Behavior of triatomines (Hemiptera: Reduviidae) vectors of Chagas' disease. III. Influence of the number of matings on the fecundity and fertility of Panstrongylus megistus (Burm., 1835) in the laboratory

A study of the effect of mating in the fecundity and fertility of females of P. megistus fed on pigeon blood every 14 days, was carried out in the laboratory. Two groups were constituted: I - females which mated only once; II - females which stayed always with the males. Only 56.7% of group I females laid fertile eggs, while as much as 90% of group II females laid fertile eggs. The duration of the fertile oviposition was greater in the females which stayed always with the males. Some females of this group were able to mate up to seven times throughout their life-span. This fact render useless sterile males in the control of these insects.     

Oviposition of potato tuber moth,Phthorimaea operculella zell. (Lepidoptera: Gelechiidae); fecundity in relation to mated state,age, and pupal weight

The fecundity of individually held potato tuber moths ranged from 0 to 236 eggs deposited over the total life span. The number of eggs laid was not correlated with pupal weight, but pupal weight and the number of mature eggs in the ovaries shortly after emergence from the pupa were positively correlated. This initial egg complement accounted for slightly more than half of the total number of eggs laid. Among moths held in groups at 25°c in the absence of host‐plant material, multiple‐mated females did not lay significantly more eggs (mean 98.4) than those mated only once (mean 91.0), but their life span was shorter (8.5 days cf. 14.4). Virgin females laid a small number of non‐viable eggs (mean 7.7), and lived about as long as single‐mated females. Males were significantly longer‐lived (23.6 days) than all groups of females. Peak oviposition of mated females occurred 2–5 days after emergence, and declined to low levels by age 7 days.     

Effects of delayed mating and male mating history on the reproductive potential of Leucoptera coffeella (Lepidoptera: Lyonetiidae)

Abstract 1 Despite the importance of Leucoptera coffeella (Guérin‐Mèneville) in coffee production worldwide, there is a lack of information on its reproduction. This knowledge will help in mass rearing, and support the development of behavioural control techniques for this insect. The present study determined the effects of delayed mating and previous matings of male L. coffeella on fecundity, egg viability and frequency of female remating. 2 The highest levels of fecundity and egg viability were obtained from matings of 1–3‐day‐old females. When females mated at 5 days of age, there were reductions of 40% in oviposition and of 43% in egg viability. 3 Females mated with 2‐day‐old virgin males were more fecund than those mated with older males; egg viability was also low (18%) from females mated with older males. 4 Virgin females that mated with virgin males laid a greater number of eggs than those mated with previously copulated males. Egg viability decreased with the increase in the number of previous male matings. 5 Five‐day‐old females remated in greater proportion than 2–3‐day‐old females. Females that copulated with males that had previously mated three times had higher rates of remating than those that copulated with virgin males. 6 The results obtained indicate that 1–3 days after emergence is the optimum age for mating. The implications of these findings for the control of L. coffeella by synthetic sex pheromone are discussed.     

Repetitive mating and female fitness in Dysdercus cardinalis (Hemiptera: Pyrrhocoridae)

Using three mating-treatment groups–pairing with a male for life, pairing with a male from adult emergence to first oviposition, and no pairing (virgin)–of Dysdercus cardinalis females in a laboratory study, the following results were obtained. Most of the virgin females did not lay eggs; those that did oviposited for the first time at a considerably older age than females in the other two groups. In a lifetime, females pairing with a male for life and those pairing with a male up to first oviposition produced essentially the same number of eggs, and this was more than 3.5 times the number of eggs laid by a virgin female. Virgin females produced an average of 1.3 clutches in a lifetime, compared with about 4.5 clutches produced by females in the other two groups. Reproductive span was significantly shorter, and fecundity per day of reproductive span significantly greater, for females pairing with males for life than for those pairing with a male up to first oviposition. Age at death was significantly different amongst females in different mating-treatment groups. Virgin females had the longest life, followed by females pairing with a male up to first oviposition and females pairing with a male for life, in that order. There was a positive correlation between lifetime gross reproduction and age at death for females pairing with a male for life. There was no relationship between these two characters for females pairing with a male up to first oviposition. Both females pairing with a male for life and those pairing with a male to first oviposition exhibited a significant inverse relationship between fecundity per day and age at death. The results obtained indicate that (1) mating is a prerequisite for normal gonadal activity in Dysdercus cardinalis , and (2) repetitive mating increases the rate of reproduction. This would reduce the mean age of parenthood which is inversely related to the intrinsic rate of increase.     

