scholarly journals Understanding spatial distributions: negative density-dependence in prey causes predators to trade-off prey quantity with quality

2016 ◽  
Vol 283 (1828) ◽  
pp. 20151557 ◽  
Author(s):  
Allert I. Bijleveld ◽  
Robert B. MacCurdy ◽  
Ying-Chi Chan ◽  
Emma Penning ◽  
Rich M. Gabrielson ◽  
...  
Keyword(s):  
Density Dependence ◽  
Functional Response ◽  
Energy Intake ◽  
Prey Density ◽  
Intake Rate ◽  
Spatial Distributions ◽  
Type Ii ◽  
Negative Density Dependence ◽  
Type Ii Functional Response

Negative density-dependence is generally studied within a single trophic level, thereby neglecting its effect on higher trophic levels. The ‘functional response’ couples a predator's intake rate to prey density. Most widespread is a type II functional response, where intake rate increases asymptotically with prey density; this predicts the highest predator densities at the highest prey densities. In one of the most stringent tests of this generality to date, we measured density and quality of bivalve prey (edible cockles Cerastoderma edule ) across 50 km² of mudflat, and simultaneously, with a novel time-of-arrival methodology, tracked their avian predators (red knots Calidris canutus ). Because of negative density-dependence in the individual quality of cockles, the predicted energy intake rates of red knots declined at high prey densities (a type IV, rather than a type II functional response). Resource-selection modelling revealed that red knots indeed selected areas of intermediate cockle densities where energy intake rates were maximized given their phenotype-specific digestive constraints (as indicated by gizzard mass). Because negative density-dependence is common, we question the current consensus and suggest that predators commonly maximize their energy intake rates at intermediate prey densities. Prey density alone may thus poorly predict intake rates, carrying capacity and spatial distributions of predators.

Functional response in coccinellid beetles (Coleoptera: Coccinellidae) is modified by prey-density experience

2022 ◽  
Vol 154 ◽  
Author(s):  
Desh Deepak Chaudhary ◽  
Bhupendra Kumar ◽  
Geetanjali Mishra ◽  
Omkar
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Biological Control Agent ◽  
Handling Time ◽  
Control Agent ◽  
Type Ii ◽  
Response Curves ◽  
Late Instar ◽  
Rearing Density ◽  
Type Ii Functional Response

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.

scholarly journals Functional and Numerical Responses of Scymnus Syriacus Marseul (Coleoptera: Coccinellidae) to the Black Bean Aphid, Aphis Fabae Scopoli (Hemiptera: Aphididae) Under Laboratory Conditions

2011 ◽  
Vol 51 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Reza Sabaghi ◽  
Ahad Sahragard ◽  
Reza Hosseini
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Least Square ◽  
Aphis Fabae ◽  
Type Ii ◽  
Black Bean ◽  
Laboratory Conditions ◽  
And Function ◽  
Type Ii Functional Response ◽  
Black Bean Aphid

Functional and Numerical Responses ofScymnus SyriacusMarseul (Coleoptera: Coccinellidae) to the Black Bean Aphid,Aphis FabaeScopoli (Hemiptera: Aphididae) Under Laboratory ConditionsFunctional and numerical responses are basic to any investigation of predator-prey relationships and key components in the selection of predators for biological control. In this study, functional and numerical responses of the female and male ladybeetles,Scymnus syriacusMarseul to different densities of third instar nymphs ofAphis fabae(i.e.5, 10, 20, 30, 40, 60 and 80) as prey, were studied in a growth chamber (25°C, 65±5% RH and a photoperiod of 16L : 8D h) on the broad bean,Vicia fabaeLinn. Using the logistic regression, a type II functional response for both female and male ladybeetles was determined. Using Nonlinear least-square regression, the searching efficiency (a') and handling times (Th) of the female and male adults were estimated as 0.123±0.006 h, 0.434±0.012 h and 0.115±0.008 h, 0.514±0.016, respectively. The Rogers model was used to estimate the maximum theoretical predations (T/Th) for female and male, which were 55.18 and 46.64, respectively. These results indicated a higher efficiency in female ladybeetles. The reproductive numerical response, in terms of eggs laid, increased curvlinearly with increasing prey density. The reproductive response trend was similar to the shape of the type II functional response. This similarity means both responses are interlinked and function simultaneously. The efficiency of the ingested food conversion (ECI) of the females decreased with prey density, as females laid 25±0.65 eggs when exposed to the highest prey density (80) and 3±0.44 eggs at lowest prey density (5).

