Effects Of Multiple Mating Research Articles

Reproductive Behaviour of 150-Gy-Treated Female Lobesia botrana (Lepidoptera: Tortricidae).

Simple SummaryEnvironment-friendly and sustainable insect pest control approaches such as the sterile insect technique/inherited sterility (SIT/IS) have been proposed against the European grapevine moth Lobesia botrana. Reproductive behaviour, such as oviposition, mating ability, and multiple mating of 150 Gy-treated females, was studied. Moreover, the last-male sperm precedence (P2 value) and male’s flight response to treated females were also investigated. The present study aims to provide basic information which is essential to ensure successful implementation of SIT/IS as part of an integrated approach for the management of L. botrana.The sterile insect technique/inherited sterility (SIT/IS) has been suggested as an eco-friendly control tactic for area-wide integrated pest management approaches in order to control the European grapevine moth, Lobesia botrana. This study assessed the effects of an irradiation dose of 150 Gy administered to newly emerged female moths on their egg laying behaviour and mating ability at different ages at mating. Moreover, the effects of multiple mating on the mating ability of treated females, pattern of sperm precedence in twice-mated females and the flight response of treated and untreated males to treated and untreated calling females were also investigated. Females treated with 150 Gy initiated calling in a way similar to untreated females. When treated females were paired with untreated males, the mean number of eggs oviposited per female during 6 days was reduced (59.6 and 82.8 eggs/female, respectively), as was their mating ability and multiple mating compared with untreated females. The proportion of offspring fertilized by the second of the two males to mate with the female or last-male sperm precedence (P2 value) constituted 97% of the eggs, suggesting that the second male mate fathered the most offspring. The outcome of this work could be viewed as an integrated approach for improving effectiveness and enabling successful implementation of a SIT/IS program against L. botrana.

Study on the Effects of Multiple Matings in Coccinella transversalis for its Behaviour and Reproduction

The evolution and maintenance of multiple mating (repeated mating or polyandry) in predaceous ladybird beetles (Coleoptera: Coccinellidae) is an adaptive puzzle; since a single ejaculate of male often provides enough sperm to female for her lifetime egg production. Despite numerous studies on multiple mating evaluating reproductive attributes, there are negligible studies that investigated changes in behavioural patterns in ladybirds during multiple mating. In the present study, effects of multiple mating on mating behavioural pattern of males and reproductive attributes of females have been assessed using Coccinella transversalis as an experimental ladybird species. Results revealed that during copulation behaviour, time for the commencement of mating, latent period, wriggling movement duration, number of bouts and mating duration decreased with increase in number of mating; whereas interval between successive bouts increased significantly. Moreover, fecundity and egg viability of females increased with increase in number of mating.

Polyandry increases reproductive performance but does not decrease survival in female Brontispa longissima.

The costs and benefits of polyandry are still not well understood. We studied the effects of multiple mating on the reproductive performance of female Brontispa longissima (Coleoptera: Chrysomelidae), one of the most serious pests of the coconut palm, by using three experimental treatments: (1) singly-mated females (single treatment); (2) females that mated 10 times with the same male (repetition treatment); and (3) females that mated once with each of 10 different males (polyandry treatment). Both multiple mating treatments resulted in significantly greater total egg production and the proportion of eggs that successfully hatched (hatching success) than with the single mating treatment. Furthermore, the polyandry treatment resulted in greater total egg production and hatching success than with the repetition treatment. Thus, mate diversity may affect the direct and indirect benefits of multiple mating. Female longevity, the length of the preoviposition period, the length of the period from emergence to termination of oviposition, and the length of the ovipositing period did not differ among treatments. The pronounced fecundity and fertility benefits that females gain from multiple mating, coupled with a lack of longevity costs, apparently explain the extreme polyandry in B. longissima.

Does polyandry really pay off? The effects of multiple mating and number of fathers on morphological traits and survival in clutches of nesting green turtles at Tortuguero.

Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradictory results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity and number of sires in 12 clutches (240 hatchlings) of green turtles (Chelonia mydas) nests at Tortuguero, Costa Rica. Paternal alleles were inferred through comparison of maternal and hatchling genotypes, and indicated multiple paternity in at least 11 of the clutches (92%). The inferred average number of fathers was three (ranging from 1 to 5). Moreover, regression analyses were used to investigate for correlation of inferred clutch paternity with morphological traits of hatchlings fitness (emergence success, length, weight and crawling speed), the size of the mother, and an environmental variable (incubation temperature). We suggest and propose two different comparative approaches for evaluating morphological traits and clutch paternity, in order to infer greater offspring survival. First, clutches coded by the exact number of fathers and second by the exact paternal contribution (fathers who gives greater proportion of the offspring per nest). We found significant differences (P < 0.05) in clutches coded by the exact number of fathers for all morphological traits. A general tendency of higher values in offspring sired by two to three fathers was observed for the length and weight traits. However, emergence success and crawling speed showed different trends which unable us to reach any further conclusion. The second approach analysing the paternal contribution showed no significant difference (P > 0.05) for any of the traits. We conclude that multiple paternity does not provide any extra benefit in the morphological fitness traits or the survival of the offspring, when analysed following the proposed comparative statistical methods.

