共查询到20条相似文献,搜索用时 31 毫秒
1.
Takayoshi Nishida 《Researches on Population Ecology》1989,31(2):211-224
Summary The mating system of the coreid bug,Colpula lativentris, was studied, and compared with those in other hemipteran bugs. Copulating pairs formed a compact aggregation on a shoot
of the Japanese knotweed,Polygonum cuspidatum, and there continued copulation and feeding for more than one day. This aggregation was defined as “a shoot aggregation”.
Other than this aggregation composed of copulating pairs, there were loose aggregations on the ground composed of males and
females not in copula. This loose aggregation was defined as “a ground aggregation”. Males searched for receptive females
mostly in a ground aggregation.
Sex ratio was constant and variance of sex ratio was also very small in any shoot aggregations and in large ground aggregations.
However, in small ground aggregations, sex ratio was strongly male biased and variance of sex ratio was fairly large. This
was because receptive females tended to leave a small ground aggregation and join a large one. These results suggest that
a male can attain higher mating success in a larger ground aggregation. 相似文献
2.
Summary Reproductive compatibility was studied among populations of different types of the citrus red mite,Panonychus citri (McGregor), i.e., the diapausing type from pear (DP), the non-diapausing type from citrus (C) and that from pear (NP).
Copulation was also observed between mates of different types (DP and C). Only in crosses between C ♀ and DP ♂, was copulation
occasionally broken off prematurely; duration of copulation varied considerably between pairs and the average duration was
much shorter than that between DP ♀ and C ♂ and than that in crosses between mates of the same types.
No F1 adult females were produced at all from crosses between DP and C, showing that there was a complete reproductive isolation
between the two types. There was a significant reciprocal difference in the egg hatchability and survival rate of immatures
in the F1 progeny; mortality in the eggs and that in the immature stage were significantly higher in crosses between DP ♀ and C ♂,
as compared to those in the reciprocal cross. This suggested that fertilization may have occurred in the former cross, whereas
it seemed that eggs were not fertilized in crosses between the C ♀ and DP ♂.
The NP was compatible with the C, whereas it was completely incompatible with the DP. Thus, there was a complete reproductive
incompatibility between the diapausing and non-diapausing type ofP. citri.
This work was supported in part by Grant-in-Aid No. 60560049 from the Ministry of Education, Science and Culture, Japan. 相似文献
3.
Summary The biology of the veliid bugM. d. atrolineata, its predatory behavior, and the effects of plural hunting were studied to evaluate its role as a predator of the brown planthopperNilaparvata lugens in the Philippines. The probability of planthoppers falling onto the water surface and provision of habitat continuity was
measured by a sticky trap placed at the base of rice hills in a greenhouse and in paddy fields.
The developmental period of immature stages combined was 21 days. If given prey, females laid 25 eggs on the average during
an adult life span of 18 days. Starved adults could survive for only 3–5 days.
The functional response to prey density was sigmoid, and the maximum number of prey killed was 7 per day. Prey feeding was
completed in 12–36 min. The percentage of successful prey attacks averaged 5–8%, decreasing with higher (and larger) developmental.
stages of prey, but adult prey were found the soonest. Plural hunting increased the probability of capturing prey by as much
as 2.5 times that by individual hunting.
Late-instar nymphs, which may be more active, fell from rice hills in a greenhouse more than early-instar nymphs, and the
number falling increased with density. In the field the percentage of planthoppers falling to the water in 1 day varied considerably,
from 1% for nymphs in one field to 67% for adults in another field.
On the basis of work described above and given the high density of veliid predators in flooded paddy fields of tropical Asia,M. d. atrolineata is considered one of the most important natural enemies of the brown planthopper. 相似文献
4.
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
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.
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
7.
