Mating Research Articles

Biological basis of pest control on pasture flies: as a case study from Uzbekistan

In this article, we aimed at studying the biology of pasture insects using the example of M. Tempestiva, developmental biology, ethology, timing of generations and life expectancy of females and males, changes in the genital organs during the maturation of egg follicles, the duration of nutrition on various substrates, the predominance of nutrition on carbohydrate media. The duration of mating, fertilization, the number of generations according to changes in the ovary of females, the development of eggs and their laying. Duration of all stages of biological development, including egg, larval stages, puparia and mature adults. Phenological dates have been established, i.e. the timing of the increase in the number of pasture insects, therefore, the study of biology and development cycles will allow us to further develop integrated methods for controlling insects in the pasture precisely during the period of their mass parasitism.

A nonsensory odorant-binding protein plays an important role in the larval development and adult mating of Spodoptera frugiperda.

Odorant-binding proteins (OBPs) play key roles in the perception of semiochemicals in insects. Several OBPs in insect olfactory systems have been functionally characterized, and they provide excellent targets for pest control. The functions of some OBPs that are highly expressed in the nonsensory organs of insects remain unclear. Here, the physiological function of an OBP (OBP27) that was highly expressed in the nonsensory organs of Spodoptera frugiperda was studied. OBP27 was nested within the Plus-C cluster according to phylogenetic analysis. The transcription of OBP27 steadily increased throughout the development of S. frugiperda, and transcripts of this gene were abundant in the fat body and male reproductive organs. An OBP27 knockout strain with an early frameshift mutation was obtained using the clustered regularly interspaced palindromic repeats (CRISPR) / CRISPR-associated protein 9 (Cas9) system. The development time of OBP27-/- larvae was significantly longer than that of other larvae. Both male and female OBP27-/- pupae weighed significantly less than wild-type (WT) pupae. In crosses of OBP27-/- males or females, the mating rate was lower and the mating duration was longer for OBP27-/- male-WT female pairs than for WT-WT pairs. By contrast, the mating rate, hatching rate, and number of eggs of OBP27-/- female-WT male pairs and WT-WT pairs were similar. These findings indicate that OBP27 plays an important role in the larval development and mating process in male adults. Generally, our findings provide new insights into the physiological roles of nonsensory OBPs.

Evaluating the Mating Competency of Genetically Modified Male Mosquitoes in Laboratory Conditions.

Efforts to eradicate mosquito-borne diseases have increased the demand for genetic control strategies, many of which involve the release of genetically modified (GM) mosquito males into natural populations. The first hurdle for GM males is to compete with their wild-type counterparts for access to females. Here, we introduce an eye color-based mating assay, in which both Lvp wild-type and kynurenine 3-monooxygenase (kmo)-null males compete for access to kmo-null females, and therefore the eye color phenotype (black or white) of the progeny is dependent on the parental mating pair. A series of tests addressed that male mating competitiveness between the two strains can significantly be influenced by adult density, light intensity, and mating duration. Interestingly, the mating competitiveness of males was not correlated with body size, which was negatively influenced by a high larval density. Lastly, this eye color-associated assay was applied to characterize GM mosquitoes in their mating competitiveness, establishing this method as a fast and precise way of benchmarking this fitness parameter for laboratory-raised males.

In Vivo Genome Editing in Type I and II Methanotrophs Using a CRISPR/Cas9 System.

Methanotrophic bacteria are Gram-negative, aerobic organisms that use methane as their sole source of carbon and energy. In this study, we constructed and exemplified a CRISPR/Cas9 genome editing system and used it to successfully make gene deletions and insertions in the type I methanotroph Methylococcus capsulatus Bath and the type II methanotroph Methylocystis parvus OBBP. High frequencies of gene deletions and insertions were achieved in combination with homology-directed repair. In M. parvus OBBP, we also investigated the impact of several parameters on the CRISPR/Cas9 genome editing, where the ligD gene was targeted with various PAM sequences and guide RNA spacer sequences, homology arms of variable length, differences in the duration of mating during conjugation, and exploiting promoters of different strengths to control the expression of cas9 and sgRNA. Although not the first attempt to develop a CRISPR/Cas system in methanotrophs, this work demonstrated for the first time an efficient CRISPR/Cas9 system generating scarless clean gene deletions and insertions in methanotroph genomes.