Effects of multiple mating on the fecundity of an invasive pest (Octodonta nipae): the existence of an intermediate optimal female mating rate

AbstractMultiple mating is found in many insect taxa where both of the sexes can mate more than once. For males, this leads to the advantage of increasing their paternity by fertilizing more females. However, there is a trade‐off of resource allocation between reproduction and other life‐history characters. In the present study, the impact of increased mating rate on reproductive fitness of the invasive nipa palm hispid beetle Octodonta nipae Maulik (Coleoptera: Chrysomelidae) is investigated. A series of mating frequencies (i.e. 1, 5, 10, 15, 20 times) is selected from video frame playback, ranking from the minimum to maximum mating rate observed under laboratory conditions over a given time period. Fecundity parameters such as lifetime egg production, egg‐hatching rate, effective oviposition period and longevity are investigated for the evaluation of reproductive efficiency. For female O. nipae, increased fecundity is correlated with the mating frequency. Females mating 15 times lay the largest number of eggs (138.82 ± 6.87) and have a hatching rate of 47.43 ± 4.08%. After mating 20 times, females suffer significant declines in oviposition (90.31 ± 8.38 eggs) and egg‐hatching rate (34.16 ± 4.93%). Moreover, the population growth rate reaches a maximum in the females that mate 15 times. The results show that multiple matings in O. nipae have an intermediate optimal range within which female reproductive success is enhanced, providing empirical evidence for the existence of a trade‐off between costs and benefits during copulation based on resource allocation.

Effects of multiple matings on reproductive fitness of male and female Diaeretiella rapae

AbstractMating frequency and the amount of sperm transferred during mating have important consequences on progeny sex ratio and fitness of haplodiploid insects. Production of female offspring may be limited by the availability of sperm for fertilizing eggs. This study examined multiple mating and its effect on fitness of the cabbage aphid parasitoid Diaeretiella rapae McIntosh (Hymenoptera: Aphidiidae). Female D. rapae mated once, whereas males mated with on average more than three females in a single day. The minimum time lag between two consecutive matings by a male was 3 min, and the maximum number of matings a male achieved in a day was eight. Sperm depletion occurred as a consequence of multiple mating in D. rapae. The number of daughters produced by females that mated with multiple‐mated males was negatively correlated with the number of matings achieved by these males. Similarly, the proportion of female progeny decreased in females that mated with males that had already mated three times. Although the proportion of female progeny resulting from multiple mating decreased, the decrease was quicker when the mating occurred on the same day than when the matings occurred once per day over several days. Mating success of males initially increased after the first mating, but then males became ‘exhausted’ in later matings; their mating success decreased with the number of prior matings. The fertility of females was affected by mating with multiple‐mated males. The study suggests that male mating history affects the fitness of male and female D. rapae.

Intraspecific support for the polygyny-vs.-polyandry hypothesis in the bulldog ant Myrmecia brevinoda

The number of queens per colony and the number of matings per queen are the most important determinants of the genetic structure of ant colonies, and understanding their interrelationship is essential to the study of social evolution. The polygyny-vs.-polyandry hypothesis argues that polygyny and polyandry should be negatively associated because both can result in increased intracolonial genetic variability and have costs. However, evidence for this long-debated hypothesis has been lacking at the intraspecific level. Here, we investigated the colony genetic structure in the Australian bulldog ant Myrmecia brevinoda. The numbers of queens per colony varied from 1 to 6. Nestmate queens within polygynous colonies were on average related (r(qq) = 0.171 ± 0.019), but the overall relatedness between queens and their mates was indistinguishable from zero (r(qm) = 0.037 ± 0.030). Queens were inferred to mate with 1-10 males. A lack of genetic isolation by distance among nests indicated the prevalence of independent colony foundation. In accordance with the polygyny-vs.-polyandry hypothesis, the number of queens per colony was significantly negatively associated with the estimated number of matings (Spearman rank correlation R = -0.490, P = 0.028). This study thus provides the rare intraspecific evidence for the polygyny-vs.-polyandry hypothesis. We suggest that the high costs of multiple matings and the strong effect of multiple mating on intracolonial genetic diversity may be essential to the negative association between polygyny and polyandry and that any attempt to empirically test this hypothesis should place emphasis upon these two key underlying aspects.

