scholarly journals Cyphoderris Strepitans (Orthoptera: Haglidae): Reproductive Biology and Geographical Distribution

1980 ◽  
Vol 4 ◽  
pp. 53-57
Author(s):  
Darryl Gwynne
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
National Parks ◽  
Egg Production ◽  
Paternal Care ◽  
Common Species ◽  
Male Reproductive Success ◽  
Male Investment ◽  
Cyphoderris Strepitans ◽  
Variance In Reproductive Success

Cyphoderris strepitans Morris and Gwynne is a common species of nocturnal insect in many sagebrush areas within Grand Tetons and Yellowstone National Parks. It is a primitive orthopteran group, a relict of the ancient family Haglidae. Only five species in three genera are currently known (Morris and Gwynne 1978, Storozhenko 1980). Males produce a calling song by rubbing their forewings together. Females are attracted to male song; during mating the female feeds on the tissues of the male's fleshy underwings. Virgin and non-virgin males can, therefore, be distinguished by examining their underwings. At the end of mating the male transfers a large proteinaceous spermatophore which the female also consumes. The main objective of this study has been to investigate the role and consequences of the male investment in his underwings and spermatophore (see Morris and Gwynne 1979). Female katydids use spermatophore proteins for egg production (Gwynne and Toalson unpublished) so these nutrients can be regarded as an important male investment likely to influence patterns of sexual selection within this group. Trivers (1972) outlined the theory of parental investment and its influence on sexual selection. Females, because they produce fewer larger gametes (eggs) are usually the limiting sex for the males which have a relatively large number of small gametes (sperm). As a result, males are predicted to maximize reproductive success by competing with each other to inseminate as many females as possible. Females, because they are limited by their fewer gametes will not gain by competing for copulations. Instead they should enhance reproductive success by being selective about which males fertilize their eggs. Sexual selection should, therefore, be stronger on males since competition for mates should produce a greater variance in the reproductive success of this sex (i.e., some males obtain few or no mates while others mate frequently). Males can offset the initial disparity of investment in gametes by investing parentally via paternal care of eggs or offspring or, as in many insects, by feeding the female with prey items or glandular products (Thornhill 1976). These sorts of male investments should decrease the variance in reproductive success of these males because the males are more "female like" in their reproductive strategy i.e., competing less because they reduce the number of potential copulations engaged in due to the large nutrient investment in each copulation. In orthopterans such as Cyphoderris where females feed on male-produced nutrients the following predictions emerge: (1) females should select a mate who is likely to provide more of the nutrient; (2) as mentioned above, the variance in male reproductive success should be low; few males should go unmated. Previous work in Grand Teton National Park has indicated that females may prefer Cyphoderris males who can supply more nutrients. Significantly more virgin males are mated than non-virgins (Morris and Gwynne 1979). Virgins are likely to be a better mate choice for females since they have not only more wing material but also would have large reproductive accessory glands capable of producing a full sized spermatophore. The main purpose of this season's work was to investigate the variance in reproductive success of males. An effort was also made to further collect information on the distribution of C. strepitans in and around Grand Teton and Yellowstone national parks. This information is presented first. (* Erratum: pp. 51 and 52 should be 56 and 57)

scholarly journals Sexual selection and hermaphroditic organisms: Testing theory

2013 ◽  
Vol 59 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Janet L. Leonard
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Multiple Mating ◽  
The Other ◽  
Operational Sex Ratio ◽  
Sexual Role ◽  
Sexual Roles ◽  
Sexual Selection Theory ◽  
Variance In Reproductive Success ◽  
Simultaneous Hermaphrodites

Abstract Sexual selection is widespread if not ubiquitous in hermaphroditic organisms. Although many phenomena that have been described as sexual selection in gonochores, (e.g. harem polygamy, multiple mating, elaborate courtship, even secondary sexual characters) can be found in some hermaphrodites, what is more interesting is the ways in which sexual selection in hermaphrodites may differ from dioecious taxa. In hermaphrodites, an individual’s mating success includes its success from both sexual roles. Secondly, in many simultaneously hermaphroditic taxa there is strong evidence of sexual selection and yet the operational sex ratio is 1:1, by definition. Many simultaneous hermaphrodites have elaborate courtship and genital anatomy, suggesting sexual selection plays an important role in reproductive success. Sperm competition and cryptic female choice mean that the number of mates acquired is not necessarily a predictor of reproductive success. Even in simultaneous hermaphrodites with reciprocal mating, variance in reproductive success through the male role and through the female role may differ in a population. Moreover hermaphrodites may choose to emphasize one sexual role over the other. Data suggest that the preferred role varies in hermaphrodites, which creates an opportunity to test fundamental predictions and assumptions of sexual selection theory. Hermaphrodites may vary their emphasis on one sexual role over the other either developmentally or behaviorally in response to environmental or social parameters. How they use this capability in acquiring more or higher quality mates still requires study.

