BIOCLIMATIC STUDIES OF THE APHID PARASITE PRAON EXSOLETUM: I. EFFECTS OF TEMPERATURE ON THE FUNCTIONAL RESPONSE OF FEMALES TO VARYING HOST DENSITIES

1968 ◽  
Vol 100 (7) ◽  
pp. 728-741 ◽  
Author(s):  
P. S. Messenger
Keyword(s):  
Functional Response ◽  
Host Density ◽  
Handling Time ◽  
Temperature Level ◽  
Wide Range ◽  
Aphid Parasite ◽  
Response Equation ◽  
Effects Of Temperature ◽  
Temperature Levels ◽  
The Relationship

AbstractUsing bioclimatic chambers to provide diurnally fluctuating temperature and humidity conditions, the relationship between fecundity of females of the aphid parasite, Praon exsoletum (Nees), and different host densities, was examined over a wide range of mean temperatures. At each temperature level the number of eggs laid by females was found to vary with host density in accordance with the functional response curve (disc equation) of Holling. Superparasitism was common at all temperature levels studied, and, irrespective of host density, eggs were found laid at random with respect to hosts present. The functional response equation was thus modified so that number of hosts attacked was determined by both number of hosts present and number of eggs laid. Using this modified disc equation, the bioclimatic characteristics of parasite oviposition were examined from rhc standpoint of varying temperature levels. Oviposition was limited to mean temperatures between 8° and 29°C; near these limits the maximum number of eggs laid and the maximum number of hosts attacked were low. At medial mean temperatures (13°–24°) the number of eggs laid per parasite was high, averaging between 70 and 110 each 12-hour day. At these same medial temperatures, according to the modified disc equation, the average "handling" time per oviposition attack was shortest, and the parasite effective searching rate fastest. Averaged over a 12-hour day (this parasite does not oviposit in darkness), females of P. exsoletum were capable of laying from seven to nine eggs per hour at temperatures between 15° and 24° respectively. In all cases, the number of hosts attacked varied with numbers of eggs laid in accordance with Thompson’s superparasitism formula.

Use of Functional Response Modeling to Evaluate the Effect of Temperature on Predation of Amblyseius swirskii (Acari: Phytoseiidae) Adults Preying on Tetranychus urticae (Acari: Tetranychidae) Nymphs

2021 ◽  
Author(s):  
Azadeh Farazmand ◽  
Masood Amir-Maafi
Keyword(s):  
Functional Response ◽  
Tetranychus Urticae ◽  
Attack Rate ◽  
Handling Time ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Temperature Threshold ◽  
Amblyseius Swirskii ◽  
Functional Responses ◽  
Wide Range

Abstract In this research, functional responses of Amblyseius swirskii Athias-Henriot preying on different Tetranychus urticae Koch nymphal densities (2, 4, 8, 16, 32, 64, and 128) were studied at eight constant temperatures (15, 20, 25, 27.5, 30, 32.5, 35 and 37.5°C) in a circular Petri dish (3-cm diameter × 1-cm height) under lab conditions. At all temperatures, the logistic regression showed a type II functional response. A nonlinear relationship was found between temperature and attack rate and the reciprocal of handling time. The reciprocal of handling time decreased exponentially with increasing temperature. In contrast, the attack rate grew rapidly with increasing temperatures up to an optimum, showing a decreasing trend at higher temperatures. In order to quantify the functional response of A. swirskii over a broad range of temperatures and to gain a better estimation of attack rate and handling time, a temperature-settled functional response equation was suited to our data. Our model showed that the number of prey consumed increased with rising prey density. Also, the predation rates increased with increasing temperatures but decreased at extremely high temperatures. Based on our model, the predation rate begins at the lower temperature threshold (11.73°C) and reaches its peak at upper temperature threshold (29.43°C). The coefficient of determination (R2) of the random predator model was 0.99 for all temperatures. The capability of A. swirskii to search and consume T. urticae over a wide range of temperatures makes it a good agent for natural control of T. urticae in greenhouses.

