Effects Of Mating Status Research Articles

Identification of additional dye tracers for measuring solid food intake and food preference via consumption-excretion in Drosophila

The Drosophila model has become a leading platform for investigating mechanisms that drive feeding behavior and the effect of diet on physiological outputs. Several methods for tracking feeding behavior in flies have been developed. One method, consumption-excretion or Con-Ex, provides flies with media labeled with dye and then quantifies the amount of dye excreted into the vial as a measure of consumption. We previously found that Blue 1 and Orange 4 work well in Con-Ex and can be used as a dye pair in food preference studies. We have expanded our development of Con-Ex by identifying two additional dyes, Orange G and Yellow 10, that detect the anticipated effects of mating status, strain, starvation and nutrient concentration. Additionally, Orange G and Yellow 10 accumulate linearly in excretion products out to 48 h and the excreted volumes of these two dyes reflect the volumes consumed. Orange G also works with Blue 1 as a dye pair in food preference studies. Finally, consumption of Blue 1, Orange 4, Orange G or Yellow 10 does not affect ethanol sedation or rapid tolerance to ethanol. Our findings establish that Orange G and Yellow 10, like Blue 1 and Orange 4, are suitable for use in Con-Ex.

Factors That Influence Flight Propensity in Anoplophora glabripennis (Coleoptera: Cerambycidae).

The effects of mating status, sex, beetle age, host quality, temperature, and wind speed on the propensity of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) to take flight were evaluated using a free flight test in the laboratory. Time to initiate flight, the angle of flight, and flight capability (when beetles were enticed to take flight) were also evaluated. Host quality, mating status, beetle age, sex, temperature, and the interactions between one or more of these were all found to be significant predictors of flight in A. glabripennis in one or more of the experiments. Female flight propensity peaked at sexual maturity and declined thereafter. Both sexes had a higher propensity to take flight from a stem section of dry host material than from a fresh one. Most (78%) males flew at least once during the four mating status/ages tested from a fresh host stem section, while only 43% of the females flew at least once after chewing an oviposition pit. Flight propensity and distance flown increased with temperature and there was no voluntary flight at 15°C. Flight propensity did not increase with wind speeds 0.0-1.0 m/s, but no ascending flight was observed at 0.5 or 1.0 m/s. Time to flight initiation did not vary with the factors evaluated. Implications these results could have on the success of eradication programs are discussed. Specifically, what factors increase the propensity of mated females to disperse, effectively expanding the infestation zone.

Effect of mating status on the fecundity of a cricket, Teleogryllus emma

Fecundity in some insects is affected by mating status. The effect of mating status on the fecundity and total egg production of Teleogryllus emma (Ohmachi et Matsumura) (Orthoptera: Gryllidae) was examined in this study. The results showed that the pre-oviposition period was shorter for amphigonic females than that for virgin females. However, no significant difference in pre-oviposition was found between amphigonic females and those that had mated with a male with either the phallodeum or testes extirpated. There is no difference in adult longevity between the above four groups. The fecundity and total egg production were much higher in amphigonic females than in those controlled under the three non-amphigonic treatments. The females of T. emma that mated with the testes-extirpated males produced more eggs (up to two-fold more) than both the virgin females and those that mated with the phallodeum-extirpated males, but there was no difference between them. The fecundity-enhancing substances transferred from male to female can stimulate the female to produce more eggs, but this stimulation has to occur in collaboration with sperm.

Mate acquisition by females in a butterfly: the effects of mating status and age on female mate-locating behaviour

In most species, female reproductive success is determined by realized fecundity, which depends on the amount of female reproductive reserves and the availability of time for oviposition. Consequently, selection is likely to favour behaviour in virgin females that increases the likelihood of encountering males and thereby minimizing time without sperm. We used the speckled wood butterfly, Pararge aegeria, to test the hypothesis that virgin females increase the probability of encountering males by behaving more conspicuously. We also tested for an effect of age on behaviour, with the prediction that females behave more conspicuously if they remain unmated for a longer period. To do this we conducted controlled behavioural studies in large outdoor cages, comparing the behaviour of young and old, virgin and mated, females. We also assessed the time it took for a male to discover virgin versus mated females. Our results show an effect of age and mating status: old virgin females behaved more conspicuously than young virgin females and mated females, and spent more time in flight and performed more individual flights. Males also discovered virgin females faster than mated females. Furthermore, virgin females did not specifically locate the large sunspot, where perching males are found. Hence, females of P. aegeria adjust their behaviour in accordance with mating status and age, making them more likely to encounter a male and thereby maximize their reproductive success. This study underlines the importance of taking the distribution and behaviour of receptive females into account when studying mate-locating behaviour.

