Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effect of larval host on life history traits of the mediterranean fruit fly, Ceratitis capitata (1987)
    Springer
    Oecologia 73 (1987), S. 583-590 
    Details
    ISSN: 1432-1939
    Keywords: Mediterranean fruit fly ; Ceratitis capitata ; Insect demography ; Insect polyphagy ; Insect-host relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Demographic parameters for the Mediterranean fruit fly reared on each of twenty four different hosts from sixteen different plant families are reported. These include cohort parameters of development, survival, pupal sizc, and fecundity as well as population parameters such as intrinsic rate of population increase (r) and mean generation time. Major findings include the following: i) no consistent quantitative relationships existed between r and its chief demographic determinants such as preadult developmental time and adult fecundity; and ii) few correlations existed among the cohort life history parameters themselves. The principle conclusion is that the medfly is a successful generalist frugivore because of its developmental ability to offset the effect of the value for a host-specific trait that tends to lower r with one that tends to increase r, the net result of which is to maintain a relatively high r.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00379420
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Male demographic constraints to extreme sex ratio in the twospotted spider mite (1990)
    Springer
    Oecologia 82 (1990), S. 417-423 
    Details
    ISSN: 1432-1939
    Keywords: Sex ratio ; Twospotted spider mite ; Demography ; Male reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Twospotted spider mites, Tetranychus urticae Koch are arrhenotokous. As a result of this genetic structure, primary and secondary sex ratios diverge from the 1:1 female:male ratio commonly found in diploid systems. Ratios vary, but 3:1 is the most common. The influence of life history parameters on spider mite sex ratio is unclear, although maternal genetic effects, resource quality and maternal age are known to play a role. An area that has not been studied is the relationship between male reproductive capabilities and spider mite sex ratio. A prior study on male reproduction in spider mites suggests that males have far too high a reproductive capacity to explain sex ratio patterns, but that study was not conducted under realistic mating conditions. Thus, this study was conducted to determine if there is a link between male reproduction and spider mite sex ratio. This was done by exposing males to various exposure regimes of females and recording the number of copulations, inseminations and daughters fathered by each male. Results include the following: i) males are most virile when one day old; ii) virgin males become nearly completely devoid of sperm (or other copulatory products) after about 15 matings and then take about four days to recover; and iii) the optimal number of matings per day (defined as that which produces the greatest number of daughters in the least number of inseminations) is four females per day. The principle conclusion is that although males have a high potential reproductive output, insemination quality is only high for the first four or five matings each day. Therefore, to ensure full inseminations of all daughters by sons, females are constrained to producing primary sex ratios of about 5:1 or less.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317492
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Demography of the twospotted spider mite, Tetranychus urticae Koch (1982)
    Springer
    Oecologia 52 (1982), S. 389-395 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A simple life table model was constructed for Tetranychus urticae in which daily survivorship of eggs and motil stages, fecundity, and development time was altered to assess the impact of each parameter on the intrinsic rate of increase. r. Interpretation of the trade-offs focused on management considerations. A second aspect of the study concerned age and stage structure in mite populations including the time path of convergence to a stable age distribution and the effect of changes in birth and death rates on the age profile. The stable stage distributions of 7 tetranychid mite species were computed using 25 separate life tables. In spite of the wide range of r-values induced by different experimental conditions, all of the stage distributions were quite similar averaging roughly 66% eggs, 26% immatures, and 8% adults. Several population studies were cited which reported stage distributions of growing mite populations. The empirical evidence suggested that natural mite populations are often quite near this stable distribution. A practical problem involving the extent to which hormoligosis (insecticide stimulation) affects mite population growth rate was addressed using the life table model and laboratory data from controlled studies. The findings suggested that mite populations treated with insecticide may attain a 1.4- to a 4.2-fold difference in population size relative to an untreated population after 2 generations and over a 1,300-fold potential difference after 10 generations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367964
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Size specific demography of three species of Anastrepha fruit flies (1992)
