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1.
Preference and performance linkage in aPhyllocolpa sawfly on the willow,Salix miyabeana, on Hokkaido
A leaf-folding sawfly in the genusPhyllocolpa (Hymenoptera: Tenthredinidae) attackingSalix miyabeana (Salicaceae) was studied near Sapporo, Hokkaido, along the Ishikari River in 1993. Host plant individuals were young trees
4–7 years old which were growing rapidly, producing some long shoots with large leaves. On a gradient of shoot length classes
from 0–5 cm long to over 80 cm long, shoots were much more abundant in the shorter shoot length classes. However, attacks
by ovipositing females increased as shoot length increase from 0 attacks on the shortest shoots to 5.17 attacks per shoot
on the longest shoots. The frequency of attack per leaf increased from 0 to 0.13 over the same range of shoot lengths. This
pattern of attack resulted in a high frequency of larval establishment in feeding sites, between 0.96 and 1.00, in all attacked
shoot length categories. However, probability of survival to a late instar larva increased with shoot length and corresponded
to the attack pattern, indicating a preference-performance linkage between female ovipositional decisions and larval survival.
The patterns found for thisPhyllocolpa species are similar for galling sawflies in North America and Europe, especially in the genusEuura, members of which make stem, bud and leaf midrib galls. Extending the pattern to aPhyllocolpa species broadens identification of pattern and ultimately the generality of the emerging theory on populations of galling
sawflies. 相似文献
2.
Summary A statistical and graphic study is presented of the wastage of eggs byVenturia (=Nemeritis) canescens when searching singly and in groups of 10 among hosts at four different host densities in laboratory universes as described
byHuffaker andMatsumoto (preceding paper of this journal). The host insect was the fluour mothAnagasta kühniella and the host densities used were 10, 30, 100 and 200 per universe. Intensity of egg wastage due to superparasitim varied
significantly according to host density, and between the two parasite densities employed, 1 and 10, using bothF-tests and chi-square tests. Plots ofk-factor analysis on this egg wastage showed high negative correlations with host density, and the raw data for single parasites
was well represented by a parabola while that for the grouped parasites departed from this relationship only at the lowest
host density.
These studies were conducted as a part of a general investigation into the processes operating in the population dynamics
of arthropods under grants from the National Institutes of Health, U. S. Public Health Service (#A10-1611), and the National
Science Foundation and Environmental Protection Agency (NSF DEB7504223) to the University of California. The findings, opinions
and recommendations expressed herein are those of the authors and not necessarily those of the University of California, the
National Institutes of Health, the National Science Foundation or the Environmental Protection Agency. 相似文献
3.
Syuniti Iwao 《Researches on Population Ecology》1970,12(1):100-110
Summary The contagiousness in the operation of mortality processes on the colonies of the western tent caterpillar,Malacosoma californicum pluviale, was analyzed from two different aspects: successive changes in the frequency distribution of the number of surviving individuals
per colony in the course of development, and the distribution pattern of the individuals killed by some biotic mortality factors.
Also, for a tachinid parasite,Tachinomyia similis, the analysis was made on the egg-laying pattern on colonies as well as on individual larvae. The methods of these analyses
were all based on the relation of mean crowding (m) on mean
.
A braconid parasite,Rogas sp., tended to kill few individuals together once it attacked a colony, but its effect on host colonies was rather equivalent
to the random removal of individuals from all the colonies. Diseases in the late-stage larvae before cocooning was contagious
in their action. Nuclear polyhedrosis virus seemed to have no basic contagiousness in its action, but it caused highly contagious
distribution of deaths among the colonies when its average incidence was high. A spore-formingBacillus had a tendency to kill several individuals once it appeared in a colony, but the distribution of its incidence (no. of times
it appeared per colony) was considered to be nearly at random.
The female ofTachinomyia tended to lay more than one egg successively on the same colony. It also attacked individual larvae with a definite tendency
for aggregation, which seemed to be resulted from the parasite’s preference to large hosts. When the number of eggs laid on
prefered hosts exceeded a certain threshold, however, the fly seemed to change its attention to less attractive, smaller individuals. 相似文献
4.