The Effect of Brief or Prolonged Bouts of Winning or Losing Male-Male Contests on Plasticity in Sexually Selected Traits.

AbstractFight outcomes often affect male fitness by determining their access to mates. Thus, "winner-loser" effects, where winners often win their next contest while losers tend to lose, can influence how males allocate resources toward pre- and postcopulatory traits. We experimentally manipulated the winning/losing experiences of pairs of size-matched male Gambusia holbrooki for 1 day, 1 week, or 3 weeks to test whether prior winning/losing experiences differentially affect the plasticity of male investment into either mating effort (precopulatory) or ejaculates (postcopulatory). When winner/loser pairs directly competed for a female, winners had better precopulatory outcomes than losers for three of the four traits we measured: mating attempts, successful attempts, and time spent with the female (but not aggression). However, winners and losers did not differ in either total sperm counts or sperm velocity. Interestingly, absolute male size, an important predictor of fighting success, mediated winner-loser effects on how long males then spent near a female. Compared with losers, smaller winners spent more time with the female than did larger winners, suggesting that how males respond to prior social experiences is size dependent. We discuss the general importance of controlling for inherent male condition when comparing male investment into condition-dependent traits.

Psychological flexibility and sociosexual orientation mediate the association between self-perceived attractiveness and mating effort

Psychological flexibility and sociosexual orientation mediate the association between self-perceived attractiveness and mating effort

Drosophila Arc1 is not required for male fertility or sperm competition success.

Activity-regulated cytoskeleton associated protein (Arc1), which is required for synaptic plasticity and metabolism in Drosophila , self-assembles into capsid-like structures that transport mRNAs in extracellular vesicles. In addition to expression in the brain and nervous system, Arc1 is expressed in the male accessory glands, an endothelial tissue that produces male seminal proteins and exosomes that impact male fertility. We thus hypothesized that Arc1 might impact male fertility. We measured the fertility, mating latency, mating duration, and sperm competition performance of Arc1 males relative to controls and found no evidence that Arc1 is required for any of these measures of male fertility.

Effect of mating duration on reproductive parameters of eri silk moth in different seasons

Effect of mating duration on reproductive parameters of eri silk moth in different seasons

Female-limited responses in remating rate and mating duration in the experimental evolution of a beetle Callosobruchus chinensis.

Mating rate optima often differ between the sexes: males may increase their fitness by multiple mating, but for females multiple mating confers little benefit and can often be costly (especially in taxa without nuptial gifts or mala parental care). Sexually antagonistic evolution is thus expected in traits related to mating rates under sexual selection. This prediction has been tested by multiple studies that applied experimental evolution technique, which is a powerful tool to directly examine the evolutionary consequences of selection. Yet, the results so far only partly support the prediction. Here, we provide another example of experimental evolution of sexual selection, by applying it for the first time to the mating behaviour of a seed beetle Callsorobruchus chinensis. We found a lower remating rate in polygamy-line females than in monogamy-line (i.e. no sexual selection) females after 21 generations of selection. Polygamy-line females also showed a longer duration of first mating than monogamy-line females. We found no effect of male evolutionary lines on the remating rate or first mating duration. Though not consistent with the original prediction, the current and previous studies collectively suggest that the observed female-limited responses may be a norm, which is also consistent with the conceptual advances in the last two decades of the advantages and limitations of experimental evolution technique.

Establishment of a laboratory‐rearing technique for the rove beetle Anotylus amicus (Coleoptera: Staphylinidae) with investigations of its life cycle, behavior and morphological variations

AbstractRove beetles (Staphylinidae) are one of the largest families in Coleoptera. Although the ecological features of rove beetles are important subjects in terms of understanding their diversification processes, laboratory‐rearing studies have only been conducted for a few species to date. In this study, we established a continuous rearing method for Anotylus amicus (Bernhauer, 1923) (Staphylinidae: Oxytelinae) using bell cricket food. In addition, its life cycle, behavior and morphological variations were investigated using the rearing technique. The mean duration of egg, first, second and third instars, prepupa and pupa were 4.3, 4.0, 4.0, 7.8, 1.7 and 4.7 days at 24°C, respectively. Adults and larvae used substrate, food and excrement for nesting. Mate guarding by males and associated male–male combat were observed. Head width and body size sexually varied; most males were larger than females, but some were comparable to females. Many individuals possessed undeveloped short hindwings, while some, especially large females, had long ones. As A. amicus can be reared simply, have a fairly short generation period, and exhibit interesting behavioral and morphological characteristics, A. amicus is suitable for clarifying the ecological aspects of rove beetles.

