Science.gov

Sample records for mating sterile male

  1. Age-dependent variation in mating success of sterile male Mediterranean fruit flies (Diptera: Tephritidae): implications for sterile insect technique.

    PubMed

    Shelly, Todd E; Edu, James; Pahio, Elaine

    2007-08-01

    The sterile insect technique (SIT) is widely used in integrated programs against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Unfortunately, the mass-rearing procedures inherent to the SIT often lead to a reduction in the mating ability of the released males. To counter this deficiency, SIT programs rely upon the production and release of large numbers of sterile males to achieve high overflooding (sterile:wild male) ratios. To ensure a high release volume, emergence facilities release adult males at a young age (2 d old in some cases). The primary objective of this study was to describe age-dependent variation in the mating propensity and competitiveness of sterile males of C. capitata. Males that were 2 or 3 d old had lower mating propensity than males that were > or =4 d old, and 3-d-old males had lower mating competitiveness than males that were > or =4 d old. Given these results, we measured the effect of a longer holding period on male mortality in storage boxes. With delayed food placement, males held in storage boxes for 4 d after emergence showed no higher mortality than males held for only 2 d (the standard interval). Using large field enclosures, we compared the levels of egg sterility attained via releases of 2- versus 4-d-old sterile males at two overflooding ratios (5:1 and 100:1). At the lower ratio, the proportion of unhatched eggs observed for trials involving 2-d-old sterile males was not, on average, significantly higher than that observed for matings between wild flies (33 versus 25%, respectively), whereas the level of egg sterility observed for releases of 4 d old sterile males was 62%. At the 100:1 overflooding ratio, the proportion of unhatched eggs associated with the 2-d-old sterile males was 58%, a level not significantly different from that induced by 4-d-old sterile males at the 5:1 ratio and significantly lower than the level (79%) observed for 4-d-old sterile males at 100:1 overflooding ratio

  2. The sterile insect technique for controlling populations of Aedes albopictus (Diptera: Culicidae) on Reunion Island: mating vigour of sterilized males.

    PubMed

    Oliva, Clelia F; Jacquet, Maxime; Gilles, Jeremie; Lemperiere, Guy; Maquart, Pierre-Olivier; Quilici, Serge; Schooneman, François; Vreysen, Marc J B; Boyer, Sebastien

    2012-01-01

    Reunion Island suffers from high densities of the chikungunya and dengue vector Aedes albopictus. The sterile insect technique (SIT) offers a promising strategy for mosquito-borne diseases prevention and control. For such a strategy to be effective, sterile males need to be competitive enough to fulfil their intended function by reducing wild mosquito populations in natura. We studied the effect of irradiation on sexual maturation and mating success of males, and compared the sexual competitiveness of sterile versus wild males in the presence of wild females in semi-field conditions. For all untreated or sterile males, sexual maturation was completed within 13 to 20 h post-emergence and some males were able to inseminate females when 15 h old. In the absence of competition, untreated and sterile males were able to inseminate the same number of virgin females during 48 h, in small laboratory cages: an average of 93% of females was inseminated no matter the treatment, the age of males, and the sex ratio. Daily mating success of single sterile males followed the same pattern as for untreated ones, although they inseminated significantly fewer females after the ninth day. The competitiveness index of sterile males in semi-field conditions was only 0.14 when they were released at 1-day old, but improved to 0.53 when the release occurred after a 5-day period in laboratory conditions. In SIT simulation experiments, a 5:1 sterile to wild male ratio allowed a two-fold reduction of the wild population's fertility. This suggests that sterile males could be sufficiently competitive to mate with wild females within the framework of an SIT component as part of an AW-IPM programme for suppressing a wild population of Ae. albopictus in Reunion Island. It will be of interest to minimise the pre-release period in controlled conditions to ensure a good competitiveness without increasing mass rearing costs. PMID:23185329

  3. The Sterile Insect Technique for Controlling Populations of Aedes albopictus (Diptera: Culicidae) on Reunion Island: Mating Vigour of Sterilized Males

    PubMed Central

    Oliva, Clelia F.; Jacquet, Maxime; Gilles, Jeremie; Lemperiere, Guy; Maquart, Pierre-Olivier; Quilici, Serge; Schooneman, François; Vreysen, Marc J. B.; Boyer, Sebastien

    2012-01-01

    Reunion Island suffers from high densities of the chikungunya and dengue vector Aedes albopictus. The sterile insect technique (SIT) offers a promising strategy for mosquito-borne diseases prevention and control. For such a strategy to be effective, sterile males need to be competitive enough to fulfil their intended function by reducing wild mosquito populations in natura. We studied the effect of irradiation on sexual maturation and mating success of males, and compared the sexual competitiveness of sterile versus wild males in the presence of wild females in semi-field conditions. For all untreated or sterile males, sexual maturation was completed within 13 to 20 h post-emergence and some males were able to inseminate females when 15 h old. In the absence of competition, untreated and sterile males were able to inseminate the same number of virgin females during 48 h, in small laboratory cages: an average of 93% of females was inseminated no matter the treatment, the age of males, and the sex ratio. Daily mating success of single sterile males followed the same pattern as for untreated ones, although they inseminated significantly fewer females after the ninth day. The competitiveness index of sterile males in semi-field conditions was only 0.14 when they were released at 1-day old, but improved to 0.53 when the release occurred after a 5-day period in laboratory conditions. In SIT simulation experiments, a 5∶1 sterile to wild male ratio allowed a two-fold reduction of the wild population’s fertility. This suggests that sterile males could be sufficiently competitive to mate with wild females within the framework of an SIT component as part of an AW-IPM programme for suppressing a wild population of Ae. albopictus in Reunion Island. It will be of interest to minimise the pre-release period in controlled conditions to ensure a good competitiveness without increasing mass rearing costs. PMID:23185329

  4. A novel molecular approach to assess mating success of sterile Ceratitis capitata (Diptera: Tephritidae) males in sterile insect technique programs.

    PubMed

    San Andrés, V; Urbaneja, A; Sabater-Muñoz, B; Castañera, P

    2007-08-01

    Areawide sterile insect technique (SIT) programs against Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), are increasingly implemented worldwide. A key issue in SIT is to assess mating success of released sterile males, which could be currently estimated by egg hatchability and by stored sperm head measurements. We report here on a novel molecular approach that would allow detecting the presence of Mediterranean fruit fly sterile male sperm in the female spermathecae under field conditions, as a precise marker to assess mating performance. The simplicity (only two polymerase chain reactions) and reliability of this method, jointly with the capability to detect Vienna sperm in wild Mediterranean fruit fly maintained in monitoring traps for 7 d under field conditions, suggest that it could be an efficient tool when coupled with areawide SIT programs. PMID:17849900

  5. Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

    PubMed

    Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

    2013-01-01

    Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence. PMID:23427657

  6. Effects of x-ray irradiation on male navel orangeworm (Lepidoptera: Pyralidae) on mating, fecundity, fertility, and inherited sterility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Male adult navel orangeworm, Amyelois transitella, were irradiated using a laboratory x-ray emitter to determine the dose needed to achieve complete egg sterility of mated female moths and inherited egg sterility of F1 generation. Adult male A. transitella were irradiated in a series of two experime...

  7. Transient Population Dynamics of Mosquitoes during Sterile Male Releases: Modelling Mating Behaviour and Perturbations of Life History Parameters

    PubMed Central

    Stone, Christopher M.

    2013-01-01

    The release of genetically-modified or sterile male mosquitoes offers a promising form of mosquito-transmitted pathogen control, but the insights derived from our understanding of male mosquito behaviour have not fully been incorporated into the design of such genetic control or sterile-male release methods. The importance of aspects of male life history and mating behaviour for sterile-male release programmes were investigated by projecting a stage-structured matrix model over time. An elasticity analysis of transient dynamics during sterile-male releases was performed to provide insight on which vector control methods are likely to be most synergistic. The results suggest that high mating competitiveness and mortality costs of released males are required before the sterile-release method becomes ineffective. Additionally, if released males suffer a mortality cost, older males should be released due to their increased mating capacity. If released males are of a homogenous size and size-assortative mating occurs in nature, this can lead to an increase in the abundance of large females and reduce the efficacy of the population-suppression effort. At a high level of size-assortative mating, the disease transmission potential of the vector population increases due to male releases, arguing for the release of a heterogeneously-sized male population. The female population was most sensitive to perturbations of density-dependent components of larval mortality and female survivorship and fecundity. These findings suggest source reduction might be a particularly effective complement to mosquito control based on the sterile insect technique (SIT). In order for SIT to realize its potential as a key component of an integrated vector-management strategy to control mosquito-transmitted pathogens, programme design of sterile-male release programmes must account for the ecology, behaviour and life history of mosquitoes. The model used here takes a step in this direction and can

  8. Mass rearing history negatively affects mating success of male Anastrepha ludens (Diptera: Tephritidae) reared for sterile insect technique programs.

    PubMed

    Rull, Juan; Brunel, Odette; Mendez, Maria Elena

    2005-10-01

    Mating competitiveness and sterility induction into cohorts of wild Anastrepha ludens (Loew) (Diptera: Tephritidae) was compared among wild and laboratory flies reared for use in the sterile insect technique Mexican program. Laboratory flies stemming from an 11-yr-old bisexual strain were either not irradiated, irradiated at 3 krad (low dose), or irradiated at 8 krad. In 30 by 30 by 30-cm Plexiglas cages, where a cohort of laboratory flies (male and female) irradiated at different doses (0, 3, and 8 krad) was introduced with a cohort of wild flies, males and females of each type mated randomly among themselves. Compared with nonirradiated laboratory and wild males, irradiated males, irrespective of dose (3 or 8 krad), induced shorter refractory periods and greater mating frequency in wild females. Nevertheless, laboratory flies irradiated at a low dose induced greater sterility into cohorts of wild flies than laboratory flies irradiated at a high dose. In a 3 by 3 by 3-m walk-in cage, wild males gained significantly more matings with wild females than nonirradiated and irradiated laboratory males a finding that revealed a strong effect of strain on mating performance. Mating incompatibility of the laboratory strain might have obscured the effect of reduced irradiation doses on male mating performance in the walk-in cage. Our results highlight an urgent need to replace the A. ludens strain currently used by the Mexican fruit fly eradication campaign and at least suggest that reducing irradiation doses result in an increase in sterility induction in wild populations. PMID:16334318

  9. Effects of X-Ray Irradiation on Male Navel Orangeworm Moths (Lepidoptera: Pyralidae) on Mating, Fecundity, Fertility, and Inherited Sterility.

    PubMed

    Light, Douglas M; Ovchinnikova, Inna; Jackson, Eric S; Haff, Ronald P

    2015-10-01

    Male adult navel orangeworm, Amyelois transitella (Walker), were irradiated using a laboratory scale x-ray irradiation unit to determine the required dose for complete egg sterility of mated female moths and inherited sterility of F1 and F2 generations. Adult male A. transitella were irradiated in two separate experiments at 100-300 Gy and 50-175 Gy. Mating frequency, fecundity, and fertility of normal females crossed with irradiated parental males was compared with the mating of nonirradiated moths. Mating frequency was 100% for females crossed with nonirradiated control males. At male treatment doses of ≥150 Gy the percentage of females found unmated increased, while multiple-mated females decreased. Female fecundity was not affected while fertility was affected in a dose-dependent relationship to exposure of parental males to x-ray irradiation. Embryonic development of eggs to the prehatch stage and egg eclosion did not occur at radiation doses ≥125 Gy. Emergence of F1 adults was low and occurred only for progeny of parental males exposed to doses ≤100 Gy, with no emergence at ≥125 Gy. Though fecundity appeared similar for control and irradiated F1 females, no F2 eggs hatched for the test exposures of 50-100 Gy. Based on our results, a dose of ≥125 Gy had efficacy in inducing both primary parental sterility in treated male moths and inherited sterility in F1 male and female moths. Results suggest that A. transitella might be considered a candidate for the sterile insect technique using adults irradiated at these relatively low x-ray exposure doses. PMID:26453709

  10. Male mating biology

    PubMed Central

    Howell, Paul I; Knols, Bart GJ

    2009-01-01

    Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings are successful. Previous failures in mosquito sterile insect technique (SIT) projects have been linked to poor knowledge of local mating behaviours or the selection of deleterious phenotypes during colonisation and long-term mass rearing. Careful selection of mating characteristics must be combined with intensive field trials to ensure phenotypic characters are not antagonistic to longevity, dispersal, or mating behaviours in released males. Success has been achieved, even when colonised vectors were less competitive, due in part to extensive field trials to ensure mating compatibility and effective dispersal. The study of male mating biology in other dipterans has improved the success of operational SIT programmes. Contributing factors include inter-sexual selection, pheromone based attraction, the ability to detect alterations in local mating behaviours, and the effects of long-term colonisation on mating competitiveness. Although great strides have been made in other SIT programmes, this knowledge may not be germane to anophelines, and this has led to a recent increase in research in this area. PMID:19917078

  11. Wing Morphometry and Acoustic Signals in Sterile and Wild Males: Implications for Mating Success in Ceratitis capitata

    PubMed Central

    de Souza, João Maria Gomes Alencar; Molina, Wagner Franco; de Almeida, Lúcia Maria; de Gouveia, Milson Bezerra; de Macêdo, Francisco Pepino; Laumann, Raul Alberto; Paranhos, Beatriz Aguiar Jordão

    2015-01-01

    The sterile insect technique (SIT) is widely utilized in the biological control of fruit flies of the family Tephritidae, particularly against the Mediterranean fruit fly. This study investigated the interaction between mating success and morphometric variation in the wings and the production of acoustic signals among three male groups of Ceratitis capitata (Wiedemann): (1) wild males, (2) irradiated with Co-60 (steriles), and (3) irradiated (steriles) and treated with ginger oil. The canonical variate analysis discriminated two groups (males irradiated and males wild), based on the morphological shape of the wings. Among males that emit buzz signals, wild males obtained copulation more frequently than males in Groups 2 and 3. The individuals of Group 3 achieved more matings than those in Group 2. Wild males displayed lower pulse duration, higher intervals between pulses, and higher dominant frequency. Regarding the reproductive success, the morphological differences in the wings' shape between accepted and nonaccepted males are higher in wild males than in the irradiated ones. The present results can be useful in programs using the sterile insect technique for biological control of C. capitata. PMID:26075293

  12. Wing Morphometry and Acoustic Signals in Sterile and Wild Males: Implications for Mating Success in Ceratitis capitata.

    PubMed

    de Souza, João Maria Gomes Alencar; de Lima-Filho, Paulo Augusto; Molina, Wagner Franco; de Almeida, Lúcia Maria; de Gouveia, Milson Bezerra; de Macêdo, Francisco Pepino; Laumann, Raul Alberto; Paranhos, Beatriz Aguiar Jordão

    2015-01-01

    The sterile insect technique (SIT) is widely utilized in the biological control of fruit flies of the family Tephritidae, particularly against the Mediterranean fruit fly. This study investigated the interaction between mating success and morphometric variation in the wings and the production of acoustic signals among three male groups of Ceratitis capitata (Wiedemann): (1) wild males, (2) irradiated with Co-60 (steriles), and (3) irradiated (steriles) and treated with ginger oil. The canonical variate analysis discriminated two groups (males irradiated and males wild), based on the morphological shape of the wings. Among males that emit buzz signals, wild males obtained copulation more frequently than males in Groups 2 and 3. The individuals of Group 3 achieved more matings than those in Group 2. Wild males displayed lower pulse duration, higher intervals between pulses, and higher dominant frequency. Regarding the reproductive success, the morphological differences in the wings' shape between accepted and nonaccepted males are higher in wild males than in the irradiated ones. The present results can be useful in programs using the sterile insect technique for biological control of C. capitata. PMID:26075293

  13. Impact of Salivary Gland Hypertrophy Virus Infection on the Mating Success of Male Glossina pallidipes: Consequences for the Sterile Insect Technique

    PubMed Central

    Mutika, Gratian N.; Marin, Carmen; Parker, Andrew G.; Boucias, Drion G.; Vreysen, Marc J. B.; Abd-Alla, Adly M. M.

    2012-01-01

    Many species of tsetse flies are infected by a virus (GpSGHV) that causes salivary gland hypertrophy (SGH). Female Glossina pallidipes (Austen) with SGH symptoms (SGH+) have reduced fecundity and SGH+ male G. pallidipes are unable to inseminate female flies. Consequently, G. pallidipes laboratory colonies with a high prevalence of SGH have been difficult to maintain and have collapsed on several occasions. To assess the potential impact of the release of SGH+ sterile male G. pallidipes on the efficacy of an integrated control programme with a sterile insect technique (SIT) component, we examined the mating efficiency and behaviour of male G. pallidipes in field cages in relation to SGH prevalence. The results showed in a field cage setting a significantly reduced mating frequency of 19% for a male G. pallidipes population with a high prevalence of SGH (83%) compared to 38% for a male population with a low prevalence of SGH (7%). Premating period and mating duration did not vary significantly with SGH status. A high percentage (>80%) of females that had mated with SGH+ males had empty spermathecae. The remating frequency of female G. pallidipes was very low irrespective of the SGH status of the males in the first mating. These results indicate that a high prevalence of SGH+ in G. pallidipes not only affects colony stability and performance but, in view of their reduced mating propensity and competitiveness, releasing SGH+ sterile male G. pallidipes will reduce the efficiency of a sterile male release programme. PMID:22912687

  14. Prerelease exposure to methyl eugenol increases the mating competitiveness of sterile males of the oriental fruit fly (Diptera: Tephritidae) in a Hawaiian orchard.

    PubMed

    McInnis, D; Kurashima, R; Shelly, T; Komatsu, J; Edu, J; Pahio, E

    2011-12-01

    Males of the oriental fruit fly, Bactrocera dorsalis (Hendel), are strongly attracted to methyl eugenol (ME), and recent work demonstrated that ingestion of this chemical enhances male mating success, apparently owing its role as a precursor in the synthesis of the male sex pheromone. The current study expanded upon earlier laboratory and field-cage experiments by assessing whether prerelease exposure to ME increased the mating competitiveness of mass-reared, sterile males in Hawaiian orchards. Releases of sterile males from a pupal color-based sexing strain were made weekly in two fruit orchards over 8 mo, with the sterile males at one site given ME for 24 h before release (treated) and the sterile males at the other site given no ME before release (control). Fruits were collected periodically during the study period, and eggs were dissected and incubated to score hatch rate. At both sites, releases of sterile males increased the proportion of unhatched eggs well above prerelease levels, but the incidence of egg sterility was consistently, and statistically, greater in the orchard receiving ME-exposed males. Computed over the entire release period, the average value of Fried's competitive index (that characterizes the mating success of sterile males relative to their wild counterparts) for ME-treated males was 3.5 times greater than that for control males, although this difference was not statistically significant. However, when computed over the period during which egg sterility values were elevated and stable, presumably when females inseminated before the releases were rare or absent, the competitive indices were significantly higher for ME-treated sterile males. The implications of these results for implementing the Sterile Insect Technique against this species are discussed. PMID:22299359

  15. Pre-release consumption of methyl eugenol increases the mating competitiveness of sterile males of the oriental fruit fly, Bactrocera dorsalis, in large field enclosures.

    PubMed

    Shelly, Todd E; Edu, James; McInnis, Donald

    2010-01-01

    The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1-4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost

  16. Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

    PubMed Central

    Shelly, Todd E.; Edu, James; McInnis, Donald

    2010-01-01

    The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost

  17. Additional tests on the efficacy of ginger root oil in enhacing the mating competitiveness of sterile males of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies have shown that exposure to the aroma of ginger root oil (Zingiber officinale Roscoe; termed GRO hereafter) increases the mating competitiveness of males of the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann). This result suggests that pre-release exposure of sterile ...

  18. Aromatherapy in the Mediterranean fruit fly (Diptera: Tephritidae): sterile males exposed to ginger root oil in prerelease storage boxes display increased mating competitiveness in field-cage trials.

    PubMed

    Shelly, Todd E; McInnis, Donald O; Pahio, Elaine; Edu, James

    2004-06-01

    Previous research showed that exposure to ginger root, Zingiber officinale Roscoe, oil increased the mating success of mass-reared, sterile males of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). This work, however, involved the exposure of small groups of males (n = 25) in small containers (volume 400 ml). Several sterile male release programs use plastic adult rearing containers (so-called PARC boxes; hereafter termed storage boxes; 0.48 by 0.60 by 0.33 m) to hold mature pupae and newly emerged adults before release (approximately = 36,000 flies per box). The objective of the current study was to determine whether the application of ginger root oil to individual storage boxes increases the mating competitiveness of sterile C. capitata males. Irradiated pupae were placed in storage boxes 2 d before adult emergence, and in the initial experiment (adult exposure) ginger root oil was applied 5 d later (i.e., 3 d after peak adult emergence) for 24 h at doses of 0.0625, 0.25, 0.5, 1.0, and 2.0 ml. In a second experiment (pupal-adult exposure), ginger root oil was applied to storage boxes immediately after pupal placement and left for 6 d (i.e., 4 d after peak adult emergence) at doses of 0.25 and 1.0 ml. Using field cages, we conducted mating trials in which ginger root oil-exposed (treated) or nonexposed (control) sterile males competed against wild-like males for copulations with wild-like females. After adult exposure, treated males had significantly higher mating success than control males for all doses of ginger root oil, except 2.0 ml. After pupal-adult exposure, treated males had a significantly higher mating success than control males for the 1.0-ml but not the 0.25-ml dose of ginger root oil. The results suggest that ginger root oil can be used in conjunction with prerelease, storage boxes to increase the effectiveness of sterile insect release programs. PMID:15279263

  19. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competit...

  20. Aromatherapy on a large scale: Exposing entire holding rooms to ginger root oil increases the mating competitiveness of sterile males of the Mediterranean fruit fly in field cage trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sterile insect technique (SIT) is widely used in integrated programs against fruit fly pests, particularly the Mediterranean fruit fly. Unfortunately, the mass-rearing procedures inherent to the SIT often lead to a reduction in male mating competitiveness. The sterile insect technique (SIT) is w...

  1. Is elytral color polymorphism in sweetpotato weevil (Coleoptera: Brentidae) a visible marker for sterile insect technique? Comparison of male mating behavior.

    PubMed

    Shiromoto, Keiko; Kumano, Norikuni; Kuriwada, Takashi; Haraguchi, Dai

    2011-04-01

    The sterile insect technique (SIT) is widely used for suppressing or eradicating target pest insect populations. In the eradication programs using the SIT, a large number of sterile insects are marked and released in the field. In Japan, Cylas fonnrmicarius (F.) group (Coleoptera: Brentidae) weevils are marked with a fluorescent powder dye to monitor the progress of such programs. However, this monitoring technique is not fully effective because of the disappearance or contamination of the dye. Therefore, an alternative marking method is required. Currently, a rare color morph such as piceous elytra (PE) is used for visible marking of C. formicarius group weevils. A PE-monomorphic strain has previously been established by artificial selection from a small locally distributed population; this can lead to reduced survival and genetic changes in behavioral traits due to inbreeding depression. In this study, we evaluated the survival rate and mating behavior of PE males of C. formicarius group. The characteristics of the PE males were similar to those of the wild strain (WS) males. Thus, we considered that PE males were suitable for visible marking in the eradication programs using the SIT. PMID:21510188

  2. Combining the Sterile Insect Technique with the Incompatible Insect Technique: III-Robust Mating Competitiveness of Irradiated Triple Wolbachia-Infected Aedes albopictus Males under Semi-Field Conditions.

    PubMed

    Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R L

    2016-01-01

    Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and females could be completely sterilized as pupae with a radiation dose of at least 28 Gy. However, whether this radiation dose can influence the mating competitiveness of the triple infected males was still unknown. In this study we aimed to evaluate the effects of irradiation on the male mating competitiveness of the triple infected strain under laboratory and semi-field conditions. The results herein indicate that irradiation with a lower, female-sterilizing dose has no negative impact on the longevity of triple infected males while a reduced lifespan was observed in the wild type males (wAlbA and wAlbB) irradiated with a higher male-sterilizing dose, in small cages. At different sterile: fertile release ratios in small cages, triple-infected males induced 39.8, 81.6 and 87.8% sterility in a wild type female population at 1:1, 5:1 and 10:1 release ratios, respectively, relative to a fertile control population. Similarly, irradiated triple infected males induced 31.3, 70.5 and 89.3% sterility at 1:1, 5:1 and 10:1 release ratios, respectively, again relative to the fertile control. Under semi-field conditions at a 5:1 release ratio, relative to wild type males, the mean male mating competitiveness index of 28 Gy irradiated triple-infected males was significantly higher than 35 Gy irradiated wild type males, while triple infected males showed no difference in mean mating competitiveness to either irradiated triple-infected or irradiated wild type males. An unexpected difference was also observed in the relative male mating competitiveness of the triple infected strain after

  3. Combining the Sterile Insect Technique with the Incompatible Insect Technique: III-Robust Mating Competitiveness of Irradiated Triple Wolbachia-Infected Aedes albopictus Males under Semi-Field Conditions

    PubMed Central

    Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R. L.

    2016-01-01

    Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and females could be completely sterilized as pupae with a radiation dose of at least 28 Gy. However, whether this radiation dose can influence the mating competitiveness of the triple infected males was still unknown. In this study we aimed to evaluate the effects of irradiation on the male mating competitiveness of the triple infected strain under laboratory and semi-field conditions. The results herein indicate that irradiation with a lower, female-sterilizing dose has no negative impact on the longevity of triple infected males while a reduced lifespan was observed in the wild type males (wAlbA and wAlbB) irradiated with a higher male-sterilizing dose, in small cages. At different sterile: fertile release ratios in small cages, triple-infected males induced 39.8, 81.6 and 87.8% sterility in a wild type female population at 1:1, 5:1 and 10:1 release ratios, respectively, relative to a fertile control population. Similarly, irradiated triple infected males induced 31.3, 70.5 and 89.3% sterility at 1:1, 5:1 and 10:1 release ratios, respectively, again relative to the fertile control. Under semi-field conditions at a 5:1 release ratio, relative to wild type males, the mean male mating competitiveness index of 28 Gy irradiated triple-infected males was significantly higher than 35 Gy irradiated wild type males, while triple infected males showed no difference in mean mating competitiveness to either irradiated triple-infected or irradiated wild type males. An unexpected difference was also observed in the relative male mating competitiveness of the triple infected strain after

  4. Effects of male sterility on female remating in the mediterranean fruitfly, Ceratitis capitata.

    PubMed

    Kraaijeveld, Ken; Chapman, Tracey

    2004-05-01

    Mating-induced reductions in female receptivity are common in insects. These responses are of interest because of their utility in insect pest control. In addition, the control of receptivity is likely to be the subject of sexual conflict over remating frequency. We investigated the specific effect of male sterility on female receptivity in an important pest species, the Mediterranean fruitfly (medfly), in which sterile males are often used for population suppression. Sterile males performed less courtship, obtained significantly fewer first and second matings than fertile males, and reduced female receptivity significantly less effectively than did fertile males. We modelled the likelihood of fertile matings and show that the low mating success of sterile males represents a significant problem for medfly sterile insect technique (SIT) programmes. PMID:15252986

  5. Mating rates between sterile and wild codling moths (Cydia pomonella) in springtime: a simulation study.

    PubMed

    Tyson, R; Newton, K D; Thistlewood, H; Judd, G

    2008-09-21

    The sterile insect technique (SIT) can be a powerful method for pest control without the negative environmental effects of conventional pesticides. The goal is to induce pest population collapse by arranging conditions where wild females mate only with sterile males and thus do not produce offspring. In applying the SIT, it can be important to understand both how subtle alterations of sterile and wild insect behaviour alter the effectiveness of the SIT in different applications, and how this is reflected in the data gathered through associated monitoring devices, often pheromone traps. Our work in this paper is motivated by the use of SIT against orchard pests, particularly the codling moth (Cydia pomonella). We investigate how individual behaviours affect the mating rate between wild females and sterile males, and the corresponding sterile to wild trap catch ratio, through a preliminary individual-based model. Our analysis suggests that the sterile males may not be effective at interfering with mating between wild moths during springtime releases, while at the same time monitoring information gathered from trap catches may give no indication of reduced effectiveness of the SIT. PMID:18597787

  6. Targeting male mosquito mating behaviour for malaria control.

    PubMed

    Diabate, Abdoulaye; Tripet, Frédéric

    2015-01-01

    Malaria vector control relies heavily on the use of Long-Lasting Insecticidal Nets (LLINs) and Indoor Residual Spraying (IRS). These, together with the combined drug administration efforts to control malaria, have reduced the death toll to less than 700,000 deaths/year. This progress has engendered real excitement but the emergence and spread of insecticide resistance is challenging our ability to sustain and consolidate the substantial gains that have been made. Research is required to discover novel vector control tools that can supplement and improve the effectiveness of those currently available. Here, we argue that recent and continuing progress in our understanding of male mating biology is instrumental in the implementation of new approaches based on the release of either conventional sterile or genetically engineered males. Importantly, further knowledge of male biology could also lead to the development of new interventions, such as sound traps and male mass killing in swarms, and contribute to new population sampling tools. We review and discuss recent advances in the behavioural ecology of male mating with an emphasis on the potential applications that can be derived from such knowledge. We also highlight those aspects of male mating ecology that urgently require additional study in the future. PMID:26113015

  7. Estimating SIT-driven population reduction in the Mediterranean fruit fly, Ceratitis capitata, from sterile mating.

    PubMed

    Juan-Blasco, M; Sabater-Muñoz, B; Pla, I; Argilés, R; Castañera, P; Jacas, J A; Ibáñez-Gual, M V; Urbaneja, A

    2014-04-01

    Area-wide sterile insect technique (SIT) programs assume that offspring reduction of the target population correlates with the mating success of the sterile males released. However, there is a lack of monitoring tools to prove the success of these programs in real-time. Field-cage tests were conducted under the environmental conditions of the Mediterranean coast of Spain to estimate: (a) the mating success of sterile Vienna-8 (V8) Ceratitis capitata males using molecular markers and (b) their efficacy to reduce C. capitata populations under six release ratios of wild females to wild males to V8 males (1:0:0, 1:1:0, 1:1:1, 1:1:5, 1:1:10, and 1:1:20). Statistical models were developed to predict: (a) the number of females captured in traps, (b) sperm ID (sterile or not) in spermathecae of the trapped females, and (c) the viable offspring produced, using release ratio and temperature as predictors. The number of females captured was affected by relative humidity. However, its influence in the model was low. Female captures were significantly higher in ratios 1:0:0 compared to ratios where V8 males were released. The proportion of V8 sperm in spermathecae increased with temperature and with the number of V8 males released, but leveled off between ratios 1:1:10 and 1:1:20. In all seasons, except winter (no offspring), viable offspring increased with temperature and was lowest for ratio 1:1:20. For the first time, a strong negative relationship between proportion of V8 sperm detected by molecular tools and C. capitata offspring was established. The models obtained should contribute to enhance the efficacy of SIT programs against this pest. PMID:24444376

  8. Male motion coordination in anopheline mating swarms

    NASA Astrophysics Data System (ADS)

    Shishika, Daigo; Manoukis, Nicholas C.; Butail, Sachit; Paley, Derek A.

    2014-09-01

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa. Most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, organized patterns in such swarms have been observed, but a detailed description of male-male interactions has not previously been available. We identify frequent, time-varying interactions characterized by periods of parallel flight in data from 8 swarms of Anopheles gambiae and 3 swarms of Anopheles coluzzii filmed in 2010 and 2011 in the village of Donéguébogou, Mali. We use the cross correlation of flight direction to quantify these interactions and to induce interaction graphs, which show that males form synchronized subgroups whose size and membership change rapidly. A swarming model with damped springs between each male and the swarm centroid shows good agreement with the correlation data, provided that local interactions represented by damping of relative velocity between males are included.

  9. Age-Dependent Male Mating Investment in Drosophila pseudoobscura

    PubMed Central

    Dhole, Sumit; Pfennig, Karin S.

    2014-01-01

    Male mating investment can strongly influence fitness gained from a mating. Yet, male mating investment often changes with age. Life history theory predicts that mating investment should increase with age, and males should become less discriminatory about their mate as they age. Understanding age-dependent changes in male behavior and their effects on fitness is important for understanding how selection acts in age-structured populations. Although the independent effects of male or female age have been studied in many species, how these interact to influence male mating investment and fitness is less well understood. We mated Drosophila pseudoobscura males of five different age classes (4-, 8-, 11-, 15-, 19-day old) to either young (4-day) or old (11-day) females, and measured copulation duration and early post-mating fecundity. Along with their independent effects, we found a strong interaction between the effects of male and female ages on male mating investment and fitness from individual matings. Male mating investment increased with male age, but this increase was more prominent in matings with young females. Male D. pseudoobscura made smaller investments when mating with old females. The level of such discrimination based on female age, however, also changed with male age. Intermediate aged males were most discriminatory, while the youngest and the oldest males did not discriminate between females of different ages. We also found that larger male mating investments resulted in higher fitness payoffs. Our results show that male and female ages interact to form a complex pattern of age-specific male mating investment and fitness. PMID:24586373

  10. The Decision for Male versus Female Sterilization.

    ERIC Educational Resources Information Center

    Clark, Margaret Pruitt; And Others

    1979-01-01

    The increasing popularity of sterilization underscores the need for knowledge about couples choosing male and female procedures. This research delineates four sets of variables that may be important for the decision and examines their relationship with the choice of male or female procedure among a sample of married couples. (Author)

  11. Covariation and repeatability of male mating effort and mating preferences in a promiscuous fish

    PubMed Central

    Godin, Jean-Guy J; Auld, Heather L

    2013-01-01

    Although mate choice by males does occur in nature, our understanding of its importance in driving evolutionary change remains limited compared with that for female mate choice. Recent theoretical models have shown that the evolution of male mate choice is more likely when individual variation in male mating effort and mating preferences exist and positively covary within populations. However, relatively little is known about the nature of such variation and its maintenance within natural populations. Here, using the Trinidadian guppy (Poecilia reticulata) as a model study system, we report that mating effort and mating preferences in males, based on female body length (a strong correlate of fecundity), positively covary and are significantly variable among subjects. Individual males are thus consistent, but not unanimous, in their mate choice. Both individual mating effort (including courtship effort) and mating preference were significantly repeatable. These novel findings support the assumptions and predictions of recent evolutionary models of male mate choice, and are consistent with the presence of additive genetic variation for male mate choice based on female size in our study population and thus with the opportunity for selection and further evolution of large female body size through male mate choice. PMID:23919148

  12. Methyl eugenol aromatherapy enhances the mating competitiveness of male Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae).

