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.

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

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.

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.

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.

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.

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