Life history strategies, body surveillance, and online interpersonal sexual objectification experiences on women's body shame

According to the life history theory, fast life history strategists are more likely to prioritize mating efforts and concentrate on appearance to match mate preferences. This mate preference may have become the social ideal through sexual selection, thus causing body shame in women. Currently, the relationship between body shame and life history strategies, and how online interpersonal sexual objectification experiences as an external environment influence these relationships should be clarified. In the current study, a sample of 710 Chinese women participants completed self-report measures of life history strategies, body shame, body surveillance, and online interpersonal sexual objectification experiences. Results showed that life history strategies indirectly affected body shame through body surveillance. Furthermore, online interpersonal sexual objectification experiences played a moderating role. These findings emphasize the evolutionary factors of body shame from a life history theory perspective and the interactive effects of the external environment.

Mating Behavior and Identification of Male-Produced Pheromone Components in Two Woodwasps, Sirex noctilio and Sirex nitobei, in China.

Simple SummaryThe woodwasp Sirex noctilio Fabricius is a major quarantine pest that was first discovered in China in 2013 and mainly harms Pinus sylvestris var. mongolica. Sirex nitobei Matsumura is native to China and closely related to S. noctilio. Recently, S. nitobei and S. noctilio were found to be attacking P. sylvestris var. mongolica from June to September successively in China. In recent years, pheromones have been useful tools for the development of pest evaluation and management strategies. Therefore, the aim of this study was to investigate the characteristics of two species of wood wasps (S. noctilio and S. nitobei): (1) mating behavior and circadian rhythms; (2) the factors influencing mating behavior; (3) the male-produced pheromone components in both species based on three reported components from S. noctilio. Finally, what we found was that most of the two species of wood wasps mated at two-days-old; within the same day, mating behavior peaks between 11:00 and 12:00; light conditions, individual size, and female–male proportion affect their mating behavior; (Z)-3-decenol became the main component of pheromone of both species. By investigating the mating behavior of two species of wood wasps and analyzing the pheromone production, we could proceed targeted control measurements during the mating period of wood wasps and provide strategic significance for the subsequent control.To protect vulnerable trees from native and invasive wood wasps, the mating behavior of these two woodwasp species (S. noctilio and S. nitobei, respectively) and factors influencing this behavior were investigated in cages outdoors. Male-produced pheromones were identified in both woodwasp species. Compared with the native species S. nitobei, the invasive species S. noctilio showed stronger mating ability, including mating frequency, time, and duration. The mating behavior of both species mainly occurred from 9:00 to 17:00 each day, peaking at 11:00 and 12:00. The daily mating behavior of both species was most directly related to light intensity. Both female and male S. noctilio and S. nitobei were capable of mating upon emergence, and most individuals mated at 2 days of age. For both species, a female-to-male ratio of 5:15 was most conducive to mating, and individuals with a larger body size were preferred as mates by males and females. (Z)-3-decenol was present in solid-phase microextraction extracts of both species. Two reported minor reference components, (Z)-4-decen-1-ol and (E, E)-2,4-decadienal, were not identified in either woodwasp species. The peak of male pheromone release occurred from 11:00–12:00 for 2-day-old individuals.

Does perception of female cues modulate male short-term fitness components in Drosophila melanogaster?

