scholarly journals Male Hemolymph Loss During Nuptial Feeding as a Proximate Mechanisim Underlying the Virgin-Male Mating Advantage in Sagebrush Crickets

2003 ◽  
Vol 27 ◽  
pp. 45-50
Author(s):  
Scott Sakaluk ◽  
Mark Campbell ◽  
Peter Keorpes ◽  
Andrew Clark
Keyword(s):  
Sexual Selection ◽  
Male Mating ◽  
Energy Reserves ◽  
Substantial Portion ◽  
Mating Advantage ◽  
Virgin Male ◽  
Cyphoderris Strepitans ◽  
Two Alternatives ◽  
Signaling Activity ◽  
Spermatophore Production

Male sagebrush crickets, Cyphoderris strepitans, offer an unusual nuptial food gift to females during mating: females chew on the ends of the males' fleshy hind wings and ingest hemolymph seeping from the wounds they inflict. Previous studies have shown that once a male had mated, his probability of obtaining an additional copulation is reduced relative to that of a virgin male seeking to secure his first mating, a pattern known as the virgin­male mating advantage. One hypothesis to account for the virgin-male mating advantage is that non­virgin males, having lost a substantial portion of their energy reserves at mating, may be unable to sustain the costly acoustical signaling activity required for the passive attraction of additional females. If the future mating prospects of non-virgin males are diminished because of sexual fatigue, this could stem either from the resources required to manufacture a new spermatophore or through the energy needed to replenish haemolymph lost through female wing­feeding. To distinguish between these two alternatives, we experimentally depleted virgin males of varying amounts haemolymph (0, 5 and 10 ul) in a way that mimicked hemolymph loss of non-virgin males, without the attendant costs of spermatophore production. After they had been treated, males were released in the field and recaptured over the course of the breeding season to monitor their mating success. Control males mated significantly sooner than did males depleted of 5 or 10 ul of hemolymph. We conclude, therefore, that the depletion of hemolymph that occurs through female wing feeding is sufficient by itself to diminish a non-virgin male's ability to secure another mating, acting as a brake on the operation of sexual selection in this species.

VIRGIN-MALE MATING ADVANTAGE IN SAGEBRUSH CRICKETS: DIFFERENTIAL MALE COMPETITIVENESS OR NON-INDEPENDENT FEMALE MATE CHOICE?

Behaviour ◽  
1999 ◽  
Vol 136 (10-11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Tracie Ivy ◽  
Scott Sakaluk
Keyword(s):  
Mating Success ◽  
Hind Wing ◽  
Video Recording ◽  
Time Lapse ◽  
Female Mate Choice ◽  
Male Mating ◽  
Mating Advantage ◽  
Significant Difference ◽  
Virgin Male ◽  
Cyphoderris Strepitans

AbstractFemale sagebrush crickets (Cyphoderris strepitans) feed on males' fleshy hind wings during copulation and ingest haemolymph oozing from the wounds they inflict. The wounds are not fatal and usually only a portion of the hind wings are eaten at any one mating, so that mated males are not precluded from mating again. However, based on their relative abundance in the population, virgin males have a higher mating success than non-virgin males. One explanation for this virgin-male mating advantage is that non-virgin males, having been depleted of their energy reserves through the wing-feeding behaviour of their mates, are unable to sustain the same level of acoustic signalling they produce prior to copulation. Previous assays of male signalling behaviour have provided some support to this hypothesis. However, an alternative explanation is that females actively seek out virgin males as mates because of the greater material resources they offer. If the acoustic structure of males' signals were systematically altered by the loss of hind-wing material underlying the sound-producing tegmina, females could potentially discriminate against mated males through reduced phonotaxis to their calls. We tested this hypothesis by experimentally removing one hind wing from virgin males, thereby simulating the non-virgin condition without the attendant costs of copulation. We compared the mating success of these 'asymmetrical' males with that of sham-operated virgin males when competing under natural conditions. In a companion laboratory study, we used time-lapse video recording to examine the possibility that female preferences are exerted only after pair formation has occurred. There was no significant difference in male mating success across treatments in either study. We conclude, therefore, that the virgin-male mating advantage does not stem from an acoustically mediated, non-independent female mating preference, but rather, from the differential competitiveness of males.

