scholarly journals Functional Response and Predation Potential of Carabus elysii Adults against the Terrestrial Slug Agriolimax agrestis

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1135
Author(s):  
Lin Jiang ◽  
Runa Zhao ◽  
Hui Tian ◽  
Xuesan Wu ◽  
Feng Guo ◽  
...  
Keyword(s):  
Biological Control ◽  
Functional Response ◽  
Laboratory Experiments ◽  
Ground Beetle ◽  
Type Ii ◽  
Adult Males ◽  
Predator Density ◽  
Negative Effects ◽  
Functional Responses ◽  
The Impact

Terrestrial slugs are a prominent agricultural pest worldwide. To mitigate the negative effects of chemical pest control, biological control involves the use of natural enemies to reduce the impact of target pests. Numerous insects are natural predators of slugs. This study evaluated potential of the predatory species, Carabus elysii Thomson (Coleoptera: Carabidae) to biologically control the terrestrial slug, Agriolimax agrestis. Laboratory experiments were conducted to investigate the functional response, searching efficiency, and interference effect of female and male C. elysii adults regarding adult, immature, and juvenile A. agrestis individuals. The results show that both female and male ground beetle adults are functionally capable of preying on different sizes of terrestrial slugs. C. elysii exhibited Holling type II functional responses when preying on A. agrestis. The maximum daily prey consumption was 35.5 juveniles, 25.1 immatures, and 17.1 adults for adult females and 26.9 juveniles, 20.3 immatures, and 11.6 adults for adult males. The searching efficiency of female C. elysii adults regarding A. agrestis was always higher than that of male adults for identical ages and densities of A. agrestis. Moreover, the predation of C. elysii on slugs was affected by predator density. The disturbance coefficient of male C. elysii were the highest on adult A. agrestis. The results of this study suggest that female C. elysii exhibit a high potential for the biological control of A. agrestis.

scholarly journals Functional response of the predatory mite Amblyseius swirskii (Acari: Phytoseiidae) to Eotetranychus frosti (Tetranychidae) and Cenopalpus irani (Tenuipalpidae)

Acarologia ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 30-39
Author(s):  
Fereshteh Bazgir ◽  
Jahanshir Shakarami ◽  
Shahriar Jafari
Keyword(s):  
Biological Control ◽  
Functional Response ◽  
Attack Rate ◽  
Biological Control Agent ◽  
Handling Time ◽  
Rate Coefficients ◽  
Immature Stages ◽  
Amblyseius Swirskii ◽  
Functional Responses ◽  
Phytoseiid Mites

Eotetranychus frosti and Cenopalpus irani Dosse are pests of apple trees that are widely distributed in apple orchards in Iran. The functional responses and predation rates of Amblyseius swirskii, one of the most commonly utilized phytoseiid mites for biological control, on these two pests were evaluated at 25 ± 1 °C, with 16:8 h L: D, and a relative humidity of 60 ± 10 % on apple leaves. The results of predation rate experiments on the two prey species indicated that the predator consumed significantly more eggs than larvae and protonymphs whereas consumption of deutonymphs were very rare. Likewise, the results of logistic regression analysis showed that A. swirskii exhibited a Type II functional response on all immature stages of E. frosti and C. irani. Handling time (Th) increased as prey size enlarged; the lowest handling times were determined as 0.4858 and 0.3819 h on eggs of E. frosti and C. irani, respectively, whereas the highest were found to be 1.4007 and 1.0190 h on deutonymphs, respectively. Amblyseius swirskii had the higher attack rate coefficient (α) on immature stages of C. irani than E. frosti. Attack rate coefficients (α) varied significantly between life stages of both pests with the highest attack rate obtained on eggs, followed by larvae, protonymphs, and deutonymphs. Results of this study suggest that A. swirskii could be a highly efficient biological control agent of E. frosti and C. irani at least at low prey densities.

scholarly journals Microzooplankton functional responses in the lab and in the field

2014 ◽  
Vol 7 (1) ◽  
pp. 149-167 ◽  
Author(s):  
S. F. Sailley ◽  
E. T. Buitenhuis
Keyword(s):  
Growth Rate ◽  
Functional Response ◽  
Laboratory Experiments ◽  
Nutrient Content ◽  
Growth Efficiency ◽  
External Factors ◽  
Data Sets ◽  
Functional Responses ◽  
Prey Concentration ◽  
Gross Growth Efficiency