Functional Response of Anisopteromalus calandrae (Hymenoptera: Pteromalidae): Influence of Host Numbers Versus Host Density

1992 ◽  
Vol 27 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Lincoln Smith ◽  
John W. Press
Keyword(s):  
Functional Response ◽  
Sitophilus Oryzae ◽  
Host Density ◽  
Handling Time ◽  
Rice Weevil ◽  
Anisopteromalus Calandrae

The functional response of Anisopteromalus calandrae (Howard) was measured on rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), in wheat at 30° C. Four female parasitoids, with males, were allowed to oviposit during their lifespan on 166 to 678 weevils per container. The data were fit by Rogers' (1972) random parasitoid model with rate of parasite search a = 0.32 lifespan−1 and handling time Th= 0.0027 lifespan. Volume of grain, in the range of 0.19 to 3.1 l wheat, had no effect on number of hosts parasitized when host numbers were held constant at 222, 398, and 572 weevils per container. Therefore, it may be more appropriate to consider numbers of hosts present rather than host density when studying functional response within a patch of uniformly distributed hosts.

Effects of temperature on pigmentation and duration of the puerulus stage in Panulirus japonicus metamorphosed from cultured phyllosomas, with reference to wild pueruli

2001 ◽  
Vol 52 (8) ◽  
pp. 1451 ◽  
Author(s):  
Hirokazu Matsuda ◽  
Taisuke Takenouchi ◽  
Takashi Yamakawa
Keyword(s):  
Water System ◽  
Second Phase ◽  
Coastal Site ◽  
First Instar ◽  
Wide Range ◽  
Panulirus Japonicus ◽  
Effects Of Temperature ◽  
The Times ◽  
Developmental Phases ◽  
The Relationship

The effects of temperature on the development of Panulirus japonicus pueruli metamorphosed from laboratory-cultured phyllosomas were investigated. Fifty pueruli were cultured individually in a still-water system at nine temperatures from 16˚C to 28˚C until moulting to the first-instar juvenile. The puerulus stage was divided into five developmental phases based on changes in pigmentation. The duration of each puerulus phase depended on the temperature; Bêlehrádek’s equation, D = a(T–α)b,appropriately expressed the relationship between the duration (D) and temperature (T), where a, b, and α are constants. From the equation, the times taken at 16, 20, 24, and 28˚C to reach the first-instar juvenile after metamorphosis were estimated at 40.0, 24.1, 16.3, and 11.9 days, respectively. Field study using collectors at one coastal site in Japan showed that P. japonicus pueruli settled from May to November and that the duration of the natural puerulus stage appears to have a rather wide range depending on the seasonal variation in temperature. Most wild pueruli of this study were beyond the second phase of development when collected, so wild pueruli may spend several days offshore before settling in coastal areas.

scholarly journals Temperature and host dependent functional response of Anisopteromalus calandrae (How.) and Choetospila elegans (Westw.) parasitods in parasitizing wheat infesting Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)

2019 ◽  
Vol 47 (1) ◽  
pp. 41-47
Author(s):  
MM Rahman ◽  
W Islam
Keyword(s):  
Functional Response ◽  
Host Density ◽  
Handling Time ◽  
Rhyzopertha Dominica ◽  
Search Rate ◽  
C Elegans ◽  
Seed Flour ◽  
Whole Wheat ◽  
Rhizopertha Dominica ◽  
Anisopteromalus Calandrae

Rhizopertha dominica (F.) (Coleoptera: Bostrichidae) is an internal feeder of whole wheat seed, flour, etc. R. dominica is parasitized by two pteromalid ectoparasitoids, Anisoptetromalus calandrae (How.) and Choetospila elegans (Westw.) in the larval and pupal stages. The effects of host density and temperature on the functional response of the parasitoids in parasitizing the larval and pupal stages of the hosts were examined. Four temperatures and five host densities were used. A functional response equation was used in which a quadratic component that included temperature was substituted for handling time. Functional response of parasitization by A. calandrae and C. elegans fit a formula of Hassell et al. (1977) type III model. The maximum rate of parasitization of A. calandrae was 8.6 larvae/24 hrs and 7.2 larvae/24 hrs of C. elegans at 30ºC, respectively. Handling time and instantaneous search rate varied with temperatures. The ability of A. calandrae and C. elegans to find and parasitize R. dominica over a broad range of temperatures demonstrate it as a good candidate for natural control of the pest. Bangladesh J. Zool. 47(1): 41-47, 2019

scholarly journals Experimental duration and predator satiation levels systematically affect functional response parameters

