Paternity success in ladybirds: function of mating interval and order

Multiple matings result in varying paternity share based on mating interval and order. Thus, assessing the effect of mating interval and order on patterns of sperm usage and paternity is crucial. We designed consecutive and delayed double-mating experiments to investigate paternity variation in ladybird, Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae), using two distinct morphs of the species as phenotypic markers of paternity. The time to commence mating, copulation duration and reproductive output were recorded. The morphs of the offspring from the two setups were taken as a measure of paternity accumulated by the males. The time to commence mating decreased for the second mating in the consecutive mating treatment, while the reverse was observed in the delayed mating treatment. Consecutive double matings reduced the mating duration. Fecundity increased when second mating occurred after a few days, though percent egg viability remained unaffected. The second male accrued higher paternity (P2?=?0.61) than the first male (P1?=?0.39) in the consecutive mating treatment, while in the delayed mating treatment, the overall paternity share of the first 0.49 (P1) and last male was equal 0.51 (P2). Thus, our study revealed that both mating order and the time interval between successive matings regulate the male paternity share. This finding is reported for the first time in this ladybird species.     

Mating behavior of the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)

Abstract  Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurred throughout the 24-h cycle but the majority of copulations occurred in the photophase with two apparent peaks, one at 8:00 and another at 16:00. Mating frequency observations for 10 consecutive days indicated that pre-mating period of C. bowringi was about 4 days, and pairs mated an average of 5 times per day and an average of 40 times during the first 10 days. There was a negative correlation between mating frequency and mating duration during the consecutive mating. The mean duration of the first copulation (136.24 ± 4.62 min) was significantly longer than those of the second (57.87 ± 2.03 min), third (53.05 ± 2.05 min) and fourth copulation (30.86 ± 2.98 min). Fecundity showed a slight increase with increasing mating duration but no significant difference among treatments. However, fertility was significantly influenced by the mating duration in this species. Mating of 20-min duration did not produce viable eggs. The mean percentage of fertile eggs with completed mating duration (204.43 ± 18.96 min, 56.75% fertile eggs) was significantly higher than those with 60 min (39.55%) and 30 min (17.91%) mating duration, suggesting that the longer mating duration might be associated with transfer of more sperm that are used to increase the fertility of eggs.     

Sexual conflict and the evolutionary ecology of mating patterns: water striders as a model system

Two core ideas in the study of mating systems and sexual selection are (1) the existence of a conflict between the sexes over mating decisions, and (2) that variation in ecological conditions drives the evolution of adaptive mating strategies and the diversification of mating systems. A recent burst of experimental studies of mating behavior and sexual selection in water striders has focused on the interaction of these ideas and led to new insights into the evolutionary ecology of mating systems and sexual selection.     

Assortative mating and offspring well-being: theory and empirical findings from a native Amazonian society in Bolivia

Mate choice matters for inclusive fitness, household economic efficiency, assimilation, stratification, and economic inequalities in society. In positive assortative mating, people pair with someone who resembles them along a trait, whereas in negative assortative mating, people pair with someone who differs from them along a trait. In industrial nations, people tend to follow positive assortative mating for fundamental demographic dimensions (e.g., age, schooling) and might practice negative assortative mating for economic outcomes (e.g., earnings). Research on assortative mating has focused on industrial nations, generally compared only one trait between couples, and paid scant attention to the effects of assortative mating for offspring well-being. If assortative mating enhances inclusive fitness, it might also enhance offspring well-being. Drawing on data from a farming–foraging society in the Bolivian Amazon (Tsimane') that practices preferential cross-cousin marriage, we (a) identify six parental traits (age, knowledge, wealth, schooling, height, and smiles) for which Tsimane' might practice assortative mating and (b) test the hypothesis that assortative mating enhances offspring well-being. Proxies for offspring well-being include height and school attainment. Tsimane' resemble people of industrial nations in practicing mostly positive assortative mating. Pairwise, mother–father and Pearson correlations of age, schooling, and earnings among Tsimane' resemble correlations of industrial nations. Correlation coefficients for the six parental traits were far higher than correlations that might happened just by chance. We found weak support for the hypothesis that assortative mating improves offspring well-being.     