scholarly journals Sexual Selection of Male Song in Free-Living Sagebrush Crickets, Cyphoderris Strepitans

2011 ◽  
Vol 33 ◽  
pp. 125-130
Author(s):  
Geoff Ower ◽  
Sandra Steiger ◽  
Kyle Caron ◽  
Scott Sakaluk
Keyword(s):  
Mating Success ◽  
Dominant Frequency ◽  
Male Mating ◽  
Proximate Mechanisms ◽  
Mating Advantage ◽  
Train Duration ◽  
Virgin Male ◽  
Field Season ◽  
Cyphoderris Strepitans ◽  
Long Pulse

Measures of lifetime mating success in the sagebrush cricket, Cyphoderris strepitans, have revealed that most males succeed in obtaining only 1 mating, while many males fail to attract a female at all and a small minority mate 2 to 4 times. Relative to their abundance in the population, virgin males have a greater likelihood of obtaining a mating than non-virgin males have of securing additional matings, a phenomenon known as the virgin male mating advantage. Previous studies of sagebrush crickets have focused primarily on determining the proximate mechanisms responsible for the virgin male mating advantage, but little work has been done to identify the factors that influence male attractiveness in the first place. Because song plays a central role in mate attraction, it’s likely that variability in song parameters among males could account for the observed differences in mating success. Song is an energetically costly signal to produce and could serve as an honest indicator of male quality. Consequently, males that are able to invest greater amounts of energy into singing should be more attractive to females. In a previous field season, we recorded and analyzed the songs of virgin and non-virgin males and indeed found some evidence that females prefer males which invest greater energy into calling. In the present study, we synthesized artificial sagebrush cricket songs and directly measured female song preference with an arena playback experiment. Females were shown to consistently prefer song characteristics that would require greater energy expenditure by males. Males that sing with long pulse duration, long train duration, and at an intermediate dominant frequency were found to be highly attractive to females.

scholarly journals Virgin Male Mating Advantage in Sagebrush Crickets: No Role for an Acoustically-Mediated Female Preference

1997 ◽  
Vol 21 ◽  
pp. 60-63
Author(s):  
Scott Sakaluk ◽  
Pamela Brady ◽  
Tracie Ivy ◽  
Marion Sakaluk ◽  
Jennifer Schaus
Keyword(s):  
Field Studies ◽  
Male Mating ◽  
Sexually Active ◽  
Bodily Fluids ◽  
Mating Advantage ◽  
Extant Species ◽  
Mating Opportunities ◽  
Virgin Male ◽  
Cyphoderris Strepitans ◽  
Number Of Males

The sagebrush cricket, Cyphoderris strepitans, is one of only five extant species belonging to an obscure orthopteran lineage, the Haglidae, closely related to the true crickets (Gryllidae) and katydids (Tettigoniidae) (Morris & Gwynne 1978). C. strepitans occurs exclusively in mountainous areas of the western United States, where it is found primarily in high-altitude sagebrush meadow habitat. Adults become sexually active in late spring, shortly after snow melt, and remain active for the following 4-6 weeks. The acoustic signals produced by males function to attract females (Snedden & Irazuzta 1994), thereby enhancing male mating opportunities (Snedden & Sakaluk 1992). Copulation is initiated when a receptive female climbs onto the dorsum of a male, at which time he attempts to transfer a spermatophore. During copulation, the female feeds on the male's fleshy hind wings and bodily fluids leaking from the wounds she inflicts. Previous field studies involving the mark­recapture of a large number of males have shown that once a male has mated, his probability of obtaining an additional copulation is reduced relative to that of a virgin male securing his first mating (Morris et al. 1989). One explanation for the virgin-male mating advantage is that non-virgin males, having lost a substantial portion of their energy reserves through sexual cannibalism by females and the transfer of a large spermatophore, may be unable to sustain the costly acoustical signaling activity required to attract additional females. In support of the "male fatigue" hypothesis, electronic assays of male signaling behavior have shown that virgin male C. strepitans call for significantly longer durations than recently mated males (Sakaluk et al. 1987; Sakaluk & Snedden 1990).