Phenotypic plasticity in reproductive behavior can be a strong driver of individual fitness. In species with high intra‐sexual competition, changes in socio‐sexual context can trigger quick adaptive plastic responses in males. In particular, a recent study in the vinegar fly (Drosophila melanogaster) shows that males derive net fitness benefits from being shortly exposed to female cues ahead of access to mating (termed sexual perception), but the underlying mechanisms of this phenomenon remain unknown. Here, we investigated the short‐term effects of female perception on male pre‐ and post‐copulatory components of reproductive performance: (a) mating success, (b) mating latency and duration, (c) sperm competitiveness, and (d) ejaculate effects on female receptivity and reproductive rate. We found that brief sexual perception increased mating duration, but had no effect on the other main pre‐ and post‐copulatory fitness proxies recorded. This suggests that perception of female cues may not yield net fitness benefits for males in the short‐term, but we discuss alternative explanations and future avenues of research.

Plastic responses of males and females interact to determine mating behavior.

Individuals can respond plastically to variation in their social environment. However, each sex may respond to different cues and contrasting aspects of competition. Theory suggests that the plastic phenotype expressed by one sex can influence evolutionary dynamics in the other, and that plasticity simultaneously expressed by both sexes can exert sex‐specific effects on fitness. However, data are needed to test this theory base. Here, we examined whether the simultaneous expression of adaptive plasticity by both sexes of Drosophila melanogaster fruit flies in response to their respective social environments interacts to determine the value of key reproductive traits (mating latency, duration, and fecundity). To vary social environments, males were kept alone, or with same sex rivals, and females were kept alone, in same‐sex, or mixed‐sex groups. Matings were then conducted between individuals from all of these five social treatments in all combinations, and the resulting reproductive traits measured in both “choice” and “no‐choice” assays. Mating latency was determined by an interaction between the plastic responses of both sexes to their social environments. Interestingly, the mating latency response occurred in opposing directions in the different assays. In females exposed to same‐sex social treatments, mating latency was more rapid with rival treatment males in the choice assays, but slower with those same males in no‐choice assays. In contrast, mating duration was determined purely by responses of males to their social environments, and fecundity purely by responses of females. Collectively, the results show that plastic responses represent an important and novel facet of sexual interactions.

Mating Competition between Wild and Artificially Reared Olive Fruit Flies

Mating success of artificially reared males of the olive fruit fly is essential for genetic control techniques for this pest. We studied the mating competition between males from a laboratory-adapted population reared with an artificial diet and wild males emerged from field-infested olives and grown in olives in the laboratory. We maintained virgin wild females or artificially reared females in cages together with virgin wild and artificially reared males and scored the percentages of different males in the mated pairs, mating latency, and mating duration. After mating, we determined the egg production and the size of spermathecae of females mated with different males. Our results indicate that artificially reared males are competitive to the wild males, and they mated in similar percentages with wild and artificially reared females. Mean mating latencies (SE) of wild females that mated with wild and artificially reared males were 69.8 (4.8) min (n = 39) and 114.6 (8.1) (n = 43) min, respectively. No difference was discovered in the mating duration or egg production between females that mated with a wild or artificially reared male. Wild females had higher spermathecae volume when they mated with wild males compared to artificially reared males (two-tailed t-test = −2.079, df = 54, p = 0.0423).

A pilot study for satellite-tracking Gadwalls Mareca strepera wintering in the Lea Valley, UK

ABSTRACT A pilot study monitored four overwintering Gadwalls fitted with satellite trackers in November 2018 at Rye Meads Nature Reserve, Hertfordshire. The research assessed the feasibility of a larger study investigating the range, movement and habitat preference of Gadwall utilising the Greater London wetland areas, and the suitability of fitting trackers using a glue-attachment method. Tracked birds varied in extent of movement. Two male Gadwalls remained largely sedentary, making use of the freshwater gravel lakes in the Lee Valley Regional Park. A pair-bonded male and female moved together, spending a number of weeks in the Lea Valley before moving 20 km to Hatfield Forest, Essex. This represented a change of habitat to a mature woodland with established lakes and ponds. We speculate that differences in movement between the male–female pair and other males may be attributable to mating effort and individual differences in migratory strategy. Considerable variation in the retention of trackers was seen, with one bird believed to have gradually removed the device through preening. Retrap data for one male showed overwinter weight loss that was higher than in any of 14 Gadwalls recorded previously. The cause of weight loss was unknown and we recommend further investigating the energetic costs of having a tracker fitted. Glue attachment may be unreliable for studies that require monitoring of Gadwalls for more than a few weeks, due to a high likelihood of attachment failure.