Myron P. Zalucki 《Researches on Population Ecology》1981,23(2):318-327
Summary The effects of age and weather conditions on egg laying inD. plexippus were determined for caged females. Age (measured in physiological time), temperature and solar radiation influence egg laying
in this species of butterfly. An algorithm taking these factors into account in presented and accounts for 88% of the daily
variation in egg laying. CagedD. plexippus begin to lay eggs six—seven days after emergence, peak egg production (about 60 eggs/♀) occurs about 15 days later. Females
continue to lay eggs throughout their adult life, which in a flight cage was about 40 days. This egg laying pattern is compared
with other published fecundity schedules. The effect and importance of a female being prevented from laying her eggs, on her
life-time egg production, is also discussed. 相似文献
8.
The thimbleberry aphid,Masonaphis maxima (Mason) lives on patches of plants that support 3,4 or 5 generations depending on site and weather. The life cycle requires
sexual females and males to produce overwintering eggs. The eggs hatch in the spring to produce the first ’fundatrix’ generation;
subsequent generations are produced parthenogenically. Males and other morphs are produced by wingless virginoparae, but sexual
females are produced by ’gynoparae’, a winged morph that is specialized to produce only sexual females. The fundatrices have
no indication of the number of generations that the plants will support in the current year. There are two fundatrix types
that coexist in different ratios depending on the number of generations supported by the patch the previous year. One type
produces sexual females in generations 3 and 5, and males in generations 4 and 5; the other type produces sexual females in
generations 4 and 5, and males in generations 3, 4 and 5. The dimorphism adapts the aphid to its heterogeneous and somewhat
unpredictable environment. The role of sex in the maintenance of the dimorphism is discussed. This is the first report of
fundatrix polymorphism and consequent differential sex expression in aphids. 相似文献
9.
K. Tanaka T. Watanabe H. Higuchi K. Miyamoto Y. Yusa T. Kiyonaga H. Kiyota Y. Suzuki T. Wada 《Researches on Population Ecology》1999,41(3):253-262
To examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint-marked snails of
15–20 mm shell height into 12 enclosures (pens) of 16 m2 at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent
of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density
dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg
masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than
3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however,
higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density.
The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult
density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering
period, was not significantly different among density treatments. These results suggest that snail density after the overwintering
period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate
the population of P. canaliculata in paddies.
Received: October 23, 1998 / Accepted: July 16, 1999 相似文献
10.
The lifetime mating frequency of female butterflies is believed tobe dependent on the reproductive status of the males which
they have mated. This report assesses those status usingPieris rapae L. Multiple mating females mated males with a short time interval after the last mating or males with many mating records.
Such males, like small ones, produced small spermatophores during copulation, which may have resulted in high mating frequency
of those females. The males with short time interval after the last mating or those with many mating records also showed a
long mating duration. Alternative interpretations of the adaptive significance of this behavior for males are discussed. 相似文献
11.
Reproductive success, copulation success, and mating success were measured for a population of male dragonflies,Orthetrum japonicum. Copulation success explained the greatest variation in reproductive success. The proportion of copulations followed by oviposition
was positively correlated with the number of oviposited eggs per mating. Directional selection on four morphological characters
was estimated. The effect of selection on correlated traits was comparable to that of direct selection. Directional selection
varied between traits and between episodes in a single trait. The probability that the observed directional selection on the
four morphological traits was expected under the condition of the selective neutrality of traits was not smaller than 5%. 相似文献
12.
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
13.