Virgin male mating advantage in a primitive acoustic insect (Orthoptera: Haglidae)

1989 ◽  
Vol 2 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Glenn K. Morris ◽  
Darryl T. Gwynne ◽  
Dita E. Klimas ◽  
Scott K. Sakaluk
Keyword(s):  
Male Mating ◽  
Mating Advantage ◽  
Virgin Male

scholarly journals Virgins are Louder: The Effect of Mating on Acoustic Signaling in Sagebrush Crickets

1995 ◽  
Vol 19 ◽  
pp. 78-83
Author(s):  
W. Snedden ◽  
Michael Greenfield
Keyword(s):  
Hind Wing ◽  
Spectral Characteristics ◽  
Signal Amplitude ◽  
Surgical Excision ◽  
Male Mating ◽  
Acoustic Signaling ◽  
Signal Characteristics ◽  
Before And After ◽  
Virgin Male ◽  
Cyphoderris Strepitans

Female sagebrush crickets, Cyphoderris strepitans, feed on the male's hind wings during copulation. Because removal of hind wing material during mating may alter male acoustic signal characteristics and account for a virgin male mating advantage (Morris et al. 1989; Snedden, in press) we recorded virgin and mated males in the field, and virgins before and after surgical excision of a portion of the hind wings. We found no significant differences in signal spectral characteristics or pulse rate between virgin and mated males following hind­wing excision. However, the signal amplitude of laboratory recorded virgins was greater than that of mated males, and song amplitude was reduced in manipulated males. In contrast, signal amplitude was lower in field recorded virgins than mated males.

scholarly journals Time-Laspe Video Study of Mating Behavior in Sagebrush Crickets (Cyphoderris strepitans)

1989 ◽  
Vol 13 ◽  
pp. 131-139
Author(s):  
Scott Sakaluk ◽  
W. Snedden
Keyword(s):  
Breeding Season ◽  
Mating Success ◽  
Time Lapse ◽  
Male Mating ◽  
Research Station ◽  
Male Mating Success ◽  
Video Study ◽  
Available Energy ◽  
Virgin Male ◽  
Cyphoderris Strepitans

Sagebrush crickets (Cyphoderris strepitans) are primitive acoustic insects which occur only in mountainous areas of Wyoming and Colorado (Morris and Gwynne 1978). In Grand Teton National Park, adults become sexually active in early May and matings subsequently occur over a 3 - 6 week period. Each night of the breeding season, males emerge from the soil litter shortly after sunset, climb into the sagebrush and begin to sing, presumably to attract sexually receptive females. Copulation is initiated when a receptive female climbs onto the dorsum of a male, at which time he attempts to transfer a spermatophore (Dodson et al. 1983, Sakaluk et al. 1987, Morris et al. 1989). During the time that the female is mounted on the male, she feeds on the male's metathoracic wings and ingests any hemolymph oozing from the wounds she inflicts. To deter the female from dismounting before the spermatophore has been transferred, males are equipped with an abdominal pinching organ which functions to secure the female during copulation (Morris 1979, Dodson et al. 1983). Once the spermatophore has disengagement. The bulk of the spermatophore remains attached outside the female's body, who invariably consumes it several hours after mating (present study). A previous field study involving the mark-recapture of a large number of males showed that once a male had mated, his probability of obtaining additional copulations was significantly reduced (Morris et al. 1986). One explanation for this result is that non-virgin males, having lost a substantial portion of available energy reserves at mating, may be unable to sustain calling at pre-mating levels. In support of this hypothesis, electronic assays of male signaling behavior (see Kidder and Sakaluk, in press) have shown that virgin male C. strepitans call for significantly longer durations than recently mated males (Sakaluk et al.1987, Sakaluk and Snedden 1990). Although virgin males call more and have significantly higher mating success than non-virgins, this does not necessarily prove that calling duration and mating success are causally related. In the past, we have experienced two difficulties in establishing a causal basis to this correlation: 1) matings are rarely observed in the field, and we have of necessity relied on wing wounding as an indicator of male mating success (Morris et al. 1989) and 2) we have been unable to demonstrate phonotaxis of females to conspecific song as broadcast either through speakers placed in the field (Sakaluk and Snedden, unpubl. data) or in the laboratory (Morris et al. 1989). To at least partially circumvent these difficulties, we employed time-lapse video photography of mating interactions staged at the UW-NPS Research Station during the 1989 breeding season. The objective of these studies was to determine how mating status, calling time and body size contribute to male mating success, either through their effect on male competitive ability and/or their effect on male attractiveness to females.