T. H. Chua 《Researches on Population Ecology》1977,19(1):125-139
Summary Studies on populations ofBrevicoryne brassicae (L.), its parasites and hyperparasites were carried out by actual counting in the sprouts field and by sticky and water traps.B. brassicae was found to be attacked by one primary parasite,Diaretiella rapae (McIntosh), which in turn is parasitized byAlloxysta brassicae (Ashm.),Asaphes vulgaris
Walker,A. suspensus (Nees),Pachyneuron minutissimum (F?rster) andDendrocerus carpenterii (Curtis). The aphid population in the field was started by immigrant alates which were found flying too early to be synchronized
with the sprouts plants. SimilarlyD. rapae was not synchronized with the aphids although many individuals could have been carried into a plot through parasitized immigrant
alates, of which less than 30% were found parasitized. Because of high hyperparasitism (especially byA. brassicae)D. rapae was not able to maintain a high rate of parasitism to curb the aphid population growth. The maximum percentage mummies being
27.8%, while the maximum, percentage parasitism being 56.6% recorded only during the early 1974 season (mean=12.9%). The decline
of aphid population from September onwards was largely due to the cold weather, Syrphid predation and occasionally fungal
attack. The high rate of hyperparasitism byA. brassicae is attributed to its better synchronization withD. rapae. The mean percentage of parasite that emerged from mummies collected during 1973–74 wereD. rapae 31.3%,A. brassicae 64.3%,A. vulgaris andA. suspensus 4.3%,D. carpenterii 0.2% andP. minutissimum 0.1%. 相似文献
5.
Tock H. Chua 《Researches on Population Ecology》1979,20(2):179-187
Summary The searching efficiencies of a primary parasite (Diaeretiella rapae (McIntosh)) and a hyperparasite (Alloxysta brassicae (Ash.)) were investigated and compared. In both species, at all parasite densities, there was a curvilinear relationship (P<0.001) between the number of hosts parasitised and the host density. A linear regression (loga=logQ−m logP) was fitted for log area of discovery against log parasite density (P<0.001). The area of discovery for its immediate (i.e. primary) host (viz.Diaeretiella for the hyperparasite and aphid forDiaeretiella) is lower in the hyperparasite than in the primary parasite. InDiaeretialla both the searching efficiency and the mutual interference constant increased (but not significantly,P>0.05) in the presence of its males. 相似文献
6.
Summary The functional response ofPseudogonatopus flavifemur E & H (Hym., Dryinidae) was investigated by offering hosts (brown planthopper) at densities ranging from 8 to 160 per cage.
The response curve was found to be sigmoid, i. e.Holling's (1959) Type III curve. In experiments involving 310 hosts per cage distributed unevenly in 5 densities (10, 20, 40, 80
and 160 per hill), and a different female parasite density each time (viz. 1, 2, 4, 8 or 16 per cage), the behavioral response
was described well by the “random predator equation” ofRoyama (1971) andRoger (1972), which is a convex exponential curve. The area of discovery (a) decreased with an increase in female parasite density (P), and the relationship was described by the equation: loga=−1.0099−0.3638 logP. There was an apparent increase in handling time per host as the number of female parasites increased. Superparasitism, a
rare phenomenon under natural conditions, was often observed in the laboratory. The potential ofP. flavifemur as a biocontrol agent of the brown planthopper is discussed. 相似文献
7.
Makoto Kat? 《Researches on Population Ecology》1984,26(1):84-96
Summary The mining pattern of the honeysuckle leaf-minerPhytomyza lonicerae which feeds onLonicera gracilipes was analyzed with special reference to the avoidance of parasitoids' attacks. The leaf-miner makes the linear mine with branches
and crosses by turning and branching, off the backtracking mine. Both average numbers of turnings and branchings were about
4. The speed of mining was 1.5 times faster in backtracking than in advancing. The mine width increased as the mining larva
grew and total volume of consumed plant tissue was nearly constant independent of variability of the number of turnings and
other characteristics of the mine. The majority of larval mortality were due to attacks by parasitoid wasps (Chrysochairs pentheus andDiglyphus minoeus), which locate the present position of leaf-miners, by tracing mine tracks, and wasps attack leaf-miners at a higher rate
in backtracking than in advancing. The adaptive significance of branching and crossing by leaf-miners was discussed in terms
of the reduction of parasitoids' attacks. 相似文献
8.
K. L. Heong 《Researches on Population Ecology》1981,23(1):177-191
Summary The functional response parameters of the parasitoid,Anisopteromalus calandrae (Howard) to the third instar, the fourth instar and the pupae ofCallosobruchus maculatus (F.) were estimated from the Random Parasitoid Equation. By modifying this equation for a two host situation and using the
parameters estimated above, a no switch model could be obtained. This model was then used to test for switching. In the preference
experiments where two stages of the host were presented to the female parasitoid, a definite preference for the fourth instar
followed by the pupa and the third instar, respectively was shown. There was, however, no evidence of switching. There was
also no evidence that the data fitted the no switch models which suggests that when the parasitoid is searching in an environment
with two or more hosts, its searching behaviour is more complex. 相似文献
9.