The effects of mating, age at mating, and plant stimuli, on the lifetime fecundity and fertility of the generalist herbivore Epiphyas postvittana

The effects of mating, age at mating, the presence or absence of a plant leaf, and the deprivation of a suitable ovipositional substrate during when the first ovipositional bout after mating would normally take place, on the lifetime fecundity and fertility (percentage of fertile eggs laid) of female Epiphyas postvittana were investigated. Mating had a significant effect on lifetime fecundity, with mated females laying 2.5 times more eggs than virgin females. Age at mating had a significant effect on both fecundity and fertility, both declining with increasing age when the female was mated. In the presence of a leaf of C. japonica, mated females had a greater lifetime fecundity than when no leaf was present; females in the presence of a C. japonica leaf consistently laid more eggs each day during the first 4–6 days after mating than females without a leaf. When females were deprived of a suitable ovipositional substrate, for the first 22 h after mating, they were significantly less fecund over their lifetime than were control females. Finally, in no-choice tests with three plants of different acceptability to females, the fecundity of females differed in the order C. japonica > Urtica ferox > Tibouchina multiflora. This different fecundity appeared to be inversely related to the pubescence of the leaves, suggesting that leaf texture may be a suitable antixenotic resistance factor for crops to be protected from this insect. These results suggest that strategies whereby mating is delayed or oviposition reduced within a critical period after mating, may result in significant reductions in pest populations.     

水稻二化螟的交配行为

在室内条件下,对水稻二化螟Chilo suppressalis的交配行为及能力进行了研究.结果表明：大多数二化螟雌蛾一生只交配一次,平均0.92次;而雄蛾具有多次交配能力,最多达4次,平均2.72次.二化螟雌蛾的日龄影响其交配率、交配起始时间和持续时间,随二化螟雌蛾日龄的增加,其交配率逐渐下降,交配起始时间逐渐提前,而交配持续时间逐渐上升.相反,二化螟雄蛾日龄对其交配率、交配起始时间和持续时间没有明显影响.交配日龄对二化螟雌蛾的生殖力也存在显著影响,随着二化螟雌蛾交配日龄的增加,雌蛾产卵量下降,卵孵化率降低,产卵期缩短,它们都与雌蛾交配日龄存在显著的负相关;而雌蛾产卵前期和雌蛾寿命随雌蛾交配日龄的增加而延长,与雌蛾交配日龄存在显著的正相关.但二化螟雄蛾交配日龄对雌蛾的生殖力没有明显影响,二化螟雄蛾一生都具有较强的交配繁殖能力.同时,不同交配史的雄蛾与雌蛾交配,对雌蛾的生殖力也没有显著影响.表明二化螟的交配活动是由雌蛾主导控制的.最后,对这些结果在二化螟性信息素防治中应用的可行性进行了探讨.在应用性信息素控制二化螟的实践中,可以在两方面取得实效,一是性信息素可以阻碍雌雄之间正常交配,降低交配率;二是可以推迟二化螟雌虫的交配,使其产卵量和卵孵化率降低.     

A survival cost to mating in a polyandrous butterfly, Colias eurytheme

Adaptations that enhance fitness in one sex may be harmful to members of the opposite sex and lead to antagonistic coevolution between the sexes. In fruit flies, for example, selection for fertilization success has rendered the male ejaculate slightly toxic to females. Here we investigated whether mating imposes a cost upon female fitness in a polyandrous pierid butterfly ( Colias eurytheme ) by comparing life history traits between once-mated females and virgins. Mated females laid relatively more eggs early in their adult life, but suffered a reduction in longevity relative to virgins held under identical experimental conditions. The effect of mating on female survivorship was statistically independent of lifetime and early life fecundity. Moreover, lifetime fecundity co-varied positively with longevity across all females, and across females within each treatment group, hence there was no phenotypic trade-off between survival and reproduction. These results suggest that the observed longevity difference between virgin and mated females represents a true cost of mating, possibly arising from a toxic side effect of the male ejaculate. However, irrespective of this cost, virgin and mated females laid an equivalent lifetime number of eggs. Female C. eurytheme are also known to use nutrients from the male ejaculate to supplement their reproductive output, hence it is presently unclear how the observed longevity cost may have influenced the evolution of lifetime mating schedules in this polyandrous species.     