Effect of multiple mating on the reproductive performance of the rice leaffolder moth,Cnaphalocrocis medinalis (Lepidoptera: Crambidae)

To clarify whether multiple mating of females and males affects the reproductive performance of the rice leaffolder moth, Cnaphalocrocis medinalis (Guenée), we examined the effect of the number of matings (once, twice, or three times) for females (female treatment) and males (male treatment) on the incidence of moth mating, number of eggs laid, egg hatchability, and adult longevity. We also compared the effect of multiple mating imposed on males or females separately with the effect of that imposed on both sexes simultaneously (both sexes treatment). The incidence of mating of females and males that mated three times (3-mated females and males) was significantly lower than for females and males that mated twice or once (2-mated or 1-mated females and males). The incidence of mating of 1-mated moths (both sexes) was significantly higher than for 2-mated or 3-mated moths (both sexes). Two-mated or 3-mated females laid significantly more eggs with significantly higher hatchability than 1-mated females. Females that mated with 1-mated males (second male mating) or 2-mated males (third male mating) laid significantly fewer eggs than those that mated with virgin males (first male mating). Females laid significantly more eggs after the second and third matings for moths of both sexes than after the first mating for moths of both sexes. The mechanisms of improvement and decline of female reproductive performance when multiple mating was imposed on males or females are also discussed in relation to the reproductive biology of C. medinalis.     

Sympatric speciation in Yponomeuta: no evidence for host plant fidelity

According to sympatric speciation theory, adaptation to different host plants is expected to pleiotropically lead to assortative mating, an important factor in the reduction of gene flow between the diverging subpopulations. This scenario predicts mating on and oviposition preference for the respective hosts in both the diverging subpopulations and recently originated species. Here, we test both predictions in the oligophagous Yponomeuta padellus (L.) and the monophagous Yponomeuta cagnagellus (Hübner) (Lepidoptera: Yponomeutidae), two closely related small ermine moth species from the western European clade of Yponomeuta for which speciation in sympatry has been proposed. Mating location and adult host acceptance were evaluated under both semi-field (in a large outdoor cage with a choice of host and non-host plants) and field conditions. In the semi-field experiment, only Y. cagnagellus showed some preference for mating on its own host (16% of all mating pairs) over non-host plants (3% of all mating pairs). However, in both species, more than 80% of the mating pairs were not formed on a plant but instead on the cage itself. Further examination of the mating site of Y. cagnagellus in the field revealed no preference for host plants over non-host plants in the two consecutive years of observation. Yponomeuta padellus females, collected from and reared on Prunus spinosa L. (Rosaceae), showed an oviposition preference for the alternative host Crataegus monogyna Jacq. (Rosaceae) in the semi-field experiment. We thus found no evidence that host-plant fidelity (in terms of mating site) has been the driving force in the speciation process of these Yponomeuta species, nor did we find evidence of host race formation in the tested population of the oligophagous Y. padellus .     

The structure and measurement of human mating strategies: toward a multidimensional model of sociosexuality

Recent theoretical perspectives concerning the structure of variation in human mating have focused less on conceptualizations of alternate mating strategies and more on the evolution of a conditional strategy. Empirical evidence suggests that this conditional strategy may involve the simultaneous pursuit of long-term and short-term mating tactics. Despite these developments, empirical measurement has proceeded using the Sociosexual Orientation Inventory (SOI), which measures restricted and unrestricted mating orientations along a single bipolar continuum. To fully capture the pluralistic nature of human mating, we suggest that a multidimensional empirical measure is required. To test our hypothesis, we subjected an expanded version of the SOI, which included items measuring psychological orientation toward short-term mating and long-term mating, to principal components analysis. A three-factor structure representing short-term mating orientation, long-term mating orientation, and previous sexual behavior emerged. In subsequent analyses, we demonstrate that our newly developed long-term and short-term dimensions (a) are largely independent and (b) correlate differentially with other theoretically relevant variables.     

Mate selection in man: Evidence,theory, and outcome

Abstract

This review presents a comprehensive survey of the literature on mate selection and non‐random mating in man. The topics discussed include: (1) genetic aspects of non‐random mating for complex traits; (2) evidence on resemblance between spouses on a large variety of traits such as intelligence, personality, physical characteristics, and sociocultural traits; (3) a critical review of sociological and psychological theories offered to account for assortative mating, and (4) implications of assortative mating for marital satisfaction. It is suggested that the factors leading to choice of marriage partners need to be studied from the point of view of multivariate profiles rather than single traits. Such studies will require sophisticated methodologies of research design and data analysis.     