Takao Itino 《Researches on Population Ecology》1986,28(2):185-199
Summary I compared life tables between the solitary eumenid waspAnterhynchium flavomarginatum
Smith and the subsocial eumenid waspOrancistrocerus drewseni
Saussure in Kyoto, Japan, during 1980–1983. The subsocial eumenid is parthenogenetic in this study area. There were 9 identified mortality
factors in the solitary eumenid and 7 in the subsocial eumenid, 6 of which were common to the two eumenids. The important
differences of mortality between the two eumenids were seen in the egg, larval, and prepupal stages. In the egg stage, mortality
by the phorid flyMegaselia sp. was much lower in the subsocial eumenid (1.4%) than in the solitary eumenid (15.0%) likely because of the matenal care
of the subsocial eumenid (progressive provisioning and other related behavior), which reduced predation pressure. In the larval
stage, mortality by the miltogrammine flyAmobia distorta was also lower in the subsocial eumenid (8.1%) than in the solitary eumenid (23.8%) also probably because of the maternal
care of the subsocial eumenid. A comparison of mortality in the two eumenids between the stable, long continuing natural nest
sites and the additional temporal ones showed that the phorid fly remained near its birth place and parasitized stable nest
sites. The miltogrammine fly followed returning eumenid wasps and parasitized those nest sites that have a high host density.
In the prepupal stage, mortality by endogenous death was higher in the subsocial eumenid than in the solitary eumenid. Mortality
due to the rhipiphorid beetle was also higher in the subsocial eumenid probably due to more frequent flower-visits by the
subsocial eumenid.
The defense mechanism of the subsocial eumenid was discussed in relation to the evolution of subsociality.
Contribution to the ecological studies of the eumenid wasps. I. 相似文献
10.
Summary We studied the stopping rule obeyed by the female parasitoid,Chrysocharis pentheus, in deciding when to leave the leaflet on which she is searching for larvae ofPhytomyza ranunculi. She seemed not to employ some stopping rules that have been suggested; i.e., a fixed-number rule and a fixed-time rule and
others. The stopping model formulated forDapsilarthra rufiventris parasitic on the same host species fitted well to the results. The model assumes that the searching female will deposit a
marking pheromone on the leaflet at a rate proportional to the search speed and will leave the leaflet when the amount of
the pheromone that has accumulated on the leaflet reaches the threshold,L. In this model,L denotes the amount of search effort spent on the leaflet. A comparison of the observed results with the predictions from
the model suggested thatL increased markedly at the first encounter with the mine (host), but less at later encounters.C. pentheus appears to employ a mixed strategy of a fixed search-effort and an area-concentrated search. This would confer an adaptive
advantage in foraging forP. ranunculi larvae, which are distributed in clumps among leaflets in the field. 相似文献
11.
T. S. Bellows Jr. 《Researches on Population Ecology》1985,27(1):55-64
Summary The effects of host age on parasitoid reproductive capacity are studied using the pteromalid parasitoidLariophagus distinguendus
F?rster and its bruchid hosts,Callosobruchus chinensis (L.) andC. maculatus (F.). A series of experiments were performed to investigate relationships between age and size of host parasitized and the
developmental period of pre-imaginal progeny, sex ratio, female size, longevity, fecundity and oviposition rate. There was
no effect of host size on preimaginal parasitoid developmental period. Sex ratio varied from less than 5% females from young
(small) hosts to 60% females from mature (large) hosts. Adult size, female longevity, fecundity, and oviposition rate were
also positively related to host age. Females provided mature hosts lived longer than those provided either young hosts or
no hosts, possibly because of an increased ability to host-feed from the larger hosts. The implications of these findings
to parasitoid population reproductive capacity and host-parasitoid synchrony are discussed. 相似文献
12.