    Springer
    Entomologia experimentalis et applicata 63 (1992), S. 135-142 
    Details
    ISSN: 1570-7458
    Keywords: Anastrepha obliqua ; A. ludens ; A. serpentina ; Tephritidae ; body size ; reproduction ; insect demography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Individuals of three Anastrepha species: A. obliqua, A. ludens, and A. serpentina (Diptera: Tephritidae), were sorted according to pupal weight in cohorts of large and small flies. Demographic parameters and reproductive patterns and heterogeneity were determined for each cohort. Large flies of the three species presented greater expectation of life and gross fecundity rates. A. ludens was the species with the longest life span (expectation of life of large adults was 110 days) and the greatest gross fecundity rates (1597 eggs/female for the large flies). While, A. obliqua had the shortest mean age of reproduction (33 days), and the greatest daily egg production (14 eggs/female/day). Net fecundity was similar in these two. A. serpentina had lower fecundity rates. Reproductive information for each size and each species include: age-by-parity relations, fraction of sexually mature life in which females lay eggs, and frequency distribution of individual egg production. Results demonstrate that even under constant laboratory conditions and using standard artificial hosts, there is a great deal of life history variation among these Anastrepha species and among other tephritid fruit flies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343573
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Age and host effects on clutch size in the Mexican fruit fly, Anastrepha ludens (1988)
    Springer
    Entomologia experimentalis et applicata 47 (1988), S. 73-80 
    Details
    ISSN: 1570-7458
    Keywords: Tephritidae ; Mexican fruit fly ; Anastrepha ludens ; clutch size ; host selection ; insect demography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'examen a porté sur l'influence du polymorphisme et des modifications dues à l'âge des mouches sur la fécondité et la taille des pontes de A. ludens Loew (Dipt. Tephritidae). L'étude a concerné aussi l'influence de la dimension, de la couleur et de la densité des hôtes sur la taille des pontes. Des mouches isolées ou par groupes ont reçu des hôtes artificiels formés de sphères d'agar enveloppées dans du parafilm. La fécondité brute de femelles isolées a été de 1000 oeufs/femelle et de 165 pontes/femelle, avec une variation de 1 à 40 oeufs/ponte. La taille moyenne des pontes des différentes femelles isolées s'étalait de 4,5 à 10,6 oeufs/ponte. Le nombre d'oeufs/ponte des femelles groupées était fortement liée à la dimension de l'hôte, s'étalant de 4,4 oeufs/ponte pour des hôtes de 2 cm de diamètre à 12,7 oeufs/ponte pour ceux de 11 cm de diamètre. Ni la couleur et la densité des hôtes, ni la densité et l'âge des mouches n'ont influé sur la taille des pontes. Ces résultats suggèrent que les variabilités du comportement des femelles et de la dimension des hôtes déterminent par priorité la taille des pontes de A. ludens.
    Notes: Abstract We document individual and age-specific variation in reproductive output and clutch size of Anastrepha ludens Loew. (Diptera: Tephritidae). The influence of host size, color, and density on clutch size are also examined. Individual and groups of flies were offered artificial hosts composed of agar spheres wrapped in Parafilm. The gross reproduction rate of individual flies was 1000 eggs/female and 165 clutches/female with a range of 1 to 40 eggs/clutch. Mean clutch sizes for these females ranged from 4.5 to 10.6 eggs/clutch. The number of eggs/clutch laid by females held in groups was highly correlated with host size, ranging from about 4.4 eggs/clutch in 2 cm diameter hosts to 12.7 eggs/clutch in 11 cm hosts. Host color, host density, fly density, and fly age did not affect clutch size. This study suggests that variation among females and host size are the principal determinants of clutch size in A. ludens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186718
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Reproductive limits and heterogeneity of male twospotted spider mites (1989)
    Springer
    Entomologia experimentalis et applicata 50 (1989), S. 209-214 
    Details
    ISSN: 1570-7458
    Keywords: Demography ; male population biology ; sex ratio ; Tetranychus urticae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La reproduction est un processus qui nécessite généralement un mâle et une femelle. Cependant la biologie des populations ne s'est traditionnellement intéressée qu'à la contribution des femelles dans ce processus. Un effet de cet accent sur les femelles est que l'activité reproductrice des mâles a été très ignorée. Cet article examine, dans un contexte démographique, l'activité reproductrice des mâles de T. urticae, acarien arrhénotoque et phytophage. Trois séquences de l'activité reproductrice des mâles ont été examinées: 1) la copulation, 2) l'insémination, 3) la reproduction. En moyenne un mâle de 1 jour a copulé 15 fois, inséminé 15 femelles et a eu 336 filles. Pendant les 8 premiers jours, le mâle moyen a inséminé 70 femelles et a eu 1145 filles. Ces résultats suggèrent que le nombre de spermatozoïdes transférés à chaque insémination, plus que le nombre d'inséminations, est le facteur limitant d'une forte contribution du mâle à la reproduction.