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

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.     

延迟交配对橘小实蝇繁殖适度的影响

橘小实蝇Bactrocera dorsalis Hendel是一种世界性的入侵害虫,严重为害多种经济果蔬。本文通过响应面分析方法,研究了延迟交配对橘小实蝇交配率、产卵量、孵化率和寿命的影响。结果表明,交配率随雌虫交配日龄的延迟先增后减,雌、雄成虫均为35日龄处理组中的交配率最高,为81.00%±2.00%;而雄虫交配日龄的延迟则对其卵孵化率有明显的负面作用,在56日龄雄虫与35日龄雌虫处理组中,其卵孵化率最低,仅为27.56%±4.55%。雌成虫产卵量和寿命受到雌、雄虫双方交配日龄的的影响,产卵量（y）与雄虫日龄（x1）和雌虫日龄（x2）的回归方程为y=514.36+3.08x1-11.05x2,雌成虫寿命（y）与雄虫日龄（x1）和雌虫日龄（x2）的回归方程为y=35.85+0.23x1+0.40x2。研究结果为田间使用性信息素迷向法防治橘小实蝇提供了理论依据。     

Condition-Dependent Effects of Mating on Longevity and Fecundity of Female Medflies: The Interplay between Nutrition and Age of Mating

Background

In various species mating exerts direct and indirect effects on female demographic traits ranging from life span shortening to behavioural shifts. A wealth of data regarding effects of nutrition on longevity and reproduction output also exists. Nonetheless, little is known regarding the interaction between the age of mating and nutrition on female fitness.

Methodology

We studied, the effects of protein deprivation and age of mating on female fitness traits, using a wild population of the Mediterranean fruit fly (medfly). We tested the hypotheses that (a) protein availability increases female lifespan and fecundity, (b) female longevity and egg production are independent of mating and the age of mating, and (c) female mating behaviour is independent of their age and nutritional status. Thus, we recorded the mating success and the copulation characteristics, as well as the egg production and survival of females mated at young or at old age and fed a full or a protein-deprived diet.

Results

Mating boosts egg production and reduces longevity of protein-fed females. On the contrary, mating increases the longevity of protein-deprived females. Mortality responses (negative or positive) to mating are expressed after a long lag phase. Old females are more receptive and less selective than young females regardless of the food regime.

Conclusions

Our findings suggest that condition (nutritional status and age) defines the positive or negative output of mating in female medflies. These results contribute towards understanding the effects of mating, aging, resource allocation and their interactions on survival and female reproduction.     

Securing paternity: mating plugs in the dwarf spider Oedothorax retusus (Araneae: Erigoninae)

One of the various male strategies to prevent or impede female remating is the production of a mating plug that covers the female genital opening or remains inside of the female genital tract after mating. Such structures have been described for many species in many animal taxa; however, in most cases, we know little or nothing about their specific adaptive value. Our investigations demonstrate that females of the dwarf spider species Oedothorax retusus (Westring, 1851) (Linyphiidae, Erigoninae) exhibit a substance on one or both of her paired genital openings only after copulation. We performed double-mating trials and forced the second male to mate into the previously used or unused spermathecal duct of the female by amputating one of his paired male gonopods (pedipalps). Furthermore, to investigate whether the duration of the first mating has an effect on the size and efficiency of the mating plug, we interrupted first matings after either 1 or 3 min, categorized plug size and recorded mating behaviour of subsequent males. The amount of secretion transferred was larger in long compared to short copulations. A long first copulation successfully prevented subsequent males from mating into the used ducts, whereas mating success after short first matings was similar to matings into unused copulatory ducts of the females. The present study demonstrates that a male O. retusus can prevent a rival from transferring sperm into the same spermatheca by applying a mating plug, but only if he mates for long enough.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 574–583.     