Multiple mating of male and female codling moth (Lepidoptera: Tortricidae) in apple orchards treated with sex pheromone

Studies were conducted with codling moth, Cydia pomonella L., to evaluate the mating status of male and female moths in apple, Malus domestica (Borkhausen), orchards treated with and without sex pheromone dispensers. Laboratory studies first examined the effect of multiple mating of male and female moths on female fecundity and egg fertility. Females that had mated three times had a significantly higher fecundity than singly mated moths. Sequential mating by male moths had no effect on the fecundity of female moths or egg fertility. However, male moth age did impact female fecundity, with significantly fewer eggs laid after mating with virgin 1- versus 3-d-old males. The mean size of the first spermatophore transferred by males was significantly larger than all subsequent spermatophores. Classifying spermatophores based on size was used in field sampling to categorize the mating status of the female's partner. The proportion of mated females with small spermatophores (partner had previously mated) was significantly higher in treated versus untreated orchards. The proportion of female moths caught in traps baited with pear ester that were virgin was low (相似文献   

Mating experience weakens starvation tolerance in the seed bug Togo hemipterus (Heteroptera: Lygaeidae)

Organisms are exposed to various stresses caused by environmental fluctuations. One of the most common stresses is the shortage of food. Individuals of many species must survive periods of starvation. There appears to be a trade‐off between reproduction and survival. When residual reproductive value declines for an individual, life‐history theory predicts an increase in current reproductive investment. Current reproductive investment differs between virgin and mated individuals. It is likely that mating experience influences starvation tolerance. However, few studies have investigated sex differences in the effect of mating experience on starvation tolerance or clarified the causes of reductions in starvation tolerance in both sexes. In the present study, these questions are investigated using the seed bug Togo hemipterus (Heteroptera: Lygaeidae).The results of the present study demonstrate that mating is costly for both sexes. Mated males show very short survival times and a daily reduction in weight, and daily energy expenditures are significantly greater in mated males than in virgin males. It is possible that starvation increases the mating effort of males, such as behavioural activities and the amount of time spent searching for females. A trade‐off between survival duration and lifetime fecundity is found in virgin females. However, there is no trade‐off in mated females, which have very short survival times. Whether male seminal substances contribute to the short survival times of mated females is considered. This is the first report demonstrating the influence of sex and mating experience on starvation tolerance. Sex‐specific causes for reductions in starvation tolerance are discussed.     

Effect of male and female multiple mating on the fecundity, fertility, and longevity of diamondback moth, Plutella xylostella (L.)

Abstract:  The effect of diamondback moth (DBM), Plutella xylostella (Lep., Plutellidae) male and female multiple mating on fecundity, fertility, and longevity was studied. Males could mate for five times with virgin females during scotophase. The successful copulation rates, fecundity of female, and longevity of both females and males decreased when male mating times increased, whereas copulation duration increased. Correlation coefficient between copulation duration and male mating times was significant ( r  = 0.7358, P = 0.0001, spearman rank-order correlation). There were linear relationships between mating history of males and longevities of males and females, and regression relationships between them were significant. Mated females had similar daily reproductive pattern, which laid the most eggs on the first day after mating in spite of their mates' mating history. Virgin females laid some infertile eggs before they died. Most of the females mated once during their lifespan but 19.9% of females mated twice when one female kept with one male during scotophase. There were no significant differences in the fecundity, fertility and longevity between the single- and twice-mated females. Correlation coefficient between copulation duration and female mating times was not significant ( r  = 0.0860, P = 0.8575). Results suggested that DBM females may be monandrous. Multiple mating did not increase male or female mating fitness.     

Lifetime ovipositional patterns of mated and virgin onion flies,Delia antiqua (Diptera: Anthomyiidae)

Over their 47.2±1.9 (mean±SEM) day lifespan, mated onion flies, Delia antiqua, oviposited more uniformly than did virgins. Mated females began ovipositing at 6.4±0.2 days old and regularly deposited 14.2±0.6 eggs/day for 3-4 weeks. Thereafter, oviposition slowed and stopped at about 1 week before death. Virgin flies began ovipositing 24.7±1.5 days into their 59.0±3.8 day lifespan, and deposited eggs at an increasing rate for 3-4 weeks, generating a mean overall ovipositional rate of 5.8±0.5 eggs/day. The later onset of virgin oviposition (ovipositional activation) and not a shorter ovipositional period largely accounted for the disparity between virgin and mated female lifespans. Mean lifetime egg production of mated females was 475±27 eggs versus 179±30 eggs for virgins. Ovipositional and post-ovipositional periods (34.4±1.8 and 7.2±1.0 days) for mated females were not significantly different from those of virgin females (30.9±3.6 and 6.7±1.2 days). Over 90% of virgin females laid eggs. The distinction between mated and virgin ovipositional patterns may be specifically attributed to differences in: (1) egg maturation, (2) age at ovipositional activation, and (3) egg-laying rate.     