    PubMed

    Haq, Ihsan; Vreysen, Marc J B; Cacéres, Carlos; Shelly, Todd E; Hendrichs, Jorge

    2014-09-01

    Males of Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) are strongly attracted to methyl eugenol (ME) (1,2-dimethoxy-4-(2-propenyl)benzene), a natural compound occurring in variety of plant species. ME-feeding is known to enhance male B. carambolae mating competitiveness 3 days after feeding. Enhanced male mating competitiveness due to ME-feeding can increase the effectiveness of sterile insect technique (SIT) manifolds. However, the common methods for emergence and holding fruit flies prior to field releases do not allow the inclusion of any ME feeding treatment after fly emergence. Therefore this study was planned to assess the effects of ME-aromatherapy in comparison with ME feeding on male B. carambolae mating competitiveness as aromatherapy is pragmatic for fruit flies emergence and holding facilities. Effects of ME application by feeding or by aromatherapy for enhanced mating competitiveness were evaluated 3d after treatments in field cages. ME feeding and ME aromatherapy enhanced male mating competitiveness as compared to untreated males. Males treated with ME either by feeding or by aromatherapy showed similar mating success but mating success was significantly higher than that of untreated males. The results are discussed in the context of application of ME by aromatherapy as a pragmatic approach in a mass-rearing facility and its implications for effectiveness of SIT. PMID:24995839

  13. Density affects mating mode and large male mating advantage in a fiddler crab.

    PubMed

    Ribeiro, Pablo D; Daleo, Pedro; Iribarne, Oscar O

    2010-12-01

    Fiddler crabs show two different mating modes: either females search and crabs mate underground in male burrows, or males search and crabs mate on the surface near female burrows. We explored the relationship between crab density, body size, the searching behavior of both sexes, and the occurrence of both mating modes in the fiddler crab Uca uruguayensis. We found that crabs change their mating mode depending on their size and crab density. Crabs mated mostly on the surface at low densities, and underground at high densities. The proportion of wandering receptive females but not courting males accounted for the variation in mating modes. This suggests that whether crabs mate underground (or on the surface) is determined by the presence (or absence) of searching females. We found that the change in the mating mode affected the level of assortative mating; males mating underground were bigger than those mating on the surface, suggesting active female choice. Given that fiddler crabs experience multiple reproductive cycles, they are prone to showing behavioral plasticity in their mating strategy whenever the payoffs of using different mating modes differ between reproductive events. Our results suggest that the incorporation of different levels of environmental variability may be important in theoretical models aimed at improving our understanding of the evolution of alternative mating tactics and strategies. PMID:20931233

  14. Male sterility and hybrid seed production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual reproduction in angiosperms is a complex process that includes a portion of the vegetative generation and all of the sexual generation. Coordination of both female and male reproduction ontogenies must occur. An abnormality anywhere in this process may lead to sterility. Genetic (nuclear) and...

  15. Male motion coordination in anopheline mating swarms.

    PubMed

    Shishika, Daigo; Manoukis, Nicholas C; Butail, Sachit; Paley, Derek A

    2014-01-01

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa. Most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, organized patterns in such swarms have been observed, but a detailed description of male-male interactions has not previously been available. We identify frequent, time-varying interactions characterized by periods of parallel flight in data from 8 swarms of Anopheles gambiae and 3 swarms of Anopheles coluzzii filmed in 2010 and 2011 in the village of Donéguébogou, Mali. We use the cross correlation of flight direction to quantify these interactions and to induce interaction graphs, which show that males form synchronized subgroups whose size and membership change rapidly. A swarming model with damped springs between each male and the swarm centroid shows good agreement with the correlation data, provided that local interactions represented by damping of relative velocity between males are included. PMID:25212874

  16. Male motion coordination in anopheline mating swarms

    PubMed Central

    Shishika, Daigo; Manoukis, Nicholas C.; Butail, Sachit; Paley, Derek A.

    2014-01-01

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa. Most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, organized patterns in such swarms have been observed, but a detailed description of male-male interactions has not previously been available. We identify frequent, time-varying interactions characterized by periods of parallel flight in data from 8 swarms of Anopheles gambiae and 3 swarms of Anopheles coluzzii filmed in 2010 and 2011 in the village of Donéguébogou, Mali. We use the cross correlation of flight direction to quantify these interactions and to induce interaction graphs, which show that males form synchronized subgroups whose size and membership change rapidly. A swarming model with damped springs between each male and the swarm centroid shows good agreement with the correlation data, provided that local interactions represented by damping of relative velocity between males are included. PMID:25212874

  17. Scented males and choosy females: does male odor influence female mate choice in the Mediterranean fruit fly?

    PubMed

    Shelly, Todd E; Edu, James; Pahio, Elaine; Nishimoto, Jon

    2007-12-01

    The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), displays a lek mating system characterized by a high level of female discrimination among potential mates. The basis of female choice is not understood, but recent studies indicate that male exposure to the aroma of certain plant structures or essential oils may increase mating success. In particular, exposure to the aroma of ginger root oil (GRO) enhances male mating frequency, and several sterile-male release programs against C. capitata have incorporated 'aromatherapy' (large-scale exposure of pre-release insects to GRO) to increase the effectiveness of control efforts. We investigated the mechanism underlying female preference for GRO-exposed males. Two sets of experiments were conducted. In the first, we monitored female attraction to (1) freshly killed flies, or (2) paper discs that contained hexane extracts from varying treatments. In these tests, females were sighted more often (1) near GRO-exposed than non-exposed males (even when the males were visually concealed) and (2) near extracts from GRO-exposed than non-exposed males. These findings suggest a 'perfume effect', whereby female mate choice is mediated by olfactory differences. In the second set, we compared (1) mate choice between intact females and females from which both antennae had been surgically removed, and (2) mating success between intact males and males from which both antennae had been surgically removed before GRO exposure. Intact females preferred GRO-exposed males, whereas females lacking both antennae rarely mated and showed no preference between GRO-exposed and non-exposed males. In the opposite treatment (intact females but surgically altered males), GRO-exposed males lacking both antennae mated as frequently as GRO-exposed intact males. These data suggest that female choice was dependent on olfactory perception of male odor but that male mating success did not depend on olfactory perception of GRO aroma, suggesting, in

  18. Effects of the juvenile hormone analogue methoprene and dietary protein on male melon fly Bactrocera cucurbitae (Diptera: Tephritidae) mating success.

    PubMed

    ul Haq, Ihsan; Cáceres, Carlos; Hendrichs, Jorge; Teal, Peter; Wornoayporn, Viwat; Stauffer, Christian; Robinson, Alan S

    2010-11-01

    The effect of access to dietary protein (P) and the topical application of a juvenile hormone analogue (methoprene (M)) on mating behaviour of male melon fly Bactrocera cucurbitae was assessed in the laboratory and in field cages. Age, dietary protein and methoprene application increased the mating success and influenced the mating behaviour. Treatment with methoprene (M+) to protein-deprived (P-) males had only a modest effect on the acceleration of sexual maturity, but application of methoprene (M+) to protein-fed (P+) males greatly accelerated sexual maturity. Protein diet (P+) increased mating success of males in comparison to protein-deprived (P-) males. Protein and methoprene have a synergistic effect on mating behaviour, since M+P+ treated males exhibit reduced mating latency and achieved higher mating in younger ages than methoprene and/or protein-deprived males. Copulation duration was correlated with nutritional status and M+P+ males copulated longer at the age of advanced sexual maturity than M-P+ males. Our results suggest that in this species with a lek mating system, females discriminate between the males based on their sexual signals, which were influenced by protein in the adult diet, methoprene application and age. The results are discussed in the light of mating competitiveness of precocious treated young males and their relevance to Sterile Insect Technique application against this pest species. PMID:20438735

  19. Improving male mating competitiveness and survival in the field for medfly, Ceratitis capitata (Diptera: Tephritidae) SIT programs.

    PubMed

    McInnis, D O; Shelly, T E; Komatsu, J

    2002-09-01

    The success of the sterile insect technique (SIT) depends critically upon mating between released sterilized males and wild females. In Hawaii, improvements in the efficiency of sterile males were attempted on two separate fronts--mating enhancement and survival improvement. In the former, two methods have been investigated--selective breeding and aromatherapy. In the latter, flies which survived in field cages for several days were selected and bred to produce progeny with enhanced survival ability compared to control flies. Regarding mating selection, standard laboratory-reared males that successfully mated with wild females in field cages were allowed to breed. F1 offspring were inbred, then the selection procedure was repeated for four additional cycles. In the aromatherapy procedure, laboratory-reared males were exposed to ginger root oil for several hours 1 day prior to testing in field cages. Compared to controls, the selected flies improved the mating competitiveness of male flies ca. 3-fold, irradiation reduced this increase to ca. 2.5-fold. Exposing the selected, hybrid strain raised the fitness of the lab males to ca. 9-fold that of wild males. In the ongoing survival selection study, we have obtained lines in which the selected males survived ca. 2-fold better than laboratory control males over several days in an outdoor field cage, with food and water provided. The goal is to combine the traits of higher survival and mating ability into a single strain for SIT release. PMID:12484531

  20. A character demonstrating the occurrence of mating in male Cactoblastis cactorum (Lepidoptera: Pyralidae)

    SciTech Connect

    Marti, O.G.; Carpenter, J.E.

    2007-03-15

    The reproductive system of adult male Cactoblastis cactorum, the cactus moth, was examined to determine whether the mating status of males could be ascertained. In unmated males, the posterior portion of the primary ductus ejaculatorius simplex is opaque yellow in color and contains many small football-shaped hyaline granules 3-5 x 5-10 {mu}m in size. In mated males, the posterior simplex is clear and contains no granules. The presence or absence of these characters was found to be highly reliable and should be of value in determining mating status in marked-recaptured males of this species in a sterile insect release program directed against Cactoblastis. (author)

  1. Optimizing methyl-eugenol aromatherapy to maximize posttreatment effects to enhance mating competitiveness of male Bactrocera carambolae (Diptera: Tephritidae).

    PubMed

    Haq, Ihsan ul; Vreysen, Marc J B; Cacéres, Carlos; Shelly, Todd E; Hendrichs, Jorge

    2015-10-01

    Methyl-eugenol (ME) (1,2-dimethoxy-4-(2-propenyl)benzene), a natural phytochemical, did enhance male Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) mating competitiveness 3 d after ingestion. Enhanced male mating competitiveness can significantly increase the effectiveness of the sterile insect technique (SIT). ME application to mass reared sterile flies by feeding is infeasible. ME application by aromatherapy however, would be a very practical way of ME application in fly emergence and release facilities. This approach was shown to enhance mating competitiveness of B. carambolae 3 d posttreatment (DPT). Despite this added benefit, every additional day of delaying release will reduce sterile fly quality and will add cost to SIT application. The present study was planned to assess the effects of ME-aromatherapy on male B. carambolae mating competitiveness 1DPT and 2DPT. ME aromatherapy 1DPT or 2DPT did enhance mating competitiveness of B. carambolae males whereas ME feeding 1DPT and 2DPT did not. Male mating competitiveness was enhanced by the ME aromatherapy irrespective if they received 1DPT, 2DPT or 3DPT. ME aromatherapy, being a viable approach for its application, did enhance mating competitiveness of male B. carambolae 1 d posttreatment as ME feeding did 3 d after ingestion. PMID:24935641

  2. Male mate preferences in mutual mate choice: finches modulate their songs across and within male-female interactions.

    PubMed

    Heinig, Abbie; Pant, Santosh; Dunning, Jeffery; Bass, Aaron; Coburn, Zachary; Prather, Jonathan F

    2014-10-01

    Male songbirds use song to advertise their attractiveness as potential mates, and the properties of those songs have a powerful influence on female mate preferences. One idea is that males may exert themselves maximally in each song performance, consistent with female evaluation and formation of mate preferences being the primary contributors to mate choice. Alternatively, males may modulate their song behaviour to different degrees in the presence of different females, consistent with both male and female mate preferences contributing to mutual mate choice. Here we consider whether male Bengalese finches, Lonchura striata domestica, express mate preferences at the level of individual females, and whether those preferences are manifest as changes in song behaviour that are sufficient to influence female mate choice. We tested this idea by recording songs performed by individual unmated males during a series of 1 h interactions with each of many unmated females. Across recording sessions, males systematically varied both the quantity and the quality of the songs that they performed to different females. Males also varied their song properties throughout the course of each interaction, and behavioural tests using female birds revealed that songs performed at the onset of each interaction were significantly more attractive than songs performed by the same male later during the same interaction. This demonstration of context-specific variation in the properties of male reproductive signals and a role for that variation in shaping female mate preference reveals that male mate preferences play an important role in mutual mate choice in this species. Because these birds thrive so well in the laboratory and are so amenable to observation and experimentation across generations, these results yield a new model system that may prove especially advantageous in disentangling the role of male and female mate preferences in shaping mutual mate choice and its long-term benefits or

  3. The evolution and significance of male mate choice.

    PubMed

    Edward, Dominic A; Chapman, Tracey

    2011-12-01

    The distinct reproductive roles of males and females, which for many years were characterised in terms of competitive males and choosy females, have remained a central focus of sexual selection since Darwin's time. Increasing evidence now shows that males can be choosy too, even in apparently unexpected situations, such as under polygyny or in the absence of male parental care. Here, we provide a synthesis of the theory on male mate choice and examine the factors that promote or constrain its evolution. We also discuss the evolutionary significance of male mate choice and the contrasts in male versus female mate choice. We conclude that mate choice by males is potentially widespread and has a distinct role in how mating systems evolve. PMID:21890230

  4. Molecular analysis of cytoplasmic male sterility

    SciTech Connect

    Hanson, M.R.

    1990-01-01

    The ultimate aims of the project are to understand the molecular mechanism of the disruption in pollen development which occurs in cytoplasmic male sterile plants and to understand the control of respiratory energy flow in the higher plant cell. A mitochondrial locus termed S-pcf segregates with sterility and with an alteration in respiration in Petunia. This cloned locus contains three genes, an abnormal fused gene termed pcf, a gene for a subunit of an NADH dehydrogenase complex, and a small ribosomal subunit protein. The pcf gene is comprised of partial sequences of ATPase subunit 9, cytochrome oxidase subunit II, and an unidentified reading frame. Components of the S-Pcf locus will be introduced into the nuclear of a fertile genotype under the control of appropriate regulatory signals, and polypeptide products of introduced genes will be directed to the mitochondrion with a transit peptide. By examining transgenic plants, we can determine what elements of the locus are critical for altered respiration or sterility. Such knowledge could explain how mitochondrial DNA affects pollen development in the large number of plant species which exhibit the agronomically important trait of male sterility. 10 refs., 3 figs.

  5. Development of male-sterile lines for breeding hybrid rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a self-pollinated crop that depends on male-sterility for F1 hybrid seed production. As an alternative to accessing existing male-sterile lines from other hybrid breeding programs, the program in Arkansas has created its own novel male-sterile sources. These were developed out of germplasm...

  6. Suppression of Pest Lepidoptera by Releasing Partially Sterile Males

    ERIC Educational Resources Information Center

    Knipling. E. F.

    1970-01-01

    Uses population growth models to calculate the theoretical suppression of reproduction achieved by releasing irradiated male moths carrying genetic sterility factors. Shows that releasing partially sterile males should be more effective than releasing fully sterile males. Discusses the costs and advantages of applying this approach to the control…

  7. The dance of male Anopheles gambiae in mating swarms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mating behavior of the malaria vector Anopheles gambiae is of great interest from a fundamental and applied perspective. One of the most important elements of mating in this species is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and inseminat...

  8. Sequential male mate choice under sperm competition risk

    PubMed Central

    2014-01-01

    Male eagerness to mate is a central paradigm of sexual selection theory. However, limited sperm supplies mean that male sexual restraint might sometimes be favored under promiscuous mating. Here, we demonstrate dynamic plasticity in male mating effort when females are encountered sequentially under varying sperm competition risk. Rather than showing consistent eagerness to mate, male house mice (Mus musculus domesticus) instead tailor their mating effort according to likely reproductive payoffs. They are significantly less likely to mate when sperm competition is certain and potential reproductive payoffs low, but dramatically increase investment if they do choose to mate under such circumstances. By contrast, male mice are significantly more likely to mate in situations simulating extra-territorial copulations, where future risk of competition is high but so too are potential reproductive rewards. Differential mating propensity appears to be the primary mechanism by which male house mice allocate sperm adaptively under sperm competition risk because we find no evidence for facultative adjustment of sperm numbers per ejaculate or ejaculation frequency in response to female-related cues. We conclude that sequential male mate choice under sperm competition risk could be a widespread but often unappreciated mechanism of strategic sperm allocation. PMID:24822023

  9. [Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success].

    PubMed

    Silva Neto, Alberto M da; Dias, Vanessa S; Joachim-Bravo, Iara S

    2009-01-01

    The objective of this study was to evaluate the effect of male ageing on male pheromone release and mating success of Ceratitis capitata (Wiedemann). The effects of male ageing on mating were evaluated on five and 21 d-old males by assessing their mating success (males chosen by a female for copulation) and the amount of males releasing the sex pheromone. The mating success was evaluated by using several ratios of young to older males by increasing the number of older males:young males from 1:1 to 5:1. The mating success of the 1:1 ratio was also evaluated in field cages. The evaluation of the mating success (in the 1:1 ratio) showed a clear preference of the females for young males. Sex pheromone emission was much more common on young than older males. Even in cases were older males were more abundant (ratios 2:1 and 3:1), females still chose the young males. However, females could not distinguish young from older males in ratios of 4:1 or 5:1. Our data indicate that the ageing of C. capitata males has a considerable negative effect on their reproductive success, especially if they are found in a proportion any lower than 3:1. PMID:19943002

  10. Exposure to ginger root oil enhances mating success of irradiated, mass-reared males of Mediterranean fruit fly (Diptera: Tephritidae).

    PubMed

    Shelly, T E; McInnis, D O

    2001-12-01

    Previous research revealed that exposure to ginger root oil, Zingiber officinale Roscoe, containing the known male attractant (a-copaene) increased the mating success of male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), from a newly established laboratory colony. The goal of the current study was to determine whether exposure to ginger root oil likewise enhanced the mating competitiveness of irradiated C. capitata males from a 5-yr-old mass-reared strain. Mating tests were conducted in field cages containing guava trees (Psidium guajava L.) to monitor the mating frequency of irradiated, mass-reared and wild males competing for wild females. In the absence of chemical exposure, wild males outcompeted the mass-reared males and obtained 74% of all matings. However, following exposure to ginger root oil (20 microl for 6 h), the mating frequencies were reversed. Whether exposed as mature (3-d-old) or immature (1-d-old) adults, mass-reared males achieved approximately 75% of all matings in tests conducted 2 or 4 d following exposure, respectively. Irradiated, mass-reared males prevented from contacting the oil directly (i.e., exposed to the odor only for 6 h) still exhibited a mating advantage over wild males. In an additional study, signaling levels and female arrivals were compared between males exposed to ginger root oil and nonexposed males, but no significant differences were detected. The implications of these findings for the sterile insect technique are discussed. PMID:11777043

  11. Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

    PubMed Central

    Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

    2014-01-01

    Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments. PMID:24805129

  12. Costs influence male mate choice in a freshwater fish.

    PubMed

    Wong, Bob B M; Jennions, Michael D

    2003-08-01

    It is well known that female mate choice decisions depend on the direct costs of choosing (either because of search costs or male-imposed costs). Far less is known about how direct fitness costs affect male mate choice. We conducted an experiment to investigate male mate choice in a fish, the Pacific blue-eye (Pseudomugil signifer). Preferred females were larger, probably because larger females are also more fecund. Males, however, were consistent in their choice of female only when the costs of associating with prospective mates were equal. By contrast, males were far less consistent in their choice when made to swim against a current to remain with their initially preferred mate. Our results suggest that males may also respond adaptively to changes in the costs of choosing. PMID:12952630

  13. The costs of parental and mating effort for male baboons

    PubMed Central

    Cheney, Dorothy L.; Crockford, Catherine; Engh, Anne L.; Wittig, Roman M.; Seyfarth, Robert M.

    2014-01-01

    Sexual selection theory predicts that males in polygynous species of mammals will invest more reproductive effort in mate competition than parental investment. A corollary to this prediction is that males will mount a stress response when their access to mates is threatened. Indeed, numerous studies have shown that males exhibit elevated stress hormones, or glucocorticoids (GCs), when their access to females, or a proxy to this access like dominance rank, is challenged. In contrast, the relationship between stress hormones and paternal effort is less obvious. We report results from a study of wild male chacma baboons indicating that males experienced elevated GC levels during periods of social instability following the immigration of a dominant male. These effects were strongest in males whose mating opportunities were at greatest risk: high-ranking males and males engaged in sexual consortships. Males involved in friendships with lactating females, a form of paternal investment, also experienced high GC levels during these periods of instability. There was a tendency for males with lactating female friends to reduce their time spent in consortships during unstable periods, when the risk of infanticide was high. Thus, even in a highly polygynous mammal, males may have to balance paternal effort with mating effort. Males who invest entirely in mating effort risk losing the infants they have sired to infanticide. Males who invest in paternal care may enhance their offspring's survival, but at the cost of elevated GC levels, the risk of injury, and the loss of mating opportunities. PMID:25620835

  14. Dual reproductive cost of aging in male medflies: dramatic decrease in mating competitiveness and gradual reduction in mating performance

    PubMed Central

    Papanastasiou, Stella A.; Diamantidis, Alexandros D.; Nakas, Christos T.; Carey, James R.; Papadopoulos, Nikos T.

    2011-01-01

    Although age-based effects on the reproductive success of males have been reported in several animal taxa the cost of aging on male mating success in lekking species has not been fully explored. We used the Mediterranean fruit fly, a lekking species, to investigate possible cost of aging on male reproductive success. We performed no choice and choice mating tests to test the hypothesis that aging does not affect the mating performance (mating success in conditions lacking competition) or the mating competitiveness (mating success against younger rivals) of males. The mating probability of older males decreased significantly when competing with younger males. Aging gradually reduced the mating performance of males but older males were still accepted as mating partners in conditions lacking competition. Therefore, older males are capable of performing the complete repertoire of sexual performance but fail to be chosen by females in the presence of young rivals. Older males achieved shorter copulations than younger ones, and female readiness to mate was negatively affected by male age. Older and younger males transferred similar amount of spermatozoids to female spermathecae. Females stored spermatozoids asymmetrically in the two spermathecae regardless the age of their mating partner. Aging positively affected the amount of spermatozoids in testes of both mated and non mated males. No significant differences were observed on the amount of spermatozoids between mated and non mated males. PMID:21801728

  15. Spatial distribution and male mating success of Anopheles gambiae swarms

    PubMed Central

    2011-01-01

    Background Anopheles gambiae mates in flight at particular mating sites over specific landmarks known as swarm markers. The swarms are composed of males; females typically approach a swarm, and leave in copula. This mating aggregation looks like a lek, but appears to lack the component of female choice. To investigate the possible mechanisms promoting the evolution of swarming in this mosquito species, we looked at the variation in mating success between swarms and discussed the factors that structure it in light of the three major lekking models, known as the female preference model, the hotspot model, and the hotshot model. Results We found substantial variation in swarm size and in mating success between swarms. A strong correlation between swarm size and mating success was observed, and consistent with the hotspot model of lek formation, the per capita mating success of individual males did not increase with swarm size. For the spatial distribution of swarms, our results revealed that some display sites were more attractive to both males and females and that females were more attracted to large swarms. While the swarm markers we recognize help us in localizing swarms, they did not account for the variation in swarm size or in the swarm mating success, suggesting that mosquitoes probably are attracted to these markers, but also perceive and respond to other aspects of the swarming site. Conclusions Characterizing the mating system of a species helps understand how this species has evolved and how selective pressures operate on male and female traits. The current study looked at male mating success of An. gambiae and discussed possible factors that account for its variation. We found that swarms of An. gambiae conform to the hotspot model of lek formation. But because swarms may lack the female choice component, we propose that the An. gambiae mating system is a lek-like system that incorporates characteristics pertaining to other mating systems such as scramble

  16. Defective pollen wall contributes to male sterility in the male sterile line 1355A of cotton

    PubMed Central

    Wu, Yuanlong; Min, Ling; Wu, Zancheng; Yang, Li; Zhu, Longfu; Yang, Xiyan; Yuan, Daojun; Guo, Xiaoping; Zhang, Xianlong

    2015-01-01

    To understand the mechanisms of male sterility in cotton (Gossypium spp.), combined histological, biochemical and transcription analysis using RNA-Seq was carried out in the anther of the single-gene recessive genic male sterility system of male sterile line 1355A and male fertile line 1355B, which are near-isogenic lines (NILs) differing only in the fertility trait. A total of 2,446 differentially expressed genes were identified between the anthers of 1355AB lines, at three different stages of development. Cluster analysis and functional assignment of differentially expressed genes revealed differences in transcription associated with pollen wall and anther development, including the metabolism of fatty acids, glucose, pectin and cellulose. Histological and biochemical analysis revealed that a major cellular defect in the 1355A was a thicker nexine, consistent with the RNA-seq data, and further gene expression studies implicated differences in fatty acids synthesis and metabolism. This study provides insight into the phenotypic characteristics and gene regulatory network of the genic male sterile line 1355A in upland cotton. PMID:26043720

  17. Female copying increases the variance in male mating success.

    PubMed

    Wade, M J; Pruett-Jones, S G

    1990-08-01

    Theoretical models of sexual selection assume that females choose males independently of the actions and choice of other individual females. Variance in male mating success in promiscuous species is thus interpreted as a result of phenotypic differences among males which females perceive and to which they respond. Here we show that, if some females copy the behavior of other females in choosing mates, the variance in male mating success and therefore the opportunity for sexual selection is greatly increased. Copying behavior is most likely in non-resource-based harem and lek mating systems but may occur in polygynous, territorial systems as well. It can be shown that copying behavior by females is an adaptive alternative to random choice whenever there is a cost to mate choice. We develop a statistical means of estimating the degree of female copying in natural populations where it occurs. PMID:2377613

  18. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus

    PubMed Central

    Atyame, Célestine M.; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  19. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus.

    PubMed

    Atyame, Célestine M; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  20. Female mate choice and male behaviour in domestic fowl.

    PubMed

    Leonard; Zanette

    1998-11-01

    The purpose of this study was to use paired choice tests to examine mate selection by female domestic chickens, Gallus gallus domesticus. We examined five behavioural and six morphological traits of 34 pairs of males to determine which male features influenced female mate choice. The frequency of a behavioural display known as wingflapping was the only variable that differed significantly between males that were chosen and males that were not. Within trials, females selected males with the highest wingflapping rate. Across trials, the wingflapping rate of chosen males ranged widely (3-82 wingflaps/h) suggesting that females used a relative choice mechanism when selecting a mate. These results differ from earlier work on the closely related red junglefowl, G. g. murghi, in which females use morphological traits and a threshold choice mechanism when selecting mates. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9819324

  1. Sensory regulation of C. elegans male mate-searching behaviour

    PubMed Central

    Barrios, Arantza; Nurrish, Stephen; Emmons, Scott W.

    2009-01-01

    Summary How do animals integrate internal drives and external environmental cues to coordinate behaviours? We address this question studying mate-searching behaviour in C. elegans. C. elgans males explore their environment in search of mates (hermaphrodites) and will leave food if mating partners are absent. However, when mates and food coincide, male exploratory behaviour is suppressed and males are retained on the food source. We show that the drive to explore is stimulated by male specific neurons in the tail, the ray neurons. Periodic contact with the hermaphrodite detected through ray neurons changes the male’s behaviour during periods of no contact and prevents the male from leaving the food source. The hermaphrodite signal is conveyed by male-specific interneurons that are post-synaptic to the rays and that send processes to the major integrative center in the head. This study identifies key parts of the neural circuit that regulates a sexual appetitive behaviour in C. elegans. PMID:19062284

  2. Dual reproductive cost of aging in male Medflies: dramatic decrease in mating competitiveness and gradual reduction in mating performance.

    PubMed

    Papanastasiou, Stella A; Diamantidis, Alexandros D; Nakas, Christos T; Carey, James R; Papadopoulos, Nikos T

    2011-10-01

    Although age-based effects on the reproductive success of males have been reported in several animal taxa the cost of aging on male mating success in lekking species has not been fully explored. We used the Mediterranean fruit fly, a lekking species, to investigate possible cost of aging on male reproductive success. We performed no choice and choice mating tests to test the hypothesis that aging does not affect the mating performance (mating success in conditions lacking competition) or the mating competitiveness (mating success against younger rivals) of males. The mating probability of older males decreased significantly when competing with younger males. Aging gradually reduced the mating performance of males but older males were still accepted as mating partners in conditions lacking competition. Therefore, older males are capable of performing the complete repertoire of sexual performance but fail to be chosen by females in the presence of young rivals. Older males achieved shorter copulations than younger ones, and female readiness to mate was negatively affected by male age. Older and younger males transferred similar amount of spermatozoids to female spermathecae. Females stored spermatozoids asymmetrically in the two spermathecae regardless the age of their mating partner. Aging positively affected the amount of spermatozoids in testes of both mated and nonmated males. No significant differences were observed on the amount of spermatozoids between mated and nonmated males. PMID:21801728

  3. Pilot field trials with Aedes albopictus irradiated sterile males in Italian urban areas.

    PubMed

    Bellini, R; Medici, A; Puggioli, A; Balestrino, F; Carrieri, M

    2013-03-01

    The pilot field studies here presented are part of a long-term research program aimed to develop a cost-effective sterile insect technique (SIT) methodology to suppress Aedes albopictus (Skuse) populations. Aedes albopictus is a mosquito species mainly developing in man-made containers and with an island-like urban and suburban distribution. These two features make the application of the sterile insect technique a possible control strategy. Five trials have been performed in three small towns from 2005 to 2009 (Emilia-Romagna region, northern Italy). Reared male pupae, sexed by a sieving technique allowing the recovery of approximately 26-29% of males, were exposed to gamma rays and immediately released in the field. Adult population density was estimated based on a weekly monitoring of egg density in the ovitraps, whereas induced sterility was estimated by measuring the hatching percentage of weekly collected eggs in SIT and control areas. Results showed that sterile males released at the rate of 896-1,590 males/ha/wk induced a significant sterility level in the local population. In addition, when the sterility level achieved values in the range of 70-80%, a similar reduction also was found for the egg density in the ovitraps. We could estimate that the minimum egg sterility value of 81% should be maintained to obtain suppression of the local population. Immigration of mated females was not a main issue in the small villages where trials have been run. PMID:23540120

  4. Male mate preference and size-assortative mating in convict cichlids: A role for female aggression?

    PubMed

    Bloch, A N; Estela, V J; Leese, J M; Itzkowitz, M

    2016-09-01

    Many monogamous species demonstrate size-assortative mating patterns within natural populations. To better understand the role of intersexual selection in this process, we examined the effect of male preference for female body size in the convict cichlid (Amatitlania siquia). We provided males with a choice between females that differed in size, relative to each other and in relation to the focal male. Based on previous work, we expected males to prefer the largest available female mates across all treatments. Surprisingly, males spent more time near the smaller of two available females, but only when the other female was larger than the male. Additionally, males spent little time with either of two potential female mates when both females were larger than the male. We hypothesized that while males might prefer the largest of available females, female behavior might limit males from acting on this preference. To test this, males were force paired with a smaller or larger female. Pair formation only occurred when the female was smaller than the male, and females that were larger than their male counterparts showed significantly more aggression when compared to smaller females. Together, these data suggest that in the absence of intrasexual competition, male mate preference for large females in convict cichlids might be limited by female aggression. PMID:27444247

  5. Investigation of methods for sterilization of potting compounds and mated surfaces

    NASA Technical Reports Server (NTRS)

    Tulius, J. J.; Daley, D. J.; Phillips, G. B.

    1972-01-01

    The feasibility of using formaldehyde-liberating synthetic resins or polymers for the sterilization of potting compounds, mated and occluded areas, and spacecraft surfaces was demonstrated. The detailed study of interrelated parameters of formaldehyde gas sterilization revealed that efficient cycle conditions can be developed for the sterilization of spacecraft components. It was determined that certain parameters were more important than others in the development of cycles for specific applications. The use of formaldehyde gas for the sterilization of spacecraft components provides NASA with a highly efficient method which is inexpensive, reproducible, easily quantitated, materials compatible, operationally simple, generally non-hazardous and not thermally destructive.

  6. Balancing sexual selection through opposing mate choice and male competition

    PubMed Central

    Moore, A. J.; Moore, P. J.

