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While male mate choice has received sparse attention in comparison to female choice, it occurs often in insects. In addition, male insects may preferentially allocate sperm and ejaculate in response to female quality. Previous research indicates that male Bicyclus anynana butterflies can learn mate preference through prior exposure to females, though naïve males mate randomly. It is unclear whether this preference learning may also influence male sperm and ejaculate allocation after mate selection, or whether males have cryptic mate preference for female wing patterns independent of preference learning. Here we test whether B. anynana males adjust their sperm and ejaculate allocation in response to a learned preference. We also assess whether males exhibit an innate cryptic preference and adjust their sperm and ejaculate in response to female wing pattern. We compared number of eggs laid by females and spermatophore (male butterfly ejaculate) weight in four no-choice treatments: naïve male butterflies (having no prior exposure to females), paired with a 2 or 0-spot female, and experienced male butterflies (having a previous three-hour interaction with a 0-spot female), paired with a 2 or 0-spot female. All females used were naturally 2-spot females, 0-spot females had artificially blocked spots. We found that 0-spot females laid significantly more eggs than 2-spot females, independent of male experience. There was no effect of female phenotype or male experience on spermatophore weight. Our findings suggest that male B. anynana have an innate cryptic preference for 0-spot females, which has been shown in other studies to only be seen as a pre-copulatory preference when enhanced by early experience.
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The function of prolonged copulations in Enchenopa treehoppers (Hemiptera: Membracidae)
Abstract Copulations are very brief in many species, sometimes taking only seconds, but in other species, they can be quite prolonged. Potential explanations for prolonged copulations include time requirements for the transfer of sperm and/or other ejaculate substances. Ejaculate substances could function to regulate female receptivity to subsequent matings, provide nutritional nuptial gifts, or hasten egg oviposition at a potential survival cost to the female. We investigated prolonged copulation in a member of the Enchenopa binotata complex of treehoppers (Hemiptera: Membracidae), in which females rarely remate and copulation can last several hours. We assigned females to treatments in which we interrupted copulation at different times. We also included a control where copulation was not interrupted. We found that females that experienced shorter copulations were more likely to be subsequently receptive to an attractive male. We also found that few females produced offspring when they engaged in short copulations compared to those with longer copulations. We did not find any differences in female survival. Our results support the sperm transfer and receptivity regulation hypotheses. We discuss potential reasons for why these processes should take so long in a species with low female remating.
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- Award ID(s):
- 1855962
- PAR ID:
- 10529454
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Journal of Evolutionary Biology
- Volume:
- 37
- Issue:
- 8
- ISSN:
- 1420-9101
- Format(s):
- Medium: X Size: p. 905-914
- Size(s):
- p. 905-914
- Sponsoring Org:
- National Science Foundation
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