Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects
Throughout most of its range the Palaearctic moth Hepialus humuli shows a striking sexual dimorphism correlated with a dimorphism in wing scale ultrastructure. Male uppersides are uniformly silvery white, due to light reflection from unpigmented scales with an elaborate internal cuticular meshwork;...
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ftczechacademysc:oai:kramerius.lib.cas.cz:uuid:74fae400-c34f-47f3-8873-25eb5dfa7987 2024-03-17T08:57:48+00:00 Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects Kaaber, Svend Kristensen , Niels P. Simonsen, Thomas https://kramerius.lib.cas.cz/view/uuid:74fae400-c34f-47f3-8873-25eb5dfa7987 unknown https://kramerius.lib.cas.cz/view/uuid:74fae400-c34f-47f3-8873-25eb5dfa7987 policy:public Hepialidae Hepialus humuli wing length wing-scale structure bird and bat predation predatory selection prey visibility polymorphism sexual dimorphism Faroe Isles Shetland Isles article model:article ftczechacademysc 2024-02-19T23:04:44Z Throughout most of its range the Palaearctic moth Hepialus humuli shows a striking sexual dimorphism correlated with a dimorphism in wing scale ultrastructure. Male uppersides are uniformly silvery white, due to light reflection from unpigmented scales with an elaborate internal cuticular meshwork; the conspicuous wings are visual cues for females when lekking males swarm at dusk. Female uppersides have a yellow-and-orange pigment pattern, and commonplace scale morphology. Male specimens from the Shetland and Faroe Islands populations are polymorphic, with wing uppersides ranging from the typical uniform white to being patterned much as in females, or even more melanic; forewing length is slightly greater in the darker and patterned male morphs. Male wing-scale polymorphism is only modest: even the superficially most female-like specimens are overall similar to typical males with respect to important details of scale structure. The polymorphic N. Atlantic forms are likely derived from dimorphic ancestors of the continental type. The principal selective force favouring male darkening in these insular populations is most probably a locally strong predation by visual hunters (primarily gulls and terns) on the lekking moths, combined with a lessened importance of the colour-related conspicuousness of males for female mate-searching at the high ambient light level at the swarming time at these high latitudes. This assumption is supported by the finding of a higher abundance of cryptic males (and perhaps by the smaller average size of the non-cryptic male morphs) in sites with intense bird predation. Article in Journal/Newspaper Faroe Islands Czech Academy of Sciences: dKNAV Faroe Islands |
institution |
Open Polar |
collection |
Czech Academy of Sciences: dKNAV |
op_collection_id |
ftczechacademysc |
language |
unknown |
topic |
Hepialidae Hepialus humuli wing length wing-scale structure bird and bat predation predatory selection prey visibility polymorphism sexual dimorphism Faroe Isles Shetland Isles |
spellingShingle |
Hepialidae Hepialus humuli wing length wing-scale structure bird and bat predation predatory selection prey visibility polymorphism sexual dimorphism Faroe Isles Shetland Isles Kaaber, Svend Kristensen , Niels P. Simonsen, Thomas Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
topic_facet |
Hepialidae Hepialus humuli wing length wing-scale structure bird and bat predation predatory selection prey visibility polymorphism sexual dimorphism Faroe Isles Shetland Isles |
description |
Throughout most of its range the Palaearctic moth Hepialus humuli shows a striking sexual dimorphism correlated with a dimorphism in wing scale ultrastructure. Male uppersides are uniformly silvery white, due to light reflection from unpigmented scales with an elaborate internal cuticular meshwork; the conspicuous wings are visual cues for females when lekking males swarm at dusk. Female uppersides have a yellow-and-orange pigment pattern, and commonplace scale morphology. Male specimens from the Shetland and Faroe Islands populations are polymorphic, with wing uppersides ranging from the typical uniform white to being patterned much as in females, or even more melanic; forewing length is slightly greater in the darker and patterned male morphs. Male wing-scale polymorphism is only modest: even the superficially most female-like specimens are overall similar to typical males with respect to important details of scale structure. The polymorphic N. Atlantic forms are likely derived from dimorphic ancestors of the continental type. The principal selective force favouring male darkening in these insular populations is most probably a locally strong predation by visual hunters (primarily gulls and terns) on the lekking moths, combined with a lessened importance of the colour-related conspicuousness of males for female mate-searching at the high ambient light level at the swarming time at these high latitudes. This assumption is supported by the finding of a higher abundance of cryptic males (and perhaps by the smaller average size of the non-cryptic male morphs) in sites with intense bird predation. |
format |
Article in Journal/Newspaper |
author |
Kaaber, Svend Kristensen , Niels P. Simonsen, Thomas |
author_facet |
Kaaber, Svend Kristensen , Niels P. Simonsen, Thomas |
author_sort |
Kaaber, Svend |
title |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
title_short |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
title_full |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
title_fullStr |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
title_full_unstemmed |
Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects |
title_sort |
sexual dimorphism and geographical male polymorphism in the ghost moth hepialus humuli (lepidoptera: hepialidae): scale ultrastructure and evolutionary aspects |
url |
https://kramerius.lib.cas.cz/view/uuid:74fae400-c34f-47f3-8873-25eb5dfa7987 |
geographic |
Faroe Islands |
geographic_facet |
Faroe Islands |
genre |
Faroe Islands |
genre_facet |
Faroe Islands |
op_relation |
https://kramerius.lib.cas.cz/view/uuid:74fae400-c34f-47f3-8873-25eb5dfa7987 |
op_rights |
policy:public |
_version_ |
1793767111635501056 |