PREFERENCE OF REDUVIOLUS AMERICOFERUS (HEMIPTERA: NABIDAE) FOR POTATO LEAFHOPPER NYMPHS AND PEA APHIDS

1985 ◽  
Vol 117 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
P.W. Flinn ◽  
A.A. Hower ◽  
R.A.J. Taylor

AbstractThe preference of the nabid, Reduviolus americoferus (L.), for potato leafhopper nymphs, Empoasca fabae (Harris), and pea aphids, Acyrthosiphon pisum (Harris), was examined using functional response models. The nabid exhibited a type-II functional response to each prey. Handling time was much higher for the aphid than for the leafhopper (3.623 vs. 0.211 h). Instantaneous search rates were also higher for the aphid (0.096 vs. 0.020 h−1). A preference index was calculated using the ratio of the instantaneous search rates. The nabid exhibited strong preference for the aphid; when both prey were present in equal numbers, the nabid consumed 3 times as many aphids. The predator did not switch to leafhopper nymphs as the proportion of leafhoppers was increased.

1997 ◽  
Vol 129 (2) ◽  
pp. 221-227 ◽  
Author(s):  
G.P. Opit ◽  
B. Roitberg ◽  
D.R. Gillespie

AbstractThe preference of the predatory midge, Feltiella acarisuga (Vallot), for adult male and female twospotted spider mite, Tetranychus urticae Koch, was examined using functional response models. The midge exhibited a type-II functional response to each prey. Handling time was estimated to be much higher for the female mites than for the males (1.52 vs. 0.40 h). Estimated instantaneous search rates for the female and male mites were similar (1.32 vs. 1.28). A preference index of 1.03 was calculated using the ratio of the instantaneous search rates. Feltiella acarisuga was found to exhibit no preference for either female or male mites; when both prey were present in equal numbers, midge larvae killed as many females as males.


2003 ◽  
Vol 135 (1) ◽  
pp. 93-101 ◽  
Author(s):  
C.E. Rutledge ◽  
S.D. Eigenbrode

AbstractCrop cultivar can affect the ability of natural enemies to control pest populations. Peas, Pisum sativum L. (Fabaceae), with a reduced epicuticular wax bloom have reduced pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), populations in the field than peas with a normal-wax bloom. In this paper we use the functional response to examine predation by Hippodamia convergens Guérin de Méneville (Coleoptera: Coccinellidae) larvae foraging on pea plants with a normal- and a reduced-wax bloom. We found that Hippodamia convergens shows a Type II functional response on both phenotypes of peas. Hippodamia convergens consumed significantly more pea aphids on reduced-wax plants than on normal-wax plants. The instantaneous search rate, a, was higher for predators on reduced-wax plants, but the handling time, Th, was similar for predators on both wax phenotypes. In addition, we tested the ability of H. convergens larvae to attach to the surface of normal-wax and reduced-wax pea leaves. We found that H. convergens larvae attach more strongly to reduced-wax peas than to normal-wax peas. These results suggest that predation of pea aphid by H. convergens is enhanced on reduced-wax peas due to increased ability of predators to attach to these plants, and as a result, search for and find aphids.


2010 ◽  
Vol 365 (1550) ◽  
pp. 2279-2288 ◽  
Author(s):  
Evelyn Merrill ◽  
Håkan Sand ◽  
Barbara Zimmermann ◽  
Heather McPhee ◽  
Nathan Webb ◽  
...  

