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1.
Kenji Fujisaki 《Researches on Population Ecology》1992,34(1):173-183
Summary A male fitness advantage to wing reduction was investigated for the oriental chinch bug,Cavelerius saccharivorus, which is wing dimorphic. Field surveys for the frequency of matings between wing morphs showed that the mating probability
was much higher in brachypterous males than in macropterous males in the early breeding season. Brachypterous males copulated
with not only brachypterous females but also macropterous females in this season. This led to a considerable rate (30%) of
insemination of macropterous females just before emigration even in the early breeding season. A rearing experiment for the
pre-reproductive period of females revealed that females mated with brachypterous males copulated and oviposited earlier than
females mated with macropterous males. These results indicate that there is a fitness advantage to wing reduction in the males
ofC. saccharivorus in terms of the earlier sexual maturation. 相似文献
2.
Reproductive behaviors related to habitat utilization were studied in males of the damsefly,Mnais nawai, which has two male forms, territorial orange-winged males (nawai) and non-territorial pale-orange-winged males (sahoi), at the upper part of a mountain stream where they partiallycoexist with a related species,Mnais pruinosa, which also has two male forms, territorial orange-winged males (esakii) and non-territorial hyaline-winged males (strigata). These two species showed parapatric distribution; the lower part of the stream was occupied byM. nawai, and the upper part byM. pruinosa. In the present study, cross-matings occurred between bothMnais species, although normal intraspecific matings occurred more frequently than cross-matings. Territorial males of both species copulated
with conspecific females that entered their territory and guarded the ovipositing females, probably to avoid sperm displacement
resulting from subsequent copulations. Severe competition for oviposition sites by territorial males even occurred between
the two species. On the other hand, non-territorial males of both species have alternative mating strategies (including several
tactics such as sneaking, takeover and interception). The possible benefits from conflict among territorial males of both
species is discussed. 相似文献
3.
Tock H. Chua 《Researches on Population Ecology》1992,34(2):285-292
Summary The effect of body size, as measured by the head width, of the femaleBactrocera sp. Malaysian A (kept separately in sexual pairs) on the demographic parameters was investigated in the laboratory under
ambient conditions of 28–30°C, 78–85% RH and natural photoperiod. Body size was shown to influence significantly all the demographic
parameters. The expectation of life of females at eclosion from pupae was respectively for head widths of 1.6, 1.8, 1.9, 2.0
and 2.1 mm: 76.2, 73.4, 73.8, 102.4 and 115.2 days. The mean number of eggs laid per female in its life time was respectively:
86.4±48.7, 181.8±56.1, 229.7±72.6, 364.3±69.4 and 477.5±109.3 which was significantly different from one another (F=3.73,P<0.05) especially the two smaller sizes from the two larger sizes. The regression line for total eggs laid (Y) against head width (X) wasY=785.2X−1208.7 (R
2=0.35,P<0.001). The net reproductive rate (R
0) was respectively 15.8, 34.0, 43.5, 66.9 and 88.8 eggs, while the intrinsic rate of increase (r) was respectivley 0.0435, 0.0538, 0.0670, 0.0665 and 0.0711. The results confirm that for mass rearing purposes, larger females
which produce more offspring are to be preferred. 相似文献
4.
Eiichiro Urano 《Researches on Population Ecology》1985,27(2):393-412
Summary Settlement date, mating status, and breeding success of individually marked great reed warblers,Acrocephalus arundinaceus, were studied during the 1980–84 breeding seasons in Kahokugata, Ishikawa Prefecture, Japan. Twenty-five per cent of the
territorial males were polygynous, of which the majority were bigamous. The settling periods of both sexes were long, extending
for 65 days in males and 49 days in females. About 80% of males and females settled in the first half of the settling period,
and the settlement date of 28–54% males overlapped with that of females. Many of the late settlers were bachelors and the
males which mated earlier tended to be polygynous. The timing of a male's settlement is important in acquiring mates. Fifty-five
per cent of eggs laid were lost before fledging, mainly due to predation. The mean number of fledglings was 3.19 per primary
female, 2.41 per secondary female, and 2.80 per monogamous female. Comparison of the number of fledglings of females which
mated during the same period showed that the presence of another female in the same territory did not adversely affect the
breeding success of either of the polygynous females. Polygynous males have the advantage of decreasing the risk of breeding
failure under high predation pressure. 相似文献
5.