アカヒゲホソミドリカスミカメ雌の雄に対する誘引性―雌の交尾の有無と羽化後日齢の影響―

The effect of mating status and adult age of the rice leaf bug, Trigonotylus caelestialium, on the attractiveness of females to males was investigated. A trap baited with virgin females tended to attract more males than one baited with mated females. This result indicates that the sex pheromone emitted by females may decrease after mating. Furthermore, more males tended to be captured in the trap baited with virgin females at three days after emergence compared with those aged six days. This result suggests that the sex pheromone emitted by virgin females may decrease with age.

Laboratory Evaluation of Flight Performance of the Plum Curculio (Coleoptera: Curculionidae)

Flight performance of laboratory-reared adults of the plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), was investigated under controlled conditions by using a flight mill system. Across all insects tested (n=198), median values of total distance traveled, total flight time, and maximum uninterrupted flight time were 122.7 m day(-1), 23.5 min day(-1), and 2.0 min, respectively. The latter result indicates that flight occurred primarily in short bursts. Although females had a significantly higher body mass than males, there were no significant differences in flight performance between the two sexes. Flight during the first 24-h test period (especially the first 6 h) was dominated by escape behavior, i.e., elevated levels of activity presumably associated with attempts by the insects to regain freedom of movement; during the second 24 h, flight activity was very limited throughout the late morning and afternoon, increased around sunset, and remained high during the night. All flight performance variables decreased linearly and significantly with insect age over the age range tested (2-16 d after emergence). Nutritional status also had a significant effect, whereby insects that had been provided with apples as a food source for 2 d after emergence showed considerably improved flight performance compared with those that had been given no food or only water during the same period. There was no significant effect of mating status on flight performance of male or female insects.

Effects of mating status on copulation investment by male bushcricket Gampsocleis gratiosa (Tettigoniidae, Orthoptera)

Male's copulation investment, including spermatophore and sperm investment were very high in the Chinese bushcricket Gampsocleis gratiosa. The effects of mating status of both males and females on male's copulation investment were examined in this study. The fresh weight of spermatophylax increased positively with the weight of males' body. This indicated that the nutritional investment during copulation depended on male's quality. Spermatophore investment showed insignificant differences in every copulation protocols. This finding supported the paternal investment hypothesis, that is, males contributed to their offspring with little attention to their partners. Sperm releasing per ejaculation varied significantly among the trials. Males decreased 54.19% sperm in second mating than in its first mating, demonsrated that males regarded the first mating highly, and were more prudent in subsequent mating. These males' strategies may contribute to the viability of the offspring.

Mobility of Mass-Reared Diapaused and Nondiapaused <I>Cydia pomonella</I> (Lepidoptera: Tortricidae): Effect of Mating Status and Treatment with Gamma Radiation

Mass-reared insects may differ in their behavioral traits depending on whether they have undergone diapause. We studied the mobility of mass-reared diapaused and nondiapaused Cydia pomonella (L.) with a focus on understanding the effect of mating status and treatment with gamma radiation as these insects are destined for use in an areawide program that uses the sterile insect technique (SIT). Actograph-measured mobility was assessed one gender at a time for 4 h during which the photoperiod transitioned from day to night. We tested 20-30 individuals per treatment. For experiments on the effect of mating status, we used 24-48-h-old adults (diapause [D]-virgin, D-mated, standard [N]-virgin, and N-mated), which is the typical age class that is released in the SIT program. Diapaused females were significantly more mobile than females reared through standard production, whereas no differences were detected in male mobility because of rearing strategy. Mated females were significantly more mobile than virgin females, whereas no difference in mobility because of mating status was detected for males. Mated females were significantly more mobile than mated males. In contrast, virgin females were significantly less mobile than virgin males. For experiments on the effect of treatment with gamma radiation, adults from all rearing strategies and treatments (D-0Gy, D-100Gy, D-250Gy, N-0Gy, N-100Gy, and N-250Gy), were tested simultaneously. Adult males were tested at two different constant temperatures (25 and 20 degrees C), whereas adult females were tested only at 25 degrees C. For standard-reared adults, we found a significant linear decrease in mobility as the radiation dose increased from 0 to 250 Gy. In contrast, the relationship between mobility and dose of radiation was quadratic for diapaused males and absent for diapaused females.

