylus dichotomus</i>) males have exaggerated head horns that they use as weapons in combat over reproductive opportunities. In these contests, there is an advantage to having a longer horn, and there seems to be little cost to horn exaggeration. However, populations vary in the amount of horn exaggeration across this widespread species. Here, we examine four populations and quantify scaling and functional morphology of the horn. We then measure force production by the horn system in a combat-relevant movement. We find that not only does horn length vary among populations, but allometry of lever mechanics and force production varies in a complex way. For instance, some beetle populations make relatively long horns, but exert relatively low forces. Other populations make shorter horns and produce higher forces during fights. We suggest that this performance variation could be associated with differences in the intensity or type of sexual selection across the species. |
| first_indexed | 2024-12-10T17:02:07Z |
| format | Article |
| id | doaj.art-175fdd6781e8422e9c78456aa3eaab9f |
| institution | Directory Open Access Journal |
| issn | 2075-4450 |
| language | English |
| last_indexed | 2024-12-10T17:02:07Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Insects |
| spelling | doaj.art-175fdd6781e8422e9c78456aa3eaab9f2022-12-22T01:40:33ZengMDPI AGInsects2075-44502019-10-01101034610.3390/insects10100346insects10100346Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) PopulationsBenjamin Buchalski0Eric Gutierrez1Douglas Emlen2Laura Lavine3Brook Swanson4Biology Department, Gonzaga University, Spokane, WA 99258, USABiology Department, Gonzaga University, Spokane, WA 99258, USADivision of Biological Sciences, University of Montana, Missoula, MT 59812, USADepartment of Entomology, Washington State University, Pullman, WA 99164, USABiology Department, Gonzaga University, Spokane, WA 99258, USAJapanese rhinoceros beetle (<i>Trypoxylus dichotomus</i>) males have exaggerated head horns that they use as weapons in combat over reproductive opportunities. In these contests, there is an advantage to having a longer horn, and there seems to be little cost to horn exaggeration. However, populations vary in the amount of horn exaggeration across this widespread species. Here, we examine four populations and quantify scaling and functional morphology of the horn. We then measure force production by the horn system in a combat-relevant movement. We find that not only does horn length vary among populations, but allometry of lever mechanics and force production varies in a complex way. For instance, some beetle populations make relatively long horns, but exert relatively low forces. Other populations make shorter horns and produce higher forces during fights. We suggest that this performance variation could be associated with differences in the intensity or type of sexual selection across the species.https://www.mdpi.com/2075-4450/10/10/346allometrysexual selectionforce productionarmament |
| spellingShingle | Benjamin Buchalski Eric Gutierrez Douglas Emlen Laura Lavine Brook Swanson Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations Insects allometry sexual selection force production armament |
| title | Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations |
| title_full | Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations |
| title_fullStr | Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations |
| title_full_unstemmed | Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations |
| title_short | Variation in an Extreme Weapon: Horn Performance Differences across Rhinoceros Beetle (<i>Trypoxylus dichotomus</i>) Populations |
| title_sort | variation in an extreme weapon horn performance differences across rhinoceros beetle i trypoxylus dichotomus i populations |
| topic | allometry sexual selection force production armament |
| url | https://www.mdpi.com/2075-4450/10/10/346 |
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