scholarly journals Sexual selection gradients change over time in a simultaneous hermaphrodite

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jeroen NA Hoffer ◽  
Janine Mariën ◽  
Jacintha Ellers ◽  
Joris M Koene
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Mating Success ◽  
Time Window ◽  
Time Frame ◽  
Male Reproductive Success ◽  
Simultaneous Hermaphrodite ◽  
Selection Gradients ◽  
Short Time Window ◽  
Over Time

Sexual selection is generally predicted to act more strongly on males than on females. The Darwin-Bateman paradigm predicts that this should also hold for hermaphrodites. However, measuring this strength of selection is less straightforward when both sexual functions are performed throughout the organism’s lifetime. Besides, quantifications of sexual selection are usually done during a short time window, while many animals store sperm and are long-lived. To explore whether the chosen time frame affects estimated measures of sexual selection, we recorded mating success and reproductive success over time, using a simultaneous hermaphrodite. Our results show that male sexual selection gradients are consistently positive. However, an individual’s female mating success seems to negatively affect its own male reproductive success, an effect that only becomes visible several weeks into the experiment, highlighting that the time frame is crucial for the quantification and interpretation of sexual selection measures, an insight that applies to any iteroparous mating system.

scholarly journals Insulin-insensitivity of male genitalia maintains reproductive success in Drosophila

2019 ◽  
Vol 15 (5) ◽  
pp. 20190057
Author(s):  
Austin P. Dreyer ◽  
Alexander W. Shingleton
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Male Genitalia ◽  
Male Reproductive Success ◽  
Evolutionary Mechanisms ◽  
Arthropod Species ◽  
Developmental Mechanisms ◽  
Negative Growth ◽  
Insulin Insensitivity ◽  
Male Genital

For most arthropod species, male genital size is relatively implastic in response to variation in developmental nutrition, such that the genitals in large well-fed males are similar in size to those in small poorly-fed males. In Drosophila melanogaster, reduced nutritional plasticity of the male genitalia is a consequence of low insulin sensitivity through a tissue-specific reduction in the expression of FOXO , a negative growth regulator . Despite an understanding of the proximate developmental mechanisms regulating organ size, the ultimate evolutionary mechanisms that may have led to reduced FOXO expression in the genitalia have not been fully elucidated. Here we show that restoring FOXO activity in the developing genitalia reduces the male genital size and decreases various aspects of male reproductive success. These data support the hypothesis that sexual selection has acted on the male genitalia to limit their nutritional plasticity through a reduction in FOXO expression, linking proximate with ultimate mechanisms of genital evolution.

scholarly journals Extrapair Paternity Increases Variability in Male Reproductive Success in the Chestnut-Sided Warbler (Dendroica Pensylvanica), A Socially Monogamous Songbird

The Auk ◽  
2004 ◽  
Vol 121 (3) ◽  
pp. 788-795
Author(s):  
Bruce E. Byers ◽  
Herman L. Mays ◽  
Ian R. K. Stewart ◽  
David F. Westneat
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Dna Typing ◽  
Bird Species ◽  
Male Reproductive Success ◽  
Extrapair Paternity ◽  
Bird Populations ◽  
Monogamous Species ◽  
Socially Monogamous ◽  
Dendroica Pensylvanica

Abstract A monogamous mating system that includes extrapair fertilization can potentially generate higher variability in male reproductive success than monogamy without extrapair fertilization. That increased variability could provide a correspondingly higher opportunity for sexual selection and, thus, for the origin and persistence of sexual dimorphism in monogamous species. To determine whether extrapair fertilization enhanced the opportunity for sexual selection in a sexually dimorphic, monogamous bird species, we used microsatellite DNA typing to assess the prevalence of extrapair fertilization and its effect on variation in male reproductive success in a population of Chestnut-sided Warblers (Dendroica pensylvanica). We found that the level of extrapair fertilization in our study population was at the upper end of the range reported for bird populations (47% of nestlings had extrapair fathers; 61% of broods contained extrapair offspring). We also discovered that almost all extrapair offspring were sired by paired males resident on nearby territories. In addition, we found that variation in male reproductive success was substantially higher than variation in female reproductive success, and that extrapair fertilizations made a significant contribution to variation in male reproductive success. Together, those findings suggest that extrapair fertilization creates an opportunity for sexual selection on male traits in this population.