Effects of Mating on Female Locomotor Activity in the Parasitoid WaspNasonia vitripennis(Hymenoptera: Pteromalidae)

Effect of mating status on locomotor activity was examined in females of the parasitoid wasp Nasonia vitripennis (Walker). Mated females were more active than virgin females in both strains of N. vitripennis that were tested and regardless of whether or not the mated female stayed with her mate before testing. Mated females were more active than virgin females when tested immediately after mating and when tested 1 h, 1.5 h, and 2 h after mating. Mated females were still more active than virgin females when both had been allowed to parasitize a host for 2 h. Mated females were not significantly more active than virgin females at 1, 3, and 5 d after mating. Mated females that were allowed to parasitize a host for 3 h before testing were less active compared with those not given a host. Amount of activity was independent of a female’s head width and did not affect a female’s subsequent offspring production. Despite being more active, mated females did not kill more hosts than virgin females. However, among mated females, females that were more active subsequently killed more hosts, whereas this was not true for virgin females. Discussion of relevance to biological control and suggestions for future research are provided.

Effects of Mating Status and Parasitoid Density on Superparasitism and Offspring Fitness in <I>Tiphodytes gerriphagus</I> (Hymenoptera: Scelionidae)

Laboratory experiments investigated the effects of mating status and wasp density on frequency of superparasitism, development time, longevity, and fecundity of offspring of the egg parasitoid Tiphodytes gerriphagus Marchal. When individual females searched a patch over a 24-h period the number of probes per egg from mated wasps was higher than that from unmated wasps, but there was no difference in number of larvae found per egg during dissections. When groups of 5 females searched a patch together, both number of probes per egg and number of larvae per egg increased significantly compared with that of individual females. Superparasitism occurred most frequently when eggs were simultaneously exposed to 5 females, and mated groups of females superparasitized more frequently than unmated groups (frequencies of 78.1 and 62.9%, respectively). Development time of wasps in superparasitized eggs was longer than that of wasps in singly parasitized eggs. Longevity of adult male parasitoids was not affected by having come from superparasitized eggs, but female longevity was decreased significantly. Mated and unmated females showed no significant differences in fecundity, regardless of whether they had emerged from superparasitized or singly parasitized eggs.

Electroantennogram Responses of Both Sexes of Grape Root Borer (Lepidoptera: Sesiidae) to Synthetic Female Sex Pheromone

The effect of mating status and sex on antennal response to sex pheromone components was tested in the grape root borer, Vitacea polistiformis (Harris). The grape root borer pheromone is a 99:1 blend of (E,Z)-2,13-octadecadien-1-ol acetate (EZ) and (Z,Z)-3,13- octadecadien-1-ol acetate (ZZ). Antennae of both virgin male and female moths exhibited similar dose—response patterns, with a threshold dosage of 1 mg of the EZ:ZZ blend on filter paper. Four treatments were tested at a dose of 5 mg on filter paper: EZ, ZZ, a blend of 99:1 EZ:ZZ, and the alcohol (E,Z)-2,13-octadecadien-1-ol (EZ-OH). Male antennae responded significantly to all compounds, regardless of mating status. Virgin female antennae responded significantly to all compounds, although their responses were significantly lower than the responses of male antennae. However, female antennae were relatively more responsive to EZ-OH than male antennae. Mated female antennae responded significantly to EZ and 99:1 EZ:ZZ. Pheromone detection by females has considerable implications to mating disruption strategies.

Effect of mating status and age of Microplitis rufiventris (Hym., Braconidae) females on the growth pattern and number of their teratocytes

The effect of mating status and age of the female of Microplitis rufiventris parasitoid on the growth pattern of its teratocytes during the larval development is described as well as the changes in the number of these cells. The growth pattern of teratocytes derived from haploid eggs significantly differed from that of eggs deposited by mated females. Both cell diameter and the number of maturing M. rufiventris teratocytes was fertilization‐dependent. Following the parasitization of Spodoptera littoralis larvae with virgin parasitoid females, the host larvae hosted a large number of cells of smaller size at the end of parasitoid development. The opposite effect was seen when the host larvae contained female parasitoid larvae. The age of the female at parasitization had an effect on the maximum cell size attained prior to parasitoid emergence. It seems that there are two factors other than mating which affect the number of teratocytes: degeneration inside the host haemolymph and to some degree accidental ingestion by parasitoid larva.