    1999-01-01

    Male–male competition and female mate choice act contemporaneously in the cockroach Nauphoeta cinerea and the social pheromone of males influences the outcome of both forms of sexual selection. We therefore examined the joint and separate effects of male–male competition and female mate choice to determine if the selective optima for the pheromone were the same or different. Dominant males in a newly established hierarchy mated more frequently, but not exclusively. Manipulations of the multi-component social pheromone produced by males of N. cinerea showed that both long- and close-range attraction of females by males were influenced by the quantity and composition of the pheromone. The most attractive composition, however, differed from that which was most likely to confer high status to males. Since the outcome of male–male competition can conflict with mating preferences exhibited by females, there is balancing sexual selection on the social pheromone of N. cinerea. Such balancing selection might act to maintain genetic variation in sexually selected traits. We suggest that the different forms of sexual selection conflict in N. cinerea because females prefer a blend different to that which is most effective in male–male competition in order to avoid mating with overly aggressive males.

  7. Reversible frequency-dependent switches in male mate choice.

    PubMed

    van Gossum, H; Stoks, R; De Bruyn, L

    2001-01-01

    Current sexual-selection theories predict that mating should occur preferentially with the highest-quality partner, and assume that for distinguishing among potential mates the choosy sex applies an internal representation of the characteristics of the desired mate, i.e. a template. Binary choice experiments were performed to test male mate choice between two different female colour morphs in the damselfly Ischnura elegans. Choice experiments were conducted before and after an habituation period, during which males were exposed to only one female colour morph. Given the choice between the two female morphs, males did exhibit a choice for the most recently experienced female morph. This is the first evidence for a reversible switch in mate choice in a frequency-dependent way. In contrast with previous studies on mate choice, template formation in male I. elegans seems not to be based on quality. Switching mate choice in a frequency-dependent manner, choosing the most common morph, probably allows males to minimize their search efforts and to maximize fitness. PMID:12123302

  8. Why do female mice mate with multiple males?

    PubMed

    Thonhauser, Kerstin E; Raveh, Shirley; Hettyey, Attila; Beissmann, Helmut; Penn, Dustin J

    2013-01-01

    Females often show multi-male mating (MMM), but the adaptive functions are unclear. We tested whether female house mice (Mus musculus musculus) show MMM when they can choose their mates without male coercion. We released 32 females into separate enclosures where they could choose to mate with two neighboring males that were restricted to their own territories. We also tested whether females increase MMM when the available males appeared unable to exclude intruders from their territories. To manipulate territorial intrusion, we introduced scent-marked tiles from the neighboring males into males' territories, or we rearranged tiles within males' own territories as a control. Each female was tested in treatment and control conditions and we conducted paternity analyses on the 57 litters produced. We found that 46 % of litters were multiply sired, indicating that multiple paternity is common when females can choose their mates. Intrusion did not increase multiple paternity, though multiple paternity was significantly greater in the first trial when the males were virgins compared to the second trial. Since virgin male mice are highly infanticidal, this finding is consistent with the infanticide avoidance hypothesis. We also found that multiple paternity was higher when competing males showed small differences in their amount of scent marking, suggesting that females reduce MMM when they can detect differences in males' quality. Finally, multiple paternity was associated with increased litter size but only in the intrusion treatment, which suggests that the effect of multiple paternity on offspring number is dependent on male-male interactions. PMID:24273373

  9. A New Adult Diet Formulation for Sterile Males of Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae).

    PubMed

    Orozco-Dávila, Dina; Quintero-Fong, Luis

    2015-08-01

    A new adult diet formulation was evaluated for sterile Anastrepha ludens (Loew) and Anastrepha obliqua (Macquart) males at the emergence and release facility of fruit flies in Mexico. The formulation consists of hydrolyzed protein, sugar, juvenile hormone analogue methoprene, and water. The proportion of the ingredients between the solute (4% hydrolyzed protein and 96% sugar) and solvent (10% methoprene and 90% water) was 5:1. This new formulation was called the 1:24 formulation. The main objectives of this study were to develop a simple way to supply the 1:24 formulation to adults and to compare the sexual performance of these flies with the performance of flies fed a standard diet (called the Mubarqui formulation) used at the emergence and release facility of fruit flies in Mexico. The preparation, time, and cost also were evaluated. The results showed no significant differences in the sexual behaviors of the males (number of males mating, number of males calling, mating latency, and mating duration) between the 1:24 formulation and the Mubarqui formulation. However, the cost and the required preparation time are much lower for the 1:24 formulation process than for the Mubarqui formulation process. Based on these results, we recommend the 1:24 formulation as an additional adult diet option in the handling of sterile flies. Its application is practical and does not require changes in packaging systems. The contribution of our findings and their potential application to the improvement of the sterile insect technique are discussed. PMID:26470310

  10. Time-pattern and frequency analyses of sounds produced by irradiated and untreated male Bactrocera tryoni (Froggatt) during mating behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Behavior and sounds associated with mating of mass-reared irradiated and untreated (non-irradiated) Bactrocera tryoni (Froggatt) males were analyzed using synchronous acoustic and video recordings. The flies tested were from a population used in sterile release programs that help maintain fruit-fly...

  11. Lovesick: immunological costs of mating to male sagebrush crickets.

    PubMed

    Leman, J C; Weddle, C B; Gershman, S N; Kerr, A M; Ower, G D; St John, J M; Vogel, L A; Sakaluk, S K

    2009-01-01

    A growing body of evidence suggests that resources invested in reproduction often come at the expense of the ability to mount an immune response. During mating, female sagebrush crickets, Cyphoderris strepitans, consume the ends of the male's hind wings and ingest his haemolymph. Previous research has shown that this behaviour impairs the ability of males to secure additional matings. One hypothesis to account for this effect is that wing wounding triggers an energetically costly immune response, such that nonvirgin males are unable to sustain the costly acoustical signalling needed to attract additional females. To test this hypothesis, we injected virgin males with lipopolysaccharides (LPS) to provoke an immune response, and monitored their mating success in the field. LPS-injected virgin males took significantly longer to mate than sham-injected virgin males, and spent significantly less time calling. We also compared virgin, nonvirgin and experimentally wing-wounded virgin males with respect to: (1) their ability to encapsulate a foreign invader via the accumulation of haemocytes and deposition of melanin and (2) baseline levels of phenoloxidase (PO), a key enzyme in the biochemical cascade leading to the production of melanin. Although encapsulation ability did not differ with reproductive experience, virgin males had significantly higher levels of PO than either nonvirgin or experimentally wing-wounded virgin males. These results suggest that wing-wounding alone is sufficient to impair male immunity, and that males trade-off investment in reproduction and immunity. PMID:19127612

  12. Male coercive mating in externally fertilizing species: male coercion, female reluctance and explanation for female acceptance.

    PubMed

    Matsumoto, Yukio; Takegaki, Takeshi

    2016-01-01

    Male coercive mating exerts a strong evolutionary pressure on mating-related traits of both sexes. However, it is extremely rare in externally fertilizing species probably because the male mating behaviour is incomplete until females release their eggs. Here we showed that males of the externally fertilizing fish Rhabdoblennius nitidus coercively confine females to the nests until spawning, and investigated why females accept male coercive mating. The females entered the males' nests following male courtship displays, but they usually tried to escape when there were no eggs because males tended to cannibalize all the eggs when there were few. Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females. Spawning tended to occur during the early/late spawning period in nests with no eggs (i.e. male coercive mating). In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings. The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints. PMID:27087584

  13. Male coercive mating in externally fertilizing species: male coercion, female reluctance and explanation for female acceptance

    PubMed Central

    Matsumoto, Yukio; Takegaki, Takeshi

    2016-01-01

    Male coercive mating exerts a strong evolutionary pressure on mating-related traits of both sexes. However, it is extremely rare in externally fertilizing species probably because the male mating behaviour is incomplete until females release their eggs. Here we showed that males of the externally fertilizing fish Rhabdoblennius nitidus coercively confine females to the nests until spawning, and investigated why females accept male coercive mating. The females entered the males’ nests following male courtship displays, but they usually tried to escape when there were no eggs because males tended to cannibalize all the eggs when there were few. Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females. Spawning tended to occur during the early/late spawning period in nests with no eggs (i.e. male coercive mating). In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings. The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints. PMID:27087584

  14. Sterility and Sexual Competitiveness of Tapachula-7 Anastrepha ludens Males Irradiated at Different Doses.

    PubMed

    Orozco-Dávila, Dina; Adriano-Anaya, Maria de Lourdes; Quintero-Fong, Luis; Salvador-Figueroa, Miguel

    2015-01-01

    A genetic sexing strain of Anastrepha ludens (Loew), Tapachula-7, was developed by the Mexican Program Against Fruit Flies to produce and release only males in programs where the sterile insect technique (SIT) is applied. Currently, breeding are found at a massive scale, and it is necessary to determine the optimum irradiation dose that releases sterile males with minimum damage to their sexual competitiveness. Under laboratory and field conditions, we evaluated the effects of gamma irradiation at doses of 0, 20, 40, 60 and 80 Gy on the sexual competitiveness of males, the induction of sterility in wild females and offspring survivorship. The results of the study indicate that irradiation doses have a significant effect on the sexual behavior of males. A reduction of mating capacity was inversely proportional to the irradiation dose of males. It is estimated that a dose of 60 Gy can induce more than 99% sterility in wild females. In all treatments, the degree of offspring fertility was correlated with the irradiation dose of the parents. In conclusion, the results of the study indicate that a dose of 60 Gy can be applied in sterile insect technique release programs. The application of this dose in the new genetic sexing strain of A. ludens is discussed. PMID:26274926

  15. Sterility and Sexual Competitiveness of Tapachula-7 Anastrepha ludens Males Irradiated at Different Doses

    PubMed Central

    Orozco-Dávila, Dina; Adriano-Anaya, Maria de Lourdes; Quintero-Fong, Luis; Salvador-Figueroa, Miguel

    2015-01-01

    A genetic sexing strain of Anastrepha ludens (Loew), Tapachula-7, was developed by the Mexican Program Against Fruit Flies to produce and release only males in programs where the sterile insect technique (SIT) is applied. Currently, breeding are found at a massive scale, and it is necessary to determine the optimum irradiation dose that releases sterile males with minimum damage to their sexual competitiveness. Under laboratory and field conditions, we evaluated the effects of gamma irradiation at doses of 0, 20, 40, 60 and 80 Gy on the sexual competitiveness of males, the induction of sterility in wild females and offspring survivorship. The results of the study indicate that irradiation doses have a significant effect on the sexual behavior of males. A reduction of mating capacity was inversely proportional to the irradiation dose of males. It is estimated that a dose of 60 Gy can induce more than 99% sterility in wild females. In all treatments, the degree of offspring fertility was correlated with the irradiation dose of the parents. In conclusion, the results of the study indicate that a dose of 60 Gy can be applied in sterile insect technique release programs. The application of this dose in the new genetic sexing strain of A. ludens is discussed. PMID:26274926

  16. Male mate choice and sperm allocation in a sexual/asexual mating complex of Poecilia (Poeciliidae, Teleostei)

    PubMed Central

    Schlupp, I; Plath, M

    2005-01-01

    Male mate choice is critical for understanding the evolution and maintenance of sexual/asexual mating complexes involving sperm-dependent, gynogenetic species. Amazon mollies (Poecilia formosa) require sperm to trigger embryogenesis, but the males (e.g. Poecilia mexicana) do not contribute genes. Males benefit from mating with Amazon mollies, because such matings make males more attractive to conspecific females, but they might control the cost of such matings by providing less sperm to Amazon mollies. We examined this at the behavioural and sperm levels. P. mexicana males preferred to mate with, and transferred more sperm to conspecific females. However, if males mated with P. formosa, sperm was readily transferred. This underscores the importance of male choice in this system. PMID:17148157

  17. Influence of methoprene and dietary protein on male Anastrepha suspensa (Diptera:Tephritidae) mating aggregations.

    PubMed

    Pereira, Rui; Sivinski, John; Teal, Peter E A

    2009-04-01

    The Caribbean fruit fly, Anastrepha suspensa (Loew), like many polyphagous tephritids, exhibits a lek polygyny mating system, and juvenile hormone levels and adult diet are known to have important positive effects on male sexual success. Among the potential components of this success are male lek tenure and female response to the sexual signals of lekking males. Male A. suspensa where submitted to four different treatments: (M(+)P(+)) application of juvenile hormone analog, methoprene (M) and sugar and hydrolyzed yeast as adult food; (M(+)P(-)) application of M and sugar as adult food; (M(-)P(+)) no application of M and sugar and hydrolyzed yeast as adult food; and (M(-)P(-)) no application of M and sugar as adult food. M(+)P(+) males initiated and participated more in aggregations, mated more frequently, and occupied the lek centers more often. They also had fewer unsuccessful mounting attempts than males in all the other treatments. M(+)P(+) males also emitted pheromones and acoustically signaled more often and attracted more females than males in other treatments. Male sexual performance was improved due to methoprene, protein supply, and the interaction of methoprene and protein for most of the parameters. Since the success of the sterile insect technique (SIT), a commonly employed technique to control pest tephritids, requires the release of males that can form leks, engage in agonistic sexual interactions, and attract females, these positive effects of protein and methoprene may substantially improve SIT programs. PMID:19185584

  18. Improving sterile male performance in support of programmes integrating the sterile insect technique against fruit flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Sterile Insect Technique (SIT) is being applied against fruit fly pests in many areas of the world. Currently, factories have the capacity to produce several billion sterile male insects per week and to make them available for, irradiatiation and shipment to their destinations, where the emergin...

  19. Sugar administration to newly emerged Aedes albopictus males increases their survival probability and mating performance.

    PubMed

    Bellini, Romeo; Puggioli, Arianna; Balestrino, Fabrizio; Brunelli, Paolo; Medici, Anna; Urbanelli, Sandra; Carrieri, Marco

    2014-04-01

    capacity of sterile (irradiated with 30 Gy) males to take a sugar meal relative to fertile males was observed in field comparison. A clear effect of temperature and relative humidity (RH) on the rate of sugar positive males was observed, with an increase of temperature and a decrease in RH strongly increasing the % of sugar positive males. In large enclosures we tested the effect of our sugar supplying tool on the mating competitiveness of sterile vs fertile males, which produced an evident favorable effect both on sterile and fertile males. PMID:24299923

  20. Male mate preferences in mutual mate choice: finches modulate their songs across and within male–female interactions

    PubMed Central

    Heinig, Abbie; Pant, Santosh; Dunning, Jeffery; Bass, Aaron; Coburn, Zachary; Prather, Jonathan F.

    2014-01-01

    Male songbirds use song to advertise their attractiveness as potential mates, and the properties of those songs have a powerful influence on female mate preferences. One idea is that males may exert themselves maximally in each song performance, consistent with female evaluation and formation of mate preferences being the primary contributors to mate choice. Alternatively, males may modulate their song behaviour to different degrees in the presence of different females, consistent with both male and female mate preferences contributing to mutual mate choice. Here we consider whether male Bengalese finches, Lonchura striata domestica, express mate preferences at the level of individual females, and whether those preferences are manifest as changes in song behaviour that are sufficient to influence female mate choice. We tested this idea by recording songs performed by individual unmated males during a series of 1 h interactions with each of many unmated females. Across recording sessions, males systematically varied both the quantity and the quality of the songs that they performed to different females. Males also varied their song properties throughout the course of each interaction, and behavioural tests using female birds revealed that songs performed at the onset of each interaction were significantly more attractive than songs performed by the same male later during the same interaction. This demonstration of context-specific variation in the properties of male reproductive signals and a role for that variation in shaping female mate preference reveals that male mate preferences play an important role in mutual mate choice in this species. Because these birds thrive so well in the laboratory and are so amenable to observation and experimentation across generations, these results yield a new model system that may prove especially advantageous in disentangling the role of male and female mate preferences in shaping mutual mate choice and its long-term benefits or

  1. The sterile male technique: irradiation negatively affects male fertility but not male courtship.

    PubMed

    Magris, Martina; Wignall, Anne E; Herberstein, Marie E

    2015-04-01

    The sterile male technique is a common method to assign paternity, widely adopted due to its relative simplicity and low cost. Male sterility is induced by exposure to sub lethal doses of chemosterilants or irradiation, the dosage of which has to be calibrated for every species to provide successful male sterilisation, without affecting male physiology and behaviour. While the physiological effects of sterilisation are usually assessed for each study, the behavioural ones are rarely analysed in detail. Using the orb web spider Argiope keyserlingi as a model we first tested (1) the validity of the thread assay, which simulates male courtship behaviour in a standardised context, as a proxy representing courtship on a female web. We then investigated (2) the effectiveness of male sterilisation via irradiation and (3) its consequences on male courtship behaviour. Our results validate the thread assay and the sterile male technique as legitimate tools for the study of male courtship behaviour and fertilisation success. We show that these techniques are time and cost effective and reduce undesirable variation, thereby creating opportunities to study and understand the mechanisms underlying sexual selection. PMID:25794431

  2. Novel male trait prolongs survival in suicidal mating.

    PubMed

    Andrade, Maydianne C B; Gu, Lei; Stoltz, Jeffrey A

    2005-09-22

    Male redback spiders (Latrodectus hasselti) maximize paternity if they copulate twice with their cannibalistic mate. Facilitating cannibalistic attack during their first copulation yields paternity benefits. However, females have paired sperm-storage organs inseminated during two separate copulations, so males that succumb to partial cannibalism during the first copulation lose at least 50% of their paternity to rivals. In this paper, we describe a novel male trait--an abdominal constriction that appears during courtship--that allows males to survive and mate with females for a second time, despite the substantial cannibalistic damage inflicted during the first copulation. Constricted males that were wounded to simulate early cannibalism had higher endurance, greater survivorship, longer subsequent courtship and higher mating success than wounded males that were not constricted. Constriction was not found in a non-sacrificial congener that rarely survived simulated cannibalism, and the protective effect of constriction in redbacks was specific to the type of damage inflicted by females during the first copulation. Thus, the abdominal constriction allows males to overcome the potential fitness limit imposed by their own suicidal strategy-paradoxically, by prolonging survival across two cannibalistic copulations. PMID:17148186

  3. Remating behavior in Anastrepha fraterculus (Diptera: Tephritidae) females is affected by male juvenile hormone analog treatment but not by male sterilization.

    PubMed

    Abraham, S; Liendo, M C; Devescovi, F; Peralta, P A; Yusef, V; Ruiz, J; Cladera, J L; Vera, M T; Segura, D F

    2013-06-01

    The sterile insect technique (SIT) has been proposed as an area-wide method to control the South American fruit fly, Anastrepha fraterculus (Wiedemann). This technique requires sterilization, a procedure that affects, along with other factors, the ability of males to modulate female sexual receptivity after copulation. Numerous pre-release treatments have been proposed to counteract the detrimental effects of irradiation, rearing and handling and increase SIT effectiveness. These include treating newly emerged males with a juvenile hormone mimic (methoprene) or supplying protein to the male's diet to accelerate sexual maturation prior to release. Here, we examine how male irradiation, methoprene treatment and protein intake affect remating behavior and the amount of sperm stored in inseminated females. In field cage experiments, we found that irradiated laboratory males were equally able to modulate female remating behavior as fertile wild males. However, females mated with 6-day-old, methoprene-treated males remated more and sooner than females mated with naturally matured males, either sterile or wild. Protein intake by males was not sufficient to overcome reduced ability of methoprene-treated males to induce refractory periods in females as lengthy as those induced by wild and naturally matured males. The amount of sperm stored by females was not affected by male irradiation, methoprene treatment or protein intake. This finding revealed that factors in addition to sperm volume intervene in regulating female receptivity after copulation. Implications for SIT are discussed. PMID:23340454

  4. DNA Loss at the Ceratocystis fimbriata Mating Locus Results in Self-Sterility

    PubMed Central

    Wilken, P. Markus; Steenkamp, Emma T.; Wingfield, Michael J.; de Beer, Z. Wilhelm; Wingfield, Brenda D.

    2014-01-01

    Fungi have evolved a remarkable diversity of reproductive strategies. Some of these, most notably those of the model fungi, have been well studied but others are poorly understood. The latter is also true for uni-directional mating type switching, which has been reported in only five fungal genera, including Ceratocystis. Mating type switching allows a self-fertile fungal isolate to produce both self-fertile and self-sterile offspring. This study considered the molecular nature of uni-directional mating type switching in the type species of Ceratocystis, C. fimbriata. To do this, the genome of C. fimbriata was first examined for the presence of mating type genes. Three mating genes (MAT1-1-1, MAT1-2-1 and MAT1-1-2) were found in an atypical organisation of the mating type locus. To study the effect that uni-directional switching has on this locus, several self-sterile offspring were analysed. Using a combination of next generation and conventional Sanger sequencing, it was shown that a 3581 base pair (bp) region had been completely deleted from the MAT locus. This deletion, which includes the entire MAT1-2-1 gene, results in the permanent loss of self-fertility, rendering these isolates exclusively self-sterile. Our data also suggest that the deletion mechanism is tightly controlled and that it always occurs at the same genomic position. Two 260 bp direct repeats flanking the deleted region are strongly implicated in the process, although the exact mechanism behind the switching remains unclear. PMID:24651494

  5. Manipulation of the microbiota of mass-reared Mediterranean fruit flies Ceratitis capitata (Diptera: Tephritidae) improves sterile male sexual performance.

    PubMed

    Ben Ami, Eyal; Yuval, Boaz; Jurkevitch, Edouard

    2010-01-01

    The sterile insect technique (SIT) is a method of biological control whereby millions of factory reared sterile male insects are released into the field. This technique is commonly used to combat the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Sterile medfly males are less competent in attracting and mating with wild females, a property commonly linked to the irradiation process responsible for the sterilization. As bacteria are important partners in the fly's life cycle, we used molecular analytical methods to study the community structure of the gut microbiota in irradiated male medflies. We find that the sterilizing irradiation procedure affects the gut bacterial community structure of the Mediterranean fruit fly. Although the Enterobacteriaceae family remains the dominant bacterial group present in the gut, the levels of Klebsiella species decreases significantly in the days after sterilization. In addition, we detected substantial differences in some bacterial species between the mass rearing strain Vienna 8 and the wild strain. Most notable among these are the increased levels of the potentially pathogenic species Pseudomonas in the industrial strain. Testing the hypothesis that regenerating the original microbiota community could result in enhanced competitiveness of the sterile flies, we found that the addition of the bacterial species Klebsiella oxytoca to the postirradiation diet enables colonization of these bacteria in the gut while resulting in decreased levels of the Pseudomonas sp. Feeding on diets containing bacteria significantly improved sterile male performance in copulatory tests. Further studies will determine the feasibility of bacterial amelioration in SIT operations. PMID:19617877

  6. Extreme costs of mating for male two-spot ladybird beetles.

    PubMed

    Perry, Jennifer C; Tse, Crystal T

    2013-01-01

    Male costs of mating are now thought to be widespread. The two-spot ladybird beetle (Adalia bipunctata) has been the focus of many studies of mating and sexual selection, yet the costs of mating for males are unknown. The mating system of A. bipunctata involves a spermatophore nuptial gift ingested by females after copulation. In this study, we investigate the cost to males of mating and of transferring spermatophores in terms of lifespan, ejaculate production and depletion of nutritional reserves. We found that males faced a strong trade-off between mating and survival, with males that were randomly assigned to mate a single time experiencing a 53% reduction in post-mating lifespan compared to non-mating males. This is among the most severe survival costs of a single mating yet reported. However, spermatophore transfer did not impact male survival. Instead, the costs associated with spermatophores appeared as a reduced ability to transfer spermatophores in successive matings. Furthermore, males ingested more food following spermatophore transfer than after matings without spermatophores, suggesting that spermatophore transfer depletes male nutritional reserves. This is to our knowledge the first report of an effect of variation in copulatory behaviour on male foraging behaviour. Overall, our study highlights the advantages of assessing mating costs using multiple currencies, and suggests that male A. bipunctata should exhibit mate choice. PMID:24339980

  7. Mitochondrially-targeted expression of a cytoplasmic male sterility-associated orf220 gene causes male sterility in Brassica juncea

    PubMed Central

    2010-01-01

    Background The novel chimeric open reading frame (orf) resulting from the rearrangement of a mitochondrial genome is generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). Both positive and negative correlations have been found between CMS-associated orfs and the occurrence of CMS when CMS-associated orfs were expressed and targeted at mitochondria. Some orfs cause male sterility or semi-sterility, while some do not. Little is currently known about how mitochondrial factor regulates the expression of the nuclear genes involved in male sterility. The purpose of this study was to investigate the biological function of a candidate CMS-associated orf220 gene, newly isolated from cytoplasmic male-sterile stem mustard, and show how mitochondrial retrograde regulated nuclear gene expression is related to male sterility. Results It was shown that the ORF220 protein can be guided to the mitochondria using the mitochondrial-targeting sequence of the β subunit of F1-ATPase (atp2-1). Transgenic stem mustard plants expressed the chimeric gene containing the orf220 gene and a mitochondrial-targeting sequence of the β subunit of F1-ATPase (atp2-1). Transgenic plants were male-sterile, most being unable to produce pollen while some could only produce non-vigorous pollen. The transgenic stem mustard plants also showed aberrant floral development identical to that observed in the CMS stem mustard phenotype. Results obtained from oligooarray analysis showed that some genes related to mitochondrial energy metabolism were down-regulated, indicating a weakening of mitochondrial function in transgenic stem mustard. Some genes related to pollen development were shown to be down-regulated in transgenic stem mustard and the expression of some transcription factor genes was also altered. Conclusion The work presented furthers our understanding of how the mitochondrially-targeted expression of CMS-associated orf220 gene causes male sterility through

  8. Inbreeding effect on male and female fertility and inheritance of male sterility in Nemophila menziesii (Hydrophyllaceae).

    PubMed

    Gomez, Nadilia N; Shaw, Ruth G

    2006-05-01

    Models of the evolution of gynodioecy assume that inbreeding affects male and female fertility equally and ignore quantitative variation in sex expression. The objectives of this study were to assess inbreeding effects, genetic background, and plant maturity on male and female fertility and the mechanism of male sterility inheritance for Nemophila menziesii (Hydrophyllaceae). Frequency of male-sterile flowers, number of anthers and ovules, and percentage of viable pollen were measured on plants from different pedigrees and five inbreeding levels (F = 0, 0.0625, 0.25, 0.5, and 0.75). Quantitative variation in male sterility was evident. As inbreeding increased, anther and ovule number decreased; the effect on anther number was greater than on ovule number. Pedigrees varied in number of male-sterile flowers and inbreeding effects. Frequency of male-sterile flowers was greatest among first flowers. No trade-off between male and female fertility was detected. A model attributing male sterility to a cytoplasmic locus and restoration to male fertility to a nuclear locus accounted for the distribution of complete sterility and hermaphroditism over the pedigrees. This study suggests that models of the evolution and maintenance of gynodioecy should allow for quantitative variation in male and female fertility components due to inbreeding, pedigree, and plant maturity. PMID:21642137

  9. Male mate choice selects for female coloration in a fish

    PubMed Central

    Amundsen, Trond; Forsgren, Elisabet

    2001-01-01

    Although sexual selection theory has proved successful in explaining a wide array of male ornaments, the function of ornaments occurring in females is largely unknown. Traditionally, female ornaments have been considered nonfunctional, being merely a genetically correlated response to selection for male ornamentation. However, this hypothesis is only relevant to species in which the ornament is basically the same in the two sexes. Alternatively, female ornaments may be influenced by selection acting directly on the females, either through female–female competition or male choice. We tested the latter hypothesis in mate-choice experiments with two-spotted gobies (Gobiusculus flavescens). In this small marine fish, females have bright yellow-orange bellies during the breeding season, a conspicuous trait that is not present in males. We conducted two aquarium experiments to test whether males preferred to mate with more colorful females. In the first experiment, males had a choice between two females that varied in natural coloration (and belly roundness). In the second experiment, we manipulated belly coloration and kept roundness constant. Males spent more time with colorful than with drab females in both experiments and also performed far more courtship displays toward colorful females. Our study provides experimental evidence that males prefer ornamented females in a fish that is not sex-role reversed, supporting the hypothesis that female ornamentation is sexually selected. PMID:11606720

  10. Study of male sterility in Taiwania cryptomerioides Hayata (Taxodiaceae).

    PubMed

    Chen, S-H; Chung, N-J; Wang, Y-N; Lee, C-L; Lee, Y-L; Tsai, P-F

    2006-08-01

    A study of male sterility over a period of three consecutive years on a conifer species endemic to Taiwan, Taiwania cryptomerioides Hayata (Taxodiaceae), was done for this article. With the aids of fluorescence and electron microscopic observations, the ontogenic processes in the fertile and sterile microsporangia are compared, using samples collected from Chitou Experimental Forest and Yeou-Shoei-Keng Clonal Orchard of the National Taiwan University, Nantou, Taiwan. The development of male strobili occurred from August to the end of March. Microsporogenesis starts with the formation of the archesporium and ends with the maturation of 2-celled pollen grains within the dehiscing microsporangium. Before meiosis, there was no significant difference in ultrastructure between the fertile and sterile microsporangia. Asynchronous pollen development with various tetrad forms may occur in the same microsporangium of either fertile or sterile strobili. However, a callose wall was observable in the fertile dyad and tetrad, but not in the sterile one. After dissolution of the callose wall, the fertile microspores were released into the locule, while some sterile microspores still retained as tetrads or dyads with intertwining of exine walls in the proximal faces. As a result, there was no well developed lamellated endexine and no granulate ectexine or intine in the sterile microspores. Eventually, the intracellular structures in sterile microspores were dramatically collapsed before anthesis. The present study shows that the abortion in pollen development is possibly attributed to the absence of the callose wall. The importance of this structure to the male sterility of T. cryptomerioides is discussed. PMID:16937067

  11. Assortative mating and differential male mating success in an ash hybrid zone population

    PubMed Central

    Gérard, Pierre R; Klein, Etienne K; Austerlitz, Frédéric; Fernández-Manjarrés, Juan F; Frascaria-Lacoste, Nathalie

    2006-01-01

    Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash) and F. angustifolia Vahl (narrow-leaved ash), which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears to maintain this hybrid

  12. Female mate preference and sexual conflict: females prefer males that have had fewer consorts.

    PubMed

    Harris, W Edwin; Moore, Patricia J

    2005-05-01

    Different aspects of male quality as a mate can vary independently. When this is the case, females may need to use multiple cues to accurately assess overall mate quality. We examined the pattern of mating preference in the cockroach Nauphoeta cinerea. Sexual conflict occurs in this species because male manipulation of female mating receptivity can result in reduced female fitness. We predicted that since females cannot remate within a single reproductive bout because of male manipulation, females should assess male mating history to avoid mating with males with low fertility caused by sperm exhaustion. In a mate-preference experiment, we found that females discriminated against males who had mated multiple times. Females also discriminated against males who had consorted with several females but had been prevented from mating with those females. Thus, females appeared to be able to detect cues on males that were derived from previous mates and to use this information to avoid mating with sperm-exhausted males. We suggest that females may commonly use multiple cues to assess different aspects of mate quality, especially when male quality changes over time. This is an under-studied phenomenon that could help explain individual variation in female mating preferences. PMID:15795863

  13. Comparative Transcriptome Analysis of Recessive Male Sterility (RGMS) in Sterile and Fertile Brassica napus Lines

    PubMed Central

    Zhao, Huiyan; Liu, Chuan; Li, Jiana; Tang, Zhanglin; Xu, Xinfu; Qiu, Xiao; Wang, Rui; Lu, Kun

    2015-01-01

    The recessive genetic male sterility (RGMS) system plays a key role in the production of hybrid varieties in self-pollinating B. napus plants, and prevents negative cytoplasmic effects. However, the complete molecular mechanism of the male sterility during male-gametogenesis in RGMS remains to be determined. To identify transcriptomic changes that occur during the transition to male sterility in RGMS, we examined the male sterile line WSLA and male fertile line WSLB, which are near-isogenic lines (NILs) differing only in the fertility trait. We evaluated the phenotypic features and sterility stage using anatomical analysis. Comparative RNA sequencing analysis revealed that 3,199 genes were differentially expressed between WSLA and WSLB. Many of these genes are mainly involved in biological processes related to flowering, including pollen tube development and growth, pollen wall assembly and modification, and pollen exine formation and pollination. The transcript profiles of 93 genes associated with pollen wall and anther development were determined by quantitative RT-PCR in different flower parts, and classified into the following three major clades: 1) up-regulated in WSLA plants; 2) down-regulated in WSLA plants; and 3) down-regulated in buds, but have a higher expression in stigmas of WSLA than in WSLB. A subset of genes associated with sporopollenin accumulation were all up-regulated in WSLA. An excess of sporopollenin results in defective pollen wall formation, which leads to male sterility in WSLA. Some of the genes identified in this study are candidates for future research, as they could provide important insight into the molecular mechanisms underlying RGMS in WSLA. PMID:26656530

  14. Comparative Transcriptome Analysis of Recessive Male Sterility (RGMS) in Sterile and Fertile Brassica napus Lines.

    PubMed

    Qu, Cunmin; Fu, Fuyou; Liu, Miao; Zhao, Huiyan; Liu, Chuan; Li, Jiana; Tang, Zhanglin; Xu, Xinfu; Qiu, Xiao; Wang, Rui; Lu, Kun

    2015-01-01

    The recessive genetic male sterility (RGMS) system plays a key role in the production of hybrid varieties in self-pollinating B. napus plants, and prevents negative cytoplasmic effects. However, the complete molecular mechanism of the male sterility during male-gametogenesis in RGMS remains to be determined. To identify transcriptomic changes that occur during the transition to male sterility in RGMS, we examined the male sterile line WSLA and male fertile line WSLB, which are near-isogenic lines (NILs) differing only in the fertility trait. We evaluated the phenotypic features and sterility stage using anatomical analysis. Comparative RNA sequencing analysis revealed that 3,199 genes were differentially expressed between WSLA and WSLB. Many of these genes are mainly involved in biological processes related to flowering, including pollen tube development and growth, pollen wall assembly and modification, and pollen exine formation and pollination. The transcript profiles of 93 genes associated with pollen wall and anther development were determined by quantitative RT-PCR in different flower parts, and classified into the following three major clades: (1) up-regulated in WSLA plants; (2) down-regulated in WSLA plants; and 3) down-regulated in buds, but have a higher expression in stigmas of WSLA than in WSLB. A subset of genes associated with sporopollenin accumulation were all up-regulated in WSLA. An excess of sporopollenin results in defective pollen wall formation, which leads to male sterility in WSLA. Some of the genes identified in this study are candidates for future research, as they could provide important insight into the molecular mechanisms underlying RGMS in WSLA. PMID:26656530

  15. Mating advantage for rare males in wild guppy populations.

    PubMed

    Hughes, Kimberly A; Houde, Anne E; Price, Anna C; Rodd, F Helen

    2013-11-01

    To understand the processes that maintain genetic diversity is a long-standing challenge in evolutionary biology, with implications for predicting disease resistance, response to environmental change, and population persistence. Simple population genetic models are not sufficient to explain the high levels of genetic diversity sometimes observed in ecologically important traits. In guppies (Poecilia reticulata), male colour pattern is both diverse and heritable, and is arguably one of the most extreme examples of morphological polymorphism known. Negative frequency-dependent selection (NFDS), a form of selection in which genotypes are favoured when they are rare, can potentially maintain such extensive polymorphism, but few experimental studies have confirmed its operation in nature. Here we use highly replicated experimental manipulations of natural populations to show that males with rare colour patterns have higher reproductive fitness, demonstrating NFDS mediated by sexual selection. Rare males acquired more mates and sired more offspring compared to common males and, as previously reported, had higher rates of survival. Orange colour, implicated in other studies of sexual selection in guppies, did predict male reproductive success, but only in one of three populations. These data support the hypothesis that NFDS maintains diversity in the colour patterns of male guppies through two selective agents, mates and predators. Similar field-based manipulations of genotype frequencies could provide a powerful approach to reveal the underlying ecological and behavioural mechanisms that maintain genetic and phenotypic diversity. PMID:24172904

  16. Effects of temperature variation on male behavior and mating success in a montane beetle.

    PubMed

    Dick, Cynthia A; Rank, Nathan E; McCarthy, Meagan; McWeeney, Stephen; Hollis, Daniel; Dahlhoff, Elizabeth P

    2013-01-01

    Locomotion and mating ability are crucial for male reproductive success yet are energetically costly and susceptible to physiological stress. In the Sierra willow beetle Chrysomela aeneicollis, male mating success depends on locating and mating with as many females as possible. Variation at the glycolytic enzyme locus phosphoglucose isomerase (Pgi) is concordant with a latitudinal temperature gradient in these populations, with Pgi-1 frequent in the cooler north, Pgi-4 in the warmer south, and alleles 1 and 4 in relatively equal frequency in areas intermediate in geography and climate. Beetles experience elevated air temperatures during a mating season that causes differential physiological stress among Pgi genotypes, and running speeds of individuals homozygous for Pgi-4 are more tolerant of repeated thermal stress than individuals possessing Pgi-1. Here the importance of running behavior for male mating activity was examined, and differential effects of thermal stress among Pgi genotypes on male mating activity were measured. In nature, males run more than females, and nearly half of males mate or fight for a mate after running. In the laboratory, mating activity was positively correlated with running speed, and repeated mating did not reduce running speed or subsequent mating activity. Males homozygous for Pgi-4 mated longer and more frequently after heat treatment than 1-1 and 1-4 males. All heat-treated males had lower mating frequencies and higher heat shock protein expression than control males; however, mating frequency of recovering 4-4 males increased throughout mating trials, while treated 1-1 and 1-4 males remained low. These results suggest that effects of stress on mating activity differ between Pgi genotypes, implying a critical role for energy metabolism in organisms' response to stressful temperatures. PMID:23799837

  17. Metabolically engineered male sterility in rapeseed (Brassica napus L.).

    PubMed

    Engelke, Thomas; Hirsche, J; Roitsch, T

    2011-01-01

    Male sterility is of special interest as a mechanism allowing hybrid breeding, especially in important crops such as rapeseed (Brassica napus). Male sterile plants are also suggested to be used as a biological safety method to prevent the spread of transgenes, a risk that is high in the case of rapeseed due to the mode of pollination, out-crossing by wind or insects, and the presence of related, cross-pollinating species in the surrounding ecosystem in Europe. Different natural occurring male sterilities and alloplasmic forms have been tried to be used in rapeseed with more or less success. Due to the difficulties and limitations with these systems, we present a biotechnological alternative: a metabolically engineered male sterility caused by interference with anther-specific cell wall-bound invertase. This is an essential enzyme for carbohydrate supply of the symplastically isolated pollen. The activity of this enzyme is reduced either by antisense interference or by expressing an invertase inhibitor under control of the anther-specific promoter of the invertase with the consequence of a strong decrease of pollen germination ability. PMID:20821307

  18. The best time to have sex: mating behaviour and effect of daylight time on male sexual competitiveness in the Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae).