Predation of Indianmeal Moth Larvae by Lyctocoris campestris (F.) (Hemiptera: Anthocoridae) in Different Stored Commodities

1997 ◽  
Vol 32 (3) ◽  
pp. 271-280 ◽  
Author(s):  
R. L. Meagher ◽  
L. A. Locke
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Plodia Interpunctella ◽  
Type Ii ◽  
Indianmeal Moth ◽  
Whole Wheat ◽  
Late Instar ◽  
Response Equation ◽  
Predation Rates ◽  
Type Ii Functional Response

Predation rates for the anthocorid predator Lyctocoris campestris (F.) against varying densities of late-instar Plodia interpunctella (Hübner) were compared in whole corn, whole wheat, or rolled oat stored commodities. More prey were attacked in corn and wheat than in oats, and female predators generally fed on more larvae than did male predators. Predation increased with an increase in prey density. This relationship was best described by a Type II functional response equation. Our results suggest that commodity type affects the number of prey attacked by this predator.

Functional and numerical responses of Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) to different biological stages of Eutetranychus orientalis (Klein) (Acari: Tetranychidae)*

2021 ◽  
Author(s):  
İsmail Döker ◽  
Kemal Yalcin ◽  
Kamil Karut ◽  
Cengiz Kazak
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Handling Time ◽  
Predatory Mite ◽  
Type Ii ◽  
Adult Males ◽  
Response Curves ◽  
Iphiseius Degenerans ◽  
Eggs And Larvae ◽  
Type Ii Functional Response

Functional and numerical responses of the predatory mite, Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) to four different biological stages (egg, larva, protonymph and adult male) of the citrus brown mite, Eutetranychus orientalis (Klein) (Acari: Tetranychidae) were determined under laboratory conditions. In the experiments, six different prey densities (5, 10, 20, 40, 60 and 80) for each biological stage of the prey were provided to the predatory mite for 24 hours. Results showed that the proportion of prey consumption of I. degenerans decelerated with increasing prey densities of all biological stages of the prey. Logistic regression analysis indicated that I. degenerans showed a Type II functional response regardless of prey stage. The attack rate (α) and the handling time (Th) varied based on the biological stages. The highest α (1.596) and the lowest Th (0.014) values were determined when the predator fed on adult males and larvae of E. orientalis, respectively. The numerical response curves were similar to those of Type II functional response. The efficiency of conversion of ingested food (ECI) of female I. degenerans decreased on all biological stages when prey density increased. The highest and the lowest average daily mean number of eggs laid by I. degenerans were found as 0.45 and 1.90 when it fed on eggs and larvae of its prey, respectively. According to the results, I. degenerans has a potential to be used as a predator in biological control of E. orientalis.

Resource partitioning in a ladybird,Menochilus sexmaculatus: function of body size and prey density

2014 ◽  
Vol 105 (1) ◽  
pp. 121-128 ◽  
Author(s):  
D.D. Chaudhary ◽  
B. Kumar ◽  
G. Mishra ◽  
Omkar
Keyword(s):  
Body Size ◽  
Functional Response ◽  
Resource Partitioning ◽  
Prey Density ◽  
Aphis Craccivora ◽  
Numerical Response ◽  
Type Ii ◽  
Choice Condition ◽  
Positive Correlation ◽  
Type Ii Functional Response

AbstractIn the present study, resource partitioning by natural conspecific size variants (small and large) of ladybird,Menochilus sexmaculatus(Fabricius) females, in response to varying prey densities was assessed using functional and numerical responses as measures of prey density. The prey provided was small (second) and large (fourth) instars ofAphis craccivoraKoch. Results revealed that under choice condition, small and large females ofM. sexmaculatusconsumed higher number of small and large instars, respectively. Small females exhibited a modified Type II functional response on small aphid instars and a Type II functional response on fourth aphid instars. Large females exhibited a Type II functional response when provided either second or fourth aphid instars. Numerical response in terms of numbers of eggs laid by both the females increased with increase in the density of either of the aphid instars. However, in small females, oviposition had a positive correlation with the numbers of small and large aphid instars consumed; being strong for the small aphid instars. While in large females, oviposition was positively correlated with the numbers of large aphid instars consumed and not small aphid instars. It therefore seems that intraspecific resource partitioning inM. sexmaculatusoccurs prominently in large females than the small females.