Quantifying kill rates and sources of variation in kill rates remains an important challenge in linking predators to their prey. We address current approaches to using global positioning system (GPS)-based movement data for quantifying key predation components of large carnivores. We review approaches to identify kill sites from GPS movement data as a means to estimate kill rates and address advantages of using GPS-based data over past approaches. Despite considerable progress, modelling the probability that a cluster of GPS points is a kill site is no substitute for field visits, but can guide our field efforts. Once kill sites are identified, time spent at a kill site (handling time) and time between kills (killing time) can be determined. We show how statistical models can be used to investigate the influence of factors such as animal characteristics (e.g. age, sex, group size) and landscape features on either handling time or killing efficiency. If we know the prey densities along paths to a kill, we can quantify the ‘attack success’ parameter in functional response models directly. Problems remain in incorporating the behavioural complexity derived from GPS movement paths into functional response models, particularly in multi-prey systems, but we believe that exploring the details of GPS movement data has put us on the right path.


1970 ◽  
Vol 102 (9) ◽  
pp. 1094-1101 ◽  
Author(s):  
Norman R. Glass

AbstractThe two primary functional response models extant in recent entomological literature were compared using a common set of data. Use of an iterative least squares parameter estimation routine was shown to be essential to a comparison of these two models. With parameters properly determined, the Watt model fit data on one out of five experiment days best, the Holling model fit data best on four out of five experiment days. The "handling time" submodel was shown to require iterative least squares parameter estimation rather than the usual log transformation and subsequent fitting of this logistic function by standard linear regression techniques. The conclusion was reached that if accuracy in prediction by nonlinear functional response models is desired, proper methods of determining parameter values are of critical importance.


2009 ◽  
Vol 9 (1) ◽  
pp. 15-21
Author(s):  
Hidrayani Hidrayani ◽  
Aunu Rauf ◽  
S. Sosromarsono ◽  
U. Kartosuwondo

The preference and functional response of Parasitoid Hemiptarsenus varicornis (Girault) (Hymenoptera:Eulophidae) on host larvae of potato leafminers. The preference of Hemiptarsenus varicornis (Girault) on host larvae of potato leafminers (Liriomyza huidobrensis) and their  functional response on host abundance were studied in laboratory. The preference test was conducted by releasing a female parasitoid in a cage containing two redbean leaves, one with 2nd instar and another one with 3rd instar.  The functional response test was conducted by providing 3rd instar  with density 1, 4, 6, 8, 10, and 13  larvae  per leaf. The result showed that  H. varicornis had the preference on 3rd instar  larvae compared to 2nd instar, either for parasitisation or paralysis. Based on logistic regression analysis it was found that the parasitoid showed type II functional response on the increase of host abundance. The searching rate (a) and handling time (Th) for paralysis were 0.038 and 1.473 based on disk equation model, and 0.076 and 2.060 on ramdom equation model.  For parasitisation activity, the value of  a and Th were  0.012 and 4.649 based on disk equation model, and 0.014 and 5.075 on random equation model.


2012 ◽  
Vol 9 (2) ◽  
pp. 220-228
Author(s):  
Baghdad Science Journal

This study evaluated the functional response of the larva of the predator Chrysoperla carnea by offering varying densities of cabbage aphid, Brevicoryne brassicae (L.) . Results showed conformity with type–II functional response, where the number of prey killed approaches asymptote hyperbolically as prey density increases (declining proportion of prey killed or the inverse density dependent) till it reached the stability stage determined by handling time and predator satiation. Also, the values of attack rate and handling time changed with age progress for both predator and prey. It has been observed an increase in the attack rate and reduction in handling time with the progress of the predator age when feeding on a particular nymphal instar. The attack rates of the predator was 1.779,3.406 and 4.219 ,while handling time was 0.015,0.010 and 0.008 (days) for 1st,2nd,3rd larval instars respectively, when fed on 1st nymphal instar. Also attack rates decreased and increases handling time with the progress in the prey. The attack rates were 1.779, 1.392, 1.096 and 1.059, due to an increase in size of the predator and in the growing efficiency in hunting the prey as well as in the increase in size of the prey and in developing its ability to defend itself and escape.