    PubMed

    Benelli, Giovanni

    2015-03-01

    Aedes albopictus is the most invasive mosquito worldwide and works as a vector for many important pathogens. Control tools rely to chemical treatments against larvae, indoor residual spraying and insecticide-treated bed nets. Recently, huge efforts have been carried out to propose new eco-friendly alternatives, such as evaluation of plant-borne compounds and sterile insect technique (SIT) programs. Success of SIT is dependent to the ability of sterile males to compete for mates with wild ones. Little is still known about mating behaviour of Aedes males. Most of the studies focus on comparisons of insemination ability in sterilised and wild males, while behavioural analyses of mating behaviour are lacking. Here, I quantified the courtship and mating behaviour of A. albopictus and evaluated how daylight hours affect male mating behaviour and success. A. albopictus males chased females facing them frontally, from behind, or from a lateral side. If the female allowed genital contact, copulation followed. Otherwise, females performed rejection kicks and/or flew away. Thirty-seven percent of males obtained a successful copulation (i.e. sperm transfer occurs), lasting 63 ± 4 s. Unsuccessful copulation (20 % of males) had shorter duration (18 ± 1 s). Successful copulations followed longer male courtships (39 ± 3 s), over courtships preceding unsuccessful copulation (20 ± 2 s) or male's rejection (22 ± 2 s). After copulation, the male rested 7 ± 0.4 s close to the female, then move off. In a semi-natural environment, male mating success was lower in early afternoon, over morning and late afternoon. However, little differences in courtship duration over daylight periods were found. This study adds knowledge to the reproductive behaviour of A. albopictus, which can be used to perform comparisons among courtship and mating ethograms from different mosquito species and strains, allowing monitoring and optimisation of mass rearing quality over time in SIT programs. PMID

  19. Evaluation of sterility and fertility of male sterile lines in the USPB farm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybrid rice has proven to have a yield advantage of 15–20% over the best inbred cultivars at the commercial scale worldwide. At present, two methods have been successfully commercialized; the three-line and two-line systems. The three-line system consists of the male sterile (MS), maintainer and res...

  20. Ethical issues in male sterilization in developing countries.

    PubMed

    Rizvi, S A; Naqvi, S A; Hussain, Z

    1995-11-01

    The history of sterilization dates back to the time of Hippocrates, when female sterilization was recommended for preventing hereditary mental diseases. James Blundell introduced surgical sterilization in 1823 for the prevention of high risk pregnancies. Vasectomy was first performed in the US at the end of the 19th century, mainly to prevent hereditary disorders. Male sterilization was a means of genocide during Nazi rule in Germany. Religious beliefs have the most powerful impact on the practice or nonpractice of family planning. In the teachings of Islam, Christianity, and Judaism, only sporadic references explicitly prohibit contraception, yet various religious edicts have interpreted these references too broadly by advocating prohibition of most contraceptive methods. Recently, the world community endorsed the basic right of couples to decide the number of children they want and the right to family planning with free informed choice. An integral part of a successful family planning program is voluntarism. In Europe and North America sterilization is legal, except in Italy, France, and Turkey. In Latin America sterilization is illegal in a number of countries; in Burma and Vietnam restrictions are in place; and in Africa fertility regulation is illegal in one-third of the countries. Informed consent before sterilization during counseling by a skilled, unbiased counselor is indispensable. All family planning services should be part of the national health care system including the voluntary contraception services. Incentives may compromise voluntarism. Most programs require a minimum age and a minimum number of children, marital status, and spousal consent. For sterilization, a waiting period of 1-30 days has been recommended. The exclusion of childless and single individuals has been challenged as a violation of human rights. For mentally retarded people parents or guardians provide consent. Major ethical issues in the future could emerge concerning novel

  1. Do male breeding displays function to attract mates or defend territories? The explanatory role of mate and site fidelity

    USGS Publications Warehouse

    Lanctot, Richard B.; Sandercock, B.K.; Kempenaers, B.

    2000-01-01

    Many shorebirds show elaborate breeding displays that include aerial flights and ground displays accompanied by song. The mate attraction hypothesis suggests that breeding displays function to attract mates and maintain pair bonds, whereas the territory defense hypothesis suggests breeding displays function in defining and defending nesting and feeding territories. We tested these hypotheses in the Western Sandpiper (Calidris mauri) by contrasting the duration and level of male breeding displays among pairs that differed in their mate and site fidelity. As predicted by the mate attraction hypothesis, males performed the highest number of song sequences during pair formation, and males paired with their mate of a prior year sang less than males paired to new mates. Further, site-faithful males mated to a new but experienced mate displayed significantly more than remated males or males new to the area. This suggests a male's prior familiarity with an area and his neighbors does not lessen his display rate as was predicted under the territory defense hypothesis. Limited support for the territory defense hypothesis came from observations of males performing breeding displays with neighboring males along nest territory boundaries. This behavior was short-lived, however, as males abandoned nesting areas after pair-formation and used adjacent or disjointed feeding areas during egg-laying and incubation. Male aggression (i.e., aerial and ground chases), as opposed to breeding displays, appeared to be the principal means of maintaining territory boundaries. Indeed, the rate at which males chased other males remained fairly constant and high throughout the breeding season. Male chasing behavior may also serve as a paternity guard to protect against extra-pair copulations. Our study also found that a female's prior breeding experience in an area correlated with a reduced display rate by her mate, particularly if that mate was new to the area. This indicates female

  2. Mating system and size advantage of male mating in the protogynous swamp eel Monopterus albus with paternal care.

    PubMed

    Matsumoto, Seiji; Takeyama, Tomohiro; Ohnishi, Nobuhiro; Kohda, Masanori

    2011-05-01

    In fish with paternal care, protogynous sex change (female to male) is rare and has only been reported from species with haremic polygyny. The swamp eel, Monopterus albus, is a protogynous fish with paternal care, but little is known about its mating system. To understand protogyny in this species, we examined the mating system and male size advantage in mating in M. albus under semi-natural condition. Females swam over wide ranges and visited multiple male nests. Males defended a narrow territory around nests against other males that approached nests; at these nests, males courted and accepted visiting females. After spawning inside nests, caring males continued to perform courtship activities, and multiple breeding was observed. These observations suggest that the M. albus mating system is male-territory-visiting (MTV)-polygamy. Larger males had nests, and mated more frequently compared with small males. Because small initial males of this species are not found in nature, and because M. albus does not engage in sneaking tactics, larger nesting males do not suffer from reproductive parasitism. Thus, protogyny in this fish is likely consistent with the predictions of the size-advantage model. Biting attacks by territorial males of this predatory fish seriously wounded intruding males, occasionally resulting in the death of the intruder. We discuss the possibility that sexual differences in mortality rates in small fish may facilitate the evolution of protogyny in this species. Protogyny of the swamp eel is, to our knowledge, the first example of an MTV-polygamous mating system in a fish with paternal care. PMID:21557660

  3. Adult female hamsters avoid interspecific mating after exposure to heterospecific males

    PubMed Central

    delBarco-Trillo, Javier; McPhee, M. E.; Johnston, Robert E.

    2010-01-01

    When females mate with a heterospecific male, they do not usually produce viable offspring. Thus, there is a selective pressure for females to avoid interspecific mating. In many species, females innately avoid heterospecific males; females can also imprint on their parents to avoid later sexual interactions with heterospecific males. However, it was previously unknown whether adult females can learn to discriminate against heterospecific males. We tested the hypothesis that adult females previously unable to avoid interspecific mating learn to avoid such mating after being exposed to heterospecific males. Syrian hamster (Mesocricetus auratus) females not previously exposed to Turkish hamster (Mesocricetus brandti) males can discriminate between odors of conspecific and heterospecific males, but they mate with either type of male. However, when we exposed adult females to both a conspecific male and a heterospecific male through wire-mesh barriers for 8 days, and then paired them sequentially with the two males, females were more receptive to conspecific males and more aggressive to heterospecific males. When females were paired with the heterospecific male first and the conspecific male second, no female was receptive and all were aggressive to heterospecific males. When females were paired with the conspecific male first, only 43% of females were then aggressive toward the heterospecific male. That is, interactions with conspecific males may decrease a female’s ability to properly avoid heterospecific males. Our study clearly shows for the first time that females can learn during adulthood to avoid interspecific mating just by being exposed to stimuli from heterospecific males. PMID:20676390

  4. Mate-choice copying in Drosophila melanogaster: Impact of demonstration conditions and male-male competition.

    PubMed

    Germain, M; Blanchet, S; Loyau, A; Danchin, É

    2016-04-01

    Individuals of many species, including invertebrates, have been shown to use social information in mate choice, notably by extracting information from the mating performance of opposite sex conspecifics, a process called "mate-choice copying" (MCC). Here, we performed four experiments with Drosophila melanogaster to investigate two aspects of MCC methodology: whether (i) providing positive and negative social information simultaneously or sequentially during the demonstration phase of the protocol, and (ii) male-male competition during the mate-choice test, affect MCC. We found that the simultaneous provision of positive and negative information during demonstrations hampered female MCC performance, compared to the sequential provision of information. This can be interpreted in two alternative, yet not exclusive, ways: (i) attentional mechanisms may restrict the focus of the brain to one source of information at a time, and/or (ii) the shorter duration of demonstrations in the simultaneous protocol may have not permit full social learning use and may explain the non-detection of MCC in that protocol. Moreover, we did not detect any significant effect of male-male competition on female choice. This study thus provides further evidence for MCC in D. melanogaster and expands on the necessary methodology for detailed studies. PMID:26851455

  5. Female and male genetic contributions to post-mating immune defence in female Drosophila melanogaster.

    PubMed

    Short, Sarah M; Lazzaro, Brian P

    2010-12-01

    Post-mating reduction in immune defence is common in female insects, and a trade-off between mating and immunity could affect the evolution of immunity. In this work, we tested the capacity of virgin and mated female Drosophila melanogaster to defend against infection by four bacterial pathogens. We found that female D. melanogaster suffer post-mating immunosuppression in a pathogen-dependent manner. The effect of mating was seen after infection with two bacterial pathogens (Providencia rettgeri and Providencia alcalifaciens), though not after infection with two other bacteria (Enterococcus faecalis and Pseudomonas aeruginosa). We then asked whether the evolution of post-mating immunosuppression is primarily a 'female' or 'male' trait by assaying for genetic variation among females for the degree of post-mating immune suppression they experience and among males for the level of post-mating immunosuppression they elicit in their mates. We also assayed for an interaction between male and female genotypes to test the specific hypothesis that the evolution of a trade-off between mating and immune defence in females might be being driven by sexual conflict. We found that females, but not males, harbour significant genetic variation for post-mating immunosuppression, and we did not detect an interaction between female and male genotypes. We thus conclude that post-mating immune depression is predominantly a 'female' trait, and find no evidence that it is evolving under sexual conflict. PMID:20573620

  6. Progress in development of male sterile germplasm for hybrid rice breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, there are two types of male sterility mainly commercialized in hybrid rice production, three-line type or cytoplasmic male sterility (CMS) and two-line type or environmental male sterility (EMS). The great majority belongs to the CMS and there are four strategies that have been proven suc...

  7. Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates

    PubMed Central

    Okanda, FM; Dao, A; Njiru, BN; Arija, J; Akelo, HA; Touré, Y; Odulaja, A; Beier, JC; Githure, JI; Yan, G; Gouagna, LC; Knols, BGJ; Killeen, GF

    2002-01-01

    Background Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release. Methods Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females. Results Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches. Conclusions Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future. PMID:12296972

  8. The effect of the radio-protective agents ethanol, trimethylglycine, and beer on survival of X-ray-sterilized male Aedes aegypti

    PubMed Central

    2013-01-01

    Background Sterile Insect Technique (SIT) has been successfully implemented to control, and in some cases, eradicate, dipteran insect populations. SIT has great potential as a mosquito control method. Different sterilization methods have been used on mosquitoes ranging from chemosterilization to genetically modified sterile male mosquito strains; however, sterilization with ionizing radiation is the method of choice for effective sterilization of male insects for most species. The lack of gentle radiation methods has resulted in significant complications when SIT has been applied to mosquitoes. Several studies report that irradiating mosquitoes resulted in a decrease in longevity and mating success compared to unirradiated males. The present study explored new protocols for mosquito sterilization with ionizing radiation that minimized detrimental effects on the longevity of irradiated males. Methods We tested three compounds that have been shown to act as radioprotectors in the mouse model system - ethanol, trimethylglycine, and beer. Male Aedes aegypti were treated with one of three chosen potential radioprotectors and were subsequently irradiated with identical doses of long-wavelength X-rays. We evaluated the effect of these radioprotectors on the longevity of male mosquito after irradiation. Results We found that X-ray irradiation with an absorbed dose of 1.17 gy confers complete sterility. Irradiation with this dose significantly shortened the lifespan of male mosquitoes and all three radioprotectors tested significantly enhanced the lifespan of irradiated mosquito males. Conclusion Our results suggest that treatment with ethanol, beer, or trimethylglycine before irradiation can be used to enhance longevity in mosquitoes. PMID:23866939

  9. Mating with an allopatric male triggers immune response and decreases longevity of ant queens.

    PubMed

    Schrempf, A; von Wyschetzki, K; Klein, A; Schrader, L; Oettler, J; Heinze, J

    2015-07-01

    In species with lifelong pair bonding, the reproductive interests of the mating partners are aligned, and males and females are expected to jointly maximize their reproductive success. Mating increases both longevity and fecundity of female reproductives (queens) of the ant Cardiocondyla obscurior, indicating a tight co-evolution of mating partners. Here, we show that mating with a male from their own population increases lifespan and reproductive success of queens more than mating with a male from a different population, with whom they could not co-evolve. A comparison of transcriptomes revealed an increased expression of genes involved in immunity processes in queens, which mated with males from a different population. Increased immune response might be proximately associated with decreased lifespan. Our study suggests a synergistic co-evolution between the sexes and sheds light on the proximate mechanisms underlying the decreased fitness of allopatrically mated queens. PMID:26059759

  10. Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster.

    PubMed

    Jagadeeshan, Santosh; Shah, Ushma; Chakrabarti, Debarti; Singh, Rama S

    2015-01-01

    The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;-females therefore may have a relatively fixed 'arousal threshold' that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females' physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster. PMID:26658421

  11. Male lifetime mating success in relation to body size in Diabrotica barberi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Body size is often an important component of male lifetime mating success in insects, especially when males are capable of mating several times over their lifespan. We paired either a large or small male northern corn rootworm with a female of random size and noted copulation success. We observed co...

  12. Mating frequency of the male cactus moth Cactoblastis cactorum (Lepidoptera:Pyralidae), under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the number of times that males of the invasive cactus moth Cactoblastis cactorum (Berg) mate under laboratory conditions. Virgin females were provided to each male at 24 h intervals until male death. Females removed from the containers were dissected to ascertain their mating ...

  13. Female sticklebacks use male coloration in mate choice and hence avoid parasitized males

    NASA Astrophysics Data System (ADS)

    Milinski, Manfred; Bakker, Theo C. M.

    1990-03-01

    AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

  14. The effects of perceived mating opportunities on patterns of reproductive investment by male guppies.

    PubMed

    Barrett, Luke T; Evans, Jonathan P; Gasparini, Clelia

    2014-01-01

    Males pay considerable reproductive costs in acquiring mates (precopulatory sexual selection) and in producing ejaculates that are effective at fertilising eggs in the presence of competing ejaculates (postcopulatory sexual selection). Given these costs, males must balance their reproductive investment in a given mating to optimise their future reproductive potential. Males are therefore expected to invest in reproduction prudently according to the likelihood of obtaining future matings. In this study we tested this prediction by determining whether male reproductive investment varies with expected future mating opportunities, which were experimentally manipulated by visually exposing male guppies (Poecilia reticulata) to high or low numbers of females in the absence of competing males. Our experiment did not reveal consistent effects of perceived future mating opportunity on either precopulatory (male mate choice and mating behaviour) or postcopulatory (sperm quality and quantity) investment. However, we did find that male size and female availability interacted to influence mating behaviour; large males visually deprived of females during the treatment phase became more choosy and showed greater interest in their preferred female than those given continuous visual access to females. Overall, our results suggest males tailor pre- rather than postcopulatory traits according to local female availability, but critically, these effects depend on male size. PMID:24705713

  15. The neural circuits of mating and fighting in male mice.

    PubMed

    Hashikawa, Koichi; Hashikawa, Yoshiko; Falkner, Annegret; Lin, Dayu

    2016-06-01

    Tinbergen proposed that instinctive behaviors can be divided into appetitive and consummatory phases. During mating and aggression, the appetitive phase contains various actions to bring an animal to a social target and the consummatory phase allows stereotyped actions to take place. Here, we summarize recent advances in elucidating the neural circuits underlying the appetitive and consummatory phases of sexual and aggressive behaviors with a focus on male mice. We outline the role of the main olfactory inputs in the initiation of social approach; the engagement of the accessory olfactory system during social investigation, and the role of the hypothalamus and its downstream pathways in orchestrating social behaviors through a suite of motor actions. PMID:26849838

  16. Male dominance, female mate choice, and intersexual conflict in the rose bitterling (Rhodeus ocellatus).

    PubMed

    Casalini, Mara; Agbali, Muna; Reichard, Martin; Konecná, Markéta; Bryjová, Anna; Smith, Carl

    2009-02-01

    An intersexual conflict arises when males and females differ in their reproductive interests. Although experimental studies have shown that females often mate with dominant males, it may not always be in the interest of a female to do so. Here we investigated the impact of male dominance on female mate choice and offspring growth and survival in the rose bitterling (Rhodeus ocellatus), a freshwater fish with a resource-based mating system. Three experimental mating trials were conducted using males of known dominance rank, but with different levels of constraint on male behavior. Thus, females were able to choose among; (1) males that were isolated from each other; (2) males that could see and smell each other, but could not directly interact; (3) males that could interact fully. Using a combination of behavioral observation and parentage analyses it was shown that female preferences did not correspond with male dominance and that male aggression and dominance constrained female mate choice, resulting in a potential intersexual conflict. The survival of offspring to independence was significantly correlated with female mate preferences, but not with male dominance. A lack of strong congruence in female preference for males suggested a role for parental haplotype compatibility in mate choice. PMID:19154367

  17. Pushy males and choosy females: courtship disruption and mate choice in the lekking great snipe

    PubMed Central

    ther, S. A. S; Fiske, P.; s, J. A. K l

    1999-01-01

    We studied the effects of male disruptive behaviour on female mate choice and male mating success in the great snipe, Gallinago media, a lekking bird. Harassment from neighbouring males, a widespread behaviour in lekking animals, was the most prevalent cause of females leaving a male territory. Several lines of evidence show that females did not prefer to mate with males able to protect them from harassment. Males that obtained mating success were no less likely to suffer disruptions and females were no less likely to be disrupted when with their preferred male. Females returned to the male they later mated with, despite being repeatedly chased away by neighbours. The probability that an individual female returned and solicited mating from a male was 15 times higher for the male she was chased away from compared to the neighbour that chased her away. Females returned as often or more to the territory owner after being disrupted, compared to after leaving the territory without being harassed. Our results suggest that female great snipes are extremely choosy, but also that females do not gain direct benefits (harassment avoidance) by mating with certain males. Females appear to have neither direct nor indirect preferences for dominance that could give them such benefits: females appeared choosy despite, not because of, harassment. If females gain indirect benefits (genetically superior offspring) by being choosy, this is also likely to be unrelated to any dominance among males.

  18. Mating sequence, dominance and paternity success in captive male tammar wallabies.

    PubMed

    Hynes, Emily F; Rudd, Carl D; Temple-Smith, Peter D; Sofronidis, George; Paris, Damien; Shaw, Geoff; Renfree, Marilyn B

    2005-07-01

    The tammar wallaby (Macropus eugenii) is a small, promiscuous, macropodid marsupial. Females usually produce a single young each year and there is a clear dominance hierarchy between adult males. The dominant male usually mates first and then guards the female to prevent access to her by other males. In this study, agonistic encounters and mating behaviour were observed to determine male dominance hierarchies in six groups of captive tammars consisting of a total of 23 males and 50 females. Mating behaviour was observed immediately post-partum when females were in oestrus and was correlated with plasma testosterone concentrations. Male mating sequences were recorded, and the paternity of offspring was determined by using seven macropodid marsupial microsatellites. Rates of sexual checking and aggression by males housed with females in oestrus in the non-breeding season were lower than in the breeding season. These males also had lower concentrations of testosterone, but were still able to sire young. High testosterone concentrations neither ensured dominance nor appeared to control directly the level of sexual activity. Females usually mated with more than one male. The dominant male most often secured the initial copulation (60%), but the first-mating male did not always secure parentage, with second and third matings resulting in as many young as first matings. Using these data, we were unable to discount first sire, last sire or equal chance models of paternity in this species. Half the young (50%) were sired by the dominant alpha male, but of the remaining progeny, the beta male sired more (35%) than gamma and delta males (15%). Dominance therefore is only a moderately effective predictor of paternity in the tammar. Although the dominant males gained most first matings and individually sired half of the offspring, the subdominant males still contributed significantly to the population, at least in captivity. PMID:15985638

  19. Do female Nicrophorus vespilloides reduce direct costs by choosing males that mate less frequently?

    PubMed Central

    Mazué, G. P. F.; Carter, M. J.; Head, M. L.; Moore, A. J.; Royle, N. J.

    2016-01-01

    Sexual conflict occurs when selection to maximize fitness in one sex does so at the expense of the other sex. In the burying beetle Nicrophorus vespilloides, repeated mating provides assurance of paternity at a direct cost to female reproductive productivity. To reduce this cost, females could choose males with low repeated mating rates or smaller, servile males. We tested this by offering females a dichotomous choice between males from lines selected for high or low mating rate. Each female was then allocated her preferred or non-preferred male to breed. Females showed no preference for males based on whether they came from lines selected for high or low mating rates. Pairs containing males from high mating rate lines copulated more often than those with low line males but there was a negative relationship between female size and number of times she mated with a non-preferred male. When females bred with their preferred male the number of offspring reared increased with female size but there was no such increase when breeding with non-preferred males. Females thus benefited from being choosy, but this was not directly attributable to avoidance of costly male repeated mating. PMID:26979560

  20. Do female Nicrophorus vespilloides reduce direct costs by choosing males that mate less frequently?

    PubMed

    Hopwood, P E; Mazué, G P F; Carter, M J; Head, M L; Moore, A J; Royle, N J

    2016-03-01

    Sexual conflict occurs when selection to maximize fitness in one sex does so at the expense of the other sex. In the burying beetle Nicrophorus vespilloides, repeated mating provides assurance of paternity at a direct cost to female reproductive productivity. To reduce this cost, females could choose males with low repeated mating rates or smaller, servile males. We tested this by offering females a dichotomous choice between males from lines selected for high or low mating rate. Each female was then allocated her preferred or non-preferred male to breed. Females showed no preference for males based on whether they came from lines selected for high or low mating rates. Pairs containing males from high mating rate lines copulated more often than those with low line males but there was a negative relationship between female size and number of times she mated with a non-preferred male. When females bred with their preferred male the number of offspring reared increased with female size but there was no such increase when breeding with non-preferred males. Females thus benefited from being choosy, but this was not directly attributable to avoidance of costly male repeated mating. PMID:26979560

  1. Effect of day and night temperature on the expression of male sterility of nuclear male-sterile (ms8ms8) soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In soybean [Glycine max (L.) Merr.], an environmentally stable male-sterility system is one of the requirements to produce large quantities of hybrid seed. Observations of the nuclear male-sterile, female-fertile mutant ms8ms8 in different environments suggested that environmental conditions affect...

  2. Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae).

    PubMed

    Wang, Qiao; He, Xiong Zhao; Yang, Linghuan; Hedderley, Duncan; Davis, Lorraine K

    2009-01-01

    Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out a series of mating trials to test how these variables affected male mating success. The two demographic factors had no significant interactions, suggesting that they affect male mating success independently in N. huttoni. In this species male mating success was significantly higher in both male- and female-biased OSR than in even OSR. It is suggested that, in male-biased OSR, the increased intensity of competition and interference does not result in lower male mating success; rather, males may make more effort in courting and females may have more chance to encounter better males, resulting in higher male mating success. In female-biased OSR, females may become less choosy and less likely to reject male mating attempt, leading to the higher male mating success. Lower male mating success in N. huttoni in high LPD may be due to increased interference between males and/or delayed female receptiveness for mating. OSR had a stronger effect on male mating success than LPD in N. huttoni, suggesting that OSR and LPD affect mating success in different ways and intensities. PMID:18839127

  3. Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)

    NASA Astrophysics Data System (ADS)

    Wang, Qiao; He, Xiong Zhao; Yang, Linghuan; Hedderley, Duncan; Davis, Lorraine K.

    2009-01-01

    Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out a series of mating trials to test how these variables affected male mating success. The two demographic factors had no significant interactions, suggesting that they affect male mating success independently in N. huttoni. In this species male mating success was significantly higher in both male- and female-biased OSR than in even OSR. It is suggested that, in male-biased OSR, the increased intensity of competition and interference does not result in lower male mating success; rather, males may make more effort in courting and females may have more chance to encounter better males, resulting in higher male mating success. In female-biased OSR, females may become less choosy and less likely to reject male mating attempt, leading to the higher male mating success. Lower male mating success in N. huttoni in high LPD may be due to increased interference between males and/or delayed female receptiveness for mating. OSR had a stronger effect on male mating success than LPD in N. huttoni, suggesting that OSR and LPD affect mating success in different ways and intensities.

  4. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps

    PubMed Central

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J.; Vermeulen, Cornelis J.; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G.; Schmitt, Thomas; Beukeboom, Leo W.

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  5. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps.

    PubMed

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J; Vermeulen, Cornelis J; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G; Schmitt, Thomas; Beukeboom, Leo W

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  6. The importance of female choice, male-male competition, and signal transmission as causes of selection on male mating signals.

    PubMed

    Sullivan-Beckers, Laura; Cocroft, Reginald B

    2010-11-01

    Selection on advertisement signals arises from interacting sources including female choice, male-male competition, and the communication channel (i.e., the signaling environment). To identify the contribution of individual sources of selection, we used previously quantified relationships between signal traits and each putative source to predict relationships between signal variation and fitness in Enchenopa binotata treehoppers (Hemiptera: Membracidae). We then measured phenotypic selection on signals and compared predicted and realized relationships between signal traits and mating success. We recorded male signals, then measured lifetime mating success at two population densities in a realistic environment in which sources of selection could interact. We identified which sources best predicted the relationship between signal variation and mating success using a multiple regression approach. All signal traits were under selection in at least one of the two breeding seasons measured, and in some cases selection was variable between years. Female preference was the strongest source of selection shaping male signals. The E. binotata species complex is a model of ecological speciation initiated by host shifts. Signal and preference divergence contribute to behavioral isolation within the complex, and the finding that female mate preferences drive signal evolution suggests that speciation in this group results from both ecological divergence and sexual selection. PMID:20624180

  7. Improving mating performance of mass-reared sterile Mediterranean fruit flies (Diptera: Tephritidae) through changes in adult holding conditions: demography and mating competitiveness

    SciTech Connect

    Liedo, P.; Salgado, S.; Oropeza, A.; Toledo, J.