2017 ◽  
Author(s):  
Yuanheng Li ◽  
Björn C. Rall ◽  
Gregor Kalinkat
Keyword(s):  
Food Web ◽  
Functional Response ◽  
Large Data ◽  
Handling Time ◽  
Set Covering ◽  
Parameter Estimates ◽  
Functional Responses ◽  
Predator Satiation ◽  
Data Set ◽  
Wide Range

AbstractEmpirical feeding studies where density-dependent consumption rates are fitted to functional response models are often used to parametrize the interaction strengths in models of population or food-web dynamics. However, the relationship between functional response parameter estimates from short-term feeding studies and real-world, long-term, trophic interaction strengths remains largely untested. In a critical first step to address this void, we tested for systematic effects of experimental duration and predator satiation on the estimation of functional response parameters, namely attack rate and handling time. Analyzing a large data set covering a wide range of predator taxonomies and body sizes we show that attack rates decrease with increasing experimental duration, and that handling times of starved predators are consistently shorter than those of satiated predators. Therefore, both the experimental duration and the predator satiation level have a strong and systematic impact on the predictions of population dynamics and food-web stability. Our study highlights potential pitfalls at the intersection of empirical and theoretical applications of functional responses. We conclude our study with some practical suggestions how these implications should be addressed in the future to improve predictive abilities and realism in models of predator-prey interactions.

scholarly journals Functional response and mutual interference of Diaeretiella rapae (Hymenoptera: Aphidiidae) on Brevicoryne brassicae (Homoptera: Aphididae)

2006 ◽  
Vol 17 (2) ◽  
pp. 90-97 ◽  
Author(s):  
Yaghoub Fathipour ◽  
Ali Hosseini ◽  
Ali Talebi ◽  
Saeid Moharramipour
Keyword(s):  
Logistic Regression ◽  
Functional Response ◽  
Host Density ◽  
Handling Time ◽  
Mutual Interference ◽  
Brevicoryne Brassicae ◽  
Least Square ◽  
Diaeretiella Rapae ◽  
Type Ii ◽  
Per Capita

Functional response and mutual interference are the most important behavioural characteristics that reveal different aspects of host–parasitoid interactions. In this study, functional response and mutual interference of the parasitoid wasp, Diaeretiella rapae (M’Intosh) attacking the cabbage aphid, Brevicoryne brassicae (Linnaeus) were investigated. Logistic regression was used to distinguish the shape of the functional response (type II or III). Nonlinear least-square regression was used to estimate the attack rate (a) and handling time (Th). Nicholson’s model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. Logistic regression suggested a type II response on B. brassicae nymphs. The per capita parasitism decreased significantly from 80.80 (67.33%) to 11.85 (9.88%) as parasitoid densities increased from 1 to 8 females. Consequently, the per capita searching efficiency decreased significantly from 1.173 to 0.205 as parasitoid densities increased from 1 to 8. The rate of parasitism increased as the host density increased from 2 to 50, and subsequently the parasitoid density decreased from 8 to 1. Therefore, different host–parasitoid ratios could affect the efficacy of D. rapae.

scholarly journals Effects of Temperature and Salinity on Seed Germination of Three Common Grass Species

2021 ◽  
Vol 12 ◽  
Author(s):  
Yongjie Liu ◽  
Shuang Zhang ◽  
Hans J. De Boeck ◽  
Fujiang Hou
Keyword(s):  
Seed Germination ◽  
Festuca Arundinacea ◽  
Germination Rate ◽  
Germination Percentage ◽  
Grass Species ◽  
Temperature Level ◽  
The Face ◽  
Salinity Levels ◽  
Effects Of Temperature ◽  
Temperature Levels