Summary Male and female prairie deermice housed singly from weaning (21 days) until 40 days of age had urine from one of the following
sources applied daily to their nostrils: sexually mature laboratory population males or females, and sexually mature breeder
males or females from our laboratory colony. Other males and females were treated with water. Records were obtained of the
weights of the tests, seminal vesicles and bacula of males and the ovaries and uteri of females at 40 days of age.
The major results of this study were as follow: Female urine from sexually mature and inhibited population or isolated mice
stimulated the development of the male reproductive organs significantly more than water or male urine. Male urine applied
to young males did not differentially affect the weights of their reproductive organs compared with water and thus showed
no inhibition effects.
The reproductive organs of females treated with male urine did not differ significantly in weight from those of females treated
with female urine. Females treated with water developed significantly larger uteri than those treated with urine from sexually
mature population females (P≤0.02), inhibited population females (P<0.001) and inhibited population males (P<0.007). 相似文献
6.
Yosiaki It? 《Researches on Population Ecology》1964,6(1):13-21
Summary To elucidate the basic food requirement of spiders, the important polyphagous predators of rice-plant insect pests, an attempt
was made to measure the respiratory energy loss of fasting spiders,Lycosa pseudoannulata.
Relationship between fresh (y) and dry (x) weights of spiders inhabiting the bottom layer of the rice-plant community was represented by the following allometric equation:y=0.428x
0.872.
The carbon dioxide production by previously fed and unfed females under the dark at 29°C 100% R. H. was measured by a titration
technique. The relationship between fresh body weight and CO2 production by unfed animals could be represented by the equationM=aW
b, M being the CO2 output per individual per day andW the fresh body weight. The constantb, which determines the slope of curve, was 0.808. Respiration of the adult female with 100 mg fresh weight was 1.155±0.250
mg CO2/100 g fresh weight/day or 48.69 mg CO2/g dry weight/day. This value corresponds to 35.81 cal/g fresh weight/day or 150.94 cal/g dry weight/day. Supposing the calorific
content of spiders to be 5820 cal/g dry weight, rate of the respiratory energy loss to total energy of the body was estimated
to be 2.60%. This rate did not strongly contradict with the loss of fresh body weight before and after the measurement.
The metabolic rate showed remarkable fluctuation with changing food supply. The CO2 production of starved individuals decreased to 83.63±16.34% as compared with individuals which were fed before the measurement. 相似文献
7.
Body masses of wild-caught habu,Trimeresurus flavoviridis, were measured with known error range. Habu larger than mature female size had steeper slope in length-mass regression than
smaller individuals. Females outweighed males in most snout-ventlength classes and in early summer. Gravid females outweighed
non-gravid ones by about 20% on the average, but the body mass ranges of the two groups overlapped. Through the body mass
change in mature females, the proportion of gravid females was estimated to be about 0.5. 相似文献
8.
Shefali Begum Ritsuko Tsukuda Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1996,38(2):257-263
The wild crucifers,Rorippa indica andLepidium virginicum, are known to serve as host plants for the diamondback moth (DBM),Plutella xylostella, but they are less suitable than the preferred cultivated cruciferous plant, cabbage, in terms of adult body size and fecundity.
The life history traits and flight activity of DBM adults grown on various host plants were investigated. The adults thus
reared on each host plant were divided into three size groups (small, medium and large). In general, female adults grown on
the wild crucifers were less fecund and lived longer than those reared on cabbage. Flight activity was higher in adults grown
on wild crucifers than in those reared on cabbage. Male adults flew longer than females. Fecundity, longevity, flight activity
and morphometrical characters of adults were positively correlated with pupal weight in individuals reared on the same host
plant. A negative relationship was found between fecundity and flight activity in females of the same size group, but a positive
one was observed in females reared on the same host plant. 相似文献
9.
Reproductive behavior of the foam-nesting treefrog,Rhacophorus arboreus, is described. Oviposition was made either by an amplectant pair (a female, and an amplectant male) alone or by an amplectant
pair and other males (joiners). The snout-vent length of males and females was negatively correlated with the date of the
first appearance in the pond. The period of staying in the pond in males was longer than that in females. Physical body contacts
of other males, and encounter calls by ampletant males were frequently observed before oviposition with joiners. Snout-vent
length of the female and an amplectant male were positively correlated. Encounter calls by amplectant males were likely to
precede movement of females. There was no difference of snout-vent length between amplectant males and joiners. Females moved
the hindlimbs more frequently than males during oviposition. Amplectant males made encounter cells more frequently in oviposition
with joiners, than oviposition without joiners. The patterns of transitions between acts of females and amplectant males were
similar between oviposition with and without joiners. Females more frequently responded to amplectant males than joiners.