Takayuki Ohgushi 《Researches on Population Ecology》1988,30(1):57-68
Summary The relationships between egg predation of an herbivorous lady beetleEpilachna niponica (Lewis) and its predator, the earwigAnechura harmandi (Burr), were examined in both time and space. In spite of little annual, changes in egg densities, egg mortality due to predation
varied considerably. There was no, clear relationship between the earwig density and the proportionate predation over the
five years. The seasonal occurrence of earwig nymphs on thistle plants, however, was closely synchronized with that of egg
predation. Predator attacks on the beetle occurred in a time-restricted manner. Thus, later cohorts mostly escape from heavy
predatory pressure. No spatially density-depent egg predation was detected at the level of either thistle plants or thistle
patches. Furthermore, there was no indication of aggregative behaviour of the earwig in response to local egg density. The
earwig density was more likely to be associated with particular localities with sandy deposits available for its nest site. 相似文献
13.
Summary Intraspecies competition in a field population ofGregopimpla himalayensis (Hym.: Ichneumonidae) parasitic on the prepupae ofMalacosoma neustria testacea (Lep.: Lasiocampidae) was investigated.
The parasite oviposits the sufficient number of progeny (5 individuals/0.1 g dry weight of host) to exhaust a single host
in a single attack. However, at the intensity less than 22–26 individuals/0.1 g d.w. of host, all individuals can emerge,
i.e. density-dependent mortality does not occur. Within this range of intensity, survival of parasite larvae is guaranteed
by diminution in body size and decreasing sex ratio. In contrast, total biomass of parasites showed a peak at 5 individuals/0.1
g d.w. of host at which a single host is exhausted.
Above the intensity of 22–26, extraordinary minute individuals appeared and they died before maturation.
If intraspecies competition play a role in regulation ofG. himalayensis population in the field, the process is usually not through density-dependent mortality but through decreasing reproductive
rate caused by decrease in the sex ratio, adult longevity and fecundity.
Contribution Ser. 2, No. 275. Entomological Laboratory, Faculty of Agriculture, Kyushu University. 相似文献
14.
Tuyosi Sugimoto Oscar P. J. M. Minkenberg Junji Takabayashi Marcel Dicke Joop C. van Lenteren 《Researches on Population Ecology》1990,32(2):381-389
Summary We studied the rules used by the female parasitoid,Dacnusa sibirica Telenga (Hymenoptera: Braconidae), for deciding when to leave a tomato leaflet on which she is searching for larvae of the
leafminer,Liriomyza bryoniae Kalt. (Diptera: Agromyzidae). Females would deposit a marking pheromone on the leaflet and would leave the leaflet when the
amount of the pheromone accumulated to the thresholdL, which is proportional to the amount of search effort on the leaflet.L appears to increase with host density since it rises after every encounter with a host (or mine).D. sibirica would employ an area-concentrated search, which is advantageous in foraging for hosts showing a clumped distribution. 相似文献
15.
Summary A series of experiments were carried out with the endophagous egg parasiteTelenomus fariai on its hostTriatoma phyllosoma pallidipennis to determine the possible role of intraspecific competition by the parasite progeny in population regulation of the parasite.
Eight parasite densities (1, 3, 5, 10, 20, 30, 40, and 50 individuals per vial) were used, and the design of sequentially
sacrificed replicates applied. Survivorship curves for each density indicated smaller number of progeny per host at higher
densities, and the shapes of the curves suggested a relatively early mortality process.Morris' linear regression technique for determining within-generation density-dependence was used, and the results showed that only
larval mortality could be identified as density dependent. The same technique applied within the larval stage proved that
only mortality of larvae in their second, third, and fourth day of development were responsible for population regulation.
The applicability of the technique, as well as the relevance of the results for natural population, is discussed. 相似文献
16.
Ei'ichi Shibata 《Researches on Population Ecology》1986,28(2):253-266
Summary Adult populations of the sugi bark borer,Semanotus japonicus
Lacordaire, which attacks the trunks of Japanese cedar and cypress, were studied in two cedar stands in 1981 and 1984, using a band-trapping
method developed by the author.
Adults began to emerge and fly earlier in 1981 than in 1984 because of the higher temperature after hibernation in 1981. Population
size wasestimated by a markrelease-recapture method. The daily survival rate ranged from 0.86 to 0.92 and the mean longevity
from 7.0 to 11.9 days. Females were fewer than males throughout the season, especially early in the flight period, because
males consistently emerged earlier. The mean distances traversed among the cedar trees were 9.2 m for males and 16.3 m for
females; maximum dispersal was 79.5 m for males, 149.5 m for females. There are two different patterns in their dispersal
movement: the small-scale movement which consists of walking at cool temperatures and large-scale flight at warm temperatures.
Adults of this species are somewhat sluggish and between-tree movement is infrequent. This lack of movement resulted in a
contagious distribution pattern of adults. 相似文献
17.