Morphological features,development and reproduction of Melittobia acasta on Bombus terrestris

Morphological features, development and reproduction behavior of the parasite Melittobia acasta (Walker) were studied when reared on the pupae of the bumblebee Bombus terrestris L. in the laboratory under 23°C, 50% relative humidity and 12 h light : 12 h dark conditions. The parasites laid transparent white and elongated eggs. Newly hatched larval size and shape were very similar to eggs but they were identified by their body segments. Larvae increased their body size through moulting and transformed into a vermiform shape. Male pupae were shiny brown with dots. The female pupae were distinguished by their black shiny color, shorter size and the presence of compound eyes. Adult male pupae were dark brown and dwarf‐winged, whereas female pupae were macropterous and brachypterous. Reproduction took place by fertilization and also parthenogenetically. Mean fecundity within 5 days by mated (47.9 ± 30.5 female^?1) and virgin (7.4 ± 6.8 female^?1) females were statistically different. Mated females laid fertilized eggs that produced adult males or females, whereas virgin females laid unfertilized eggs that produced males. Development durations of the virgin female originated eggs, larvae, pupae and adults were statistically identical with those of mated females. The parasites were female‐biased and foundress number did not affect offspring sex ratio. This study shows that both mated and virgin females of M. acasta can produce many offspring on B. terrestris pupae within a short period, indicating that they are dangerous parasites of the bumblebee in a mass rearing system.     

Effects of male mating interval on spermatophore formation,transfer, and subsequent female receptivity and fecundity in the sorghum plant bug,Stenotus rubrovittatus

Males of the sorghum plant bug, Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae), transfer a spermatophore to females during copulation. After a 1‐day interval between the first and second copulation, males transferred both sperm and a spermatophore to females during the second copulation. However, when male mating interval was <1 h, they transferred sperm but no spermatophores to females during the second copulation. Therefore, the male mating interval probably produces two types of mated females, those with and those without a spermatophore. Mated females of S. rubrovittatus do not remate for at least 3 days after mating, even when courted, and lay more eggs than virgin females at the beginning of the oviposition period. The effects of spermatophores on female sexual receptivity and fecundity were examined using mated females with or without a spermatophore. Only one of the 40 (2.5%) mated females with a spermatophore remated, whereas 10 of the 26 (38.5%) without a spermatophore remated. Furthermore, mated females with a spermatophore laid more eggs than those without a spermatophore. These results suggest that spermatophores participate in reducing female sexual receptivity and enhancing female fecundity in S. rubrovittatus.     

Egg dumping and life history strategy of Callosobruchus maculatus

Abstract.  Previous studies have demonstrated that female Callosobruchus maculatus adjust oviposition rates to cope with changes in host availability. A female lays fewer eggs when host availability is low, and hence decreases larval competition. However, females will also dump eggs on unsuitable substrates under conditions of host deprivation. Because the female does not feed as an adult, egg dumping possibly wastes energy and may thus be a maladaptive behaviour. In this study, the effect of mating and age on the egg-dumping behaviour and the life history strategy of the female are explored. Under host-deprived conditions, mating is seen to trigger egg-dumping behaviour. Also, females mated at 6 days dump significantly fewer eggs and live longer than females mated at 0 or 3 days. Thus, a trade-off between fecundity and longevity is seen among females subjected to different manipulations. In addition, 6-day-old virgin females contain more mature eggs than females mated at 6 days can produce when deprived of hosts. This finding indicates that the female reallocates internal energy resources by oosorption in a resource-limited environment. To test the maladaptive hypothesis, mated females were deprived of a host for 6 days and then given sufficient hosts each day. The results show that the more eggs dumped by a female in the first 6 days, the more eggs are laid later on beans. Egg dumping is thus not maladaptive.     

FEMALES RECEIVE A LIFE-SPAN BENEFIT FROM MALE EJACULATES IN A FIELD CRICKET

Abstract.— Mating has been found to be costly for females of some species because of toxic products that males transfer to females in their seminal fluid. Such mating costs seem paradoxical, particularly for species in which females mate more frequently than is necessary to fertilize their eggs. Indeed, some studies suggest that females may benefit from mating more frequently. The effect of male ejaculates on female life span and lifetime fecundity was experimentally tested in the variable field cricket, Gryllus lineaticeps. In field crickets, females will mate repeatedly with a given male and mate with multiple males. Females that were experimentally mated either repeatedly or multiply lived more than 32% longer than singly mated females. In addition, multiply mated females produced 98% more eggs than singly mated females. Because females received only sperm and seminal fluid from males in the experimental matings, these life‐span and fecundity benefits may result from beneficial seminal fluid products that males transfer to females during mating. Mating benefits rather than mating costs may be common in many animals, particularly in species where female mate choice has a larger effect on male reproductive success than does the outcome of sperm competition.     