Both the duration of a bout of the movements of hindlimbs of females and the interval between the bouts were longer in oviposition
without joiners than that with joiners. The number of the movements per bout in oviposition without joiners was smaller than
that with joiners. Encounter calls by amplectant males during oviposition tended to precede the hindlimb movements of females. 相似文献
10.
Masakazu Shiga 《Researches on Population Ecology》1977,18(2):284-301
Summary Stabilizing mechanism in population ofMalacosoma neustria testacea was investigated in a central part of Japan based on eight year survey.
Population fluctuation in each developmental stage in the experimental field was rather small, i.e., 5.9 times in egg and
85.0 times in female adult. Pupal weight negatively correlated with the densities of 5th instar larvae and prepupae (cocoons)
and correlation coefficient was highly significant in females. Population density was stabilized by density-dependent dispersal
of female moths in preovipositional period. Comparison between fecundity of emerged moths and that of actually oviposited
ones in the experimental field suggested that density-dependent dispersal took place as the result of density-dependent size
variation, i.e., small-sized female months have higher flying ability. This hypothesis was supported by the experiment in
which flying ability of newly emerged female moth was measured. Similar stabilizing mechanism is expected to occur in semelparous
or pro-ovigenic insects.
Contribution Ser. A, No. 64 from Fruit Tree Research Station, Ministry of Agriculture and Forestry, Japan 相似文献
11.
Adult, male white-footed mice (Peromyscus leucopus) were subjected to a variety of social situations ranging from isolation during the 20 day experimental period to constant
contact with both females and other adult males. Contacts included grouping (three or four males per cage) and exposure to
fighters (once daily for 20 minutes). The following measurements were recorded: weights of the body, testes, epididymides,
vesicular glands, vesicular gland tissue (wet and dry), seminal fluid of the vesicular gland, adrenal glands, and baculum;
spermatozoan reserves of the testes and epididymides. Grouping significantly affected both the weight and spermatozoan reserves
of the testes and epididymides, as well as both the tissue and seminal fluid weight of the vesicular glands. The results suggested
a graded effect of all treatments on the reproductive tract. In order of magnitude of the associated response, from none to
greatest, the treatments may be ranked as follows: pairing with females, isolating, handling, fighting, and grouping. All
reproductive parameters measured showed this general ranking, suggesting that the response to the various treatments was similar
and differed only quantitatively. The results further suggested decreased secretion of LH and testosterone, although measurements
of testosterone did not substantiate this conclusion. The lack of significant effects of grouping on adrenal gland weights
strengthened the argument that adrenal involvement is not a necessary adjunct to the suppression of the reproductive tract
in groupedPeromyscus, but the adrenal may be involved if contacts between males result in overt fighting. 相似文献
12.
Takaki Kondo 《Researches on Population Ecology》1982,24(1):85-96
Summary The role of social behavior on the population regulation of the Japanese wood mouse,Apodemus speciosus, was studied in the Ashu Experimental Forest of Kyoto University by monthly trapping and direct observation on the social
behavior at the artificial feeding site. The census was carried out from May to October in 1974 and 1975, and the direct observation
in June, August and October, 1975.
In the study area, the Japanese wood mouse has two breeding seasons in a year: in spring and in autumn. Minimum survival rate
was high in the non-breeding season and low in the breeding season. It was negatively correlated to the number of sexually
active adults in both sexes.
Home ranges of females tended to be mutually exclusive, and female residents prevented the settlement of female immigrants.
On the other hand, home ranges of males overlapped largely and males had a straight social hierarchy. Subordinate males tended
to disappear more often than dominant males did, but male residents did not hinder the settlement of male immigrants. Males
may regulate their number by driving out the subordinate males, while females by spacing behavior.
Contribution from the Laboratory of Animal Ecology, Department of Zoology, Kyoto University, No. 445. 相似文献
13.
Summary Larval growth patterns ofHemipyrellia ligurriens (Calliphoridae) andBoettcherisca formosensis (Sacophagidae) in crowded and uncrowded cultures were compared. Growth of the larvae followed a sigmoid curve. The highest
larval growth rates were 0.33 and 0.36 mg h−1 for uncrowded and crowdedH. ligurriens respectively. The corresponding figures were 2.38 and 1.23 mg h−1 forB. formosensis. Larvae of both species attained maximum weight earlier in crowded cultures than in uncrowded cultures, although the final
weights attained in crowded cultures were less. The earlier period of most rapid growth in both species was interpreted as
a result of intraspecific facilitation at higher larval densities. UncrowdedB. formosensis had a shorter larval to pupal development and an earlier period of most rapid growth than uncrowdedH. ligurriens, suggesting the former may be superior in exploiting carcasses with limiting food. 相似文献
14.