    2007-03-15

    with wild flies. As colonization progressed, life expectancy and fecundity rates increased in the 3 rearing systems. There was no significant difference in standard quality control parameters among the 3 rearing systems. Wild males always achieved more matings than any of the mass reared males. Mating competitiveness of males from the IS, although surprisingly not from the SS, was significantly greater than that of males from the MS. Our results indicate that these slight changes in the adult holding conditions can significantly reduce the harmful effects of mass rearing on the mating performance of sterile flies. (author) [Spanish] Se ha demostrado que las condiciones de cria masiva afectan el comportamiento de apareamiento de la mosca del Mediterraneo Ceratitis capitata (Wiedemann). Nosotros evaluamos el efecto de ligeros cambios en las condiciones en las que los adultos son mantenidos para la produccion de huevos, en el desempeno de apareamiento de las moscas esteriles. La colonizacion se inicio con moscas silvestres colectadas como larvas en cerezas de cafe (Coffea arabica L.) infestadas. Cuando las pupas estuvieron cerca de la emergencia de los adultos, se dividieron en tres grupos al azar y los adultos recien emergidos fueron criados en las siguientes condiciones: (1) Sistema Metapa (MS, testigo), consistente en jaulas con marco de aluminio de 70 x 45 x 15 cm, cubiertas con malla, con una densidad de 2,200 moscas por jaula y una relacion de sexos inicial de 1:1; (2); Sistema Insertos (IS), con el mismo tipo de jaula, densidad de moscas, y relacion de sexos que en el MS, pero conteniendo 12 piezas de plexiglas (23 x 8.5 cm) para proporcionar superficie horizontal al interior de la jaula; y (3) Sistema de Relacion de Sexos (SS), igual que el IS, pero en este caso la relacion inicial macho: hembra fue de 4:1, tres dias despues se introdujeron hembras recien emergidas para tener una relacion de 3:1 y en el 6 dia se anadio otro grupo de hembras para tener una relacion

  8. Roving females and patient males: a new perspective on the mating strategies of chimpanzees.

    PubMed

    Newton-Fisher, Nicholas E

    2014-05-01

    Mating strategies are sets of decisions aimed at maximizing reproductive success. For male animals, the fundamental problem that these strategies address is attaining mating access to females in a manner that maximizes their chances of achieving paternity. For chimpanzees (Pan troglodytes), despite substantial interest in mating strategies, very little attention has been paid to the most fundamental problem that mating strategies need to solve: finding mates. Only a single model, Dunbar's general model of male mating strategies, exists to explain mate-searching behaviour in chimpanzees. Under this model, males in most populations are regarded as pursuing a 'roving' strategy: searching for and sequestering fertile females who are essentially passive with respect to mate searching. The roving mating strategy is an assumption deeply embedded in the way chimpanzee behaviour is considered; it is implicit in the conventional model for chimpanzee social structure, which posits that male ranging functions both to monitor female reproductive state and to ward these females from other groups of males through collective territoriality: essentially, ranging as mating effort. This perspective is, however, increasingly at odds with observations of chimpanzee behaviour. Herein, I review the logic and evidence for the roving-male mating strategy and propose a novel alternative, a theoretical framework in which roving is a strategy pursued by female chimpanzees in order to engage successfully in promiscuous mating. Males, unable to thwart this female strategy, instead maximise the number of reproductive opportunities encountered by focusing their behaviour on countering threats to health, fertility and reproductive career. Their prolonged grooming bouts are seen, in consequence, as functioning to mitigate the negative impacts of socially induced physiological stress. In this new framework, the roving-male strategy becomes, at best, a 'best of a bad job' alternative for low

  9. Female and Male Moths Display Different Reproductive Behavior when Facing New versus Previous Mates

    PubMed Central

    Lu, Qin; Xu, Jin; Ye, Hui

    2014-01-01

    Multiple mating allows females to obtain material (more sperm and nutrient) and/or genetic benefits. The genetic benefit models require sperm from different males to fertilize eggs competitively or the offspring be fathered by multiple males. To maximize genetic benefits from multiple mating, females have evolved strategies to prefer novel versus previous mates in their subsequent matings. However, the reproductive behavior during mate encounter, mate choice and egg laying in relation to discrimination and preference between sexes has been largely neglected. In the present study, we used novel and previous mate treatments and studied male and female behavior and reproductive output in Spodoptera litura. The results of this study do not support the sperm and nutrient replenishment hypotheses because neither the number of mates nor the number of copulations achieved by females significantly increased female fecundity, fertility and longevity. However, females showed different oviposition patterns when facing new versus previous mates by slowing down oviposition, which allows the last male has opportunities to fertilize her eggs and the female to promote offspring diversity. Moreover, females that have novel males present called earlier and more than females that have their previous mates present, whereas no significant differences were found on male courtship between treatments. These results suggest that S. litura females can distinguish novel from previous mates and prefer the former, whereas males generally remate regardless of whether the female is a previous mate or not. In S. litura, eggs are laid in large clusters and offspring competition, inbreeding and disease transfer risks are thus increased. Therefore, offspring diversity should be valuable for S. litura, and genetic benefits should be the main force behind the evolution of female behavioral strategies found in the present study. PMID:25290195

  10. Female and male moths display different reproductive behavior when facing new versus previous mates.

    PubMed

    Li, Yan-Ying; Yu, Jin-Feng; Lu, Qin; Xu, Jin; Ye, Hui

    2014-01-01

    Multiple mating allows females to obtain material (more sperm and nutrient) and/or genetic benefits. The genetic benefit models require sperm from different males to fertilize eggs competitively or the offspring be fathered by multiple males. To maximize genetic benefits from multiple mating, females have evolved strategies to prefer novel versus previous mates in their subsequent matings. However, the reproductive behavior during mate encounter, mate choice and egg laying in relation to discrimination and preference between sexes has been largely neglected. In the present study, we used novel and previous mate treatments and studied male and female behavior and reproductive output in Spodoptera litura. The results of this study do not support the sperm and nutrient replenishment hypotheses because neither the number of mates nor the number of copulations achieved by females significantly increased female fecundity, fertility and longevity. However, females showed different oviposition patterns when facing new versus previous mates by slowing down oviposition, which allows the last male has opportunities to fertilize her eggs and the female to promote offspring diversity. Moreover, females that have novel males present called earlier and more than females that have their previous mates present, whereas no significant differences were found on male courtship between treatments. These results suggest that S. litura females can distinguish novel from previous mates and prefer the former, whereas males generally remate regardless of whether the female is a previous mate or not. In S. litura, eggs are laid in large clusters and offspring competition, inbreeding and disease transfer risks are thus increased. Therefore, offspring diversity should be valuable for S. litura, and genetic benefits should be the main force behind the evolution of female behavioral strategies found in the present study. PMID:25290195

  11. Male sterility and enhanced radiation sensitivity in TLS(-/-) mice.

    PubMed

    Kuroda, M; Sok, J; Webb, L; Baechtold, H; Urano, F; Yin, Y; Chung, P; de Rooij, D G; Akhmedov, A; Ashley, T; Ron, D

    2000-02-01

    TLS (also known as FUS) is an RNA-binding protein that contributes the N-terminal half of fusion oncoproteins implicated in the development of human liposarcomas and leukemias. Here we report that male mice homozygous for an induced mutation in TLS are sterile with a marked increase in the number of unpaired and mispaired chromosomal axes in pre-meiotic spermatocytes. Nuclear extracts from TLS(-/-) testes lack an activity capable of promoting pairing between homologous DNA sequences in vitro, and TLS(-/-) mice and embryonic fibroblasts exhibit increased sensitivity to ionizing irradiation. These results are consistent with a role for TLS in homologous DNA pairing and recombination. PMID:10654943

  12. Identification of molecular markers linked to a new nuclear male-sterility gene ms7 in sunflower (Helianthus annuus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nuclear male sterility (NMS) is an important alternative system to the cytoplasm male sterility (CMS) in hybrid breeding programs because of its stable male sterility and abundant available restorer resources. For sunflower (Helianthus annuus L.), NMS 89-552, a nuclear male-sterile mutant induced by...

  13. Female aggression and the maintenance of monogamy: female behaviour predicts male mating status in European starlings

    PubMed Central

    Sandell, M. I.

    1998-01-01

    Any reduction in the fitness of a breeding female induced by the settlement of additional females with her mate creates a conflict between the sexes over mating system. In birds, females are often aggressive towards other females but few studies have been able to quantify the importance of female-female aggression for the maintenance of monogamy. This study of the European starling, Sturnus vulgaris, quantifies male and female behaviour towards a potential prospecting female, presented in a cage during the pre-laying period, and relates it to the subsequent mating status of the male. A solitary breeding male was given the opportunity to attract an additional mate, which almost half of the males did. No biometric characters of the male or female were related to the subsequent mating status. Males demonstrated mate-attraction behaviour towards the caged female but the behaviour of the male did not predict the likelihood to attract an additional female. However, the proportion of time that the female spent near the potential settler was related to mating status, indicating that females that reacted more strongly towards a potential female competitor maintained their monogamous status. These results suggest that female behaviour may play an important role in shaping the mating system of facultatively polygynous species.

  14. Low-quality females prefer low-quality males when choosing a mate

    PubMed Central

    Holveck, Marie-Jeanne; Riebel, Katharina

    2010-01-01

    Mate choice studies routinely assume female preferences for indicators of high quality in males but rarely consider developmental causes of within-population variation in mating preferences. By contrast, recent mate choice models assume that costs and benefits of searching or competing for high-quality males depend on females' phenotypic quality. A prediction following from these models is that manipulation of female quality should alter her choosiness or even the direction of her mating preferences. We here provide (to our knowledge) the first example where an experimental manipulation of female quality induced a mating preference for low-quality males. Zebra finches (Taeniopygia guttata) reared in small or large experimental broods became high- or low-quality adults, respectively. Only high-quality females preferred high-quality males' mate-advertising songs, while all low-quality females preferred low-quality males' song. Subsequent breeding trials confirmed this pattern: latency until egg laying was shortest in quality-matched pairs, indicating that quality-matched birds were accepted faster as partners. Females produced larger eggs when mated with high-quality males, regardless of their own quality, indicating consensus regarding male quality despite the expression of different choices. Our results demonstrate the importance of considering the development of mating preferences to understand their within-population variation and environmentally induced change. PMID:19812084

  15. Low-quality females prefer low-quality males when choosing a mate.

    PubMed

    Holveck, Marie-Jeanne; Riebel, Katharina

    2010-01-01

    Mate choice studies routinely assume female preferences for indicators of high quality in males but rarely consider developmental causes of within-population variation in mating preferences. By contrast, recent mate choice models assume that costs and benefits of searching or competing for high-quality males depend on females' phenotypic quality. A prediction following from these models is that manipulation of female quality should alter her choosiness or even the direction of her mating preferences. We here provide (to our knowledge) the first example where an experimental manipulation of female quality induced a mating preference for low-quality males. Zebra finches (Taeniopygia guttata) reared in small or large experimental broods became high- or low-quality adults, respectively. Only high-quality females preferred high-quality males' mate-advertising songs, while all low-quality females preferred low-quality males' song. Subsequent breeding trials confirmed this pattern: latency until egg laying was shortest in quality-matched pairs, indicating that quality-matched birds were accepted faster as partners. Females produced larger eggs when mated with high-quality males, regardless of their own quality, indicating consensus regarding male quality despite the expression of different choices. Our results demonstrate the importance of considering the development of mating preferences to understand their within-population variation and environmentally induced change. PMID:19812084

  16. Effects of diet, ginger root oil, and elevation on the mating competitiveness of male Mediterranean fruit flies (Diptera: Tephritidae) from a mass-reared, genetic sexing strain in Guatemala.

    PubMed

    Shelly, Todd E; Rendon, Pedro; Hernandez, Emilio; Salgado, Sergio; McInnis, Donald; Villalobos, Ethel; Liedo, Pablo

    2003-08-01

    The release of sterile males is a key component of an areawide program to eradicate the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), from Guatemala and southern Mexico. The objective of our study was to assess the effects of adult diet, exposure to ginger root oil (Zingiber officinale Roscoe), and elevation on the mating competitiveness of the sterile males used in an areawide program. Sterile males were maintained on a protein-sugar (protein-fed) or a sugar-only (protein-deprived) diet and were exposed (for 4 h 1 d before testing) or not exposed to ginger root oil. In field-cage trials conducted at a high (1,500 m) and low (700 m) site, we monitored the influence of these treatments on the mating success of sterile males in competition with wild males (reared exclusively on the protein-sugar diet and without ginger root oil exposure) for wild females. Elevation and ginger root oil exposure had significant effects, with sterile males having higher mating success at the low-elevation site and ginger root oil-exposed males having greater success than ginger root oil-deprived males at both sites. Diet did not have a significant overall effect, and its influence varied with elevation (dietary protein seemed to provide an advantage at the high-elevation site but not at the low-elevation site). Possible implications of these findings for eradication programs against the Mediterranean fruit fly are discussed. PMID:14503584

  17. Females prefer carotenoid colored males as mates in the pentamorphic livebearing fish, Poecilia parae.

    PubMed

    Bourne, Godfrey R; Breden, Felix; Allen, Teresa C

    2003-09-01

    The first results of female preference and chosen male mating success in a new model organism, the pentamorphic livebearing fish, Poecilia parae, are presented. Poecilia parae is a relative of the guppy, P. reticulata, and is assumed to have similar reproductive behavior. We tested the hypothesis that P. parae females, like female guppies, prefer carotenoid colored males as mates. Here we show that the time a female spent with males was significantly greater for carotenoid coloration in red and yellow melanzona, but time with these two morphs did not differ. The preferred red and yellow males mated significantly more often with their choosing females than did the non-preferred blue and parae males. The few blue melanzona and parae males that mated did so without performing courtship displays. Some females mated with all phenotypes including immaculata males during open group trials. Female P. parae clearly preferred males with carotenoid coloration, thereby corroborating the hypothesis. Alternative male mating tactics by blue melanzona, parae, and immaculata morphs and promiscuous mating by females also resembled features of reproductive behaviors exhibited by guppies. PMID:14504782

  18. All Male Strains and Chemical Stimulants: Two Ways to Boost Sterile Males in SIT Programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic and chemical means have been developed to significantly improve the effectiveness of the sterile insect technique against tephritid fruit flies in recent years. Beginning with the development of genetic sexing techniques some 25 years ago, all-male strains of several species of fruit flies h...

  19. Or47b-neurons promote male-mating success in Drosophila

    PubMed Central

    Lone, Shahnaz Rahman; Venkataraman, Archana; Srivastava, Manishi; Potdar, Sheetal; Sharma, Vijay Kumar

    2015-01-01

    Drosophila performs elaborate well-defined rituals of courtship, which involve several types of sensory inputs. Here, we report that Or47b-neurons promote male-mating success. Males with Or47b-neurons silenced/ablated exhibit reduced copulation frequency and increased copulation latency. Copulation latency of Or47b-manipulated flies increased proportionately with size of the assay arena, whereas in controls it remained unchanged. While competing for mates, Or47b-ablated males are outperformed by intact controls. These results suggest the role of Or47b-neurons in promoting male-mating success. PMID:26018835

  20. Mating system and sex ratios of a pollinating fig wasp with dispersing males.

    PubMed Central

    Greeff, Jaco M

    2002-01-01

    Recent studies have used sex ratios to quantify the mating systems of organisms, the argument behind it being that more female-biased sex ratios are an indication of higher local mate competition, which goes hand-in-hand with higher levels of inbreeding. Although qualitative tests of the effects of mating systems on sex ratios abound, there is a dearth of studies that quantify both the mating system and the sex ratio. I use a colour dimorphism with a simple Mendelian inheritance to quantify the mating system of an unusual fig-pollinating wasp in which males disperse to obtain matings on non-natal mating patches. In qualitative agreement with initial expectations, the sex ratios of single foundresses are found to be higher than those of regular species. However, by quantifying the mating system, it is shown that the initial expectation is incorrect and this species' sex ratio is a poor predictor of its mating system (it underestimates the frequency of sib-mating). The species has a very high variance in sex ratio suggesting that excess males can simply avoid local mate competition (and hence a lowered fitness to their mother) by dispersing to other patches. PMID:12495498

  1. Genetic studies on cytoplasmic male sterility in maize

    SciTech Connect

    Laughnan, J.R.

    1992-01-01

    Our research concerns the basic mechanisms of cytoplasmic male sterility (CMS) and fertility restoration in maize. The molecular determination of CMS is in the DNA of the mitochondria (mtDNA) but specific nuclear restorer-of-fertility (Rf) genes can overrule the male-sterile effect of the cytoplasm. Our approach to the study of the Rf genes is threefold. We are attempting to tag the cms-S Rf genes and the cms-T Rf2 gene with controlling elements (CEs). Since we have identified a number of spontaneous Rf genes for cms-S and have demonstrated that they are themselves transposable, we are also searching for cases in which an Rf gene is inserted into a wild-type gene. The other aspect of our research involves the nuclear control over the organization of the mitochondrial genome. We found that the changes in mtDNA organization upon cytoplasmic reversion to fertility were characteristic of the nuclear background in which the reversion event occurred. We have investigated whether these differences are a reflection of differences in the organization of the mtDNA genome before reversion.

  2. Condition-dependent ejaculate production affects male mating behavior in the common bedbug Cimex lectularius.

    PubMed

    Kaldun, Bettina; Otti, Oliver

    2016-04-01

    Food availability in the environment is often low and variable, constraining organisms in their resource allocation to different life-history traits. For example, variation in food availability is likely to induce condition-dependent investment in reproduction. Further, diet has been shown to affect ejaculate size, composition and quality. How these effects translate into male reproductive success or change male mating behavior is still largely unknown. Here, we concentrated on the effect of meal size on ejaculate production, male reproductive success and mating behavior in the common bedbug Cimex lectularius. We analyzed the production of sperm and seminal fluid within three different feeding regimes in six different populations. Males receiving large meals produced significantly more sperm and seminal fluid than males receiving small meals or no meals at all. While such condition-dependent ejaculate production did not affect the number of offspring produced after a single mating, food-restricted males could perform significantly fewer matings than fully fed males. Therefore, in a multiple mating context food-restricted males paid a fitness cost and might have to adjust their mating strategy according to the ejaculate available to them. Our results indicate that meal size has no direct effect on ejaculate quality, but food availability forces a condition-dependent mating rate on males. Environmental variation translating into variation in male reproductive traits reveals that natural selection can interact with sexual selection and shape reproductive traits. As males can modulate their ejaculate size depending on the mating situation, future studies are needed to elucidate whether environmental variation affecting the amount of ejaculate available might induce different mating strategies. PMID:27066237

  3. The role of male age, sperm age and mating history on fecundity and fertilization success in the hide beetle.

    PubMed Central

    Jones, Therésa M.; Elgar, Mark A.

    2004-01-01

    Models of age-related mate choice predict female preference for older males as they have proven survival ability. However, these models rarely address differences in sperm age and male mating history when evaluating the potential benefits to females from older partners. We used a novel experimental design to assess simultaneously the relative importance of these three parameters in the hide beetle, Dermestes maculatus. In a two-part experiment we first explored age-related male mating success and subsequently examined the consequences of male age, sperm age and male mating history on female fecundity and fertilization success. In a competitive mating environment, intermediate-age males gained significantly higher mating success than younger or older males. To test the consequences for females of aged-related male mating success, a second set of females were mated to males varying in age (young, intermediate-age and old), in numbers of matings and in timing of the most recent mating. We found that male age had a significant impact on female fecundity and fertilization success. Females mated to intermediate-age males laid more eggs and attained consistently higher levels of fertilization success than females with young and old mates. A male's previous mating history determined his current reproductive effort; virgin males spent longer in copula than males with prior mating opportunities. However, differences in copulation duration did not translate into increased fecundity or fertilization success. There was also little evidence to suggest that fertilization success was dependent on the age of a male's sperm. The experiment highlights the potential direct benefits accrued by females through mating with particular aged males. Such benefits are largely ignored by traditional viability models of age-related male mating success. PMID:15306356

  4. Male coercion and the costs of promiscuous mating for female chimpanzees

    PubMed Central

    Muller, Martin N; Kahlenberg, Sonya M; Emery Thompson, Melissa; Wrangham, Richard W

    2007-01-01

    For reasons that are not yet clear, male aggression against females occurs frequently among primates with promiscuous mating systems. Here, we test the sexual coercion hypothesis that male aggression functions to constrain female mate choice. We use 10 years of behavioural and endocrine data from a community of wild chimpanzees (Pan troglodytes schweinfurthii) to show that sexual coercion is the probable primary function of male aggression against females. Specifically, we show that male aggression is targeted towards the most fecund females, is associated with high male mating success and is costly for the victims. Such aggression can be viewed as a counter-strategy to female attempts at paternity confusion, and a cost of multi-male mating. PMID:17264062

  5. Female mating strategy and male brood cannibalism in a sand-dwelling cardinalfish.

    PubMed

    Okuda

    1999-08-01

    I investigated male and female sexual strategies of a cardinalfish, Apogon niger, which breeds in sandy areas at sporadic coral colonies. Males mouthbrood an egg mass received from one female at a time. Because of the lengthy mouthbrooding period, the interspawning interval was shorter for females than for males. Females moved between coral colonies to find mates more extensively than did males, and more frequently deserted mates after spawning. The females shortened their interspawning intervals by changing mates, especially in the late breeding season, when their mobility was highest. Their mobility was positively correlated with their disappearance rate, suggesting that mate search increases mortality. This may reduce competition between females for males, resulting in an unbiased rather than female-biased operational sex ratio. Males, on the other hand, practised filial cannibalism of entire broods, which might allow them partially to compensate for the lack of food during the mouthbrooding period. The reproductive loss entailed by filial cannibalism could be effectively offset if males remate soon afterwards. However, cannibal males took a long time to remate because few females were available. Filial cannibalism was less frequent than in a boulder-dwelling congener in which males have easy access to mates. Low mate availability may inhibit male A. niger from committing filial cannibalism. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10458878

  6. Mating Experience and Food Deprivation Modulate Odor Preference and Dispersal in Drosophila melanogaster Males

    PubMed Central

    Wang, Shu-Ping; Guo, Wei-Yan; Muhammad, Shahid Arain; Chen, Rui-Rui; Mu, Li-Li; Li, Guo-Qing

    2014-01-01

    Rotting fruits offer all of the known resources required for the livelihood of Drosophila melanogaster Meigen (Diptera: Drosophilidae). During fruit fermentation, carbohydrates and proteins are decomposed to produce volatile alcohols and amines, respectively. It is hypothesized that D. melanogaster adults can detect these chemical cues at a distance to identify and locate the decaying fruits. In the present paper, we compared the olfactory responses and movement of male flies varying in mating status and nutritional state to methanol, ethanol, and ammonia sources using a glass Y-tube olfactometer. In general, ethanol vapor at low to moderate concentrations repelled more hungry mated males than satiated ones. In contrast, methanol showed little difference in the attractiveness to males at different nutritional states and mating status. Moreover, ammonia attracted more hungry mated males. The attractiveness increased almost linearly with ammonia concentration from lowest to highest. When ammonia and artificial diet were put together in the odor arm, the responses of male flies to mixed odor mimicked the response to ammonia. Furthermore, odorant concentration, mating status, and nutritional state affected the flies' dispersal. Mated and starved males dispersed at a higher rate than virgin and satiated ones. Thus, our results showed that starved, mated males increased dispersal and preferred ammonia that originated from protein. PMID:25368075

  7. Low mate encounter rate increases male risk taking in a sexually cannibalistic praying mantis.

    PubMed

    Brown, William D; Muntz, Gregory A; Ladowski, Alexander J

    2012-01-01

    Male praying mantises are forced into the ultimate trade-off of mating versus complete loss of future reproduction if they fall prey to a female. The balance of this trade-off will depend both on (1) the level of predatory risk imposed by females and (2) the frequency of mating opportunities for males. We report the results of a set of experiments that examine the effects of these two variables on male risk-taking behavior and the frequency of sexual cannibalism in the praying mantis Tenodera sinensis. We experimentally altered the rate at which males encountered females and measured male approach and courtship behavior under conditions of high and low risk of being attacked by females. We show that male risk taking depends on prior access to females. Males with restricted access to females showed greater risk-taking behavior. When males were given daily female encounters, they responded to greater female-imposed risk by slowing their rate of approach and remained a greater distance from a potential mate. In contrast, males without recent access to mates were greater risk-takers; they approached females more rapidly and to closer proximity, regardless of risk. In a second experiment, we altered male encounter rate with females and measured rates of sexual cannibalism when paired with hungry or well-fed females. Greater risk-taking behavior by males with low mate encounter rates resulted in high rates of sexual cannibalism when these males were paired with hungry females. PMID:22558146

  8. Specific expression in reproductive tissues and fate of a mitochondrial sterility-associated protein in cytoplasmic male-sterile bean.

    PubMed Central

    Abad, A R; Mehrtens, B J; Mackenzie, S A

    1995-01-01

    In common bean, cytoplasmic male sterility has been associated with a unique sequence found in the mitochondrial genome, designated pvs (for Phaseolus vulgaris sterility sequence). Within the pvs sequence, two open reading frames are encoded, ORF98 and ORF239. We have raised rabbit polyclonal antibodies against Pvs-ORF239 to evaluate the role of this putative male sterility-associated protein. Histological investigation of pollen development revealed that in the male-sterile bean line, callose deposition was abnormal and microspores remained as tetrads as previously reported. Pvs-ORF239 was found to be localized within the reproductive tissues of the male-sterile bean line, in contrast to all other cytoplasmic male sterility systems studied to date. This protein was associated with mitochondria, the callose layer, and developing primary cell walls during microsporogenesis. Expression of pvs-orf239 was not detected in fertile plants containing restorer gene Fr2. These observations, together with previous reports, suggest that nuclear restorer gene Fr2 interferes with expression of the pvs region post-transcriptionally. PMID:7734962

  9. An experimental test of condition-dependent male and female mate choice in zebra finches.

    PubMed

    Holveck, Marie-Jeanne; Geberzahn, Nicole; Riebel, Katharina

    2011-01-01

    In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences), sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology). While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study. PMID:21901147

  10. An Experimental Test of Condition-Dependent Male and Female Mate Choice in Zebra Finches

    PubMed Central

    Holveck, Marie-Jeanne; Geberzahn, Nicole; Riebel, Katharina

    2011-01-01

    In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences), sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology). While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study. PMID:21901147

  11. Transgenic male mating advantage provides opportunity for Trojan gene effect in a fish.

    PubMed

    Howard, Richard D; DeWoody, J Andrew; Muir, William M

    2004-03-01

    Genetically modified (GM) strains now exist for many organisms, producing significant promise for agricultural production. However, if these organisms have some fitness advantage, they may also pose an environmental harm when released. High mating success of GM males relative to WT males provides such an important fitness advantage. Here, we provide documentation that GM male medaka fish modified with salmon growth hormone possess an overwhelming mating advantage. GM medaka offspring possess a survival disadvantage relative to WT, however. When both of these fitness components are included in our model, the transgene is predicted to spread if GM individuals enter wild populations (because of the mating advantage) and ultimately lead to population extinction (because of the viability disadvantage). Mating trials indicate that WT males use alternative mating tactics in an effort to counter the mating advantage of GM males, and we use genetic markers to ascertain the success of these alternative strategies. Finally, we model the impact of alternative mating tactics by WT males on transgene spread. Such tactics may reduce the rate of transgene spread, but not the outcome. PMID:14976259

  12. Evaluating the potential of the sterile insect technique for malaria control: relative fitness and mating compatibility between laboratory colonized and a wild population of Anopheles arabiensis from the Kruger National Park, South Africa

    PubMed Central

    2011-01-01

    Background The successful suppression of a target insect population using the sterile insect technique (SIT) partly depends on the premise that the laboratory insects used for mass rearing are genetically compatible with the target population, that the mating competitiveness of laboratory reared males is at least comparable to that of their wild counterparts, and that mass rearing and sterilization processes do not in themselves compromise male fitness to a degree that precludes them from successfully competing for mates in the wild. This study investigated the fitness and sexual cross-compatibility between samples of field collected and laboratory reared An. arabiensis under laboratory conditions. Results The physiological and reproductive fitness of the MALPAN laboratory strain is not substantially modified with respect to the field population at Malahlapanga. Further, a high degree of mating compatibility between MALPAN and the Malahlapanga population was established based on cross-mating experiments. Lastly, the morphological characteristics of hybrid ovarian polytene chromosomes further support the contention that the MALPAN laboratory colony and the An. arabiensis population at Malahlapanga are genetically homogenous and therefore compatible. Conclusions It is concluded that the presence of a perennial and isolated population of An. arabiensis at Malahlapanga presents a unique opportunity for assessing the feasibility of SIT as a malaria vector control option. The MALPAN laboratory colony has retained sufficient enough measures of reproductive and physiological fitness to present as a suitable candidate for male sterilization, mass rearing and subsequent mass release of sterile males at Malahlapanga in order to further assess the feasibility of SIT in a field setting. PMID:22041133

  13. Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

    PubMed

    Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

    2015-01-01

    Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

  14. Sex recognition and mate choice by male Bufo gargarizans in central China.

    PubMed

    Yu, Tong Lei; Sharma, Manmohan D

    2012-06-01

    Mate choice is important for successful reproduction, and consequently species have evolved various ways to choose potential high-quality mates. Anuran mate choice and underlying processes have been the subject of several recent investigations, however we are far from a complete understanding of mate choice in this system. In the present study, when given a simultaneous choice between a male and a female of identical size, males did not discriminate between the sexes, and attempted to clasp a male or a female with equal frequency. Test males only released the stimulus toad when a release call was emitted by the stimulus male. When two males with distinct size differences were provided with a male, the male chose the larger one. Moreover, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones. These results suggest that male Bufo gargarizans can discriminate between the sexes, probably based on male release calls, and prefer to mate with larger individual using visual cues. PMID:22639803

  15. Conspicuous Female Ornamentation and Tests of Male Mate Preference in Threespine Sticklebacks (Gasterosteus aculeatus)

    PubMed Central

    Wright, Daniel Shane; Pierotti, Michele E. R.; Rundle, Howard D.; McKinnon, Jeffrey S.

    2015-01-01

    Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

  16. Mating enhances the probability of winning aggressive encounters in male lobster cockroaches.

    PubMed

    Kou, Rong; Hsu, Chu-Chun

    2013-08-01

    In the present study, we report that contact with isolated female antenna significantly increases both the pheromone 3-hydroxy-2-butanone (3H-2B) release and the hemolymph JH III level in all examined aggressive posture-adopting (AP) and NP (non-AP-adopting) socially naïve males, with significantly faster concomitant pre-mating wing-raising behavior in AP as compared to NP males. 3H-2B release and JH III level were significantly increased after mating in both AP and NP males. A positive correlation was observed between mating experience and dominant status. Furthermore, mated-AP males initiated fights more rapidly and fought for a significantly longer duration than mated-NP males; retention with the paired female for 24h did not affect this increase. JH III level and 3H-2B release were significantly increased in dominant males as compared to subordinates. These results suggest that prior mating experience in invertebrates may enhance aggression in subsequent male-male encounters, with accompanying physiological (hormone and pheromone) responses. PMID:23939458

  17. [Importance of adult protein ingestion on the mating success of Ceratitis capitata Wiedemann males (Diptera: Tephritidae)].

    PubMed

    Silva Neto, Alberto M da; Dias, Vanessa S; Joachim-Bravo, Iara S

    2010-01-01

    The importance of the protein ingestion during the adult stage on the mating success of males of Ceratitis capitata Wiedemann was evaluated in experiments of laboratory and field cage. In laboratory, the effects of protein ingestion during the first four or 12 days of the male adult life was assessed by the following parameters: mating success (capacity of being chosen by the female) and the number of males that give out pheromonal signals. Some experiments of mating success had been carried through with males in different ratios. In these tests, the number of males which had ingested protein (an unique male) was remained constant and the number of males fed without protein was gradually increased from 1:1 to 1:5. In the field cages, the mating success experiments were done using a 1:1 ratio. The results showed that the protein ingestion in the first four days of life did not influence any of the analyzed parameters. When the period of ingestion of protein was extended to 12 days, protein-fed males fed produced more pheromonal signals and had a higher mating success when at a 1:1 ratio in laboratory and field cage assays. In laboratory, females randomly chose males in any other tested ratio (1:2, 1:3, 1:4 and 1:5), indicating that the female may lose the perception to identify the male who ingested protein in the first 12 days. PMID:20498961

  18. When not to copy: female fruit flies use sophisticated public information to avoid mated males

    NASA Astrophysics Data System (ADS)

    Loyau, Adeline; Blanchet, Simon; van Laere, Pauline; Clobert, Jean; Danchin, Etienne

    2012-10-01

    Semen limitation (lack of semen to fertilize all of a female's eggs) imposes high fitness costs to female partners. Females should therefore avoid mating with semen-limited males. This can be achieved by using public information extracted from watching individual males' previous copulating activities. This adaptive preference should be flexible given that semen limitation is temporary. We first demonstrate that the number of offspring produced by males Drosophila melanogaster gradually decreases over successive copulations. We then show that females avoid mating with males they just watched copulating and that visual public cues are sufficient to elicit this response. Finally, after males were given the time to replenish their sperm reserves, females did not avoid the males they previously saw copulating anymore. These results suggest that female fruit flies may have evolved sophisticated behavioural processes of resistance to semen-limited males, and demonstrate unsuspected adaptive context-dependent mate choice in an invertebrate.

  19. Pest management programmes in vineyards using male mating disruption.

    PubMed

    Harari, Ally R; Zahavi, Tirtza; Gordon, Dvora; Anshelevich, Leonid; Harel, Miriam; Ovadia, Shmulik; Dunkelblum, Ezra

    2007-08-01

    Israeli vine growers have been reluctant to adopt the mating disruption technique for control of the European vine moth, Lobesia botrana Den. & Schiff. Since the chemically controlled honeydew moth, Cryptoblabes gnidiella Mill., coexists with the European vine moth, growers have maintained that the use of mating disruption would fail to bring about a significant reduction in pesticide use. In this study, the efficacy of mating disruption techniques against C. gnidiella was tested, as well as the effect of these methods on pesticide use and damage to clusters when the method was employed against both of the pests in wine grapes. Comparisons were made between plots treated with (1) L. botrana mating disruption pheromone, (2) L. botrana and C. gnidiella mating disruption pheromones and (3) control plots. A significant difference in the number of clusters infested with the developmental stages of the moths was seen between pheromone-treated plots and controls, while no such difference was observed between plots treated with one versus two pheromones. A similar pattern was observed in the number of insecticide applications; the greatest number of applications was used in control plots, followed by plots treated with L. botrana mating disruption pheromone and by plots treated with pheromones against both pests, in which no pesticides were applied. PMID:17523143

  20. Sterilizing effects of cobalt-60 and cesium-137 radiation on male sea lampreys

    USGS Publications Warehouse

    Hanson, L.H.