Effect of Delayed Mating on Oviposition Pattern, Fecundity and Fertility in Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae)

Female codling moth ( Cydia pomonella ) were mated either on the day of emergence or 2 or 4 d after emergence. Oviposition was checked daily and fertility (% egg hatch) of eggs laid 1–4 d and 5 + d after mating was determined from a sub-sample of females in each treatment. From these data, net reproduction rate (R₀) was calculated. the effect of delayed mating of males was also determined. Mean fecundity, fertility and net reproduction rate of females mated 4 d after emergence were significantly lower than for females mated either on the day of emergence (day 0) or 2 d after emergence. There were no significant differences between the three treatments in terms of the proportion of females that mated or female longevity, although there was a trend towards increased longevity with increasing delays in mating. Mean longevity of unmated females was significantly greater than that of mated females. Oviposition pattern was similar in females regardless of when they were mated and in all cases maximum oviposition took place 2 d after mating. There was no effect on the fecundity of 2 d old females or on the fertility of their eggs when they were paired with either 2 or 6 d old males. the significance of these findings in relation to control of codling moth by mating disruption is discussed.     

Post‐mating enhancement of fecundity in female Lygus hesperus

Although mated females of the western tarnished plant bug Lygus hesperus Knight are known to produce more eggs than virgins, the nature of the inducing stimuli and the specific changes occurring in the female require additional elucidation. Compared with virgin females isolated from males, those exposed to male precopulatory behaviours produce similar numbers of eggs, whereas inseminated females produce 50% more during the observation period. Although the quantity of seminal fluids received by a female does not influence egg number, mating twice within a 10‐day span causes a 16% increase in fecundity, on average. Females mating more than twice during the same period do not exhibit additional increases in egg number. Because virgin females contain more chorionated eggs than are laid, mating appears to enhance the rate of oviposition. However, to achieve a sustained increase in fecundity, an augmented rate of oocyte maturation would also be required. Male‐derived spermatophores lack substantive quantities of nutrients that might otherwise have enhanced female fecundity. The total amounts of carbohydrate, protein and lipid, as well as eight essential minerals transferred by the male, are insufficient for producing even a single egg, and the female has already produced a large number of chorionated oocytes before she mates. Collectively, the data suggest that seminal fluid contains one or more activational molecules, such as a peptide, which triggers an increase in egg deposition. A prolonged increase in oviposition rate may be achieved through multiple matings to ensure a supply of sperm or to offset the degradation of the putative activational factor.     

Some aspects of oögenesis in the stable fly Stomoxys calcitrans (Diptera: Muscidae)

Two distinct patterns of blood ingestion in the female stable fly, Stomoxys calcitrans L. were observed, based on whether or not the female was mated. Mating is not required for oögenesis, but is necessary for oviposition. Virgin females develop eggs but, in the absence of mating, they retain eggs until death. In stable flies, oögenesis appears to be atypical among other dipterans as the penultimate follicles develop and deposit up to 50% yolk before the terminal follicles are matured. Oösorption was seen in the penultimate follicles of virgin females retaining eggs. Accessory-gland implants initiated oviposition in virgin females. However, the total number of eggs laid by such females was 50% less than the number of eggs laid by mated flies.     

The effect of male mating history on paternal investment, fecundity and female remating in the seed beetle Callosobruchus maculatus

1. In many organisms, males provide nutrients to females via ejaculates that can influence female fecundity, longevity and mating behaviour. The effect of male mating history on male ejaculate size, female fecundity, female longevity and female remating behaviour in the seed beetle Callosobruchus maculatus was determined.
2. The quantity of ejaculate passed to females declined dramatically with successive matings. Despite the decline, a male's ability to fertilize a female fully did not appear to decline substantially until his fourth mating.
3. When females multiply mated with males of a particular mated status, the pattern of egg production was cyclic, with egg production increasing after mating. Females multiply mated to virgins had higher fecundity than females mated to non-virgins, and females mated to twice-mated males had disproportionately increased egg production late in their life.
4. Females that mated to multiple virgins, and consequently laid more eggs, experienced greater mortality than females mated only once or mated to non-virgins, suggesting that egg production is costly, and rather than ameliorating these costs, male ejaculates may increase them by allowing or stimulating females to lay more eggs.
5. Females mating with non-virgin males remated more readily than did females mated to virgins. Females given food supplements were less likely to remate than females that were nutritionally stressed, suggesting that females remate in part to obtain additional nutrients.     

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.