2022 ◽  
Vol 154 ◽  
Author(s):  
Desh Deepak Chaudhary ◽  
Bhupendra Kumar ◽  
Geetanjali Mishra ◽  
Omkar

Abstract In the present study, we assessed functional response curves of two generalist coccinellid beetles (Coleoptera: Coccinellidae), specifically Menochilus sexmaculatus and Propylea dissecta, using fluctuating densities of aphid prey as a stimulus. In what may be the first such study, we investigated how the prey density experienced during the early larval development of these two predatory beetle species shaped the functional response curves of the late instar–larval and adult stages. The predators were switched from their rearing prey-density environments of scarce, optimal, or abundant prey to five testing density environments of extremely scarce, scarce, suboptimal, optimal, or abundant prey. The individuals of M. sexmaculatus that were reared on either scarce- and optimal- or abundant-prey densities exhibited type II functional response curves as both larvae and adults. However, individuals of P. dissecta that were reared on scarce- and abundant-prey densities displayed modified type II functional response curves as larvae and type II functional response curves as adults. In contrast, individuals of P. dissecta reared on the optimal-prey density displayed type II functional response curves as larvae and modified type II functional response curves as adults. The fourth-instar larvae and adult females of M. sexmaculatus and P. dissecta also exhibited highest prey consumption (T/Th) and shortest prey-handling time (Th) on the scarce-prey rearing density. Thus, under fluctuating-prey conditions, M. sexmaculatus is a better biological control agent of aphids than P. dissecta is.


2017 ◽  
Vol 66 (2) ◽  
Author(s):  
Víctor Ernesto Tello Mercado ◽  
Miguel Esteban Zarzar Maza ◽  
Angélica María Suarez Pantoja

The functional response of adult females of predatory mite Cydnodromus picanus Ragusa (Acari: Phytoseiidae) was evaluated at different egg densities (5, 10, 20, 30, 40, 50, 60, 70, 80, 100 and 150 eggs per predator) of Tetranychus urticae Koch (Acari: Tetranychidae), which had 16, 42 and 65 h since oviposition. The experimental design was in a completely randomized blocks with five replicates per treatment. The environmental conditions of the trials were 25±2°C temperature, 50±2% of relative humidity and a photoperiod of 16:8 hours (light: dark). The average consumption rates for the three kinds of prey showed no significant differences (p>0.05) being 20.56±1.02, 18.59±0.79 and 18.38±0.94 prey/predator for eggs of 16, 42 and 65 h age, respectively. Using a logistic regression, a type II functional response on C. picanus females for the three kinds of eggs was determined. The values of response parameters for C. picanus females were as follows: Attack rate (a): 0.055±0.006, 0.076±0.009 and 0.073±0.016; Handling time (Th): 0.684±0.036, 0.894±0.034 and 0.898±0.062; for eggs of 16, 42 and 65 h age, respectively. These values are within the range of variation for different species of phytoseiids. These results suggest that C. picanus could effectively regulate populations of T. urticae in the field.  


2015 ◽  
Vol 282 (1801) ◽  
pp. 20142121 ◽  
Author(s):  
Henrik Sjödin ◽  
Åke Brännström ◽  
Göran Englund

We derive functional responses under the assumption that predators and prey are engaged in a space race in which prey avoid patches with many predators and predators avoid patches with few or no prey. The resulting functional response models have a simple structure and include functions describing how the emigration of prey and predators depend on interspecific densities. As such, they provide a link between dispersal behaviours and community dynamics. The derived functional response is general but is here modelled in accordance with empirically documented emigration responses. We find that the prey emigration response to predators has stabilizing effects similar to that of the DeAngelis–Beddington functional response, and that the predator emigration response to prey has destabilizing effects similar to that of the Holling type II response. A stability criterion describing the net effect of the two emigration responses on a Lotka–Volterra predator–prey system is presented. The winner of the space race (i.e. whether predators or prey are favoured) is determined by the relationship between the slopes of the species' emigration responses. It is predicted that predators win the space race in poor habitats, where predator and prey densities are low, and that prey are more successful in richer habitats.


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