    1990-01-01

    Male spawning-run sea lampreys Petromyzon marinus were exposed to various doses of cobalt-60 or cesium-137 radiation in an attempt to sterilize them for use in a program for controlling sea lampreys through the release of sterile males. Males captured and irradiated during the early part of the upstream migration were not effectively sterilized at the doses tested. After irradiation, the sea lampreys were more susceptible to fungal infections by Saprolegnia sp., and many died without attempting to spawn. Males captured and irradiated during the middle and late parts of the spawning migration were effectively sterilized at a dose of 2,000 rads. However, some radiation-induced mortality was observed in males captured and irradiated during the middle part of the spawning migration. Radiation is not as effective as the chemosterilant bisazir for sterilizing male sea lampreys.

  1. Male and female mate choice affects offspring quality in a sex-role-reversed pipefish.

    PubMed

    Sandvik, M; Rosenqvist, G; Berglund, A

    2000-11-01

    Where both sexes invest substantially in offspring, both females and males should discriminate between potential partners when choosing mates. The degree of choosiness should relate to the costs of choice and to the potential benefits to be gained. We measured offspring quality from experimentally staged matings with preferred and non-preferred partners in a sex-role-reversed pipefish, Syngnathus typhle L. Here, a substantial male investment in offspring results in a lower potential reproductive rate in males than in females, and access to males limits female reproductive success rather than vice versa. Thus, males are choosier than females and females compete more intensely over mates than do males. Broods from preferred matings were superior at escaping predation, when either males or females were allowed to choose a partner. However, only 'choosing' females benefited in terms of faster-growing offspring. Our results have important implications for mate-choice research: here we show that even the more competitive and less choosy sex may contribute significantly to sexual selection through mate choice. PMID:11413626

  2. Chemical and Physical Cues Synergistically Affect Mating Behavior Sequences of Male Dasylepida ishigakiensis (Coleoptera: Scarabaeidae).

    PubMed

    Fujiwara-Tsujii, Nao; Yasui, Hiroe; Arakaki, Norio

    2014-09-01

    We investigated physical and chemical cues involved in male mating behavior of the white grub beetle, Dasylepida ishigakiensis (Scarabaeidae). When presented with female attractant pheromone (R)-2-butanol lures in a flight tunnel, nearly all males exhibited orientation and touching behaviors to freshly killed males and females and to intact glass models. Males landed and bent their abdomens on male and female bodies, but not on intact glass models. When treated with one female equivalent (FE) extract, washed immature male bodies and glass models both evoked stronger male responses than untreated equivalents, with the former eliciting a greater response than the treated glass models. Male responses to target male and female bodies decreased with increased numbers of washings of target bodies with organic solvents. These results suggest that the chemical factors that elicit male abdominal bending behavior are present on the body surface in both sexes. Washed immature male bodies treated with 1 FE or one male equivalent (ME) of extract induced strong male abdominal bending behavior. Washed mature female bodies treated with 1 ME extract also evoked male responses. Extracts of both sexes included factors eliciting male abdominal bending behavior. These results suggest that both physical and chemical cues derived from conspecifics cooperate to facilitate male mating recognition in D. ishigakiensis. The mating process of this species in the field is highly synchronized. Thus, after orienting to a female-like object, the only information males require by touching is whether the sex attractant pheromone that attracted them is indeed from a conspecific. PMID:25186925

  3. Hybridization using cytoplasmic male sterility and herbicide tolerance from nuclear genes

    SciTech Connect

    Beversdorf, W.D.; Erickson, L.R.; Grant, I.

    1987-04-14

    An improved process is described for producing a substantially homogeneous population of plants of a predetermined hybrid variety of a crop which is capable of undergoing both self-pollination and cross-pollination. This process comprises: growing in a first planting area a substantially random population of cytoplasmic male sterile plants which exhibit tolerance to at least one herbicide attributable solely to homozygous dominant nuclear genes, and male fertile plants which are capable of pollinating the cytoplasmic male sterile plants and which lack the herbicide tolerance because the presence of homozygous recessive nuclear genes for such trait. The cytoplasmic male sterile plants and the male fertile plants are pollinated with pollen derived from the male fertile plants. Seed is formed on the cytoplasmic male sterile plants and on the male fertile plants. Harvesting in bulk the seed is formed on the plants of the first planting area.

  4. Incestuous Sisters: Mate Preference for Brothers over Unrelated Males in Drosophila melanogaster

    PubMed Central

    Loyau, Adeline; Cornuau, Jérémie H.; Clobert, Jean; Danchin, Étienne

    2012-01-01

    The literature is full of examples of inbreeding avoidance, while recent mathematical models predict that inbreeding tolerance or even inbreeding preference should be expected under several realistic conditions like e.g. polygyny. We investigated male and female mate preferences with respect to relatedness in the fruit fly D. melanogaster. Experiments offered the choice between a first order relative (full-sibling or parent) and an unrelated individual with the same age and mating history. We found that females significantly preferred mating with their brothers, thus supporting inbreeding preference. Moreover, females did not avoid mating with their fathers, and males did not avoid mating with their sisters, thus supporting inbreeding tolerance. Our experiments therefore add empirical evidence for inbreeding preference, which strengthens the prediction that inbreeding tolerance and preference can evolve under specific circumstances through the positive effects on inclusive fitness. PMID:23251487

  5. Effects of visual exposure to the opposite sex: cognitive aspects of mate attraction in human males.

    PubMed

    Roney, James R

    2003-03-01

    This research is an investigation into the cognitive aspects of mate attraction in human males. Two experiments demonstrate that visual exposure to women (in person or within photographs) can prime large changes in the attitudes, mood states, and personality trait descriptions of male participants. These changes, furthermore, are such that participants show greater conformity to female mate preferences as described in the extant literature: In particular, men exposed to potential mates reported higher valuations of material wealth, greater momentary feelings of ambition, higher valuations of other indicators of social status, and personality trait descriptions indicative of high surgency/extraversion. All such effects occurred without participants' awareness that their responses had been affected by the experimental manipulations. These findings suggest a model of mate attraction mechanisms in which input cues from potential mates can prime those psychological representations that facilitate the behavioral expression of courtship tactics. PMID:15273016

  6. Methoprene treatment reduces the pre-copulatory period in Anastrepha fraterculus (Diptera: Tephritidae) sterile males

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anastrepha fraterculus is a major fruit pest in South America. Ongoing studies encourage the implementation of the sterile insect technique (SIT) against this pest. Sexual readiness of sterile males is a key point for SIT. The time required for A. fraterculus males to become sexually mature is unkn...

  7. DNA methylation affected by male sterile cytoplasm in rice (Oryza sativa L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Male sterile cytoplasm plays an important role in hybrid rice and cytoplasmic effects are sufficiently documented. However, no reports are available on DNA methylation affected by male sterile cytoplasm in hybrid rice. We used a methylation sensitive amplified polymorphism (MSAP) technique to charac...

  8. Diverse germplasm to devleop male-sterile lines for hybrid breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybrid rice breeding in the US has depended largely upon male-sterile lines originating in China or from other Asian sources. By contrast, the program in Arkansas has developed all of its male-sterile lines at Stuttgart,AR using germplasm accessions available in the USDA Rice Germplasm Collection st...

  9. Female mate preferences for male body size and shape promote sexual isolation in threespine sticklebacks

    PubMed Central

    Head, Megan L; Kozak, Genevieve M; Boughman, Janette W

    2013-01-01

    Female mate preferences for ecologically relevant traits may enhance natural selection, leading to rapid divergence. They may also forge a link between mate choice within species and sexual isolation between species. Here, we examine female mate preference for two ecologically important traits: body size and body shape. We measured female preferences within and between species of benthic, limnetic, and anadromous threespine sticklebacks (Gasterosteus aculeatus species complex). We found that mate preferences differed between species and between contexts (i.e., within vs. between species). Within species, anadromous females preferred males that were deep bodied for their size, benthic females preferred larger males (as measured by centroid size), and limnetic females preferred males that were more limnetic shaped. In heterospecific mating trials between benthics and limnetics, limnetic females continued to prefer males that were more limnetic like in shape when presented with benthic males. Benthic females showed no preferences for size when presented with limnetic males. These results show that females use ecologically relevant traits to select mates in all three species and that female preference has diverged between species. These results suggest that sexual selection may act in concert with natural selection on stickleback size and shape. Further, our results suggest that female preferences may track adaptation to local environments and contribute to sexual isolation between benthic and limnetic sticklebacks. PMID:23919161

  10. Role of no scalpel vasectomy in male sterilization.

    PubMed

    Bhuyan, K; Ali, Ilias; Barua, S J

    2012-08-01

    No Scalpel Vasectomy (NSV) is a modern method of delivery, ligation and excision of vas deference without use of a knife. It provides a permanent sterilization option for male. It is a safe, effective method of vasectomy with low complication and greater patient compliance. To evaluate effectiveness and its acceptance of the procedure data were collected on men who accepted NSV between Jan'2008 to Mar'09. Demographic information, motivating factors, educational status and surgical complications were recorded. The cases were done in rural hospitals & Primary health centers as camp procedure. A total of 649 vasectomies performed using NSV method from Jan'08 to Mar'09. The mean age of the acceptors was 35 years with 4 numbers of children on average. Complications included bleeding during surgery in 4 cases (0.6%), haematoma in one case (0.2%), and superficial wound infection occurred in two cases (0.3%) and scrotal pain in 4 cases (0.6%). NSV is an effective, minimal access method of vas delivery, ligation and excision. It provides safe and effective contraceptive option to male population with minimal complications. Doctors, health workers along with the simplicity of procedure and early return to work are great motivating factors. It is easily performed as camp procedure in a simple medical setup. Doctors can be effectively trained hands on during the camp procedure. PMID:23904714

  11. Mate choice and male behaviour following castration and replacement of testosterone in mallards (Anas platyrhynchos ).

    PubMed

    Klint, T

    1985-11-01

    Male sexual behaviour was controlled by castration and testosterone replacement. The first experiment shows that, within a group of similarly coloured and castrated male mallards, females preferred males treated with testosterone. The second experiment shows that a testosterone-treated male was always preferred by the females, irrespective of plumage colour, in a choice between a wild and a white mallard drake. The results shows that testosterone dependent male cues is important in mate choice in the mallard duck. PMID:24896699

  12. Sexual selection on Drosophila serrata male pheromones does not vary with female age or mating status.

    PubMed

    Gershman, S; Delcourt, M; Rundle, H D

    2014-06-01

    Mate preferences are costly and are thought to evolve due to the direct and/or indirect benefits they provide. Such costs and benefits may vary in response to intrinsic and extrinsic factors with important evolutionary consequences. Limited attention has been given to quantifying such variation and understanding its causes, most notably with respect to the direction and strength of preferences for multivariate sexual displays. In Drosophila serrata, female preferences target a pheromone blend of long-chain cuticular hydrocarbons (CHCs). We used a factorial design to test whether female age and mating status generated variation in the strength and direction of sexual selection on male CHCs. Replicate choice mating trials were conducted using young and old females (4 or 10 days post-emergence) that were either virgin or previously mated. The outcome of such trials is known to capture variation in female mate preferences, although male-male interactions may also contribute. Directional sexual selection on male CHCs was highly significant within each treatment, but there was little evidence of any variation among treatments. The absence of treatment effects implies that the multivariate combination of male CHCs preferred by females was constant with respect to female age and mating status. To the extent that male-male interactions may also contribute, our results similarly imply that these did not vary among treatments groups. With respect to D. serrata mate preferences, our results suggest that either plasticity with respect to age and mating status is not beneficial to females, or preference expression is somehow constrained. PMID:24828752

  13. Male mating behaviour and sperm production characteristics under varying sperm competition risk in guppies.

    PubMed

    Evans; Magurran

    1999-11-01

    Since natural populations of guppies, Poecilia reticulata, often differ from one another in social structure, the intensity of sperm competition is likely to vary between localities. Guppies are promiscuous, with female choice for colourful males playing a central role in the mating system. In addition, male guppies use forced copulations to circumvent female choice. Both methods of copulation are used interchangeably by individual males, but the degree to which either is used may depend on the social environment into which males are born. Here we show that male mating behaviour varies according to the rearing sex ratio: when reared in male-biased groups, males performed more forced copulations and fewer courtship displays but showed the opposite pattern of behaviour when reared in female-biased groups. Our prediction, based on sperm competition theory, that stripped sperm number would reflect social structure was not supported by our results. Instead, the overall level of sexual activity (gonopodial thrusts+sigmoid displays) was a better predictor of sperm number in the different groups of males. Rearing density, where sex ratio was controlled, did not significantly affect male mating behaviour or sperm traits. Males reared under the different sex ratios continued to show their characteristic behaviour patterns when placed in equal sex ratio tanks. We conclude, therefore, that males adopt mating strategies to suit their social environment, and that these strategies remain fixed, for short periods at least, if population structure changes. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10564602

  14. Sexual conflict and the evolution of female mate choice and male social dominance.

    PubMed Central

    Moore, A. J.; Gowaty, P. A.; Wallin, W. G.; Moore, P. J.

    2001-01-01

    Conflicts between the sexes over control of reproduction are thought to lead to a cost of sexual selection through the evolution of male traits that manipulate female reproductive physiology and behaviour, and female traits that resist this manipulation. Although studies have begun to document negative fitness effects of sexual conflict, studies showing the expected association between sexual conflict and the specific behavioural mechanisms of sexual selection are lacking. Here we experimentally manipulated the opportunity for sexual conflict in the cockroach. Nauphoeta cinerea and showed that, for this species, odour cues in the social environment influence the behavioural strategies and fitness of males and females during sexual selection. Females provided with the opportunity for discriminating between males but not necessarily mating with preferred males produced fewer male offspring than females mated at random. The number of female offspring produced was not affected, nor was the viability of the offspring. Experimental modification of the composition of the males' pheromone showed that the fecundity effects were caused by exposure to the pheromone component that makes males attractive to females but also makes males less likely to be dominant. Female mate choice therefore carries a demographic cost but functions to avoid male manipulation and aggression. Male-male competition appears to function to circumvent mate choice rather than directly manipulating females, as the mate choice can be cryptic. The dynamic struggle between the sexes for control of mating opportunities and outcomes in N. cinerea therefore reveals a unique role for sexual conflict in the evolution of the behavioural components of sexual selection. PMID:11296864

  15. Sexual conflict and the evolution of female mate choice and male social dominance.

    PubMed

    Moore, A J; Gowaty, P A; Wallin, W G; Moore, P J

    2001-03-01

    Conflicts between the sexes over control of reproduction are thought to lead to a cost of sexual selection through the evolution of male traits that manipulate female reproductive physiology and behaviour, and female traits that resist this manipulation. Although studies have begun to document negative fitness effects of sexual conflict, studies showing the expected association between sexual conflict and the specific behavioural mechanisms of sexual selection are lacking. Here we experimentally manipulated the opportunity for sexual conflict in the cockroach. Nauphoeta cinerea and showed that, for this species, odour cues in the social environment influence the behavioural strategies and fitness of males and females during sexual selection. Females provided with the opportunity for discriminating between males but not necessarily mating with preferred males produced fewer male offspring than females mated at random. The number of female offspring produced was not affected, nor was the viability of the offspring. Experimental modification of the composition of the males' pheromone showed that the fecundity effects were caused by exposure to the pheromone component that makes males attractive to females but also makes males less likely to be dominant. Female mate choice therefore carries a demographic cost but functions to avoid male manipulation and aggression. Male-male competition appears to function to circumvent mate choice rather than directly manipulating females, as the mate choice can be cryptic. The dynamic struggle between the sexes for control of mating opportunities and outcomes in N. cinerea therefore reveals a unique role for sexual conflict in the evolution of the behavioural components of sexual selection. PMID:11296864

  16. Alternative mating tactics in the yellow dung fly: resolving mechanisms of small-male advantage off pasture.

    PubMed

    Gress, Brian E; Waltzer, Ryan J; Lüpold, Stefan; Droge-Young, Elizabeth M; Manier, Mollie K; Pitnick, Scott

    2014-01-01

    Recent work suggests that the yellow dung fly mating system may include alternative patroller-competitor mating tactics in which large males compete for gravid females on dung, whereas small, non-competitive males search for females at foraging sites. Small males obtain most matings off pasture, yet the behavioural mechanism(s) giving rise to this pattern are unknown. We investigated the male and female behaviours that determine mating success in this environment by conducting field mating experiments and found small males to benefit from several attributes specific to the off-pasture mating environment. First, small males from foraging sites exhibited higher mating propensity, indicating that large males away from dung may be depleted of energy and/or sperm. Second, small males were more discriminating, being significantly less likely to attempt with non-gravid females, which are absent on dung but common off pasture. Third, non-gravid females were generally more likely to actively struggle and reject mating attempts; however, such behaviours occurred disproportionately more often with large males. Female Scathophaga stercoraria thus appear to preferentially mate with small males when off pasture. These findings challenge assumptions about male-female interactions in systems with alternative mating tactics and reveal hidden processes that may influence selection patterns in the field. PMID:24225455

  17. No evidence for the effect of MHC on male mating success in the brown bear.

    PubMed

    Kuduk, Katarzyna; Babik, Wieslaw; Bellemain, Eva; Valentini, Alice; Zedrosser, Andreas; Taberlet, Pierre; Kindberg, Jonas; Swenson, Jon E; Radwan, Jacek

    2014-01-01

    Mate choice is thought to contribute to the maintenance of the spectacularly high polymorphism of the Major Histocompatibility Complex (MHC) genes, along with balancing selection from parasites, but the relative contribution of the former mechanism is debated. Here, we investigated the association between male MHC genotype and mating success in the brown bear. We analysed fragments of sequences coding for the peptide-binding region of the highly polymorphic MHC class I and class II DRB genes, while controlling for genome-wide effects using a panel of 18 microsatellite markers. Male mating success did not depend on the number of alleles shared with the female or amino-acid distance between potential mates at either locus. Furthermore, we found no indication of female mating preferences for MHC similarity being contingent on the number of alleles the females carried. Finally, we found no significant association between the number of MHC alleles a male carried and his mating success. Thus, our results provided no support for the role of mate choice in shaping MHC polymorphism in the brown bear. PMID:25470381

  18. No Evidence for the Effect of MHC on Male Mating Success in the Brown Bear

    PubMed Central

    Kuduk, Katarzyna; Babik, Wieslaw; Bellemain, Eva; Valentini, Alice; Zedrosser, Andreas; Taberlet, Pierre; Kindberg, Jonas; Swenson, Jon E.; Radwan, Jacek

    2014-01-01

    Mate choice is thought to contribute to the maintenance of the spectacularly high polymorphism of the Major Histocompatibility Complex (MHC) genes, along with balancing selection from parasites, but the relative contribution of the former mechanism is debated. Here, we investigated the association between male MHC genotype and mating success in the brown bear. We analysed fragments of sequences coding for the peptide-binding region of the highly polymorphic MHC class I and class II DRB genes, while controlling for genome-wide effects using a panel of 18 microsatellite markers. Male mating success did not depend on the number of alleles shared with the female or amino-acid distance between potential mates at either locus. Furthermore, we found no indication of female mating preferences for MHC similarity being contingent on the number of alleles the females carried. Finally, we found no significant association between the number of MHC alleles a male carried and his mating success. Thus, our results provided no support for the role of mate choice in shaping MHC polymorphism in the brown bear. PMID:25470381

  19. Courtship raises male fertilization success through post-mating sexual selection in a spider.

    PubMed

    Schneider, Jutta M; Lesmono, Kristiani

    2009-09-01

    Courtship is well known for its positive effects on mating success. However, in polyandrous species, sexual selection continues to operate after copulation. Cryptic female choice is expected under unpredictable mating rates in combination with sequential mate encounters. However, there are very few accounts of the effects of courtship on cryptic female choice, and the available evidence is often correlative. Mature Argiope bruennichi females are always receptive and never attack or reject males before mating, although sexual cannibalism after mating occurs regularly. Still, males usually perform an energetic vibratory display prior to copulation. We tested the hypothesis that beneficial effects of courtship arise cryptically, during or after mating, resulting in increased paternity success under polyandry. Manipulating courtship duration experimentally, we found that males that mated without display had a reduced paternity share even though no differences in post-copulatory cannibalism or copulation duration were detected. This suggests that the paternity advantage associated with courtship arose through female-mediated processes after intromission, meeting the definition of cryptic female choice. PMID:19515667

  20. Courtship raises male fertilization success through post-mating sexual selection in a spider

    PubMed Central

    Schneider, Jutta M.; Lesmono, Kristiani

    2009-01-01

    Courtship is well known for its positive effects on mating success. However, in polyandrous species, sexual selection continues to operate after copulation. Cryptic female choice is expected under unpredictable mating rates in combination with sequential mate encounters. However, there are very few accounts of the effects of courtship on cryptic female choice, and the available evidence is often correlative. Mature Argiope bruennichi females are always receptive and never attack or reject males before mating, although sexual cannibalism after mating occurs regularly. Still, males usually perform an energetic vibratory display prior to copulation. We tested the hypothesis that beneficial effects of courtship arise cryptically, during or after mating, resulting in increased paternity success under polyandry. Manipulating courtship duration experimentally, we found that males that mated without display had a reduced paternity share even though no differences in post-copulatory cannibalism or copulation duration were detected. This suggests that the paternity advantage associated with courtship arose through female-mediated processes after intromission, meeting the definition of cryptic female choice. PMID:19515667

  1. Male Age Affects Female Mate Preference, Quantity of Accessory Gland Proteins, and Sperm Traits and Female Fitness in D. melanogaster.

    PubMed

    Rezaei, Abolhasan; Krishna, Mysore Siddaiah; Santhosh, Hassan T

    2015-01-01

    For species in which mating is resource-independent and offspring do not receive parental care, theoretical models of age-based female mate preference predict that females should prefer to mate with older males as they have demonstrated ability to survive. Thus, females should obtain a fitness benefit from mating with older males. However, male aging is often associated with reductions in quantity of sperm. The adaptive significance of age-based mate choice is therefore unclear. Various hypotheses have made conflicting predictions concerning this issue, because published studies have not investigated the effect of age on accessory gland proteins and sperm traits. D. melanogaster exhibits resource-independent mating, and offspring do not receive parental care, making this an appropriate model for studying age-based mate choice. In the present study, we found that D. melanogaster females of all ages preferred to mate with the younger of two competing males. Young males performed significantly greater courtship attempts and females showed least rejection for the same than middle-aged and old males. Young males had small accessory glands that contained very few main cells that were larger than average. Nevertheless, compared with middle-aged or old males, the young males transferred greater quantities of accessory gland proteins and sperm to mated females. As a result, females that mated with young male produced more eggs and progeny than those that mated with older males. Furthermore, mating with young male reduced female's lifespan. These studies indicate that quantity of accessory gland proteins and sperm traits decreased with male age and females obtain direct fitness benefit from mating with preferred young males. PMID:25660692

  2. [Inheritance of reversions to male fertility in male-sterile sorghum hybrids with 9E cytoplasm male sterility induced by environmental conditions].

    PubMed

    Elkonin, L A; Gerashchenkov, G A; Domanina, I V; Rozhnova, N A

    2015-03-01

    Heritable phenotypic alterations occurring during plant ontogenesis under the influence of environmental factors are among the most intriguing genetic phenomena. It was found that male-sterile sorghum hybrids in the 9E cytoplasm from the F1 and F2 generations, which were obtained by crossing CMS lines with different fertile lines grown in field conditions, were transferred to greenhouse produce fertile tillers. Lines created by the self-pollination of revertant tillers exhibit complete male fertility upon cultivation under various environments (in the field, Tdry plot,(y) Tirrigated plot(y)). In a number of test-crosses of revertants to CMS lines in the 9E cytoplasm, restoration of male fertility in F1 hybrids was found, indicating that revertants possess functional fertility-restoring genes. A high positive correlation was found between the fertility level of the test-cross hybrids and the hydrothermal coefficient (the ratio of the sum of precipitation to the sum of temperatures) during the booting stage and pollen maturation (r = 0.75...0.91; P<0.01), suggesting that a high level of plant water availability is needed for the expression of fertility-restoring genes of revertants. These data show that the fertility-restoring genes for the 9E cytoplasm are dominant in conditions of high water availability and recessive in drought conditions; reversions to male fertility are due to up-regulation of fertility-restoring genes by a high level of water availability. Comparative MSAP-analysis of DNA of male-sterile and male-fertile test-cross hybrids using HpaII/MspI restrictases and primers to polygalacturonase gene ADPG2, which is required for cell separation during reproductive development, and gene MYB46, the transcription factor regulating secondary wall biosynthesis, revealed differences in the number and the length of amplified fragments. Changes in the methylation of these genes in conditions of drought stress are apparently the reason for male sterility of

  3. Effect of adult screwworm male size on mating competence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were devastating pests in parts of North America and Central America before their eradication by means of the sterile insect technique (SIT). Now, a barrier is maintained to prevent re-entry of screwworms from endemic regions t...

  4. Size-dependent response to conspecific mating calls by male crickets.

    PubMed Central

    Kiflawi, M; Gray, D A

    2000-01-01

    Male sexual displays provide females with information that is crucial to their reproductive decisions. That same information is available to eavesdroppers, with potential consequences for both signaller and receiver. We present empirical evidence for size-dependent responses to intersexual communication by conspecific rivals. Acoustic features of a male house cricket's (Acheta domesticus) mating call are positively associated with its size, with females preferring the calls of larger males. In order to investigate whether conspecific males make use of the information content of mating calls, we examined their phonotactic responses to call recordings that differ in attractiveness to females. Males of all sizes exhibited positive phonotaxis, with smaller males showing a clear preference for female-preferred calls. Smaller males were also less likely to seek contact with the speaker playing their chosen call. We discuss possible explanations for this size-dependent male behaviour. PMID:11413627

  5. Alternative mating tactics in the yellow dung fly: resolving mechanisms of small-male advantage off pasture

    PubMed Central

    Gress, Brian E.; Waltzer, Ryan J.; Lüpold, Stefan; Droge-Young, Elizabeth M.; Manier, Mollie K.; Pitnick, Scott

    2014-01-01

    Recent work suggests that the yellow dung fly mating system may include alternative patroller–competitor mating tactics in which large males compete for gravid females on dung, whereas small, non-competitive males search for females at foraging sites. Small males obtain most matings off pasture, yet the behavioural mechanism(s) giving rise to this pattern are unknown. We investigated the male and female behaviours that determine mating success in this environment by conducting field mating experiments and found small males to benefit from several attributes specific to the off-pasture mating environment. First, small males from foraging sites exhibited higher mating propensity, indicating that large males away from dung may be depleted of energy and/or sperm. Second, small males were more discriminating, being significantly less likely to attempt with non-gravid females, which are absent on dung but common off pasture. Third, non-gravid females were generally more likely to actively struggle and reject mating attempts; however, such behaviours occurred disproportionately more often with large males. Female Scathophaga stercoraria thus appear to preferentially mate with small males when off pasture. These findings challenge assumptions about male–female interactions in systems with alternative mating tactics and reveal hidden processes that may influence selection patterns in the field. PMID:24225455

  6. Genetic determination of male sterility in gynodioecious Silene nutans

    PubMed Central

    Garraud, C; Brachi, B; Dufay, M; Touzet, P; Shykoff, J A

    2011-01-01

    Gynodioecy, the coexistence of female and hermaphrodite plants within a species, is often under nuclear–cytoplasmic sex determination, involving cytoplasmic male sterility (CMS) genes and nuclear restorers. A good knowledge of CMS and restorer polymorphism is essential for understanding the evolution and maintenance of gynodioecy, but reciprocal crossing studies remain scarce. Although mitochondrial diversity has been studied in a few gynodioecious species, the relationship between mitotype diversity and CMS status is poorly known. From a French sample of Silene nutans, a gynodioecious species whose sex determination remains unknown, we chose the four most divergent mitotypes that we had sampled at the cytochrome b gene and tested by reciprocal crosses whether they carry distinct CMS genes. We show that gynodioecy in S. nutans is under nuclear–cytoplasmic control, with at least two different CMSs and up to four restorers with epistatic interactions. Female occurrence and frequency were highly dependent on the mitotype, suggesting that the level of restoration varies greatly among CMSs. Two of the mitotypes, which have broad geographic distributions, represent different CMSs and are very unequally restored. We discuss the dynamics of gynodioecy at the large-scale meta-population level. PMID:20808324

  7. Choosy males from the underground: male mating preferences in surface- and cave-dwelling Atlantic mollies ( Poecilia mexicana)

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Seggel, Uta; Burmeister, Heike; Heubel, Katja U.; Schlupp, Ingo

    2006-03-01

    Atlantic mollies ( Poecilia mexicana) inhabit a variety of surface habitats, but they also occur in a sulfur cave in southern Mexico. We examined male mate choice relative to female body size in the cave population and in the most closely related surface-dwelling population from a nearby river. Males from both populations were either light- or dark-reared and could choose between two differently sized females either on the basis of visual cues in light or on the basis of solely nonvisual cues in darkness. Sexual preferences were estimated from the degree of association. Cave molly males always showed a preference for the larger female, both in light and in darkness. Among the surface males, only light-reared males showed a preference in the visual cues test, but not in darkness. In a control experiment, we demonstrated that male association preferences directly translate into actual mating preferences. Apparently, using visual cues for mate choice is the ancestral state in this system, and using nonvisual cues has evolved as a novel trait in the cave population. We discuss the evolution of nonvisual male mate choice in the context of changed environmental conditions, namely the absence of light, hypoxia, and toxic hydrogen sulfide in the cave.

  8. Choosy males from the underground: male mating preferences in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana).

    PubMed

    Plath, Martin; Seggel, Uta; Burmeister, Heike; Heubel, Katja U; Schlupp, Ingo

    2006-03-01

    Atlantic mollies (Poecilia mexicana) inhabit a variety of surface habitats, but they also occur in a sulfur cave in southern Mexico. We examined male mate choice relative to female body size in the cave population and in the most closely related surface-dwelling population from a nearby river. Males from both populations were either light- or dark-reared and could choose between two differently sized females either on the basis of visual cues in light or on the basis of solely nonvisual cues in darkness. Sexual preferences were estimated from the degree of association. Cave molly males always showed a preference for the larger female, both in light and in darkness. Among the surface males, only light-reared males showed a preference in the visual cues test, but not in darkness. In a control experiment, we demonstrated that male association preferences directly translate into actual mating preferences. Apparently, using visual cues for mate choice is the ancestral state in this system, and using nonvisual cues has evolved as a novel trait in the cave population. We discuss the evolution of nonvisual male mate choice in the context of changed environmental conditions, namely the absence of light, hypoxia, and toxic hydrogen sulfide in the cave. PMID:16404589

  9. Mating-induced differential coding of plant odour and sex pheromone in a male moth.

    PubMed

    Barrozo, Romina B; Jarriault, David; Deisig, Nina; Gemeno, Cesar; Monsempes, Christelle; Lucas, Philippe; Gadenne, Christophe; Anton, Sylvia

    2011-05-01

    Innate behaviours in animals can be influenced by several factors, such as the environment, experience, or physiological status. This behavioural plasticity originates from changes in the underlying neuronal substrate. A well-described form of plasticity is induced by mating. In both vertebrates and invertebrates, males experience a post-ejaculatory refractory period, during which they avoid new females. In the male moth Agrotis ipsilon, mating induces a transient inhibition of responses to the female-produced sex pheromone. To understand the neural bases of this inhibition and its possible odour specificity, we carried out a detailed analysis of the response characteristics of the different neuron types from the periphery to the central level. We examined the response patterns of pheromone-sensitive and plant volatile-sensitive neurons in virgin and mated male moths. By using intracellular recordings, we showed that mating changes the response characteristics of pheromone-sensitive antennal lobe (AL) neurons, and thus decreases their sensitivity to sex pheromone. Individual olfactory receptor neuron (ORN) recordings and calcium imaging experiments indicated that pheromone sensory input remains constant. On the other hand, calcium responses to non-pheromonal odours (plant volatiles) increased after mating, as reflected by increased firing frequencies of plant-sensitive AL neurons, although ORN responses to heptanal remained unchanged. We suggest that differential processing of pheromone and plant odours allows mated males to transiently block their central pheromone detection system, and increase non-pheromonal odour detection in order to efficiently locate food sources. PMID:21488987

  10. Molecular mapping of a new induced gene for nuclear male sterility in sunflower (Helianthus annuus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new NMS line, NMS HA89-872, induced by mitomycin C and streptomycin carries a single recessive male-sterile gene ms6. An F2 population of 88 plants was obtained from a cross between nuclear male-sterile mutant NMS HA89-872 (msms) and male-fertile line RHA271 (MsMs). 225 SSR primers and 9 RFLP-deri...

  11. Egg Viability, Mating Frequency and Male Mating Ability Evolve in Populations of Drosophila melanogaster Selected for Resistance to Cold Shock

    PubMed Central

    Singh, Karan; Kochar, Ekta; Prasad, N. G.