Abstract. We present a collection of data relating to microzooplankton physiological traits collected from the literature. We define microzooplankton as unicellular zooplankton (protozoans). The collected data mostly relates to grazing rates collected either in the field or through laboratory experiments. There is an equal number of grazing and growth rate measured through laboratory experiments and a smaller number of Gross Growth Efficiency (GGE), respiration and egestion values. Although the collected data showed inconsistencies in units, or gaps in knowledge of microzooplankton (e.g. effect of prey nutrient content, combined measurement of grazing and growth), they also contained information on microzooplankton functional response, and how some external factors affect them (e.g. prey concentration, prey offered, temperature). Link to the repository: doi:10.1594/PANGAEA.820368 and doi:10.1594/PANGAEA.826106. Note that the sum of all data sets differs from the present data compilations which provides harmonized units and temperature adjusted metabolic. Within the repository there is a link to the "raw" dataset.

scholarly journals Predator type influences the frequency of functional responses to prey in marine habitats

2020 ◽  
Vol 16 (1) ◽  
pp. 20190758 ◽  
Author(s):  
Robert P. Dunn ◽  
Kevin A. Hovel
Keyword(s):  
Functional Response ◽  
Handling Time ◽  
Type Ii ◽  
Population Stability ◽  
Functional Responses ◽  
Type Iii ◽  
Marine Habitats ◽  
Per Capita ◽  
Predatory Fishes ◽  
Parameter Values

The functional response of a consumer to a gradient of resource density is a widespread and consistent framework used to quantify the importance of consumption to population dynamics and stability. Within benthic marine ecosystems, both crustaceans and fishes can provide strong top-down pressure on prey populations. Taxon-specific differences in biomechanics or habitat use, among other factors, may lead to variable functional response forms or parameter values (attack rate, handling time). Based on a review of 189 individual functional response fits, we find that these predator guilds differ in their frequency distribution of functional response types, with crustaceans exhibiting nearly double the proportion of sigmoidal, density-dependent functional responses (Holling type III) as predatory fishes. The implications of this finding for prey population stability are significant because type III responses allow prey persistence while type II responses are de-stabilizing and can lead to extinction. Comparing per capita predation rates across diverse taxa can provide integrative insights into predatory effects and the ability of predation to drive community structure.

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.

Functional response of kokanee salmon (Oncorhynchus nerka) to Daphnia at different light levels

2002 ◽  
Vol 59 (4) ◽  
pp. 707-716 ◽  
Author(s):  
Marci L Koski ◽  
Brett M Johnson
Keyword(s):  
Functional Response ◽  
Oncorhynchus Nerka ◽  
Search Time ◽  
Type I ◽  
Type Ii ◽  
Functional Responses ◽  
Foraging Mode ◽  
Kokanee Salmon ◽  
Light Levels ◽  
Type Ii Functional Response

In laboratory experiments, fingerling kokanee salmon (Oncorhynchus nerka, 3–8 g) were presented with varying densities of zooplankton prey (Daphnia spp.) ranging from 3 to 55 Daphnia·L–1, under three light intensities (30, 15, and 0.1 lx). Kokanee exhibited a type I functional response at 0.1 lx (Daphnia consumption·min–1 = 1.74 prey·L–1), a light level typical of moonlit epilimnetic conditions, but shifted to a type II functional response at higher light levels. Both 15 and 30 lx light levels occur during crepuscular periods when kokanee feeding is maximal in the wild, and consumption rates at these light levels were not significantly different (Daphnia consumption·min–1 = (163.6 prey·L–1)(42.2 prey·L–1)–1). The shift from the type I to type II functional response may be attributed to a foraging mode switch and the incorporation of search time instead of random encounters with prey. Using these models to simulate feeding rates in a Colorado reservoir, attenuation of light intensity and prey density between the epilimnion and hypolimnion resulted in a 100-fold increase in predicted feeding duration. Functional responses that incorporate environmental characteristics like light are important components of foraging models that seek to understand fish consumption, growth, and behavior.

Evaluation of alternative prey-, predator-, and ratio-dependent functional response models in a zooplankton microcosm

2017 ◽  
Vol 95 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Christina M. Prokopenko ◽  
Katrine Turgeon ◽  
John M. Fryxell
Keyword(s):  
Functional Response ◽  
Theoretic Approach ◽  
Type Ii ◽  
Predator Density ◽  
Response Models ◽  
Predator Interference ◽  
Kill Rate ◽  
Ratio Dependent ◽  
Functional Response Models ◽  
Rotifer Brachionus Calyciflorus