No fitness consequence of experimentally induced polyandry in a monandrous wasp

AbstractTests of the effects of multiple mating by females on female fitness have been primarily with polyandrous species, where a benefit to multiple mating has usually been found. In contrast, no such benefit was found here for the parasitic wasp Spalangia endius, a highly monandrous species. Females that mated only once prior to oviposition exhibited a rapid decline in daughter production long before they died. The production of daughters, but not sons, is sexual in this species, i.e., requires sperm. Nevertheless, females with greatly decreased daughter production did not then remate. When such females were experimentally manipulated into copulating with a second male, additional sperm were stored in the females' sperm storage organs. However, this sperm increase had no significant effect on daughter production, total offspring production or longevity. There was no evidence that either immediate or delayed polyandry currently benefits females. The lack of benefit may be a general feature of highly monandrous species or a common feature of parasitic hymenopterans regardless of mating system.

Effect of multiple mating on reproduction and longevity of the phytoseiid mite Neoseiulus californicus

Females of some insects and mites that mate repeatedly (multiple-mated females) or that have limited food supply have a shortened life span, compared to females that are allowed to mate only once (single-mated females) or that have ample food. The present study focused on the relationship between mating frequency and various reproduction-related parameters in a commercial strain (Spical) of the phytoseiid mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). The impetus for this study came from the previous finding that single-mated females displayed an extremely long postoviposition period (ca. 60 days), accounting for more than 75% of the total adult longevity. In the present study it was found that the postoviposition period in the multiple-mated females was shorter than in the single-mated females and that longevity was gradually shortened with increasing mating frequency. Total egg production in females that mated twice or more was higher than in single-mated females, but egg production did not increase further with more than two matings. Single- and multiple-mated females ceased oviposition on the 24th and 34th day of adult life, respectively; multiple-mated females produced only male progeny on and after the 30th day. The postoviposition period of multiple-mated females was 40% shorter than that of single-mated females. Yet, the postoviposition period of the multiple-mated females is still more than 30 days, suggesting that other factors besides mating frequency have an influence on the prolonged postoviposition period. The reproductive ability of the Spical strain females gradually decreased with increasing virgin period (i.e. with increasing age), but they did not lose their reproductive potential--not even when mating was delayed for more than 2 months (i.e. females remained virgin for 70 days).

Nuptial food gifts influence female egg production in the scorpionfly Panorpa cognata

Abstract 1. Before copulation, male Panorpa cognata scorpionflies offer females a salivary secretion, which is consumed by the female during copulation. It has previously been demonstrated that this nuptial food gift functions as mating effort by increasing male attractiveness and by increasing ejaculate transfer during copulation.2. In this study, the effect of saliva consumption on female reproductive output was investigated, and thus the possibility that nuptial food gifts also serve as paternal investment. The experimental design enabled the effect of nuptial gift consumption to be disentangled from other possible effects of multiple mating or increased copula duration.3. The results showed that saliva consumption increases female egg production by on average 8% (4.5 eggs) per consumed salivary mass, whereas mean egg weight was not influenced.4. These results have important implications for the evolution and maintenance of both male nuptial gifts and female polyandry in this and other species.

Effects of male harassment on females' oviposition behaviour in Libellulidae (Odonata)

Abstract I investigated whether the level of male harassment affects females’ ovipositionbehaviour, such that females oviposit unguarded under suboptimal conditionsand/or vary oviposition duration, dip number, dip frequency or number of oviposi-tion site changes. The study species were the libellulids Crocothemis erythraea , Orthetrum chrysostigma , Pantala flavescens , Sympetrum fonscolombii , Trithemisannulata and T. kirbyi ardens . Only a few ovipositions under suboptimal conditionswere observed and females hovered lower under high male harassment. However,in only a few species studied oviposition behaviour differed with the level ofharassment. No evidence for a special female strategy to avoid the negative effectsof males’ harassment was found. Due to the great intraspecific variability females seemed to be able to react flexibly to current conditions, such as changing maledensity and the level of male harassment. Introduction Density has an important influence on the behaviour of mature male libellulids atreproduction sites (Pezalla 1979). High density intensifies male-male competitionso that males have a lower chance to mate and face higher costs due to fights(Corbet 1999: 375). For males, several behavioural parameters are known to changeunder high densities, for example: (1) a reduction in territorial size (Alcock 1998),(2) a decreasing duration of territorial occupancy (Sherman 1983), (3) shortercourtship (Martens 1996), (4) shorter (Miller 1982) or longer (Rehfeldt 1989) co-pulation, and (5) increased aggressive behaviour in some species (Pajunen 1966;Wolf & Waltz 1984; Corbet 1999: 657). As most of the literature on odonate mating patterns has focused on males, whilefemales were often ignored or just considered as passive partners (Fincke et al.1997), less is known about possible effects of multiple mating and male harassmentduring oviposition under high male density on females. Multiple mating causesbenefits and costs for females. Whereas males can increase their reproductive success