    Notes: Abstract This paper determines reproductive limits and variation in performance of male twospotted spider mites Tetranychus urticae Koch when virgin females are provided ad libitum over the first eight days of adult life. Theree phases of male reproduction were studied: copulations, insemination and reproduction. An average one day old male copulated 15 times, inseminated 15 females, and contributed to 336 daughters. All parameters declined with age. The average male inseminated 70 females and contributed to 1145 daughters in the first days. Variability between males was small for all parameters considered. These data suggest that the number of sperm transferred at each insemination, rather than the number of inseminations, is the limiting step to higher male reproductive output.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341169
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Demography of a native strain of the melon fly, Dacus cucurbitae, from Hawaii (1985)
    Springer
    Entomologia experimentalis et applicata 38 (1985), S. 195-199 
    Details
    ISSN: 1570-7458
    Keywords: melon fly ; Dacus cucurbitae ; demography ; life tables ; host studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le développement préimaginal et les taux de survie d'une souche sauvage de D. cucurbitae de Hawaí sur six hôtes courants ont été examinés à 25°C. Ces résultats ont été combinés aux informations récoltées sur la survie des adultes, la fécondité et la fertilité pour réaliser des tables de vie. La durée du stade oeuf est légèrement supérieure à un jour pour cette espèce. La durée de développement de l'éclosion de l'oeuf à l'imago et les taux de survie ont été respectivement de 17 à 20 jours et de 35 à 85% suivant les hôtes. La fécondité brute (ponte totale) a été de 1293 oeufs par femelle, tandis qui ‘la fertilité’ (nombre total d'oeufs fertiles pondéré par les taux d'éclosion et de survie des adultes) était de 518 oeufs fertiles par femelle. Le taux d'accroissement (λ) variait de 1,08 à 1,12 suivant l'hôte sur lequel D. cucurbitae a été élevé. La proportion d'adultes dans une distribution en âge stable était d'environ 14% sur tous les hôtes.
    Notes: Abstract Preadult development and survival rates for a wild strain of melon fly in Hawaii were examined when reared on six common hosts at 25°C. These data were combined with information gathered on adult survival, fecundity and fertility in order to construct life tables. The duration of the egg stage was slightly over 1 day for this species. Depending on host, larval-to-adult development and survival rates were 17–20 days and 35–85%, respectively. Gross fecundity (total eggs) was 1293 eggs/♀ while net fertility (total fertile eggs weighted by hatch and adult survival) was 518 fertile eggs/♀. The finite rate of increase (λ) for the species was conditional on the host on which it was reared and ranged from 1.08 to 1.12. The percent of adults in the stable age distribution averaged around 14% over all hosts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00361932
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Life history response of female Mediterranean fruit flies, Ceratitis capitata, to periods of host deprivation (1986)
    Springer
    Entomologia experimentalis et applicata 42 (1986), S. 159-167 
    Details
    ISSN: 1570-7458
    Keywords: Mediterranean fruit fly ; Ceratitis capitata ; host deprivation ; senescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les femelles de C. capitata ont été privées d'hôtes suivant 4 modalités pendant 3 durées (33, 50 et 67% de leur vie) par période de 24 heures. Les modalités se répartissaient de la privation pendant 8 jours après l'éclosion jusqu'à 1 jour sur 3. La survie a été notée chaque jour et la ponte pour tous les jours où il y avait des hôtes. L'effect direct de l'absence d'hôte est d'empêcher la femelle de pondre. Ceci interrompt leur cycle de ponte et réduit leur activité reproductrice totale. Un effort reproductif réduit des femelles jeunes augmente la survie (jusqu'à 2 fois) et la ponte quotidienne (jusqu'à 8 fois) chez les femelles plus âgées. Ainsi, l'effet à long terme de la privation d'hôtes est d'ajourner la sénescence. Les implications de ces observations sur la sénescence de C. capitata sont discutées quant à: (1) la réduction des taux d'extinction des populations pendant les périodes de rareté d'hôtes; et: (2) les stratégies d'obtention de pontes dan les élevages de masse de C. capitata.