Anuran mating calling circuits: inhibition by prostaglandin

Male American toads (Bufo americanus) were induced to mating call in response to electronically simulated, conspecific mating calls. The injection of prostaglandin (PG) F2 alpha caused suppression of mating call answering. Neural correlates of mating calling were triggered by electrical stimulation of the anterior preoptic nucleus in the isolated brainstem of male, Northern leopard frogs (Rana p. pipiens). The addition of PGF2 alpha to the bath completely abolished the correlates of mating calling without changing the correlates of pulmonary respiration. The suppression of mating calling shown here, along with the suppression of release signalling described by Diakow and Nemiroff (1981), supports the hypothesis of a close interrelation between the neural circuits of these two calls. The suppression of the neural correlates of mating calling in an isolated preparation shows a central site of action of the PG. The retention of normal correlates of pulmonary respiration, even after suppression of mating calling correlates, suggests that the generation of mating calling patterns involves the extension and pulsing of the expiratory phase of breathing.     

Mating behavior in eight rotifer species: using cross-mating tests to study species boundaries

We characterized the mating behavior of eight freshwater rotifer species from five different families of Monogononts (Asplanchnidae, Brachionidae, Euchlanidae, Lecanidae, and Trichocercidae). Were corded the percentages of male-female encounters resulting in mating attempts and the number of completed copulations. The characterization of mating behavior also included data on: (1) duration of copulation, (2) female and male swimming speed, (3) sites of initial mating attempts, (4) sites of copulation, and (5) sizes of males and females. In the five families investigated, cross-mating tests may be used to assess the ability of males to discriminate conspecifics, establishing limits to gene flow. We also present data on two families, Brachionidae and Lecanidae where we used cross-mating tests to compare discrimination between conspecific females and those of other species. Brachionus calyciflorus males attempted mating with females of the closely related genus Plationus, but did not attempt mating with Keratella Americana females. Males of other three Brachionidae species only attempted mating with nonspecific females. Lecane quadridentata males attempted to mate with females of two different Lecane species besides their own. Percentages of mating attempts and completed copulations were quantified in all crosses. Lower percentages of copulation after a mating attempt were found among brachionids than among non-brachionids. These data demonstrate that male discrimination of females is an effective pre-mating reproductive barrier in several species of Monogonont rotifers. These results, further suggest that investigations of mating behavior are useful for determining species boundaries in rotifers and perhaps other zooplankters. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sexual conflict in simultaneous hermaphrodites: evidence from serranid fishes

Synopsis Much of modern mating systems theory is founded on the assumption that a conflict of interests between males and females acts to shape reproductive strategies. If sexual conflict exists it should extend to simultaneous hermaphrodites. Here, the suggestion is made that hermaphrodite mating systems can be used to explore the assumptions associated with sexual conflict and (a) predictions about hermaphrodite mating systems, and (b) a comparative analysis of the mating systems described for a group of species of simultaneously hermaphroditic serranid fishes. Theories based on Bateman's principle predict that there should be a preferred role in hermaphrodites; i.e. the male role ought to offer potential fitness advantages to all serranids and serranid mating systems reflect this. The comparative analysis offers evidence that cheating in the male role is found in all of the species studied and explains the harem polygyny system of two species. This preference for the male role in this group offers the best evidence currently available for the existence of sexual conflict as a factor shaping mating systems.     

Copulation, the dynamics of sperm transfer and female refractoriness in the leafhopper Balclutha incisa (Hemiptera: Cicadellidae: Deltocephalinae)

Abstract.  Mature sperm of the leafhopper Balclutha incisa (Matsumara) (Cicadellidae: Auchenorrhyncha: Hemiptera) are stored as a series of sperm bundles within seminal vesicles prior to ejaculation. During transfer, sperm are pumped from the vesicles into the ejaculatory duct to the complex aedeagus. Sperm transfer is marked by a c . 30-fold expansion of the spermatheca to accommodate both sperm and seminal fluid. Sperm number increases exponentially with male age, reaching a maximum of 700 000 after 14 days, while the number of sperm available on days 2–5 is between 70 000 and 100 000. During mating, maximum sperm transfer occurs after 7 min and mating is complete after about 10 min. Ejaculate size, defined by both sperm and associated accessory gland fluid, is influenced by male mating status and the interval since the previous mating. There is a positive correlation between duration of copulation and both ejaculate and the time to subsequent mating. Sperm are more likely to be retained in the testes during mating by males of 2–5 days post-emergence than older males. The number of sperm received by the female can be manipulated experimentally by mating males once (medium ejaculate) or twice (small ejaculate) immediately after their first mating. Females that receive small ejaculates from sperm-depleted males have a far shorter refractory period than females receiving medium to large ejaculates. Both ejaculate size and the time after males have mated influence the female post-mating refractory period as measured by the female's responsiveness to male sexual signalling.     