Summary Functional responses of the wolf spider,Pardosa pseudoannulata (Boesenberg et Strand) attacking the rice brown planthopper,Nilaparvata lugens (St?l.), and the mirid predatorCyrtorhinus lividipennis Reuter were both those of Holling Type II. The attack rate was higher and handling time lower forC. lividipennis. However, when caged with the two prey, the wolf spider showed a significant preference forN. lugens at a lower prey proportion. Proportions of prey attacked were significantly different from the expected ratios of prey available
as well as from the predicted preferences derived from the functional response parameters. As proportions ofN. lugens attacked changed from greater to less than expected as the proportions ofN. lugens available increased, a “reverse switch” behaviour seems to be evident. 相似文献
18.
Mun Il Ryoo 《Researches on Population Ecology》1986,28(1):17-26
Summary The basic components of the predation ofPhytoseiulus persimilis
Athias-Henriot feeding upon eggs ofTetranychus urticae
Koch were studied in an open system where the predator could disperse freely.
The type of the functional response of the predator to the density of its prey was the same as that studied so far in a closed
system, i.e.,Holling's Type 2. The search rate of the predator, however, was much lower in comparison with the result from a closed system. The
oviposition of the predator per day was only weakly related to prey densities higher than 10 per leaf disc. But the emigration
rate was inversely dependent upon the initial prey density up to 60 per leaf disc. The searching behaviour of the predator
was influenced by both the web density spun byT. urticae and the density of the prey: the predator searched for its prey intensively only after it had contact with web. Mutual interference
was observed in prey consumption, but not in the emigration rate. The emigration rate was largely dependent upon the prey
density available per predator. 相似文献
19.
Summary Experimental results, and interpretation, are presented which relate to oviposition behaviour in four species of parasitic
wasp (Hymenoptera: Chalcidoidea). All lay their eggs in pupae of the common house fly (Musca domestica) and of other flies associated with man. Probability models suggested byD. J. Daley for describing the avoidance of superparasitism are used to analyse the data. Certain of the models considered by previous
authors appear as specieal cases. A satisfactory fit was obtained either by assuming a fixed probability of oviposition in
an already parasitised pupa, or by using a model motivated by supposing that a female will tolerate without oviposition some
fixed number of visits to already parasitised pupae. A third model was considered which makes the probability depend on the
number of previous ovipositions in the pupae now visited. In all four species the presence of other females (with parasite:
host ratio unchanged) increased the probability of oviposition upon encountering an already parasitised pupa. In the presence
of other femalesSpalangia endius laid an increased number of eggs, whereas the other three species laid fewer eggs. 相似文献
20.
Wolbachia bacteria are obligatory intracellular parasites of arthropods and have been detected in about 70 species of parasitic wasps
and three parasitoid flies. Wolbachia are transmitted cytoplasmically (maternally) and modify host reproduction in different ways to enhance their own transmission:
parthenogenesis induction (PI), cytoplasmic incompatibility (CI), or feminization (F) of genetic males. Only PI and CI are
known in parasitoids. PI-Wolbachia cause thelytoky in otherwise arrhenotokous parasitoids by generating diploid (rather than haploid) unfertilized wasp eggs.
CI-Wolbachia cause incompatibility of crosses between infected males and uninfected females because the paternally derived chromosomes
fail to decondense and are destroyed after syngamy. More complex situations arise when hosts harbor multiple infections, which
can lead to bidirectional incompatibility and may be involved in parasitoid speciation. The relative fitness of infected and
uninfected hosts is important to the population dynamics of Wolbachia, and more data are needed. Evolutionary conflict should be common between host genes, Wolbachia genes, and other "selfish" genetic elements. Wolbachia-specific PCR primers are now available for several genes with different rates of evolution. These primers will permit rapid
screening in future studies of spatial and temporal patterns of single and multiple infection. Molecular phylogenies show
that CI- and PI-Wolbachia do not form discrete clades. In combination with experimental transfection data, this result suggests that host reproductive
alterations depend on the interaction between attributes of both Wolbachia and host. Moreover, Wolbachia isolates from closely related hosts do not usually cluster together, and phylogenies suggest that Wolbachia may have radiated after their arthropod hosts. Both results support considerable horizontal transmission of Wolbachia between host species over evolutionary time. Natural horizontal transmisson between parasitoids and their hosts, or with
entomoparasitic nematodes or ectoparasitic mites, remains a tantalizing but equivocal possibility.
Received: November 27, 1998 / Accepted: January 15, 1999 相似文献