    Notes: Abstract Female medflies were subjected to four different patterns of host deprivation at each of three levels for a 24-day period. Treatments ranged from host absence 8 days post-eclosion to host absence 2 out of 3 days. Survival was recorded daily and egg production was recorded on the days in which hosts were present. The direct effect of host deprivation is to deny females the opportunity to oviposit. This disrupts their reproductive cycle and reduces their overall reproductive effort. Reduced reproductive effort at young ages increases survival (up to 2-fold) and daily reproduction (up to 8-fold) at older ages. Therefore, the long term effect of host deprivation is to postpone senescence. The implications of these findings regarding medfly sensescence are discussed in relation to: (i) reduction in population extinction rates during periods of host scarcity and (ii) egging strategies in medfly mass-rearing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343543
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Maternal heterogeneity in primary sex-ratio of three tetranychid mites (1988)
    Springer
    Experimental and applied acarology 5 (1988), S. 151-162 
    Details
    ISSN: 1572-9702
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of maternal age on primary sex ratio was determined forTetranychus urticae, T. pacificus andT. turkestani (Acari:Tetranychidae). All females were allowed to mate once.Tetranychus urticae had the highest production of daughters and the lowest production of sons. The sex ratio ofT. urticae was nearly 2∶1 (daughters∶sons), whereas for the other species it was 0.6∶1. Net sex ratios were all shifted in favor of daughters, suggesting that most son-production occurs late in life. Demographic techniques are applied to tetranychid populations, including the concepts of reproductive concentration curves and expectation of future reproduction based on age and previous offspring.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02053824
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Demographic analyses of organophosphate-resistant and susceptible strains of greenhouse whitefly, Trialeurodes vaporariorum, on three cotton cultivars (1992)
    Springer
    Entomologia experimentalis et applicata 65 (1992), S. 21-30 
    Details
    ISSN: 1570-7458
    Keywords: Greenhouse whitefly ; Trialeurodes vaporariorum ; demography ; resistant ; susceptible ; cotton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Laboratory experiments were conducted using organophosphate-resistant and susceptible strains of greenhouse whitefly, Trialeurodes vaporariorum Westwood, to assess age-specific vital rates in individually-held adults, and development and survival in preadults on three cotton cultivars at 27±1 °C, 50±10% RH, and a photoperiod of 16:8 (L:D). Female whiteflies lived longer than males, with a maximum life expectancy of 29 days. Heaviest egg laying occurred at ages between 7 and 18 days when individual whiteflies laid 〉 10 eggs/day. Greenhouse whitefly populations doubled weekly, with stable age distribution of 63% eggs, 28% larvae, 5% pupae, and 4% adults. Analysis of various life history parameters that combine aspects of survival, developmental rates, and fecundity indicated no consistent differences in reproductive fitness between the two greenhouse whitefly strains. Of the three cotton cultivars tested, Pima S-6 was most susceptible, Acala SJ-2 was intermediate and Gumbo 500 was most resistant to greenhouse whitefly. Resistance of Gumbo 500 was expressed as slower developmental rates, reduced survival to adulthood, lower reproductive rates, and lower intrinsic rate of increase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189713
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...