Individual's Reproductive Strategies Moderates the Association Between Facial Width-to-Height and Risk-Taking Propensity.

Previous research has yielded mixed findings on the relationship between facial width-to-height ratio (fWHR), an androgen-dependent feature, and risk-taking propensity. We argue that mixed findings might result from overlooked variables. Given that risk-taking propensity might be ultimately linked to a search for mating opportunities, we analyze if reproductive strategies moderate the relationship between fWHR and risk-taking propensity. Our results, obtained from a sample of 434 male participants, show a positive association between fWHR and recreational and social risk-taking only for men who are more motivated to focus on mating effort over offspring survival. This finding aligns with research arguing that risk-taking may be a mating strategy since being social and recreational risk-prone might illustrate physical and psychological qualities and improve one's ability to attract mates. Our results support the notion that risk-taking might be a domain-specific construct. Overall, our research is in line with recent findings suggesting that the impact of testosterone exposure on risk-taking propensity is best understood when considering the role of contextual variables. Consequently, we add to previous research that studies related to risk-taking propensity should account for reproductive strategies.

Evaluation of oviposition substrates and mating duration on fecundity and egg hatchability of Samia ricini Donovan (Lepidoptera: Saturniidae)

Assessment of oviposition substrates and mating duration on the fecundity and egg hatchability of eri silkworm Samia ricini Donovan, revealed that maximum disease free layings were recorded in the control (353 eggs with 98 % hatchability) followed by the treatment, mating duration of six hours (332 eggs with 96 % hatchability). Poor egg laying and egg hatchability was noticed in one hour (151 eggs with 41 % hatchability). Correlation coefficients between mating duration, fecundity and egg hatchability showed strong positive correlation. Oviposition substrate’s impact on fecundity and egg hatchability revealed that gada cloth gave better results (344 eggs with 96% hatchability) whereas polythene cover recorded poor fecundity (203 eggs) and jack fruit kharika recorded poor hatchability (90 %). A minimum of six hours of mating duration is needed for the eri moth to attain its full fecundity potential and better egg hatchability.

Sexual Selection and the Treatment of Predecessors' Progeny by Replacement Mates.

Darwin’s theory of sexual selection provides a useful framework for understanding the behavior of stepparents. A non-human animal whose new mate has dependent young may kill, ignore, or adopt the predecessor’s progeny. The third option has been interpreted as courtship (“mating effort”), and whether selection favors such investment over killing or ignoring the young apparently depends on aspects of the species-typical ecology and demography. The tripartite categorization of responses is a simplification, however, There is variability both within and between species along a continuum from rejection to “full adoption.” The average stepparent invests less than the average birth parent, but more than nothing. Human stepparents have often been found to kill young children at higher rates than birth parents, but stepparental infanticide cannot plausibly be interpreted as a human adaptation, both because it is extremely rare and because it is almost certainly more likely to reduce the killer’s fitness than to raise it. How sexual selection theory remains relevant to human stepparenting is by suggesting testable hypotheses about predictors of the variability in stepparental investment.

Separating the effects of paternal age and mating history: Evidence for sex-specific paternal effect in eastern mosquitofish.

Paternal age and past mating effort by males are often confounded, which can affect our understanding of a father's age effects. To our knowledge, only a few studies have standardized mating history when testing for effects of paternal age, and none has simultaneously disentangled how paternal age and mating history might jointly influence offspring traits. Here, we experimentally manipulated male mating history to tease apart its effects from those of paternal age on female fertility and offspring traits in the eastern mosquitofish (Gambusia holbrooki). Male age did not affect female fertility. However, males with greater past mating effort produced significantly larger broods. Paternal age and mating history interacted to affect sons' body size: sons sired by old‐virgin males were larger than those sired by old‐mated males, but this was not the case for younger fathers. Intriguingly, however, sons sired by old‐virgin males tended to produce fewer sperms than those sired by old‐mated males, indicating a potential trade‐off in beneficial paternal effects. Finally, neither paternal age nor mating history affected daughter's fitness. Our results highlight that variation in offspring traits attributed to paternal age effect could partly arise due to a father's mating history, and not simply to his chronological age.