1. | The effects of larval rearing density and species relative proportions on life-history parameters of two necrophagous Diptera,Hemipyrellia ligurriens (Wiedemann) (Calliphoridae) andBoettcherisca formosensis Kirner and Lopes (Sarcophagidae), were investigated in mixed cultures. Larval rearing density had a significant effect on larval to adult survivorship, duration of immature development, adult size and relative performance (measured by the composite index of performance,r′) of both species. However, species relative proportions affected adult size of both flies and the duration of immature development ofB. formosensis only. |
2. | B. formosensis had a higher survivorship thanH. ligurriens in all mixed cultures and showed a similar survivorship pattern to that in pure cultures. By contrast, survivorship ofH. ligurriens was lower in mixed than in pure cultures. |
3. | H. ligurriens adults reared from mixed cultures were smaller than those from pure cultures of comparable density, butB. formosensis adults from pure and mixed cultures were of similar size. |
4. | The results suggest that competition betweenB. formosensis andH. ligurriens larvae was asymmetric and the former was the superior competior. |
5. | At low larval densities in mixed cultures, the presence ofH. ligurriens enhanced the performance (as measured byr′) ofB. formosensis, a consequence of suspected interspecific facilitation of larval growth. |
15.
Yozo Koshiyama Hisaaki Tsumuki Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1996,38(1):51-56
Menida scotti (Puton) males have been shown to transfer secretions from their bulbus ejaculatorius and reservoir of ectodermal accessory
gland to females by mating during hibernation. In the present study, the major components of the secretions were found to
be proteins and lipids. To specify the female organ incorporating the male secretions, a radiotracer experiment in which the
male secretions were labeled by [14C]valine was conducted in nine tissues of females collected in the fall and spring of the hibernation period. Relatively high
radioactivities were detected in the haemolymph and the residual carcass (head, legs, air-sacs, exoskeleton, etc.) in the
fall females, and in CO2 gas evolved and carcasses in the spring females. The radioactivities in the fat body were significantly higher in the fall
mating females than in the spring mating females, and vice versa in the ovary. The radioactivities in six fractions (lipids,
proteins, glycogen, sugars, free amino acids and the residues) were also assayed in the five organs of females that had a
relatively high radioactivity. The highest radioactivity was detected in the protein fraction of the haemolymph in fall and
spring females. There were significant differences in the radioactivities incorporated into the lipid fractions of the carcass
between fall and spring females. 相似文献
16.
Enrico Gandolfi 《Feminist Media Studies》2019,19(3):331-347
This article investigates the cultural mediatization of the relationship between gender and war by looking at the representation and agency of female presence in one of the most popular sagas in video games: Metal Gear Solid. We have specifically focused on the last chapter of the series, Metal Gear Solid V (MGS5) by putting under scrutiny the character of Quiet. The analysis draws upon the rich theoretical corpus of feminist film studies, with reference to two main concepts: the “visual pleasure” by Laura Mulvey and the “female voice” by Kaja Silverman. These analytic tools are employed in order to scrutinize both the visual representation and the design of the game. We argue that MGS5 is a relevant instance of a large part of gaming production that develops a war imagery characterized by (a) the exploitation of women and (b) an employment of female body as a tool to fulfill the visual pleasure of the male gaze. The figure of Quiet, with the oversexualization of her body and the deprivation of her voice, is particularly telling in this respect. Our analysis aims to identify effective solutions in order to think about more inclusive digital games able to address conflictual issues without surrendering to sexism. 相似文献
17.
Summary The populations of native male adult oriental fruit flyDacus dorsalis (Hendel) and artocarpus fruit flyD. umbrosus (F.) in two selected site (BU and SD) were estimated weekly by the capture-recapture technique using live traps baited with
methyl eugenol. In BU where many varieties of fruit trees were grown, the estimated population densities ofD. dorsalis were between 980 and 3100 male flies per ha between May and July, 1984. During the same period, in SD where there were fewer
number and varieties of fruit trees, the estimated population densities were between 300 and 1000 flies per ha. The estimated
population densities ofD. umbrosus over the same period were between 570 and 1290 flies per ha in BU; and between 5 and 95 flies per ha in SD.