Fitness Consequences of Multiple Mating on FemaleSitophilus oryzaeL. (Coleoptera: Curculionidae)

The effects of multiple mating on fitness in the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), were studied. In the first of a series of experiments, the impact of multiple mating on female fitness was determined by evaluating the effects of a single mating period with one male, continuous exposure to one male, and continuous exposure to five males. Continuous exposure to one male increased lifetime fecundity by extending the period of time progeny were produced compared with a single mating period with one male, although average progeny size was reduced. Exposure to five males significantly reduced female survival and the number and size of progeny produced compared with the other treatments. In the second experiment, the number of progeny and the length of time progeny could be produced from a single copulation were determined. Females became sperm depleted within 7 ± 1 wk after laying 259 ± 22 progeny, but a second mating period 9 wk after the first copulation extended progeny production. In the final experiment, the mechanism for the decline in progeny production at high male densities was determined to be reduced oviposition, caused at least in part by a high proportion of time spent in copula. The number of copulations has costs and benefits for females that may affect population dynamics.

POLYANDRY PROMOTES ENHANCED OFFSPRING SURVIVAL IN DECORATED CRICKETS

Although female multiple mating is ubiquitous in insects, its adaptive significance remains poorly understood. Benefits to multiple mating can accrue via direct material benefits, indirect genetic benefits, or both. We investigated the effects of multiple mating in the decorated cricket, Gryllodes sigillatus, by simultaneously varying the number of times that females mated and the number of different males with which they mated, measuring aspects of female fecundity and elements of offspring performance and viability. Multiple matings resulted in enhanced female fitness relative to single matings when females mated with different partners, but not when females mated repeatedly with the same male. Specifically, polyandrous females produced significantly more offspring surviving to reproductive maturity than did monogamous females mating once or mating repeatedly with the same male. These results suggest that the benefit females gain from multiple mating is influenced primarily by genetic and not material benefits.

Remating Behavior of Cnephasia jactatana Walker Females (Lepidoptera: Tortricidae)

Cnephasia jactatana Walker is an important pest of kiwifruit in New Zealand. We investigated, under laboratory conditions, the effects of multiple mating on the reproductive performance of C. jactatana females and how such effects varied with male virginity and larval nutrition. We found that in permanent pairs, remating increased female fecundity and fertility but suboptimally fed females benefited more from remating. Regardless of this benefit, mass-reared pairs had a lower remating frequency. Females remating with a virgin male or a male that had delivered a spermatophore presented similar fecundity and fertility; however, females receiving a second ejaculate from a virgin male had increased daily fecundity. Female weight clearly affected remating behavior since those that received a second ejaculate were significantly heavier. Neither mating length nor size of the first spermatophore influenced female remating. Further, mass-reared and individually reared males produced spermatophores of similar size.

Trade-off between fitness components in males of the polygynous butterfly Callophrys xami (Lycaenidae): the effect of multiple mating on longevity

The differential costs of mating paid by males and females influence the nature and strength of sexual selection. In butterflies, males invest a relatively large amount of time and resources in each mating, but male survival costs of mating have not been demonstrated. I present the results of experiments designed to measure the effect of different aspects of mating on male longevity in the polygynous butterfly Callophrys xami. In experiment 1, I compared the longevity of pairs of males that produced similar amounts of spermatophore, but that mated at different rates, a different numbers of times, and that produced spermatophores at different rates, and found that the longevity of ”low-mating-rate” males was not different from that of ”high-mating-rate” males. In experiment 2, the longevity of virgin males was not significantly different from that of multiply mated males. In experiment 3, I used resource-limited males resulting from experimental food limitation of last-instar larvae; resource-limited virgin males lived significantly more days than resource-limited multiply mated males. Since ecological costs of mating (e.g., disease transmission, predation risk) were excluded in the experiment, diminished male longevity was a product of physiological costs of sexual interactions. These results suggest that the cost of ejaculate production is an important cause of longevity reduction when there are resource limitations; however, the role of other possible physiological costs of mating in longevity reduction is still unknown.