Effect of mating on female phonotactic response in Gryllus integer (Orthoptera: Gryllidae)

Little work has examined the importance of the variation in mating preferences shown by individual females in a population. In acoustical insects, female response in terms of orientation and movement towards the male calling song is one aspect of female mating preferences. In this study, the effects of mating status on female phonotactic responses in the field cricket, Gryllus integer, were investigated. All test subjects were 10-14 days old and varied in their pretrial mating history. Mated females had copulated 24 h prior to testing. Virgin females, however, had visual, olfactory, and acoustical exposure to males during the pretrial matings of the mated females. Phonotactic responses were measured using a noncompensating treadmill called the kugel. Females were presented with simulated conspecific calling songs differing in trill length in either choice or no-choice protocols. Virgin females exhibited greater overall movement than mated females as well as increased directional movement in multi-stimulus presentations but not in single-stimulus presentations. Neither virgin nor mated females differentiated between the two songs differing in trill length. The data demonstrate that female G. integer phonotaxis is influenced, in part, by both mating status and the availability of mates.

Effects of mating status and age on dispersal behavior in the twospotted spider mite, Tetranychus urticae in response to fenvalerate‐treated leaf surfaces

AbstractEffects of variation in age and mating status on dispersal of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), from fenvalerate‐treated leaf surfaces were investigated. Unmated and mated female mites, 1 to 6 days in age, were scored for walkoff and spindown dispersal response on bean leaves treated with a sub‐lethal, residual dose of fenvalerate. Variation in mite age did not have a pronounced effect on dispersal response. Significant differences in dispersal response due to mating type were observed, yet the mean differences in dispersal response between unmated and mated females was generally small. Our data suggest that the current practice of using mated female mites of unknown age when testing for among‐population differences in dispersal response, in most cases, provides an adequate estimate of population response when differences among treatments in dispersal response are large. However, when testing for within‐population differences in dispersal response, small treatment effects may be more easily measured using a single age class of mites, because this could decrease within‐treatment variance.

Schistosoma mansoni: Influence of the female parasite on glutathione biosynthesis in the male

The glutathione (GSH) content of male Schistosoma mansoni increases in the absence of the female. This phenomenon, originally observed in vitro, also occurs within the host. At the time of recovery from mice, the GSH content of males from single-sex infections was 1.7-fold higher than that of paired males from mixed sex infections ( P < 0.01). The effect of mating status on male GSH biosynthetic and turnover rates was examined to determine the basis for increased GSH content in unpaired males. GSH turnover rates, measured when GSH biosynthesis was inhibited by >95% with 5.0 m M- dl-buthionine- SR-sulfoximine, were indistinguishable between unpaired and paired males with a first-order rate constant of 0.018 hr −1. In contrast, incorporation of l-[ 35S]cysteine into GSH revealed that GSH biosynthesis was 5-fold higher in unpaired than in paired males. Transport of l-cystine into male schistosomes, the presumed rate-limiting step in GSH biosynthesis, was unaffected by mating status. The GSH content increased when males were incubated in medium that had previously contained females or when separated from females by a microporous membrane. Males paired to 50% ethanol-fixed females had unchanged GSH content in vitro. It appears that male GSH biosynthesis may be regulated by a response stimulated by the female's physical presence in the gynechophoral canal and not by a soluble factor released from the female.

The effect of mating status on lifespan, egg laying, and starvation resistance in Drosophila melanogaster in relation to selection on longevity

Virgin D. melanogaster of both sexes lived longer than mated flies. Differences in longevity between populations that had been selected for early-life or late-life fitness were not affected by mating status. Short-lived females had higher early-age fecundity than long-lived females regardless of mating status. Among young, virgin females, those from short-lived populations were more likely to lay eggs than were those from long-lived populations. Mated males had lower starvation resistance than virgin males. The difference between selection regimes in male starvation resistance was not affected by mating status. These results are consistent with the hypothesis that selection for late-life fitness has produced physiological differences between selected strains that are independent of the effects of mating or the presence of flies of the other sex. The loss of male starvation resistance that was caused by keeping males and females together was reversible. There was a strong interaction between mating status and selection regime with regard to female starvation resistance. Confinement with males increased the starvation resistance of long-lived females, but had no consistent effect on the starvation resistance of short-lived females. Flies transferred daily to fresh vials lived longer than those transferred three times per week: the increase in longevity was greater for mated flies than for virgins.