scholarly journals Immuniological Costs of Mating to Male Sagebrush Crickets

2006 ◽  
Vol 30 ◽  
pp. 114-118
Author(s):  
Joseph Leman ◽  
Carie Weddle ◽  
Geoff Ower ◽  
Scott Sakulak
Keyword(s):  
Immune Response ◽  
Time Lapse ◽  
Male Mating ◽  
Mating Effort ◽  
Immune Challenge ◽  
Mating Status ◽  
Virgin Male ◽  
Immune Pathways ◽  
Bacterial Lipopolysaccharides ◽  
Cyphoderris Strepitans

Male sagebrush crickets, Cyphoderris strepitans, offer an unusual nuptial food gift to females during mating: females chew on the ends of the males' fleshy hind wings and ingest hemolymph seeping from the wounds they inflict. Previous research has shown that once a male has mated, his probability of obtaining an additional copulation is reduced relative to that of a virgin male seeking to secure his first mating, a pattern known as the virgin-male mating advantage. One hypothesis that may explain this phenomenon is that mated males experience an energetically costly immune response via their wounds and therefore may be unable to sustain the costly acoustical signaling needed to attract additional females. To distinguish between the effects of mounting a costly immune response and the costs of producing a spermatophore, we mimicked a non­virgin mating status by injecting virgin males with bacterial lipopolysaccharides, a non-living elicitor of several immune pathways. After they had been treated, males were released in the field and recaptured over the course of the breeding season to monitor their mating success. Contrary to our prediction, LPS injected males did not take longer to secure matings than sham-injected virgin males. However, a companion study revealed that immunochallenged virgin males spent significantly less time calling (as assayed using time-lapse video photography) than sham­control virgin males. This confirms work in other cricket species showing a decline in mating effort following an immune challenge.

Size does not matter for male Marbled Salamanders (Ambystoma opacum)

2015 ◽  
Vol 93 (10) ◽  
pp. 735-740
Author(s):  
D.A. Croshaw ◽  
J.H.K. Pechmann
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Reproductive Success ◽  
Large Male ◽  
Male Mating ◽  
Ambystoma Opacum ◽  
Positive Assortative Mating ◽  
Important Trait ◽  
Breeding Groups ◽  
Gravid Females

Understanding the phenotypic attributes that contribute to variance in mating and reproductive success is crucial in the study of evolution by sexual selection. In many animals, body size is an important trait because larger individuals enjoy greater fitness due to the ability to secure more mates and produce more offspring. Among males, this outcome is largely mediated by greater success in competition with rival males and (or) advantages in attractiveness to females. Here we tested the hypothesis that large male Marbled Salamanders (Ambystoma opacum (Gravenhorst, 1807)) mate with more females and produce more offspring than small males. In experimental breeding groups, we included males chosen specifically to represent a range of sizes. After gravid females mated and nested freely, we collected egg clutches and genotyped all adults and samples of hatchlings with highly variable microsatellite markers to assign paternity. Size had little effect on male mating and reproductive success. Breeding males were not bigger than nonbreeding males, mates of polyandrous females were not smaller than those of monogamous females, and there was no evidence for positive assortative mating by size. Although body size did not matter for male Marbled Salamanders, we documented considerable fitness variation and discuss alternative traits that could be undergoing sexual selection.

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