Fecundity and Longevity of Helicoverpa armigera (Lepidoptera: Noctuidae): Effects of Multiple Mating

Under a reverse photoperiod, the effects of multiple mating by female and male Helicoverpa armigera (Hübner) moths on female reproductive fitness were investigated. Comparisons of numbers of eggs laid and longevity of singly and multiply mated females revealed a positive relationship between the number of spermatophores received by a female and her oviposition rate in eggs laid per day and fecundity, and a negative relationship between the number of spermatophores and longevity. Male mating history had a significant influence on female fecundity. The fecundity of females mated to virgin males was higher than the fecundity of females mated to previously mated males. These results are discussed in relation to the possible benefits derived by females from multiple mating.

Reproductive performance and longevity of female European corn borer, Ostrinia nubilalis: effects of multiple mating, delay in mating, and adult feeding

In a recent study on the pheromone-mating disruption of the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), we recorded a significant reduction in mating frequency, as well as a marked delay in mating in feral females captured in disruptant-treated fields. In order to be able to accurately interpret the results in terms of effective population control, the current study was undertaken on the effects of multiple matings and a delay in mating on reproductive performance. Female O. nubilalis that mated at least twice had significantly higher fecundity and fertility, compared with once-mated females. In addition, multiple-mated females deposited a significantly larger portion of their egg complement, relative to single-mated or unmated females. Females that experienced a 3-day delay in mating showed a significant reduction in fecundity compared with females that mated soon after emergence. A 1-week delay in mating resulted in a further reduction in fecundity and a near zero fertility. The effect of sugar feeding on reproduction was not significant. In general, unmated females lived longer than mated females, and sugar-fed mated females had a higher longevity than water-fed mated females.

Sperm competition and the significance of female multiple mating in the predatory miteParasitus fimetorum

Females of the predatory miteParasitus fimetorum (Gamasida; Parasitina) inhabiting animal manure indiscriminately copulate with many mates. The sperm competition between the males was estimated by electrophoresis of allozymes and the effects of multiple mating on female reproduction were investigated. When females were forced to mate only once, their fecundity decreased drastically compared to the case of multiple mating (but longevity was unaffected). When one female mated with two males, the outcome of sperm competition depended greatly upon the mating interval. When the second mating occurred immediately after the first, the female fecundity decreased as in the case of single mating and the second male fertilized only a few eggs. However, when there was an interval of 1 day between the two matings, the females achieved normal fecundity and the second male fertilized approximately half the eggs. This suggests that the spermatophore deposited by the first male may act as a short-term copulatory ‘plug’ in the female's genital opening. When one female mated with several males with 1 day intervals, three or more males shared fertilization of the eggs. This study suggests that the multiple mating of females is a necessary stimulus to continue oogenesis and some physiological factors for this stimulation may exist in spermatophores.

A "Good-Sperm" Model Can Explain the Evolution of Costly Multiple Mating by Females

A "Good-Sperm" Model Can Explain the Evolution of Costly Multiple Mating by Females

The effect of multiple mating on female reproductive success in the simultaneously hermaphroditic land snail Arianta arbustorum

The simultaneously hermaphroditic land snail Arianta arbustorum mates several times in the course of a reproductive season. Repeated matings might be adaptive for the male function of A. arbustorum to inseminate several "females." We designed an experiment to evaluate the effects of repeated mating on the female reproductive success of this hermaphrodite. Reproductive traits and survival were examined over 2 years in individuals that copulated several times per year (snails were kept in pairs), in individuals that copulated twice (once at the beginning of each year) or once (at the beginning of the first year only), and in individuals prevented from copulating (they were kept isolated). Copulations were not always reciprocally successful: 3 of 57 snails (5.3%) failed to produce fertile eggs, although their mates reproduced successfully. Similarly, 2 of 15 pairs (13.3%) failed to reproduce successfully. Snails allowed to mate repeatedly within each season tended to lay more eggs than snails that mated once per year. However, the numbers of hatchlings did not differ significantly between the two treatment groups, because eggs laid by snails allowed to mate repeatedly had a lower hatching success. Snails that remated in the second year laid more eggs that had higher hatching success, and thus produced more hatchlings than snails that mated once at the beginning of the first year only. Snails that were prevented from mating produced a few hatchlings (by self-fertilization) in the second year; their reproductive success was less than 1% of that of mated snails. Our results suggest that multiple mating is also adaptive for the female function of A. arbustorum by increasing female fecundity and fertility and serving as a hedge against unsuccessful copulations.