Temperature and salinity significantly affect seed germination, but the joint effects of temperature and salinity on seed germination are still unclear. To explore such effects, a controlled experiment was conducted, where three temperature levels (i.e., 15, 20, and 25°C) and five salinity levels (i.e., 0, 25, 50, 100, and 200 mmol/L) were crossed, resulting in 15 treatments (i.e., 3 temperature levels × 5 salinity levels). Three typical grass species (Festuca arundinacea, Bromus inermis, and Elymus breviaristatus) were used, and 25 seeds of each species were sown in petri dishes under these treatments. Germination percentages and germination rates were calculated on the basis of the daily recorded germinated seed numbers of each species. Results showed that temperature and salinity significantly affected seed germination percentage and germination rate, which differed among species. Specifically, F. arundinacea had the highest germination percentage, followed by E. breviaristatus and B. inermis, with a similar pattern also found regarding the accumulated germination rate and daily germination rate. Generally, F. arundinacea was not sensitive to temperature within the range of 15–25°C, while the intermediate temperature level improved the germination percentage of B. inermis, and the highest temperature level benefited the germination percentage of E. breviaristatus. Moreover, F. arundinacea was also not sensitive to salinity within the range of 0–200 mmol/L, whereas high salinity levels significantly decreased the germination percentage of B. inermis and E. breviaristatus. Thus, temperature and salinity can jointly affect seed germination, but these differ among plant species. These results can improve our understanding of seed germination in saline soils in the face of climate change.

QUANTITATIVE ASSESSMENT OF APHIDIUS SMITHI (HYMENOPTERA: APHIDIIDAE): FECUNDITY, INTRINSIC RATE OF INCREASE, AND FUNCTIONAL RESPONSE

1983 ◽  
Vol 115 (4) ◽  
pp. 399-415 ◽  
Author(s):  
Manfred Mackauer
Keyword(s):  
Sex Ratio ◽  
Functional Response ◽  
Acyrthosiphon Pisum ◽  
Host Density ◽  
Handling Time ◽  
Intrinsic Rate ◽  
Natural Increase ◽  
Intrinsic Rate Of Increase ◽  
Regression Equations ◽  
Rate Of Increase

AbstractThe reproductive and demographic statistics of Aphidius smithi Sharma & Subba Rao parasitizing third-instar pea aphids, Acyrthosiphon pisum Harris, were determined under constant laboratory conditions. At host densities of 5, 10, 20, 40, 60 or 100 aphids/day, the parasite lived an average of 7 days at 20.5 °C. At host densities of ≤20 aphids/day, the total number of eggs laid and the total number of hosts attacked were limited by the numbers of hosts available. Fecundity was highest with an average of 870 eggs/female at density 100; the maximum number of eggs laid by any female was 1770. Superparasitism was common at all densities, resulting in up to 84% (at density 5) of all eggs being wasted. The relationship between host density and the number of aphids attacked per egg laid was linear for densities of ≥20 aphids/day. The intrinsic rate of natural increase (r) varied with the host density. It reached maximum value at density 100, calculated as 0.358 female/female/day and assuming an overall sex ratio of 1:1 males:females. Regression equations describing r as a function of host density and parasite sex ratio are provided. It is shown that the potential rate of increase of A. smithi exceeds that of the pea aphid over a broad range of average conditions. The parasite's functional response was convex (Holling type II) and decelerated with increasing density. The intrinsic attack rate (a′) and handling time (Th) were estimated from the functional response curve as a′ = 6.62 days−1 and Th = 0.0033 day (4.7 min). The ‘random parasite’ equation satisfactorily predicted the number of aphids attacked at each density.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

scholarly journals Polymorphic Iterable Sequential Effect Systems

2021 ◽  
Vol 43 (1) ◽  
pp. 1-79
Author(s):  
Colin S. Gordon
Keyword(s):  
Algebraic Structure ◽  
Position Effect ◽  
Type Systems ◽  
Sequential Effect ◽  
Prior Work ◽  
Sequential Effects ◽  
Wide Range ◽  
The Relationship ◽  
Categorical Semantics

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.

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