    2015-01-01

    Background Ability to resist temperature shock is an important component of fitness of insects and other ectotherms. Increased resistance to temperature shock is known to affect life-history traits. Temperature shock is also known to affect reproductive traits such as mating ability and viability of gametes. Therefore selection for increased temperature shock resistance can affect the evolution of reproductive traits. Methods We selected replicate populations of Drosophila melanogaster for resistance to cold shock. We then investigated the evolution of reproductive behavior along with other components of fitness- larval survivorship, adult mortality, fecundity, egg viability in these populations. Results We found that larval survivorship, adult mortality and fecundity post cold shock were not significantly different between selected and control populations. However, compared to the control populations, the selected populations laid significantly higher percentage of fertile eggs (egg viability) 24 hours post cold shock. The selected populations had higher mating frequency both with and without cold shock. After being subjected to cold shock, males from the selected populations successfully mated with significantly more non-virgin females and sired significantly more progeny compared to control males. Conclusions A number of studies have reported the evolution of survivorship in response to selection for temperature shock resistance. Our results clearly indicate that adaptation to cold shock can involve changes in components of reproductive fitness. Our results have important implications for our understanding of how reproductive behavior can evolve in response to thermal stress. PMID:26065704

  12. Cytoplasmic male sterility in Mimulus hybrids has pleiotropic effects on corolla and pistil traits

    PubMed Central

    Barr, C M; Fishman, L

    2011-01-01

    The mechanisms underlying genetic associations have important consequences for evolutionary outcomes, but distinguishing linkage from pleiotropy is often difficult. Here, we use a fine mapping approach to determine the genetic basis of association between cytonuclear male sterility and other floral traits in Mimulus hybrids. Previous work has shown that male sterility in hybrids between Mimulus guttatus and Mimulus nasutus is due to interactions between a mitochondrial gene from M. guttatus and two tightly linked nuclear restorer alleles on Linkage Group 7, and that male sterility is associated with reduced corolla size. In the present study, we generated a set of nearly isogenic lines segregating for the restorer region and male sterility, but with unique flanking introgressions. Male-sterile flowers had significantly smaller corollas, longer styles and greater stigmatic exsertion than fertile flowers. Because these effects were significant regardless of the genotypic composition of introgressions flanking the restorer region, they suggest that these floral differences are a direct byproduct of the genetic incompatibility causing anther abortion. In addition, we found a non-significant but intriguing trend for male-sterile plants to produce more seeds per flower than fertile siblings after supplemental pollination. Such pleiotropic effects may underlie the corolla dimorphism frequently observed in gynodioecious taxa and may affect selection on cytoplasmic male sterility genes when they initially arise. PMID:21245895

  13. Male Texas Horned Lizards increase daily movements and area covered in spring: A mate searching strategy?

    USGS Publications Warehouse

    Stark, Richard C.; Fox, S. F.; David, M.L., Jr.

    2005-01-01

    Texas Horned Lizards, Phrynosoma cornutum, were tracked using fluorescent powder to determine exact daily movements. Daily linear movements and daily space use were compared between adult males and females. Lizards that traveled the greatest linear distances also covered the largest areas. In Oklahoma, adults emerge from hibernation in late April and early May and mate soon afterward. Males traveled significantly greater distances (and covered significantly larger areas in a day) than females in May but not after May. We propose that males move more and cover more area than females early in the mating season to intercept receptive females. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  14. Interdependent effects of male and female body size plasticity on mating behaviour of predatory mites

    PubMed Central

    Walzer, Andreas; Schausberger, Peter

    2015-01-01

    The adaptive canalization hypothesis predicts that traits with low phenotypic plasticity are more fitness relevant, because they have been canalized via strong past selection, than traits with high phenotypic plasticity. Based on differing male body size plasticities of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity), we accordingly hypothesized that small male body size entails higher costs in female choice and male–male competition in P. persimilis than N. californicus. Males of both species are highly polygynous but females differ in the level of polyandry (low level in P. persimilis; medium level in N. californicus). We videotaped the mating interactions in triplets of either P. persimilis or N. californicus, consisting of a virgin female (small or standard-sized) and a small and a standard-sized male. Mating by both small and standard-sized P. persimilis females was biased towards standard-sized males, resulting from the interplay between female preference for standard-sized males and the inferiority of small males in male–male competition. In contrast, mating by N. californicus females was equally balanced between small and standard-sized males. Small N. californicus males were more aggressive (‘Napoleon complex’) in male–male competition, reducing the likelihood of encounter between the standard-sized male and the female, and thus counterbalancing female preference for standard-sized males. Our results support the hypothesis that male body size is more important to fitness in the low-level polyandrous P. persimilis than in the medium-level polyandrous N. californicus and provide a key example of the implications of sexually selected body size plasticity on mating behaviour. PMID:25673881

  15. Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

    NASA Astrophysics Data System (ADS)

    Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

    2014-03-01

    Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

  16. Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk.

    PubMed

    Fowler-Finn, Kasey D; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L

    2014-03-01

    Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers-a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators. PMID:24487912

  17. Female mating preference for bold males in the guppy, Poecilia reticulata.

    PubMed

    Godin, J G; Dugatkin, L A

    1996-09-17

    Although females prefer to mate with brightly colored males in numerous species, the benefits accruing to such females are virtually unknown. According to one hypothesis of sexual selection theory, if the expression of costly preferred traits in males (such as conspicuous colors) is proportional to the male's overall quality or reveals his quality, a well-developed trait should indicate good condition and/or viability for example. A female choosing such a male would therefore stand to gain direct or indirect fitness benefits, or both. Among potential phenotypic indicators of an individual's quality are the amount and brightness of its carotenoid-based colors and its boldness, as measured by its willingness to risk approaching predators without being killed. Here, we show experimentally that in the Trinidadian guppy (Poecilia reticulata) the visual conspicuousness of the color pattern of males correlates positively with boldness toward, and with escape distance from, a cichlid fish predator. Bold individuals are thus more informed about nearby predators and more likely to survive encounters with them. Mate-choice experiments showed that females prefer colorful males as mates, but prefer bolder males irrespective of their coloration when given the opportunity to observe their behavior toward a potential fish predator. By preferentially mating with colorful males, female guppies are thus choosing on average, relatively bold, and perhaps more viable, individuals. In doing so, and to the extent that viability is heritable, they potentially gain indirect fitness benefits by producing more viable offspring than otherwise. PMID:11607706

  18. FACTORS ASSOCIATED WITH REDUCED FERTILITY AND IMPLANTATION RATES IN FEMALES MATED TO ACRYLAMIDE TREATED MALES

    EPA Science Inventory

    A series of studies was conducted to examine the role of copulatory dysfunction, spermatotoxicity, and/or impaired fertilization in the reduced rates of fertility and implantation observed in females mated to acrylamid-treated male rats. In initial experiments, males were gavaged...

  19. Exposure to tea tree oil enhances the mating success of male Mediterranean fruit flies (Diptera: Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aroma of various plant essential oils has been shown to enhance the mating competitiveness of males of the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann). Laboratory observations revealed that male medflies show strong short-range attraction to tea tree oil (TTO hereafter) deri...

  20. Female mating preference for bold males in the guppy, Poecilia reticulata.

    PubMed Central

    Godin, J G; Dugatkin, L A

    1996-01-01

    Although females prefer to mate with brightly colored males in numerous species, the benefits accruing to such females are virtually unknown. According to one hypothesis of sexual selection theory, if the expression of costly preferred traits in males (such as conspicuous colors) is proportional to the male's overall quality or reveals his quality, a well-developed trait should indicate good condition and/or viability for example. A female choosing such a male would therefore stand to gain direct or indirect fitness benefits, or both. Among potential phenotypic indicators of an individual's quality are the amount and brightness of its carotenoid-based colors and its boldness, as measured by its willingness to risk approaching predators without being killed. Here, we show experimentally that in the Trinidadian guppy (Poecilia reticulata) the visual conspicuousness of the color pattern of males correlates positively with boldness toward, and with escape distance from, a cichlid fish predator. Bold individuals are thus more informed about nearby predators and more likely to survive encounters with them. Mate-choice experiments showed that females prefer colorful males as mates, but prefer bolder males irrespective of their coloration when given the opportunity to observe their behavior toward a potential fish predator. By preferentially mating with colorful males, female guppies are thus choosing on average, relatively bold, and perhaps more viable, individuals. In doing so, and to the extent that viability is heritable, they potentially gain indirect fitness benefits by producing more viable offspring than otherwise. PMID:11607706

  1. Influence of methoprene and dietary protein on male Anastrepha suspensa (Diptera: Tephritidae) mating aggregations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Caribbean fruit fly, Anastrepha suspensa (Loew), like many polyphagous tephritids, exhibits a lek polygyny mating system. Juvenile hormone levels and adult diet have important effects on male sexual success. The components of this success, male attractiveness and competitiveness, and consequentl...

  2. Regulation of Caenorhabditis elegans Male Mate Searching Behavior by the Nuclear Receptor DAF-12

    PubMed Central

    Kleemann, Gunnar; Jia, Lingyun; Emmons, Scott W.

    2008-01-01

    Coordination of animal behavior with reproductive status is often achieved through elaboration of hormones by the gonad. In the nematode Caenorhabditis elegans, adult males explore their environment to locate mates. Mate searching is regulated by presence of mates, nutritional status, and a signal from the gonad. Here we show that the gonadal signal acts via the nuclear receptor DAF-12, a protein known to regulate several C. elegans life-history traits. DAF-12 has both activational and organizational functions to stimulate exploratory behavior and acts downstream of the gonadal signal, outside of the gonad. DAF-12 acts upstream of sensory input from mating partners and physiological signals indicating nutritional status. Mate searching was rescued in germ-line ablated animals, but not if both germ line and somatic gonad were ablated, by a precursor of the DAF-12 ligand, dafachronic acid (DA). The results are interpreted to suggest that the germ line produces a DA precursor that is converted to DA outside of the germ line, possibly in the somatic gonad. As it does in other pathways in which it functions, in regulation of male mate searching behavior DAF-12 acts at a choice point between alternatives favoring reproduction (mate searching) vs. survival (remaining on food). PMID:18854588

  3. Sex recognition and mate choice by male western toads, Bufo boreas.

    PubMed

    Marco; Kiesecker; Chivers; Blaustein

    1998-06-01

    In field-based choice experiments, we examined sex recognition and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male-male amplexus never lasted more than 3 s, but male-female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females or non-gravid females of equal size. In choice tests that excluded chemical cues, males jumped more frequently towards large females than small ones. Given that females are significantly larger than males, selecting larger individuals as potential mates increases the probability that males amplex with a female. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9642006

  4. X-ray-induced sterility in Aedes albopictus (Diptera: Culicidae) and male longevity following irradiation.

    PubMed

    Yamada, H; Parker, A G; Oliva, C F; Balestrino, F; Gilles, J R L

    2014-07-01

    The mosquito Aedes albopictus (Skuse, 1895) is a potent vector of several arboviral diseases, most notably chikungunya and dengue fever. In the context of the sterile insect technique (SIT), the sterilization of the male mosquitoes before their release can be achieved by gamma-ray irradiation. As gamma-ray irradiators are becoming increasingly problematic to purchase and transport, the suitability of an X-ray irradiator as an alternative for the sterilization of Ae. albopictus males was studied. The sterilization of up to 200,000 pupae at one time can be achieved with relative ease, and the sterility results obtained were comparable with those achieved by gamma irradiation, where 99% sterility is induced with a dose of 40 Gy. A significant reduction of longevity was observed in the latter stages of the males' life after irradiation treatments, especially at doses > 40 Gy, which is consistent with the negative effects on longevity induced by similar radiation doses using gamma rays. Females irradiated at 40 Gy were not only 100% sterile, but also failed to oviposit entirely, i.e., all of the females laid 0 eggs. Overall, it was found that the X-ray irradiator is generally suitable for the sterilization process for sterile insect technique programs, as it showed a high processing capacity, practicality, high effectiveness, and reproducibility. PMID:25118413

  5. Ability of male Queensland fruit flies to inhibit receptivity in multiple mates, and the associated recovery of accessory glands.

    PubMed

    Radhakrishnan, Preethi; Taylor, Phillip W

    2008-02-01

    Mating success of male insects is commonly determined by their ability to find and copulate with multiple females, but is also determined by their ability to transfer an effective ejaculate. In order to succeed in these tasks, males must first succeed in replenishing the necessary reproductive reserves between mating opportunities. We here investigate the ability of male Queensland fruit flies ('Q-fly') to recover from their first matings in time to both mate again the following day and to induce sexual inhibition in successive mates. We have previously found that accessory gland fluids (AGFs) transferred in the ejaculate of male Q-flies are directly responsible for induction of sexual inhibition in their mates. We here investigate changes in male accessory gland, testis and ejaculatory apodeme dimensions that are likely to reflect depletion and recovery of contents. We found no differences between virgin and previously mated males in their ability to obtain matings or to induce sexual inhibition in their mates, indicating a full recovery of the necessary reproductive reserves between mating opportunities. Whereas no changes were detected in testis or ejaculatory apodeme size following mating, the recovery of male ability to inhibit female remating was closely reflected in the mesodermal accessory gland dimensions; these accessory glands greatly diminished in size (length and area) immediately after mating, with recovery commencing between 5.5 and 11 h after mating. The accessory glands then expanded to reach their original size in time to mate the following day and induce sexual inhibition in the next mate. PMID:18083187

  6. Monitoring gene flow from transgenic sugar beet using cytoplasmic male-sterile bait plants.

    PubMed

    Saeglitz, C; Pohl, M; Bartsch, D

    2000-12-01

    One of the most discussed environmental effects associated with the use of transgenic plants is the flow of genes to plants in the environment. The flow of genes may occur through pollen since it is the reproductive system that is designed for gene movement. Pollen-mediated gene escape is hard to control in mating plants. Pollen from a wind pollinator can move over distances of more than 1000 m. To investigate the efficiency of transgenic pollen movement under realistic environmental conditions, the use of bait plants might be an effective tool. In this study, cytoplasmic male-sterile (CMS) sugar beets were tested with regard to their potential for monitoring transgene flow. As the pollen source, transgenic sugar beets were used that express recombinant DNA encoding viral (beet necrotic yellow vein virus) resistance, and antibiotic (kanamycin) and herbicide (glufosinate) tolerance genes. In a field trial, the effectiveness of a hemp (Cannabis sativa) stripe containment strategy was tested by measuring the frequency of pollinated CMS bait plants placed at different distances and directions from a transgenic pollen source. The results demonstrated the ineffectiveness of the containment strategy. Physiological and molecular tests confirmed the escape and production of transgenic offspring more than 200 m behind the hemp containment. Since absolute containment is unlikely to be effective, the CMS-bait plant detection system is a useful tool for other monitoring purposes. PMID:11123616

  7. Husband-Wife Communication, Wife's Employment, and the Decision for Male or Female Sterilization.

    ERIC Educational Resources Information Center

    Bean, Frank D.; And Others

    1983-01-01

    Examined relationships between perceptions of marital communication and the choice of male or female sterilization in 313 couples. The wife's perception of marital communication was negatively related to the tendency for the couple to choose female sterilization, conditional on female labor force participation. Communication questions are…

  8. Methoprene and protein supplements accelerate reproductive development and improve mating success of male tephritid flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have been studying the physiological mechanisms responsible for coordination of reproductive maturity and sex pheromone communication in males of tephritid flies in order to develop methods for acceleration of reproductive maturity among sterilized males. Our studies revealed that the juvenile ho...

  9. Variation in fecal testosterone levels, inter-male aggression, dominance rank and age during mating and post-mating periods in wild adult male ring-tailed lemurs (Lemur catta).

    PubMed

    Gould, L; Ziegler, T E

    2007-12-01

    In primate species exhibiting seasonal reproduction, patterns of testosterone excretion in adult males are variable: in some species, peaks correlate with female receptivity periods and heightened male-male aggression over access to estrous females, in others, neither heightened aggression nor marked elevations in testosterone have been noted. In this study, we examined mean fecal testosterone ( f T) levels and intermale aggression in wild adult male ring-tailed lemurs residing in three groups at Beza Mahafaly Reserve, Madagascar. Results obtained from mating and post-mating season 2003 were compared to test Wingfield et al. [1990. Am Nat 136:829-846] "challenge hypothesis", which predicts a strong positive relationship between male testosterone levels and male-male competition for access to receptive females during breeding season. f T levels and rates of intermale aggression were significantly higher during mating season compared to the post-mating period. Mean f T levels and aggression rates were also higher in the first half of the mating season compared with the second half. Number of males in a group affected rates of intermale agonism, but not mean f T levels. The highest-ranking males in two of the groups exhibited higher mean f T levels than did lower-ranking males, and young males exhibited lower f T levels compared to prime-aged and old males. In the post-mating period, mean male f T levels did not differ between groups, nor were there rank or age effects. Thus, although male testosterone levels rose in relation to mating and heightened male-male aggression, f T levels fell to baseline breeding levels shortly after the early mating period, and to baseline non-breeding levels immediately after mating season had ended, offsetting the high cost of maintaining both high testosterone and high levels of male-male aggression in the early breeding period. PMID:17427976

  10. Testosterone positively associated with both male mating effort and paternal behavior in savanna baboons (Papio cynocephalus)

    PubMed Central

    Onyango, Patrick Ogola; Gesquiere, Laurence R.; Altmann, Jeanne; Alberts, Susan C.

    2012-01-01

    Testosterone (T) is often positively associated with male sexual behavior and negatively associated with paternal care. These associations have primarily been demonstrated in species where investment in paternal care begins well after mating activity is complete, when offspring are hatched or born. Different patterns may emerge in studies of species where investment in mating and paternal care overlap temporally, for instance in non-seasonal breeders in which males mate with multiple females sequentially and may simultaneously have multiple offspring of different ages. In a 9-year data set on levels of T in male baboons, fecal concentrations of T (fT) were positively associated with both mate guarding (“consortship”) – a measure of current reproductive activity – and with the number of immature offspring a male had in his social group – a measure of past reproductive activity and an indicator of likely paternal behavior. To further examine the relationship between T and potential paternal behavior, we next drew on an intensive 8-month study of male behavior, and found that fathers were more likely to be in close proximity to their offspring than expected by chance. Because male baboons are known to provide paternal care, and because time in proximity to offspring would facilitate such care, this suggests that T concentrations in wild male baboons may be associated with both current reproductive activity and with current paternal behavior. These results are consistent with the predicted positive association between T a mating effort but not nd with a negative association between T a paternal care; in male baboons, high levels of nd T occur in males that are differentially associating with their offspring. PMID:23206991

  11. Genetic basis of X-Y chromosome dissociation and male sterility in interspecific hybrids.

    PubMed Central

    Matsuda, Y; Hirobe, T; Chapman, V M

    1991-01-01

    A high frequency of X-Y chromosome dissociation (95%) was found at first meiotic metaphase (MI) in spermatocytes of interspecific hybrids between laboratory mice, C57BL/6J (BL/6) and Mus spretus, compared with an X-Y dissociation frequency of only 3-4% in parental mice. The X-Y dissociation in F1 hybrids occurred before diakinesis rather than as a precocious dissociation at MI. The high X-Y dissociation was accompanied by spermatogenic breakdown after MI, resulting in male sterility. All F1 males were sterile and approximately half of the backcross males from fertile F1 females crossed with either BL/6 or M. spretus males were sterile. Male sterility was highly correlated with X-Y dissociation in both backcrosses. All of the mice with high X-Y dissociation were sterile and all of the males with low X-Y dissociation were fertile or subfertile. This correlation suggested that genetic divergence of the X-Y pairing region could contribute to the male sterile phenotype such that the BL/6 X chromosome would not pair with the M. spretus Y chromosome. The segregation of species-type alleles of amelogenin (Amelb and Amels), a distal X chromosome locus adjacent to the X-Y pairing region, was followed in backcross males that were analyzed for X-Y dissociation and sterility (we have used Amel as the designation for the mouse amelogenin locus; the current designation for this locus is Amg). A 95% concordance between Amelb with fertility and Amels with sterility was observed in backcrosses with BL/6, whereas the converse was observed in the backcross to M. spretus. These results imply that X-Y pairing plays an important role in male fertility and suggest that genetic divergence in X-Y pairing region between Mus species can contribute to the reproductive barriers between species and the process of speciation. Images PMID:2052565

  12. Male-to-female transfer of 5-hydroxytryptophan glucoside during mating in Zygaena filipendulae (Lepidoptera).

    PubMed

    Zagrobelny, Mika; Motawia, Mohammed Saddik; Olsen, Carl Erik; Bak, Søren; Møller, Birger Lindberg

    2013-11-01

    Zygaena filipendulae accumulates the cyanogenic glucosides linamarin and lotaustralin by larval sequestration from the food plant or de novo biosynthesis. We have previously demonstrated that the Z. filipendulae male transfers linamarin and lotaustralin to the female in the course of mating. In this study we report the additional transfer of 5-hydroxytryptophan glucoside (5-(β-d-glucopyranosyloxy)-L-Tryptophan) from the Z. filipendulae male internal genitalia to the female spermatophore around 5 h into the mating process. 5-Hydroxytryptophan glucoside is present in the virgin male internal genitalia, and production continues during the early phase of mating. Following initiation of 5-hydroxytryptophan glucoside transfer to the female, the amount in male internal genitalia is drastically reduced until after mating where it is slowly replenished. For unambiguous structural identification, 5-hydroxytryptophan glucoside was chemically synthesized and used as an authentic standard. The biological function of 5-hydroxytryptophan glucoside remains to be established, although we have indications that it may be involved in inducing the female to stay in copula and delay egg-laying to prevent re-mating of the female. To our knowledge 5-hydroxytryptophan glucoside has not previously been reported present in animal tissues. PMID:24012995

  13. Trading or coercion? Variation in male mating strategies between two communities of East African chimpanzees

    PubMed Central

    Kaburu, Stefano S. K.; Newton-Fisher, Nicholas E.

    2015-01-01

    Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolize access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (Pan troglodytes schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading—of grooming for mating—by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism–egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees’ willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness. PMID:26279605

  14. Segregation and Heritability of Male Sterility in Populations Derived from Progeny of Satsuma Mandarin.

    PubMed

    Goto, Shingo; Yoshioka, Terutaka; Ohta, Satoshi; Kita, Masayuki; Hamada, Hiroko; Shimizu, Tokurou

    2016-01-01

    Male sterility derived from Satsuma mandarin (Citrus unshiu) has been used in Japanese citrus breeding programs to obtain seedless cultivars, which is a desirable trait for consumers. Male sterility has often been evaluated by anther development or pollen fertility; however, the inheritance and heritability of male sterility derived from Satsuma is poorly understood. In this study, we investigated the mode of inheritance and broad-sense heritability of male sterility derived from Satsuma. Initially, we evaluated the total number of pollen grains per anther and apparent pollen fertility, as indicated by lactophenol blue staining, in 15 citrus cultivars and selections to understand the male sterility of Satsuma. The results indicated that male sterility was primarily caused by decreased number of pollen grains per anther in progeny of Satsuma. We also evaluated these traits in three F1 populations (hyuganatsu × 'Okitsu No. 56', 'Okitsu No. 46' × 'Okitsu No. 56' and 'Okitsu No. 46' × 'Kara'), of which the parents are derived from Satsuma. Individuals in these populations showed strong segregation for number of pollen grains per anther. The apparent fertility of pollen also showed segregation but was almost constant at 70%-90%. The estimated broad-sense heritability for the number of pollen grains per anther was as high as 0.898 in the 'Okitsu No. 46' × 'Okitsu No. 56' and 'Okitsu No. 46' × 'Kara' populations. These results indicated that the number of pollen grains per anther primarily determined male sterility among progeny of Satsuma, and this trait was inherited by the progeny. Development of DNA markers closely linked to male sterility using the F1 populations of 'Okitsu No. 46' × 'Okitsu No. 56' and 'Okitsu No. 46' × 'Kara' is expected to contribute to the breeding of novel seedless citrus cultivars. PMID:27589237

  15. Transgenic induction of mitochondrial rearrangements for cytoplasmic male sterility in crop plants.

    PubMed

    Sandhu, Ajay Pal S; Abdelnoor, Ricardo V; Mackenzie, Sally A

    2007-02-01

    Stability of the mitochondrial genome is controlled by nuclear loci. In plants, nuclear genes suppress mitochondrial DNA rearrangements during development. One nuclear gene involved in this process is Msh1. Msh1 appears to be involved in the suppression of illegitimate recombination in plant mitochondria. To test the hypothesis that Msh1 disruption leads to the type of mitochondrial DNA rearrangements associated with naturally occurring cytoplasmic male sterility in plants, a transgenic approach for RNAi was used to modulate expression of Msh1 in tobacco and tomato. In both species, these experiments resulted in reproducible mitochondrial DNA rearrangements and a condition of male (pollen) sterility. The male sterility was, in each case, heritable, associated with normal female fertility, and apparently maternal in its inheritance. Segregation of the transgene did not reverse the male sterile phenotype, producing stable, nontransgenic male sterility. The reproducible transgenic induction of mitochondrial rearrangements in plants is unprecedented, providing a means to develop novel cytoplasmic male sterile lines for release as non-GMO or transgenic materials. PMID:17261806

  16. Melanic body colour and aggressive mating behaviour are correlated traits in male mosquitofish (Gambusia holbrooki).

    PubMed Central

    Horth, Lisa

    2003-01-01

    Correlated traits are important from an evolutionary perspective as natural selection acting on one trait may indirectly affect other traits. Further, the response to selection can be constrained or hastened as a result of correlations. Because mating behaviour and body colour can dramatically affect fitness, a correlation between them can have important fitness ramifications. In this work, melanic (black) male mosquitofishes (Gambusia holbrooki) with temperature-sensitive body-colour expression are bred in captivity. Half of the sons of each melanic sire are reared at 19 degrees C (and express a black body colour) and half are reared at 31 degrees C (and express a silver body colour). The two colour morphs are placed in the same social setting and monitored for behavioural differences. Mating behaviour and colour are correlated traits. Mating behaviour differs markedly between the two phenotypes, despite high genetic relatedness. Melanic (black) phenotypes are more aggressive towards females, chasing them and attempting more matings than their silver siblings. Females avoid melanic-male mating attempts more than silver-male mating attempts. When males with temperature-sensitive colour expression are melanic and aggressive, they probably experience a very different selective regime in nature from when they are silver and less aggressive. Under some conditions (e.g. predation), melanic coloration and/or aggression is advantageous compared with silver coloration and/or less aggressive behaviour. However, under different conditions (e.g. high-frequency melanism), melanism and/or aggression appears to be disadvantageous and melanic males have reduced survival and reproduction. Selective advantages to each morph under different conditions may enable the long-term persistence of this temperature-sensitive genotype. PMID:12803892

  17. Female house mice avoid fertilization by t haplotype incompatible males in a mate choice experiment.

    PubMed

    Manser, A; König, B; Lindholm, A K

    2015-01-01

    The t haplotype in house mice is a well-known selfish genetic element with detrimental, nonadditive fitness consequences to its carriers: recessive lethal mutations cause t/t homozygotes to perish in utero. Given the severe genetic incompatibility imposed by the t haplotype, we predict females to avoid fertilization by t haplotype incompatible males. Indeed, some of the strongest evidence for compatibility mate choice is related to the t haplotype in house mice. However, all previous evidence for compatibility mate choice in this system is based on olfactory preference. It is so far unknown how general these preferences are and whether they are relevant in an actual mating context. Here, we assess female compatibility mate choice related to t haplotypes in a setting that--for the first time--allowed females to directly interact and mate with males. This approach enabled us to analyse female behaviour during the testing period, and the resulting paternity success and fitness consequences of a given choice. We show that genetic incompatibilities arising from the t haplotype had severe indirect fitness consequences and t females avoided fertilization by t incompatible males. The results are inconclusive whether this avoidance of t fertilization by t females was caused by pre- or post-copulatory processes. PMID:25494878

  18. Female house mice avoid fertilization by t haplotype incompatible males in a mate choice experiment

    PubMed Central

    Manser, A; König, B; Lindholm, A K

    2015-01-01

    The t haplotype in house mice is a well-known selfish genetic element with detrimental, nonadditive fitness consequences to its carriers: recessive lethal mutations cause t/t homozygotes to perish in utero. Given the severe genetic incompatibility imposed by the t haplotype, we predict females to avoid fertilization by t haplotype incompatible males. Indeed, some of the strongest evidence for compatibility mate choice is related to the t haplotype in house mice. However, all previous evidence for compatibility mate choice in this system is based on olfactory preference. It is so far unknown how general these preferences are and whether they are relevant in an actual mating context. Here, we assess female compatibility mate choice related to t haplotypes in a setting that – for the first time – allowed females to directly interact and mate with males. This approach enabled us to analyse female behaviour during the testing period, and the resulting paternity success and fitness consequences of a given choice. We show that genetic incompatibilities arising from the t haplotype had severe indirect fitness consequences and t females avoided fertilization by t incompatible males. The results are inconclusive whether this avoidance of t fertilization by t females was caused by pre- or post-copulatory processes. PMID:25494878

  19. Audience Effect Alters Male Mating Preferences in Zebra Finches (Taeniopygia guttata)

    PubMed Central

    Dubois, Frédérique; Belzile, Alexandra

    2012-01-01

    The social environment of animals strongly influences the mating preferences of both the choosing and the observing individuals. Notably, there is recent evidence that polygamous males decrease their selectivity when being observed by competitors in order to direct their rivals’ attention away from their true interest and, consequently, reduce sperm competition risk. Yet, other mechanisms, whose importance remains unexplored, could induce similar effects. In monogamous species with mutual choice, particularly, if males adjust their selectivity according to the risk of being rejected by their preferred mate, they should as well become less selective when potential rivals are present. Here, we investigated whether the presence of bystanders modifies male mating preferences when the risk of sperm competition is low, by carrying out mate-choice experiments with male zebra finches (Taeniopygia guttata) whose preferences for two females were measured twice: with and without an audience. We found that the presence of potential rivals had no effect on the males’ choosiness. However, with an audience, they spent more time with the female that was considered as the less attractive one in the control condition. These findings support the hypothesis that monogamous males alter their mate choice decisions in the presence of a male audience to reduce the risk of remaining unpaired. Thus, our results indicate that several explanations can account for the changes in male preferences due to the presence of competitors and highlight the importance of assessing the relative role of each mechanism potentially involved, to be able to make conclusions about the effect of an audience on signal evolution. PMID:22916298

  20. The quantitative genetic basis of male mating behavior in Drosophila melanogaster.

    PubMed Central

    Moehring, Amanda J; Mackay, Trudy F C

    2004-01-01

    Male mating behavior is an important component of fitness in Drosophila and displays segregating variation in natural populations. However, we know very little about the genes affecting naturally occurring variation in mating behavior, their effects, or their interactions. Here, we have mapped quantitative trait loci (QTL) affecting courtship occurrence, courtship latency, copulation occurrence, and copulation latency that segregate between a D. melanogaster strain selected for reduced male mating propensity (2b) and a standard wild-type strain (Oregon-R). Mating behavior was assessed in a population of 98 recombinant inbred lines derived from these two strains and QTL affecting mating behavior were mapped using composite interval mapping. We found four QTL affecting male mating behavior at cytological locations 1A;3E, 57C;57F, 72A;85F, and 96F;99A. We used deficiency complementation mapping to map the autosomal QTL with much higher resolution to five QTL at 56F5;56F8, 56F9;57A3, 70E1;71F4, 78C5;79A1, and 96F1;97B1. Quantitative complementation tests performed for 45 positional candidate genes within these intervals revealed 7 genes that failed to complement the QTL: eagle, 18 wheeler, Enhancer of split, Polycomb, spermatocyte arrest, l(2)05510, and l(2)k02206. None of these genes have been previously implicated in mating behavior, demonstrating that quantitative analysis of subtle variants can reveal novel pleiotropic effects of key developmental loci on behavior. PMID:15280239

  1. Is reduced female survival after mating a by-product of male-male competition in the dung fly Sepsis cynipsea?

    PubMed Central

    Teuschl, Y; Hosken, DJ; Blanckenhorn, WU

    2007-01-01

    Background In a number of species males damage females during copulation, but the reasons for this remain unclear. It may be that males are trying to manipulate female mating behaviour or their life histories. Alternatively, damage may be a side-effect of male-male competition. In the black scavenger or dung fly Sepsis cynipsea (Diptera: Sepsidae) mating reduces female survival, apparently because males wound females during copulation. However, this damage does not seem to relate to attempted manipulation of female reproduction by males. Here we tested the hypothesis that harming females during mating is an incidental by-product of characters favoured during pre-copulatory male-male competition. We assessed whether males and their sons vary genetically in their ability to obtain matings and harm females, and whether more successful males were also more damaging. We did this by ranking males' mating success in paired competitions across several females whose longevity under starvation was subsequently measured. Results As previously reported, our results show mating is costly for female S. cynipsea. However, variance in female longevity was not explained by male identity, family, body size, number of previous copulations, or copulation duration. Nevertheless, there was a positive correlation between the harm fathers inflicted on their mates (affecting female longevity) and the harm sons inflicted on theirs. Additionally, family identity significantly influenced male copulation success. Conclusion Our results indicate a heritable component of some yet unspecified male trait(s) that influence harm and mating success. However, there was no relationship between copulation success of fathers or sons and the mean longevity of their mates. We therefore found no support for harm being a side effect of traits favoured in pre-copulatory male-male competition. PMID:17941983

  2. Complex mitonuclear interactions and metabolic costs of mating in male seed beetles.

    PubMed

    Immonen, E; Rönn, J; Watson, C; Berger, D; Arnqvist, G

    2016-02-01

    The lack of evolutionary response to selection on mitochondrial genes through males predicts the evolution of nuclear genetic influence on male-specific mitochondrial function, for example by gene duplication and evolution of sex-specific expression of paralogs involved in metabolic pathways. Intergenomic epistasis may therefore be a prevalent feature of the genetic architecture of male-specific organismal function. Here, we assess the role of mitonuclear genetic variation for male metabolic phenotypes [metabolic rate and respiratory quotient (RQ)] associated with ejaculate renewal, in the seed beetle Callosobruchus maculatus, by assaying lines with crossed combinations of distinct mitochondrial haplotypes and nuclear lineages. We found a significant increase in metabolic rate following mating relative to virgin males. Moreover, processes associated with ejaculate renewal showed variation in metabolic rate that was affected by mitonuclear interactions. Mitochondrial haplotype influenced mating-related changes in RQ, but this pattern varied over time. Mitonuclear genotype and the energy spent during ejaculate production affected the weight of the ejaculate, but the strength of this effect varied across mitochondrial haplotypes showing that the genetic architecture of male-specific reproductive function is complex. Our findings unveil hitherto underappreciated metabolic costs of mating and ejaculate renewal, and provide the first empirical demonstration of mitonuclear epistasis on male reproductive metabolic processes. PMID:26548644

  3. Piecing together female extra-pair mate choice: females really do prefer more ornamented males.

    PubMed

    Wells, Sarah J; Safran, Rebecca J; Dale, James

    2016-08-01

    Evolutionary biologists have long been fascinated by extravagant male traits that abound across the animal kingdom and yet convey no apparent benefits to survival. From isopods to elephants, from armaments to ornaments, researchers have spent decades studying male-male competition and female mate choice in an effort to understand the significance of these secondary sexual characteristics. Among socially monogamous species, a frequently proposed explanation for the existence of male ornaments is that they are indicators of male genetic quality subject to female extra-pair mate choice. However, despite over two decades of extensive research into extra-pair paternity (EPP), the evidence that females actually choose more ornamented extra-pair sires is surprisingly scant. Consequently, whether EPP and female choice have contributed to the evolution of male ornaments in socially monogamous species, and what fitness benefits (if any) they signal to females, remains unclear. Progress in this field has been hampered by the challenge of dissociating clear female choice for ornamentation from confounding factors. In this issue of Molecular Ecology, Whittingham & Dunn (2016) use an experimental approach in a bird species with very high rates of EPP to tease apart these correlative effects. In doing so, they demonstrate clearly that male ornamentation is subject to female extra-pair mate choice. Their findings further suggest that EPP can be adaptive for females, and represent an important step forward in validating the role of EPP as an evolutionary driver of ornamental elaboration in socially monogamous species. PMID:27463236

  4. Do unattractive friends make you look better? Context-dependent male mating preferences in the guppy.

    PubMed

    Gasparini, Clelia; Serena, Giovanna; Pilastro, Andrea

    2013-04-01

    Recent theory predicts that in species where females tend to mate with the relatively most ornamented males, males may increase their attractiveness to females, and hence mating success, by preferentially associating with females that are surrounded by less ornamented competitors. Despite this prediction, we still lack explicit experimental evidence that males strategically prefer females surrounded by less attractive competitors to maximize their relative attractiveness. In this paper, we provide a comprehensive test of this hypothesis in the guppy (Poecilia reticulata), a species where a female's perception of a male's attractiveness depends on his coloration relative to that of surrounding males. We found that males preferentially associated with females that were surrounded by relatively drab competitors, and that the strength of an individual male's preference was negatively correlated with his level of ornamentation. A series of control experiments made it possible to exclude the potentially confounding effects of male-male competition or social motivations when drawing these conclusions. The ability of males to choose social context to increase their relative attractiveness has important evolutionary consequences, for example, by contributing towards the maintenance of variability in male sexual ornamentation despite the strong directional selection exerted by female preferences. PMID:23407839

  5. Low incidence of miscarriage induced by the scent of male littermates of original mates: male kinship reduces the bruce effect in female mice, Mus musculus.