Correlates of male mating success in the lekking great snipe (Gallinago media): results from a four-year study

To investigate behavioral or morphological traits importantas mate choice cues, we measured selection differentials (s)as the covariances between each trait and male mating success,and directional selection gradients (J3) from multiple linearregression of the standardized traits on male mating success.Data from two leks in four consecutive years were included,and the annual data were analyzed separately. The main findingsare: (1) the distribution of male mating success proved to beless skewed than those found in many other lekking species,(2) only a few traits yielded significant selection gradients,(3) the importance of age on male mating success changed acrossyears, (4) females may use traits with a high variance as matechoice cues, and (5) individual males achieved similar matingsuccesses between years. Attendance and age were the traitsmost consistently correlated with male mating success, but notraits showed significant selection gradients in all years.Our results indicate that variable sexual selection pressuresexisted between years, but the high correlation found betweenthe mating success of individual males in successive seasonsalso indicates that permanent differences in male traits areimportant. Key words: lek, mate choice, sexual selection.     

The notal organ of the scorpionfly (Panorpa vulgaris): an adaptation to coerce mating duration

The notal organ in P. vulgaris (Insecta: Mecoptera) is a clamplikestructure on the dorsum of the middle of the male’s abdomenthat holds one of the female’s forewings throughout mating.Males often provide salivary masses as food to their mates duringmating, and a male’s ability to produce saliva dependsupon whether he has fed adequately before mating. To test thehypothesis that the evolutionary function of the notal organis to coerce longer matings than are in the interests of females,the notal organ and the amount of food males and females receivebefore mating were experimentally manipulated. In support ofthe hypothesis, copulation was reduced when the notal organwas made inoperative under the following four conditions: (1)female fed and male starved before mating, no saliva duringmating; (2) same as in condition 1 but with one salivary massduring mating; (3) both sexes starved before mating, no salivarymass during mating; and (4) both sexes fed before mating. However,when females were starved before mating and males were fed,resulting in multiple masses being provided during mating, thenotal organ had no effect on length of copulation, and thusthere was no sexual conflict over mating duration. In addition,the larger the female relative to her mate, the briefer thecopulation when the notal organ was operative, which suggeststhat a physical struggle between the male and female may occurduring sexual conflict about mating duration. This is one ofonly a few studies that provide evidence of adaptation to thedomain of sexual coercion. [Behav Ecol 1991;2:156–164]     

Mating distribution and its temporal dynamics affect operational sex ratio: a simulation study

The present study investigated how variation in mating distribution in time and among males influences the operational sex ratio (OSR) with a simulation inspired by paternally caring fish. Varying (1) the potential reproductive rate of each sex, (2) the mating distribution among males, and (3) the length of male mating phase, we created different mating patterns. In each case, we searched for the adult sex ratio that resulted in an OSR of 50% (where sex-roles switch). This approach enabled a comparison with a previous model. We found that the OSR was influenced by the distribution of matings in time and among males when the male mating phase was limited by a parental phase. Furthermore, the mating dynamics were shaped by the fact that the numbers of males and females and their capacities for collateral investment affected OSR immediately from the start of the reproductive season, whereas their times-out had a delayed effect on OSR.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 551–559.     

Demographic analysis of delayed mating in mating disruption: a case study with Cryptophelbia illepida (Lepidoptera: Tortricidae)

Laboratory-derived life tables were used to determine the effect of delaying mating of adult female koa seedworm, Cryptophlebia illepida (Butler) (Lepidoptera: Tortricidae), 4 and 6 d on population growth rates. Leslie matrices were developed from the life tables and used to project the effects for approximately four generations. Delay of mating caused a decrease in population growth rate and also resulted in asynchronous population cycling between control (1-d delay) and the delayed treatments. By the fourth generation, the control population began to increase 10 and 14 d before the 4- and 6-d delay treatments, respectively. Increasing the mortality of females during the first 7 d of adult life resulted in a greater reduction of the populations where mating was delayed than in the control populations. This result suggests that even at relatively low levels of natural enemy mortality, there is a synergistic effect when mating is delayed. The implications of these effects on mating disruption management programs are discussed.