特有於北美的一個族 Asidini (擬步行蟲科，漠甲亞科）的貝氏擬態斑紋演化
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| photo from BugGuide |
摘要
The asidine darkling beetles (Coleoptera: Tenebrionidae: Asidini) are a diverse tribe of flightless tenebrionids found in many arid and sub-arid habitats around the world. The 263 currently described North American species are contained in ten genera, all of which are restricted to the western half of the continent. The Asidini, like all members of the subfamily Pimeliinae, lack defensive glands. Instead, several phenotypic traits occur within the tribe that may help limit predation. These include the contrasting defensive strategies of crypsis, through either background matching or pattern disruption, and Batesian mimicry of the chemically defended genus Eleodes. Dorsal elytral morphology was assessed between 53 North American asidine species and 13 common Eleodes model species using multiple methodologies to assess similarities between species in the two groups that might indicate mimetic relationships. A phylogeny of the North American asidines is used to map the occurrence of differing defensive strategies within the tribe. Crypsis is reconstructed as the ancestral state, with two origins for Batesian mimicry and multiple reversals. The combination of strongly to weakly cryptic species and varying levels of mimetic fidelity to Eleodes model species make the asidines a promising lineage upon which to further explore the evolution of defensive phenotypes.
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| 八種顯示隱蔽色的Pelecyphorus spp photo from Fig. 1 |
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| photo from Fig. 2 中間、正下方、左下為擬態者Stenomorpha spp. 其餘為擬態模型Eleodes spp. |
結果發現支持這兩類看起來想似的主要特徵是「背面不反光」與「顏色斑紋單一」，而整體的演化趨勢來看的話，如同大部分其他的例子，隱蔽色是祖徵，可能與Eleodes spp.的擬態特徵是複數起源。
雖然說擬態起來的相似度還是要從整體的行為斑紋來看，但分別把特徵拆開追溯其演化趨勢，有助於讓我們了解究竟相似度從何而來，也可以為未來更細膩的研究打下基礎。
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