    PubMed

    Wang, Yuting; Liu, Dingzhen

    2013-01-01

    The scent of a novel male can elicit pregnancy block in recently mated female mice (Mus musculus), a phenomenon known as the Bruce effect. Despite abundant literature on the Bruce effect in rodents, it remains unclear whether males related to a female's original mate can induce the Bruce effect in out-bred, communally living mice. We investigated this question using Kunming (KM) male mice of varying genetic relatedness. Recently mated females were subjected to three treatments: exposure to the urine of the mate, urine of the mate's male littermate, and urine of a male unrelated to the mate. It was found that the urine of male littermates of the females' mates did not elicit more pregnancy block than that of the females' mates. However, the urine of novel males caused a higher rate of female miscarriage than that of the females' mates. By using a habituation-dishabituation paradigm, we found that unmated females could discriminate the urine scents of two male littermates from those of a novel male unrelated to the littermates. To understand how females use urinary cues to discriminate between males with different genetic relationships, we used gas chromatography coupled with mass spectrometry (GC-MS) to examine the volatile composition of urine from males with varying relatedness. It was found that KM male littermates shared similar volatile compositions in their urine. Our results suggest that male kinship reduces the Bruce effect in female KM mice, and provide additional evidence for mate choice being partly mediated by the Bruce effect in KM mice. PMID:23874716

  6. Mating season aggression and fecal testosterone levels in male ring-tailed lemurs (Lemur catta).

    PubMed

    Cavigelli, S A; Pereira, M E

    2000-05-01

    The challenge hypothesis (J. C. Wingfield, R. E. Hegner, B. G. Ball, and A. M. Duffy, 1990, Am. Nat. 136, 829-846) proposes that in birds, reptiles, and fish, "the frequency or intensity of reproductive aggression as an effect of T[estosterone] is strongest in situations of social instability, such as during the formation of dominance relationships, the establishment of territorial boundaries, or challenges by a conspecific male for a territory or access to mates" (p. 833). To determine the extension of this hypothesis to mammalian species, we tested predictions of the hypothesis in a nonpaternal, seasonal breeding, prosimian primate (ring-tailed lemurs, Lemur catta). Semi-free-ranging males were studied during periods of social stability (premating period) and instability (mating period). The annual mating season consists of several days during which males fight for access to promiscuous group females as each individually becomes sexually receptive for 1 day. Male rates of aggression were compared to fecal testosterone levels within premating and mating periods. In the premating period male rate of aggression was not significantly correlated with testosterone level. By contrast, during the mating season testosterone and aggression levels were positively and significantly correlated. However, on days just preceding estrus, male rate of aggression was not significantly correlated with testosterone, but on days of estrus, when aggressive challenges peaked sharply, testosterone and aggression were highly positively correlated. These results suggest that the challenge hypothesis applies to mammals as well as to birds, reptiles, and fish. In addition, elevations in testosterone were tightly circumscribed around days of estrus, suggesting a compromise between costs and benefits of elevated testosterone levels. PMID:10868488

  7. A potential mate influences reproductive development in female, but not male, pine siskins.

    PubMed

    Watts, Heather E; Edley, Bruce; Hahn, Thomas P

    2016-04-01

    The role of photoperiod in avian reproductive timing has been well studied, and we are increasingly recognizing the roles of other environmental cues such as social cues. However, few studies have evaluated the extent to which males and females of the same species respond similarly to the same type of cue. Moreover, previous studies have rarely examined how variation in the quality or nature of a given social cue might modulate its effect. Here, we examine the sensitivity of male and female pine siskins (Spinus pinus) to a potential mate as a stimulatory cue for gonadal recrudescence, and we investigate whether variation in the relationship between a bird and its potential mate modulates the effect of that potential mate. Birds were initially housed without opposite sex birds on a 12L:12D photoperiod with ad libitum food. After gonadal recrudescence had begun males and females were randomly paired with an opposite sex bird or housed alone. An additional group of males was paired with estradiol-implanted females. In males, these social treatments had no effect on testis length, cloacal protuberance length, luteinizing hormone (LH) levels, or testosterone levels. In females, presence of a potential mate had a significant and positive effect on ovary score, defeathering of the brood patch, and LH levels. Among paired birds, the degree of affiliation within a pair corresponded to the extent of reproductive development in females, but not males. Thus, reproductive timing in females appears to be sensitive to both the presence of a potential mate and her relationship with him. PMID:26836771

  8. Male foraging efficiency, but not male problem-solving performance, influences female mating preferences in zebra finches

    PubMed Central

    Chantal, Véronique

    2016-01-01

    Experimental evidence suggests that females would prefer males with better cognitive abilities as mates. However, little is known about the traits reflecting enhanced cognitive skills on which females might base their mate-choice decisions. In particular, it has been suggested that male foraging performance could be used as an indicator of cognitive capacity, but convincing evidence for this hypothesis is still lacking. In the present study, we investigated whether female zebra finches (Taeniopygia guttata) modify their mating preferences after having observed the performance of males on a problem-solving task. Specifically, we measured the females’ preferences between two males once before and once after an observation period, during which their initially preferred male was incapable of solving the task contrary to their initially less-preferred male. We also conducted a control treatment to test whether the shift in female preferences was attributable to differences between the two stimulus males in their foraging efficiency. Finally, we assessed each bird’s performance in a color associative task to check whether females can discriminate among males based on their learning speed. We found that females significantly increased their preference toward the most efficient male in both treatments. Yet, there was no difference between the two treatments and we found no evidence that females assess male cognitive ability indirectly via morphological traits. Thus, our results suggest that females would not use the males’ problem-solving performance as an indicator of general cognitive ability to gain indirect fitness benefits (i.e., good genes) but rather to assess their foraging efficiency and gain direct benefits.

  9. Molecular mapping of three male-sterile, female-fertile mutants and generation of a comprehensive map of all known male sterility genes in soybean.

    PubMed

    Yang, Yang; Speth, Benjamin D; Boonyoo, Napatsakorn; Baumert, Eric; Atkinson, Taylor R; Palmer, Reid G; Sandhu, Devinder

    2014-03-01

    In soybean, an environmentally stable male sterility system is vital for making hybrid seed production commercially viable. Eleven male-sterile, female-fertile mutants (ms1, ms2, ms3, ms4, ms5, ms6, ms7, ms8, ms9, msMOS, and msp) have been identified in soybean. Of these, eight (ms2, ms3, ms5, ms7, ms8, ms9, msMOS, and msp) have been mapped to soybean chromosomes. The objectives of this study were to (i) locate the ms1, ms4, and ms6 genes to soybean chromosomes; (ii) generate genetic linkage maps of the regions containing these genes; and (iii) develop a comprehensive map of all known male-sterile, female-fertile genes in soybean. The bulked segregant analysis technique was used to locate genes to soybean chromosomes. Microsatellite markers from the corresponding chromosomes were used on F2 populations to generate genetic linkage maps. The ms1 and ms6 genes were located on chromosome 13 (molecular linkage group F) and ms4 was present on chromosome 2 (molecular linkage group D1b). Molecular analyses revealed markers Satt516, BARCSOYSSR_02_1539, and AW186493 were located closest to ms1, ms4, and ms6, respectively. The ms1 and ms6 genes, although present on the same chromosome, were independently assorting with a genetic distance of 73.7 cM. Using information from this study and compiled information from previously published male sterility genes in soybean, a comprehensive genetic linkage map was generated. Eleven male sterility genes were present on seven soybean chromosomes. Four genes were present in two regions on chromosome 2 (molecular linkage group D1b) and two genes were present on chromosome 13 (molecular linkage group F). PMID:24814801

  10. Methoprene modulates the effect of diet on male melon fly, Bactrocera cucurbitate, performance at mating aggregations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of dietary protein (P) and the topical application of juvenile hormone analogue (methoprene (M)) on mating behaviour of male melon fly, Bactrocera cucurbitae, was assessed in the laboratory and in field cages. Age, dietary protein and methoprene application improved the sexual success and...

  11. Reproductive character displacement of female mate preferences for male cuticular hydrocarbons in Drosophila subquinaria.

    PubMed

    Rundle, Howard D; Dyer, Kelly A

    2015-10-01

    Several lines of evidence implicate sexual isolation in both initiating and completing the speciation process. Although its existence is straightforward to demonstrate, understanding the evolution of sexual isolation requires identifying the underlying phenotypes responsible so that we can determine how these have diverged. Here, we study geographic variation in female mate preferences for male sexual displays in the fly Drosophila subquinaria. Female D. subquinaria that are sympatric with its sister species D. recens discriminate strongly against both D. recens and allopatric conspecific males, whereas females from allopatric populations do not. Furthermore, female mate preferences target at least in part a suite of cuticular hydrocarbons (CHCs) in males and geographic variation in CHCs mirrors the pattern of mate discrimination. In this study, we quantify female mate preferences for male CHCs from populations that span the geographic range of D. subquinaria. We find that the direction of linear sexual selection varies significantly between populations that are sympatric versus allopatric with D. recens in a pattern of reproductive character displacement. Differences in preference partially align with existing differences in CHCs and patterns of sexual isolation, although discrepancies remain that suggest the involvement of additional traits and/or more complex, nonlinear preference functions. PMID:26299584

  12. Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones.

    PubMed

    Laturney, Meghan; Billeter, Jean-Christophe

    2016-01-01

    Males from many species ensure paternity by preventing their mates from copulating with other males. One mate-guarding strategy involves marking females with anti-aphrodisiac pheromones (AAPs), which reduces the females' attractiveness and dissuades other males from courting. Since females benefit from polyandry, sexual conflict theory predicts that females should develop mechanisms to counteract AAPs to achieve additional copulations, but no such mechanisms have been documented. Here we show that during copulation Drosophila melanogaster males transfer two AAPs: cis-Vaccenyl Acetate (cVA) to the females' reproductive tract, and 7-Tricosene (7-T) to the females' cuticle. A few hours after copulation, females actively eject cVA from their reproductive tract, which results in increased attractiveness and re-mating. Although 7-T remains on those females, we show that it is the combination of the two chemicals that reduces attractiveness. To our knowledge, female AAP ejection provides the first example of a female mechanism that counter-acts chemical mate-guarding. PMID:27484362

  13. Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones

    PubMed Central

    Laturney, Meghan; Billeter, Jean-Christophe

    2016-01-01

    Males from many species ensure paternity by preventing their mates from copulating with other males. One mate-guarding strategy involves marking females with anti-aphrodisiac pheromones (AAPs), which reduces the females' attractiveness and dissuades other males from courting. Since females benefit from polyandry, sexual conflict theory predicts that females should develop mechanisms to counteract AAPs to achieve additional copulations, but no such mechanisms have been documented. Here we show that during copulation Drosophila melanogaster males transfer two AAPs: cis-Vaccenyl Acetate (cVA) to the females' reproductive tract, and 7-Tricosene (7-T) to the females' cuticle. A few hours after copulation, females actively eject cVA from their reproductive tract, which results in increased attractiveness and re-mating. Although 7-T remains on those females, we show that it is the combination of the two chemicals that reduces attractiveness. To our knowledge, female AAP ejection provides the first example of a female mechanism that counter-acts chemical mate-guarding. PMID:27484362

  14. MALE COMBAT AND MATING BEHAVIOR OF DONACIA CRASSIPES F. AND OTHER CHRYSOMELIDS (COLEOPTERA: CHRYSOMELIDAE: DONACIINAE).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A previously unknown aggressive component of the mating behavior of Donacia crassipes F. is described and illustrated. Male fights were observed in June, July and August from 1980 to 1982 on Unecha river in southwestern Russia. During the fights the following combat techniques are employed: warning ...

  15. Scheduled Daily Mating Induces Circadian Anticipatory Activity Rhythms in the Male Rat

    PubMed Central

    Landry, Glenn J.; Opiol, Hanna; Marchant, Elliott G.; Pavlovski, Ilya; Mear, Rhiannon J.; Hamson, Dwayne K.; Mistlberger, Ralph E.

    2012-01-01

    Daily schedules of limited access to food, palatable high calorie snacks, water and salt can induce circadian rhythms of anticipatory locomotor activity in rats and mice. All of these stimuli are rewarding, but whether anticipation can be induced by neural correlates of reward independent of metabolic perturbations associated with manipulations of food and hydration is unclear. Three experiments were conducted to determine whether mating, a non-ingestive behavior that is potently rewarding, can induce circadian anticipatory activity rhythms in male rats provided scheduled daily access to steroid-primed estrous female rats. In Experiment 1, rats anticipated access to estrous females in the mid-light period, but also exhibited post-coital eating and running. In Experiment 2, post-coital eating and running were prevented and only a minority of rats exhibited anticipation. Rats allowed to see and smell estrous females showed no anticipation. In both experiments, all rats exhibited sustained behavioral arousal and multiple mounts and intromissions during every session, but ejaculated only every 2–3 days. In Experiment 3, the rats were given more time with individual females, late at night for 28 days, and then in the midday for 28 days. Ejaculation rates increased and anticipation was robust to night sessions and significant although weaker to day sessions. The anticipation rhythm persisted during 3 days of constant dark without mating. During anticipation of nocturnal mating, the rats exhibited a significant preference for a tube to the mating cage over a tube to a locked cage with mating cage litter. This apparent place preference was absent during anticipation of midday mating, which may reflect a daily rhythm of sexual reward. The results establish mating as a reward stimulus capable of inducing circadian rhythms of anticipatory behavior in the male rat, and reveal a critical role for ejaculation, a modulatory role for time of day, and a potential confound role

  16. Scheduled daily mating induces circadian anticipatory activity rhythms in the male rat.

    PubMed

    Landry, Glenn J; Opiol, Hanna; Marchant, Elliott G; Pavlovski, Ilya; Mear, Rhiannon J; Hamson, Dwayne K; Mistlberger, Ralph E

    2012-01-01

    Daily schedules of limited access to food, palatable high calorie snacks, water and salt can induce circadian rhythms of anticipatory locomotor activity in rats and mice. All of these stimuli are rewarding, but whether anticipation can be induced by neural correlates of reward independent of metabolic perturbations associated with manipulations of food and hydration is unclear. Three experiments were conducted to determine whether mating, a non-ingestive behavior that is potently rewarding, can induce circadian anticipatory activity rhythms in male rats provided scheduled daily access to steroid-primed estrous female rats. In Experiment 1, rats anticipated access to estrous females in the mid-light period, but also exhibited post-coital eating and running. In Experiment 2, post-coital eating and running were prevented and only a minority of rats exhibited anticipation. Rats allowed to see and smell estrous females showed no anticipation. In both experiments, all rats exhibited sustained behavioral arousal and multiple mounts and intromissions during every session, but ejaculated only every 2-3 days. In Experiment 3, the rats were given more time with individual females, late at night for 28 days, and then in the midday for 28 days. Ejaculation rates increased and anticipation was robust to night sessions and significant although weaker to day sessions. The anticipation rhythm persisted during 3 days of constant dark without mating. During anticipation of nocturnal mating, the rats exhibited a significant preference for a tube to the mating cage over a tube to a locked cage with mating cage litter. This apparent place preference was absent during anticipation of midday mating, which may reflect a daily rhythm of sexual reward. The results establish mating as a reward stimulus capable of inducing circadian rhythms of anticipatory behavior in the male rat, and reveal a critical role for ejaculation, a modulatory role for time of day, and a potential confound role for

  17. Do unattractive friends make you look better? Context-dependent male mating preferences in the guppy

    PubMed Central

    Gasparini, Clelia; Serena, Giovanna; Pilastro, Andrea

    2013-01-01

    Recent theory predicts that in species where females tend to mate with the relatively most ornamented males, males may increase their attractiveness to females, and hence mating success, by preferentially associating with females that are surrounded by less ornamented competitors. Despite this prediction, we still lack explicit experimental evidence that males strategically prefer females surrounded by less attractive competitors to maximize their relative attractiveness. In this paper, we provide a comprehensive test of this hypothesis in the guppy (Poecilia reticulata), a species where a female's perception of a male's attractiveness depends on his coloration relative to that of surrounding males. We found that males preferentially associated with females that were surrounded by relatively drab competitors, and that the strength of an individual male's preference was negatively correlated with his level of ornamentation. A series of control experiments made it possible to exclude the potentially confounding effects of male–male competition or social motivations when drawing these conclusions. The ability of males to choose social context to increase their relative attractiveness has important evolutionary consequences, for example, by contributing towards the maintenance of variability in male sexual ornamentation despite the strong directional selection exerted by female preferences. PMID:23407839

  18. Heterozygous alleles restore male fertility to cytoplasmic male-sterile radish (Raphanus sativus L.): a case of overdominance

    PubMed Central

    Wang, Zhi Wei; Wang, Chuan; Gao, Lei; Mei, Shi Yong; Zhou, Yuan; Xiang, Chang Ping; Wang, Ting

    2013-01-01

    The practice of hybridization has greatly contributed to the increase in crop productivity. A major component that exploits heterosis in crops is the cytoplasmic male sterility (CMS)/nucleus-controlled fertility restoration (Rf) system. Through positional cloning, it is shown that heterozygous alleles (RsRf3-1/RsRf3-2) encoding pentatricopeptide repeat (PPR) proteins are responsible for restoring fertility to cytoplasmic male-sterile radish (Raphanus sativus L.). Furthermore, it was found that heterozygous alleles (RsRf3-1/RsRf3-2) show higher expression and RNA polymerase II occupancy in the CMS cytoplasmic background compared with their homozygous alleles (RsRf3-1/RsRf3-1 or RsRf3-2/RsRf3-2). These data provide new insights into the molecular mechanism of fertility restoration to cytoplasmic male-sterile plants and illustrate a case of overdominance. PMID:23630327

  19. Mobile mating disruption of light brown apple moths using pheromone-treated sterile Mediterranean fruit flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Public opposition to aerial application of sex pheromone for mating disruption of light brown apple moth (Epiphyas postvittana, LBAM) in California stopped its further use in the ca. $74 million eradication programme in 2008, underscoring the need for other eradication tactics. We demonstrate that ...

  20. Mating increases neuronal tyrosine hydroxylase expression and selectively gates transmission of male chemosensory information in female mice.

    PubMed

    Matthews, Gillian A; Patel, Ronak; Walsh, Alison; Davies, Owain; Martínez-Ricós, Joana; Brennan, Peter A

    2013-01-01

    Exposure to chemosensory signals from unfamiliar males can terminate pregnancy in recently mated female mice. The number of tyrosine hydroxylase-positive neurons in the main olfactory bulb has been found to increase following mating and has been implicated in preventing male-induced pregnancy block during the post-implantation period. In contrast, pre-implantation pregnancy block is mediated by the vomeronasal system, and is thought to be prevented by selective inhibition of the mate's pregnancy blocking chemosignals, at the level of the accessory olfactory bulb. The objectives of this study were firstly to identify the level of the vomeronasal pathway at which selective inhibition of the mate's pregnancy blocking chemosignals occurs. Secondly, to determine whether a post-mating increase in tyrosine hydroxylase-positive neurons is observed in the vomeronasal system, which could play a role in preventing pre-implantation pregnancy block. Immunohistochemical staining revealed that mating induced an increase in tyrosine-hydroxylase positive neurons in the arcuate hypothalamus of BALB/c females, and suppressed c-Fos expression in these neurons in response to mating male chemosignals. This selective suppression of c-Fos response to mating male chemosignals was not apparent at earlier levels of the pregnancy-blocking neural pathway in the accessory olfactory bulb or corticomedial amygdala. Immunohistochemical staining revealed an increase in the number of tyrosine hydroxylase-positive neurons in the accessory olfactory bulb of BALB/c female mice following mating. However, increased dopamine-mediated inhibition in the accessory olfactory bulb is unlikely to account for the prevention of pregnancy block to the mating male, as tyrosine hydroxylase expression did not increase in females of the C57BL/6 strain, which show normal mate recognition. These findings reveal an association of mating with increased dopaminergic modulation in the pregnancy block pathway and support the

  1. Subadult experience influences adult mate choice in an arthropod: Exposed female wolf spiders prefer males of a familiar phenotype

    PubMed Central

    Hebets, Eileen A.

    2003-01-01

    Current sexual selection theory proposes several potential mechanisms driving the evolution of female mating preferences, few of which involve social interactions. Although vertebrate examples of socially influenced mating preferences do exist, the invertebrate examples are virtually nonexistent. Here I demonstrate that the mating preferences of female wolf spiders can be acquired through exposure as subadults to unrelated, sexually active adult males. I first conducted exposure trials during which subadult females of the wolf spider Schizocosa uetzi were allowed to interact with mature males of an experimentally manipulated phenotype (either black or brown forelegs). After maturation, these previously exposed females were paired with a male of either a familiar or unfamiliar manipulated phenotype for mate-choice trials. Subadult females that were exposed to directed courtship by mature males of a particular morphological phenotype were subsequently more likely to mate with a male of a familiar phenotype as adults. Furthermore, females that were exposed as subadults were more likely, as adults, to cannibalize a courting male with an unfamiliar phenotype. Unexposed females did not distinguish between phenotypes in either mate choice or cannibalism frequency. These results suggest a previously uncharacterized mechanism influencing the origin of female mating preferences and ultimately the evolution of male traits: subadult experience. This study also stresses the potential importance of learning and memory on adult mate choice in an arthropod. PMID:14597702

  2. Sexual Signalling in Propithecus verreauxi: Male “Chest Badge” and Female Mate Choice

    PubMed Central

    Dall'Olio, Stefania; Norscia, Ivan; Antonacci, Daniela; Palagi, Elisabetta

    2012-01-01

    Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition). The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This “grooming for sex” tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates. PMID:22615982

  3. Low Incidence of Miscarriage Induced by the Scent of Male Littermates of Original Mates: Male Kinship Reduces the Bruce Effect in Female Mice, Mus musculus

    PubMed Central

    Wang, Yuting; Liu, Dingzhen

    2013-01-01

    The scent of a novel male can elicit pregnancy block in recently mated female mice (Mus musculus), a phenomenon known as the Bruce effect. Despite abundant literature on the Bruce effect in rodents, it remains unclear whether males related to a female’s original mate can induce the Bruce effect in out-bred, communally living mice. We investigated this question using Kunming (KM) male mice of varying genetic relatedness. Recently mated females were subjected to three treatments: exposure to the urine of the mate, urine of the mate’s male littermate, and urine of a male unrelated to the mate. It was found that the urine of male littermates of the females’ mates did not elicit more pregnancy block than that of the females’ mates. However, the urine of novel males caused a higher rate of female miscarriage than that of the females’ mates. By using a habituation-dishabituation paradigm, we found that unmated females could discriminate the urine scents of two male littermates from those of a novel male unrelated to the littermates. To understand how females use urinary cues to discriminate between males with different genetic relationships, we used gas chromatography coupled with mass spectrometry (GC-MS) to examine the volatile composition of urine from males with varying relatedness. It was found that KM male littermates shared similar volatile compositions in their urine. Our results suggest that male kinship reduces the Bruce effect in female KM mice, and provide additional evidence for mate choice being partly mediated by the Bruce effect in KM mice. PMID:23874716

  4. Female Japanese quail (Coturnix japonica) mated with males that harassed them are unlikely to lay fertilized eggs.

    PubMed

    Persaud, Kamini N; Galef, Bennett G

    2005-11-01

    Results of previous studies of courtship and mating in Japanese quail (Coturnix japonica) suggest that females avoid conspecific males because, while courting and mating, males engage in behaviors that are potentially injurious to females. However, prior experiments provided no direct evidence that females avoided harassing males. Here the authors show that a female quail choosing between a previous sex partner and an unfamiliar male avoids the former if he engaged in relatively many potentially injurious acts while courting and mating, (Experiments 1 and 2) and that males behaving aggressively toward mates are less likely than are gentler males to fertilize the females' eggs (Experiment 3). Male sexual harassment appears to be a tactic both aversive to female quail and relatively ineffective in fertilizing them. PMID:16366777

  5. Gay male attraction toward muscular men: does mating context matter?

    PubMed

    Varangis, Eleanna; Lanzieri, Nicholas; Hildebrandt, Tom; Feldman, Matthew

    2012-03-01

    The purpose of this study was to examine gay men's perceived attractiveness of male figures based on short-term and long-term partner contexts. A sample of 190 gay adult men rated the attractiveness of line-drawings depicting male figures varying systematically in muscularity and body fat percentage in both short-term and long-term dating contexts. Mixed effects modeling was used to estimate the effects of figure (muscularity and body fat), dating context (short-term vs. long-term), and individual rater characteristics on attractiveness ratings. Results indicated that figure muscularity and body-fat had significant non-linear (i.e., quadratic) relationships with attractiveness ratings, and short-term dating context was associated with more discriminating ratings of attractiveness. Interactions between individual characteristics and figure characteristics indicated that the more available the individual and lower body fat, the more discriminating they were in ratings of attractiveness. The implications for future investigations considering both object and observer characteristics of attractiveness preferences are discussed. PMID:22342537

  6. Behavioral correlates of male mating success in a multisire flock as determined by DNA fingerprinting.

    PubMed

    Jones, M E; Mench, J A

    1991-07-01

    The fertility of an individual rooster within a multi-sire flock may be influenced by a number of behavioral considerations, including frequency and timing of matings and the male's position in the social dominance hierarchy. The relationship between behavior and fertility has proven difficult to assess, however, because there are a limited number of heritable morphological traits that can be used to determine paternity. The objectives of the present study were to use DNA fingerprinting to determine paternity in domestic fowl and to assess some behavioral and physiological correlates of mating success. Sixty day-old chicks from each of two commercial breeds, DeKalb White Leghorn (L) and Warren Color-Sexed (W), were reared in either same-breed or mixed-breed groups. At 43 wk of age, all females and six randomly selected males were mixed into one large pen. Male aggressive and mating behaviors were recorded over a 4-mo period. Fertility of individual sires was determined by DNA fingerprinting and pedigree analysis of chicks. Dominance rank and the frequencies of both completed matings and mating attempts were positively correlated with fertility (P less than .01). In addition, wing flapping was correlated with both dominance (P less than .001) and fertility (P less than .05). There was no correlation between fertility and plasma testosterone. There were breed effects on dominance status, with W dominating L. Multiple paternity was demonstrated in 4 out of 10 families by DNA fingerprinting. The present study is the first one to demonstrate a correlation between dominance and fertility in a flock containing several males of the same breed and morphology. PMID:1886859

  7. Downy mildew incidence of pearl millet hybrids with different male-sterility inducing cytoplasms.

    PubMed

    Yadav, O P

    1996-02-01

    The use of different sources of cytoplasmic male sterility (CMS) in hybrid seed production of pearl millet [Pennisetum glaucum (L.) R. Br.] is advocated to avoid possible disease epidemics occurring due to cytoplasmic uniformity. The effects of commercially unexploited, but potentially exploitable, sources of CMS, like A2, A3 and A4, on downy mildew [Sclerospora graminicola (Sacc.) Schroet] incidence were studied by using the disease incidence of isonuclear hybrids with male-sterile and fertile cytoplasm. The mean downy mildew incidence of hybrids carrying different male-sterile cytoplasm was similar to that of hybrids retaining the fertile cytoplasm. The cytoplasm accounted for only 0.6% of the total variation and its effect was non-significant; pollinators could explain most of the variation in determining the disease incidence of hybrids. This suggested that these male-sterile cytoplasms are not linked to downy mildew susceptibility and thus can be exploited commercially to broaden the cytoplasmic base of the male-sterile lines and, ultimately, of hybrids. PMID:24166178

  8. Reed bunting females increase fitness through extra-pair mating with genetically dissimilar males

    PubMed Central

    Suter, Stefan M; Keiser, Martin; Feignoux, Raoul; Meyer, Dietrich R

    2007-01-01

    Females of many socially monogamous species accept or even actively seek copulations outside the social pair bond. As females cannot increase the number of offspring with promiscuous behaviour, the question arises why they engage in extra-pair mating. We used microsatellite data to determine paternity, heterozygosity and genetic relatedness in the reed bunting (Emberiza schoeniclus), a species with high levels of extra-pair paternity (EPP). We found that extra-pair young (EPY) were more heterozygous than within-pair young (WPY). The high heterozygosity of the EPY resulted from a low genetic similarity between females and their extra-pair mates. EPY were heavier and larger when compared with their maternal half-siblings shortly before they left the nest. Recapture data indicated a higher fledgling survival of EPY compared with WPY. Our data suggest that reed bunting females increase the viability of their offspring and thus fitness through extra-pair mating with genetically dissimilar males. PMID:17785270

  9. Release of thiotepa sterilized males into caged populations of Aedes aegypti: life table analysis.

    PubMed

    Gato, René; Companioni, Ariamys; Bruzón, Rosa Y; Menéndez, Zulema; González, Aileen; Rodríguez, Misladys

    2014-04-01

    Successful SIT trials against mosquitoes in the 1960-70s were achieved by sterilizing male mosquitoes using chemosterilants. Their use was discontinued after concerns were raised about the effect of residues on non-target organisms, although scant evidence has been published. Irradiation is an expensive process; chemosterilization could be an affordable option for implementing SIT programs in developing countries. We compare life table parameters of three Aedes aegypti populations comprising different ratios of thiotepa-treated and non-treated males in order to identify the impact on reproductive potential of the presence of sterile males. No difference was observed in the survival of the treated and untreated males. The release of thiotepa sterilized males into caged Ae. aegypti populations had no effect on death or survival probability of the individuals in the cages but the fecundity of females was significantly reduced, as evaluated by hatch rate and stable age structure parameters. The significant decreases in net reproduction rate, finite rate of natural increase and intrinsic rate of natural increase in populations including sterile males are sufficient to indicate that such populations would not be able to proliferate in natural conditions. This suggests that release of Ae. aegypti thiotepa-treated males could be effective in reducing the reproductive capability of the target population and consequently contribute to vector control. PMID:24513037

  10. Genetic Variation and Covariation in Male Attractiveness and Female Mating Preferences in Drosophila melanogaster

    PubMed Central

    Ratterman, Nicholas L.; Rosenthal, Gil G.; Carney, Ginger E.; Jones, Adam G.

    2013-01-01

    How mating preferences evolve remains one of the major unsolved mysteries in evolutionary biology. One major impediment to the study of ornament-preference coevolution is that many aspects of the theoretical literature remain loosely connected to empirical data. Theoretical models typically streamline mating preferences by describing preference functions with a single parameter, a modeling convenience that may veil important aspects of preference evolution. Here, we use a high-throughput behavioral assay in Drosophila melanogaster to quantify attractiveness and multiple components of preferences in both males and females. Females varied genetically with respect to how they ranked males in terms of attractiveness as well as the extent to which they discriminated among different males. Conversely, males showed consistent preferences for females, suggesting that D. melanogaster males tend to rank different female phenotypes in the same order in terms of attractiveness. Moreover, we reveal a heretofore undocumented positive genetic correlation between male attractiveness and female choosiness, which is a measure of the variability in a female’s response to different male phenotypes. This genetic correlation sets the stage for female choosiness to evolve via a correlated response to selection on male traits and potentially adds a new dimension to the Fisherian sexual selection process. PMID:24212081