Takayoshi Nishida 《Researches on Population Ecology》1994,36(2):209-218
Spatio-temporal variations of lifetime reproductive succes (LRS) of both male and female individuals of a coreid bugColpula lativentris were measured and analyzed using the multiple regression method of Arnold and Wade (1984a, b). The standardized variance
of LRS was larger in males than that in females as males often to secure mates for a long period whereas females could easily
find mates and oviposit simply dependent on ovarial maturation. LRS was partitioned into 4 consecutive fitness components:
(1) reproductive lifespan, (2) copulating efficiency, (3) guarding efficiency (for males) or oviposition efficiency (for females),
and (4) number of eggs per clutch. In males copulating efficiency was the largest determining factor of LRS, whereas in females
reproductive lifespan was the most important factor. Such tendencies were stable on both a yearly and local basis. Patterns
of relative contribution of natural selection (reproductive lifespan and number of eggs per clutch) and sexual selection (copulating
efficiency and guarding or oviposition efficiency) to LRS were clearly different between males and females. This sexual difference
is, at least to some extent, thought to be brought about by sexual selection among males for mating opportunity, though no
physical fight was observed among males. Directional selection on body length was found only in relation to the clutch size
of females because large females tended to lay larger clutches. No significant directional selection was found in other fitness
components. 相似文献
14.
Masaya Matsumura 《Researches on Population Ecology》1996,38(1):19-25
A population census was conducted to describe the effects of the growth stage of rice on the population dynamics ofS. furcifera, in particular, on immigration, seasonal abundance, population growth rate, and wing-form expression. The number of immigrants
was highest on rice plants 17 to 30 days after transplanting (DAT), which suggested that immigrants prefer to settle or remain
more on rice plants at the tillering stage (approximately 20–30 DAT). Population growth rate from immigration to the 1st generation
decreased with an increase in rice plant age. In contrast, population growth rate from the 1st to 2nd generation was not influenced
by rice plant age and was negatively density-dependent. The percentage of macropters (flyers) was positively related to the
growth stage of rice when rice was in the vegetative or early part of the reproductive stage, and reached 100% at about 10
days before heading (booting stage). Threafter, most adult females molted into macropters regardless of population density.
The roles of host plant age and crowding effect on the population dynamics ofS. furcifera are discussed. 相似文献
15.
Tomoyuki Kameyama Rhett Harrison Norio Yamamura 《Researches on Population Ecology》1999,41(3):243-252
The relationship between fig trees and their pollinator wasps is a well-known example of species-specific obligate mutualism.
In this article we present a stochastic model of this mutualistic system, referring to data on a dioecious fig (Ficus schwarzii) in Borneo, and examine the conditions for the persistence of a wasp population for a given period. (1) When the average
duration of the flowering interval of fig trees is short, even a small fig population can sustain a wasp population successfully.
A population whose average period of flowering cycle is half that of another population can sustain a wasp population with
a number of trees less than half of the other population. (2) The wasp survival rate (WSR) is higher when (a) the variation
of the interval periods of fig flowering is smaller, (b) the fig population size is larger, and (c) figs can prolong their
receptivity to wait for a wasp if no wasps are available. (3) WSR is predictable from the average proportion of the fig's
receptive phases, in which wasps are available, to their total receptive phases. (4) The persistence period of a wasp population
increases exponentially with the number of fig trees. Based on these results we propose a new hypothesis, as a possible scenario,
on the evolution of dioecy from monoecy in Ficus.
Received: November 13, 1998 / Accepted: July 14, 1999 相似文献
16.
Koh-ichi Takakura 《Researches on Population Ecology》1999,41(3):269-273
Mating behavior and the male's contribution to female fecundity were studied in the bean weevil Bruchidius dorsalis (Fahraeus) (Coleoptera: Bruchidae) in comparison with two other species, Callosobruchus chinensis (which infests stored beans) and Kytorhinus sharpianus (which feeds on wild legumes). Only females of B. dorsalis showed multiple mating and characteristic precopulatory behavior that appeared to solicit the male's nutritious secretion.
In contrast, all females of the other two species did not copulate multiply and did not show such precopulatory behavior.
In B. dorsalis, the decrement of male body weight just after copulation indicated that seminal fluid weighing as much as approximately 7%
of the male's body weight was transferred to the female. Fecundity was more than eight times higher in females that had copulated
ten times than in females that had copulated only once, indicating that males paid most of the nutritional cost of egg production.