Of a total 6828 markedD. dorsalis flies released only one fly (released 6 weeks earlier in BU) was caught in a different site. 相似文献
18.
Toshiya Masumoto Shintaro Nomakuchi Kouji Sawada 《Researches on Population Ecology》1993,35(2):241-250
Summary We investigated how the distribution pattern of eggs and larval on the host plant,Turritus glabra, was influenced by the oviposition behavior of the pierid butterflyAnthocharis scolymus. Females searched for the host plants visually and they frequently approached taller host plants with sparse surrounding
vegetation. After encountering host plants, oviposition behavior of females was independent of host plant characteristics
such as height, density, and type of surrounding vegetation. A female laid eggs singly on a host plants. Most females appeared
to lay their eggs regardless of the presense of eggs on the host plant. Consequently egg and larva tended to be abundant on
conspicuous host plants as measured by height or relative isolation from other plants. However, overcrowding of eggs on an
individual host decreased the survival rate of larvae. 相似文献
19.
Yutaka Sait 《Researches on Population Ecology》1987,29(1):57-71
Summary Experimental observations on the arrenotokous reproductive patterns of two spider mite species (Acari: Tetranychidae), the
long-seta form ofSchizotetranychus celarius (Banks) andTetranychus urticae
Koch, revealed that reproduction of unfertilized females of the former is very differnt from that of the latter. Unfertilized
females ofS. celarius, which has a subsocial life, laid a few eggs and then became inactive. In contrast, the fecundity of unfertilizedT. urticae females was only slightly reduced as compared with fertilized females. Mother-son matings may thus sometimes occur in naturalS. celarius populations.
A two-year field survey revealed that, in the absence of males, overwintering females ofS. celarius occasionally remain unfertilized until early spring. Furthermore, nest foundation observed in late spring indicated that
most of the season's first nests were founded by single females. These two sets of observations strongly suggest that motherson
mating takes places in nature, corresponding to the reproductive trait seen in the experiment.
Mother-son mating inevitably increases the relatedness between nest members. The estimated father's relatedness to its offspring
is extraordinarily high under such condition. The possibility that kin-selection in the long seta-form ofS. celarius led to subsociality, especially paternal care, is suggested.
This study was supported in part by Grant-in-Aid No. 61540468 from the Ministry of Education, Science and Culture, Japan. 相似文献
20.
Summary Effects of starvation on the suryival period and the respiratory rate in adults of a wolf spider,Pardosa astrigera (L. Koch), were investigated. The spiders used were divided into four groups: well-fed, starved and two limited food groups; in the
latter two, each spider was supplied with one leafhopper every second or third day. Adult males and females ofP. astrigera could survive for a long time; 28.8±2.7 days and 54.4±18.9 days, respectively, without any food. The longevities shown here
were 73.8% for males and 78.6% for females of those of well-fed spiders, indicating thatP. astrigera adults have a strong tolerance to starvation. The respiratory rate of well-fed adults showed no tendency to increase or decrease
with their aging; the mean respiratory rates were 4.86×10−4 mg CO2/mg f.w. (fresh body weight)/hr for males and 3.80×10−4 mg CO2/mg f.w./hr for females. The respiratory rates of starved spiders increased during the first two days of starvation but decreased
markedly from the third to the twelfth day, and thereafter retained an almost constant level for each sex. The mean respiratory
rates after the twelfth day of starvation were 2.49×10−4 mg CO2/mg f.w./hr for males and 2.76×10−4 mg CO2/mg f.w./hr for females; these values were respectively 48.4% and 63.0% of those prior to starvation. The fresh body weight
of starved spiders decreased linearly with time but the rate was small. The respiratory rates of the limited food groups tended
to decline with time and thereby their weight losses were minimized. The decrease in the respiratory rate under starvation
was considered not to be due to spider exhaustion or senescence but due to an intrinsic change in behaviour and/or metabolism,
because when the spiders were supplied with ample food for five days after starvation, the respiratory rate and the body weight
rapidly recovered to near the levels prior to starvation. It is suggested that starved spiders use a higher ratio of fat as
catabolic substrate than normally fed or satiated ones. Feeding strategies of poikilo-therm predators are discussed.
This work was partially supported by the Nippon Life Insurance Foundation Research Fund and Grant-in-Aid (No. 56480039) from
the Ministry of Education, Science and Culture, Japan. 相似文献