Sexual Selection: Harem Size and the Variance in Male Reproductive Success

2004 ◽  
Vol 164 (4) ◽  
pp. E83-E89 ◽  
Author(s):  
Michael J. Wade ◽  
Stephen M. Shuster
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Male Reproductive Success ◽  
Harem Size

PARENTAL CARE AND PARENTAGE IN MONOGAMOUS GREAT SPOTTED WOODPECKERS (PICOIDES MAJOR) AND MIDDLE SPOTTED WOODPECKERS (PICOIDES MEDIUS)

Behaviour ◽  
2001 ◽  
Vol 138 (10) ◽  
pp. 1259-1285 ◽  
Author(s):  
Hans Winkler ◽  
Klaus Michalek
Keyword(s):  
Reproductive Success ◽  
Parental Care ◽  
Dna Fingerprinting ◽  
Paternal Care ◽  
Brood Care ◽  
Low Frequencies ◽  
Male Investment ◽  
Paternal Effort ◽  
Certainty Of Paternity ◽  
Very High

AbstractPaternal effort is high in some monogamous mating systems. Trivers' (1972) model predicts that high male investment in brood care should evolve only when males have a high certainty of paternity. For this study, we chose two woodpecker species: the great spotted woodpecker (Picoides major) and the middle spotted woodpecker (Picoides medius). Both species were socially monogamous despite a very high breeding density in the study area. We used DNA fingerprinting to determine whether these two species were also genetically monogamous. We found that in great spotted and middle spotted woodpeckers paternal effort was high. Multi-locus DNA-fingerprinting showed that its actual paternity was also very high. In P. major all 161 young from 36 broods and in P. medius all 61 young from 13 broods were sired by the male feeding at the nest hole. There were also no cases of intraspecific brood parasitism or quasi parasitism (P. major: 114 chicks from 24 broods; P.medius: 33 chicks from 8 broods). We further found no case of mate switching during the fertile period of the female. Great spotted and middle spotted woodpeckers are typical of a group of monogamous nonpasserine birds with high male investment in brood care having low frequencies of EPP. We did not find efficient paternity guards. High certainty of paternity may be explained by paternal care being essential for female reproductive success, as in many seabirds and birds of prey. Females rarely engage in extra-pair copulations probably because they are constrained by male care. Males in both species spend little effort in acquiring mates as well as in extrapair copulations. They expend their reproductive effort in defending territories and in parental care. Females compete intensely with members of their own sex for pair formation before the time of frequent copulation. Choosing and securing a high quality partner is the only possibility to achieve high reproductive success for both sexes.

scholarly journals Determinants of reproductive success across sequential episodes of sexual selection in a firefly

2012 ◽  
Vol 279 (1741) ◽  
pp. 3201-3208 ◽  
Author(s):  
A. South ◽  
S. M. Lewis
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Male Reproductive Success ◽  
Nuptial Gifts ◽  
Courtship Signal ◽  
Courtship Signals ◽  
Paternity Success ◽  
Paternity Share ◽  
Multiple Episodes ◽  
Insight Into

Because females often mate with multiple males, it is critical to expand our view of sexual selection to encompass pre-, peri- and post-copulatory episodes to understand how selection drives trait evolution. In Photinus fireflies, females preferentially respond to males based on their bioluminescent courtship signals, but previous work has shown that male paternity success is negatively correlated with flash attractiveness. Here, we experimentally manipulated both the attractiveness of the courtship signal visible to female Photinus greeni fireflies before mating and male nuptial gift size to determine how these traits might each influence mate acceptance and paternity share. We also measured pericopulatory behaviours to examine their influence on male reproductive success. Firefly males with larger spermatophores experienced dual benefits in terms of both higher mate acceptance and increased paternity share. We found no effect of courtship signal attractiveness or pericopulatory behaviour on male reproductive success. Taken together with previous results, this suggests a possible trade-off for males between producing an attractive courtship signal and investing in nuptial gifts. By integrating multiple episodes of sexual selection, this study extends our understanding of sexual selection in Photinus fireflies and provides insight into the evolution of male traits in other polyandrous species.

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