These facts suggest that the sex role is reversed in B. dorsalis.
Received: May 22, 1998 / Accepted: July 19, 1999 相似文献
17.
Summary The present paper dealt with the sequential changes of the distribution pattern of apterous females aphid populations, that
were artificially settled at the beginning on the experimental barley ‘field’. The aphids were settled at random or even with
a fixed denisty per plant. For five or six days after the settling, the number of individuals followed the negative binomial
distributions in all cases while the parametersk andp were varying. The estimated values ofk were rather small for the first one week after the settling, which may suggest that the number of moving aphids between plants
was relatively small and the degree of concentration expressing the intrinsic increase was high. After that, as the number
of individuals increased, the number of moving aphids between plants would be considered to be increased. It was found that
with the lapse of time the degree of concentration decreased ork became larger.
The distribution of aphids per blade in a plant was also described briefly. 相似文献
18.
Yoichi Shirai 《Researches on Population Ecology》1995,37(2):269-277
Plutella xylostella in the temperate zone shows a clear seasonal change in adult body size. In the laboratory, large and small moths were produced
during immature stages at 15°C and 25°C, respectively. These moths were then used to evaluate longevity, age-specific flight
ability, flight ability of mated and unmated females, and the influence of flight experience on the subsequent reproductive
success. The large moths lived longer and displayed a greater flight ability over 3 weeks. Irrespective of body size, unmated
females flew for a longer time than mated females, and flight experience affected their subsequent reproductive success. Females
of both sizes mated and laid eggs soon after emergence, without any obvious pre-reproductive period. More flight experience
did not delay oviposition, but did reduce egg production. It is likely that large moths with a longer adult life span and
greater flight ability are better fitted for long-distance flight and more fecund than small ones. These experimental results
may explain why long-distance migration ofP. xylostella is mostly seen during cool seasons, when relatively large moths with long forewing appear in the field. 相似文献
19.
Summary Population behaviour of adults and 5th-instar nymphs ofNezara viridula L. was analysed by means of the marking-and-recapture method in an early-planted paddy field. The field contained five varieties
of rice which differend in growth states. It was estimated that a total of more, than 7,000 adults of the first generation,
in which at least 3,000 were females, invaded the field from early July to middle August. Egg-mass census data, however, indicated
that only 10 per cent or less of the females participated in egg-laying. This was largely due to the, low rate of adult survival.
The adults preferred younger plants, for both feeding and oviposition.
The method described byIwao
et al. (1966) permitted estimate that 3,300–3,400 of the 5 th-instar nymphs and 1,100–1,200 of the adults of the second generation
were produced from 298 egg-masses (25, 700 eggs); while 95–6 per cent of the individuals were thought to have died before
reaching adulthood. Most of the 5 th-instar nymphs moved less than 4 m in three days as long as the condition of food plants
remained suitable, but they tended to move more towards younger plants when those on which they lived became too mature. The
apparent survival rate of the second generation adults was very low, probably due both to a rapid emigration and a high mortality
of newly-emerged adults. 相似文献
20.
Contest competition inDrosophila subobscura 总被引:1,自引:0,他引:1
T. H. Jones ?. Langefors M. B. Bonsall M. P. Hassell 《Researches on Population Ecology》1996,38(1):105-110
The role of larval intraspecific competition in laboratory populations ofDrosophila subobscura was investigated. Mortality is density-independent during the first 3 days after hatching but becomes density dependent as
development proceeds to pupation. Although total biomass per patch was independent of initial egg density, competition betweenDrosophila larvae leads to the formation of smaller pupae. This resulted in a population that was dominated by suppressed individuals.
Development rate ofD. subobscura larvae was not affected by high larval densities. Smaller pupae give rise to females with fewer eggs in their ovarioles.
A simple simulation model, predicting the effects of intraspecific competition on the fecundity of the nextDrosophila generation is described. 相似文献