There is strenuous debate among ecologists regarding the inclusion of predator density into the originally prey-dependent functional response. We provided comprehensive empirical comparisons of alternative functional response models for the predatory ostracod Heterocypris incongruens (Ramdohr, 1808) and the rotifer Brachionus calyciflorus (Pallas, 1766) as its prey in small freshwater microcosms. Prey killed was measured at factorial combinations of four predator densities and five prey densities, and was recorded at 3 min intervals over 60 min experiments. To support the potential effect of predator interference on per capita kill rate, we recorded ostracod activity and aggression. Kill rate increased following a saturating function with increasing prey density and decreased with increasing predator density. Model evaluation using an information–theoretic approach indicated that the Arditi–Ginzburg type II ratio-dependent model performed best, followed by the Arditi–Akcakaya and Beddington–DeAngelis type II predator-dependent models, suggesting that predator interference was important in predicting kill rates. Interference among predators increased and their activity decreased with increasing predator density, providing confirmation that interference was responsible for the predator-dependent effect. By combining a microcosm experiment and behavioral observations, our results suggest that predator interference at realistic population densities influences ostracod kill rates and this form of interference was best accommodated by predator-dependent models.

scholarly journals The functional response of, Chrysoperla carnea (Stephens) larvae on different nymphal instars of Dubas bug Ommatissus lybicus De Berg.

2014 ◽  
Vol 8 (2) ◽  
pp. 80-85
Author(s):  
Bassim. Sh. Hamad ◽  
Ryadh A. Okaily ◽  
George S. B. Yousif ◽  
Ahmed M. Abdullatif ◽  
Hussain F. Alrubeai
Keyword(s):  
Functional Response ◽  
Attack Rate ◽  
Larval Instar ◽  
Handling Time ◽  
Chrysoperla Carnea ◽  
Type Ii ◽  
Nymphal Instar ◽  
Functional Responses ◽  
Larval Instars ◽  
The Third

The functional response of second and third larval instars of Chrysoperla carnea (Stephens), against different nymphal instars of Dubas bug Ommatissus lybicus De Berg. was studied.The larval instars of the predator exhibited Type II functional responses against the prey. Based on disk equation the attack rate (a) of the second larval instars of the predator were estimated to 1.03± 0.043 , 0.94± 0.015 , 0.88± 0.009 and 0.77 ± 0.02 and the handling time (Th) were 0.0031, 0.0039, 0.0083, and 0.008 day for second, third, fourth and fifth nymphal instars respectively. The third instars larvae of the predator, the attack rate against these nymphal instars were 1.11± 0.01, 1.04 ± 0.29 , 0.97± 0.017 and 0.89 with handling time 0.0019, 0.0028, 0.0064, and 0.0067 day respectively. The theoretical maximum predation(T/Th) of the second larval instars were 322, 256, 120 and114 nymphs for second, third, fourth and fifth nymphal instar respectively; while they were 526, 357, 156, and 149 for the third larval instar. According to this study this predator have a good predation potential in preying on nymph of Dubas bug especially the small nymphs (second and third ).

scholarly journals Local Stability Analysis On Lotka-Volterra Predator-Prey Models Functional Responses With Constant prey Refuge

2021 ◽  
Author(s):  
Chongming Li
Keyword(s):  
Stability Analysis ◽  
Functional Response ◽  
Local Stability ◽  
Equilibrium Points ◽  
Saddle Points ◽  
Stable Node ◽  
Type I ◽  
Type Ii ◽  
Functional Responses ◽  
Type Ii Functional Response

The dynamical behaviours of the predators and prey can be described by studying the local stability of the planar systems. Type I functional response shows that the rate of consumption per predator is proportional to prey’s density while type II functional response is related to the situation that predators would reach satiation as they consumed sufficient amount of prey. We seek out a method of using transformation to reduce the number of parameters of original models and then study the stability analysis of equilibrium points. Under suitable restrictions on the new parameters, we prove that the positive interior equilibrium is a stable node for the system of type I and type II functional responses. Moreover, in the case of type II functional response, the boundary equilibria can have more types of stability other than saddle points.

Challenges for the Future of Functional Response Research

2021 ◽  
pp. 133-144
Author(s):  
John P. DeLong
Keyword(s):  
Food Webs ◽  
Functional Response ◽  
Individual Variation ◽  
Functional Responses ◽  
Community Interactions ◽  
Invasive Predators ◽  
The Future ◽  
Behavioral Mechanisms ◽  
Future Work ◽  
The Impact

Being recognized for more than 70 years and estimated thousands of times, with numerous analyses of compilations, it would seem there is a lot we should know about functional responses. Indeed, we know some of the ways in which functional responses vary, how foraging mechanisms combine to determine, to at least some extent, functional response parameters, and how functional responses influence community interactions from biocontrol impacts to invasive predators to food webs. I suggest, however, that there remains a considerable amount that we do not know, in particular for field-based functional responses, multi-species functional responses, individual variation, behavioral mechanisms, and the impact and evolution of underlying traits. I suggest these areas should be high priorities for future work on functional responses.

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