Functional and numerical responses of Neoseiulus barkeri (Acari: Phytoseiidae) on two-spotted spider mite: the effect of patch condition and additional food source

2021 ◽  
Vol 26 (3) ◽  
pp. 543-556
Author(s):  
Yaghoub Fathipour ◽  
Bahador Maleknia ◽  
Abdoolnabi Bagheri ◽  
Mahmoud Soufbaf ◽  
Myron P. Zalucki
Keyword(s):  
Biological Control ◽  
Functional Response ◽  
Foraging Behavior ◽  
Prey Density ◽  
Food Source ◽  
Numerical Response ◽  
Type Ii ◽  
Additional Food ◽  
Neoseiulus Barkeri ◽  
Type Ii Functional Response

Parameters that describe foraging behavior play a key role in selection of natural enemies used in biological control programs. These parameters are greatly affected by patch condition and food source type. This study was carried out to evaluate foraging behavior in Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae), a predatory mite of Tetranychus urticae Koch under different patch and diet conditions. The predation rate of N. barkeri at different egg and nymph densities of T. urticae (2, 4, 8, 16, 32, 64, 128) was investigated in both limited and unlimited patches either in the presence or absence of pollen as an additional food source under laboratory conditions. A Type II functional response was determined for N. barkeri on eggs or nymphs of T. urticae in both unlimited and limited patches. The type of functional response was not affected by presence or absence of pollen. The numerical response, in terms of eggs laid, increased curvilinear with increasing prey density. The numerical response was similar in shape to a Type II functional response. The efficiency of conversion of ingested food (ECI) of female N. barkeri decreased in all treatments when prey density increased. The type of patch (limited or unlimited) and prey stage (egg or nymph in the presence or absence of pollen) can affect searching efficiency (a) and handling time (Th) (functional response) as well as daily fecundity and ECI (numerical response) of the phytoseiid predator mite, N. barkeri with implications for its use in biological control.

Predator-dependent transmissible disease spreading in prey under Holling type-II functional response

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dipankar Ghosh ◽  
Prasun K. Santra ◽  
Abdelalim A. Elsadany ◽  
Ghanshaym S. Mahapatra
Keyword(s):  
Functional Response ◽  
Prey Species ◽  
Linearization Method ◽  
Logistic Growth ◽  
Type Ii ◽  
Disease Spreading ◽  
Predator Interactions ◽  
The Stability ◽  
Infected Prey ◽  
Type Ii Functional Response

Abstract This paper focusses on developing two species, where only prey species suffers by a contagious disease. We consider the logistic growth rate of the prey population. The interaction between susceptible prey and infected prey with predator is presumed to be ruled by Holling type II and I functional response, respectively. A healthy prey is infected when it comes in direct contact with infected prey, and we also assume that predator-dependent disease spreads within the system. This research reveals that the transmission of this predator-dependent disease can have critical repercussions for the shaping of prey–predator interactions. The solution of the model is examined in relation to survival, uniqueness and boundedness. The positivity, feasibility and the stability conditions of the fixed points of the system are analysed by applying the linearization method and the Jacobian matrix method.

scholarly journals Demography and feeding behavior of Stenostomum leucops (Dugés, 1828)

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Alma R. Núñez-Ortiz ◽  
Sarma Nandini ◽  
S.S.S. Nandini
Keyword(s):  
Functional Response ◽  
Food Preference ◽  
Type Ii ◽  
Final Density ◽  
Two Temperatures ◽  
The Difference ◽  
Growth Experiments ◽  
Pelagic Communities ◽  
Type Ii Functional Response ◽  
Planktonic Communities

<p>Freshwater turbellarians, despite their mainly benthic habits, interact with pelagic communities of rotifers and cladocerans. However, very little is known about their demographic characteristics, food preference and functional response. To fill that gap we studied one of the most widely spread species, <em>Stenostomum leucops</em>.  We conducted population growth experiments using abundant food (several rotifer and cladocerans species). To evaluate possible impact of <em>S. leucops</em> on planktonic communities, we conducted prey preference experiments at two temperatures: 18 and 23°C. The number of rotifers and cladocerans consumed was calculated by the difference between the initial and final density. We found that diets supplemented with fresh algae achieved higher <em>S. leucops</em> densities than those with detritus supplements in their diets. In the case of animal diets, <em>Euchlanis dilatata</em> allowed <em>S. leucops</em> reach higher densities than the other zooplankton species; <em>E. dilatata</em> was positively selected for in the selectivity study at both 18 and 23°C.  <em>Stenostomum leucops</em> showed a type II functional response on rotifers and the cladoceran <em>Alona glabra</em>. Our results suggest that <em>S. leucops</em> select their prey according to their vulnerability using different mechanisms, which optimize their food intake.</p>

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