scholarly journals Differential Interaction Strengths and Prey Preferences Across Larval Mosquito Ontogeny by a Cohabiting Predatory Midge

2019 ◽  
Vol 56 (5) ◽  
pp. 1428-1432 ◽  
Author(s):  
Ross N Cuthbert ◽  
Amanda Callaghan ◽  
Jaimie T A Dick
Keyword(s):  
Functional Response ◽  
Natural Enemy ◽  
Population Level ◽  
Prey Type ◽  
Water Volume ◽  
Feeding Rates ◽  
Larval Stages ◽  
Prey Preferences ◽  
Late Instar ◽  
Size Refuge

Abstract Understandings of natural enemy efficacy are reliant on robust quantifications of interaction strengths under context-dependencies. For medically important mosquitoes, rapid growth during aquatic larval stages could impede natural enemy impacts through size refuge effects. The identification of biocontrol agents which are unimpeded by ontogenic size variability of prey is therefore vital. We use functional response and prey preference experiments to examine the interaction strengths and selectivity traits of larvae of the cohabiting predatory midge Chaoborus flavicans (Meigen 1830) (Diptera: Chaoboridae) towards larval stages of the Culex pipiens (Diptera: Culicidae) mosquito complex. Moreover, we examine the influence of search area variation on selectivity traits, given its importance in consumer-resource interactions. Chaoborids were able to capture and consume mosquito prey across their larval ontogeny. When prey types were available individually, a destabilizing Type II functional response was exhibited towards late instar mosquito prey, whereas a more stabilizing Type III functional response was displayed towards early instars. Accordingly, search efficiencies were lowest towards early instar prey, whereas, conversely, maximum feeding rates were highest towards this smaller prey type. However, when the prey types were present simultaneously, C. flavicans exhibited a significant positive preference for late instar prey, irrespective of water volume. Our results identify larval chaoborids as efficacious natural enemies of mosquito prey, with which they frequently coexist in aquatic environments. In particular, an ability to prey on mosquitoes across their larval stages, coupled with a preference for late instar prey, could enable high population-level offtake rates and negate compensatory reductions in intraspecific competition through size refuge.

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.

Detecting Prey Preferences and Prey Switching

2021 ◽  
pp. 89-100
Author(s):  
John P. DeLong
Keyword(s):  
Functional Response ◽  
Single Species ◽  
Prey Choice ◽  
Prey Switching ◽  
Prey Preferences ◽  
Different Types ◽  
Simplified Analysis

In this chapter I consider the question of whether predators switch their preference for different types of prey as those prey change in abundance. There are numerous experiments in the literature focusing on this, but generally they have focused on a simplified analysis that ignores the functional response. Here I show why the functional response is crucial for understanding prey choice, and I show that null expectations considering a multi-species functional response lead to different interpretations than standard null expectations. I also derive null expectations for the proportion of prey consumed given the single-species functional response.

scholarly journals Functional Response of Chrysoperla carnea (Neuroptera: Chrysopidae) Larvae on Saissetia oleae (Olivier) (Hemiptera: Coccidae): Implications for Biological Control

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1511
Author(s):  
Abdelkader Meni Mahzoum ◽  
María Villa ◽  
Jacinto Benhadi-Marín ◽  
José Alberto Pereira
Keyword(s):  
Functional Response ◽  
Attack Rate ◽  
Larval Instar ◽  
Food Resource ◽  
Handling Time ◽  
Scale Insects ◽  
Chrysoperla Carnea ◽  
Larval Stages ◽  
The Third ◽  
Saissetia Oleae

Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a voracious predator of soft-bodied insects such as juveniles of scale insects and the black scale Saissetia oleae (Olivier) (Hemiptera: Coccidae) is an important pest of several crops, such as the olive tree. However, the predatory efficiency of C. carnea on S. oleae has been unstudied yet. The present work aimed to study the functional response of larvae of C. carnea fed on S. oleae nymphs. In a controlled laboratory environment, increasing densities of S. oleae second and third nymph stages were offered to newly emerged specimens of the three larvae instars of C. carnea. After 24 h, the number of killed S. oleae was recorded and the functional response of C. carnea was assessed. The three larval stages of C. carnea displayed a type-II functional response, i.e., killed prey increased with higher S. oleae densities up to a maximum limited by the handling time. The attack rate did not significantly differ among the three instars while the maximum attack rate was significantly higher for the third instar. The handling time of the first larval instar of C. carnea was higher than that of the third instar. Our results demonstrated that S. oleae could act as a food resource for all larval stages of C. carnea. Furthermore, the third larval stage of the predator was the most efficient in reducing S. oleae densities. These results suggest that C. carnea larvae could contribute to S. oleae control in sustainable agriculture.

scholarly journals Population dynamics of rice leaffolders (Lepidoptera: Pyralidae) and their natural enemies in irrigated rice in the Philippines

1999 ◽  
Vol 89 (5) ◽  
pp. 411-421 ◽  
Author(s):  
J. de Kraker ◽  
A. van Huis ◽  
K.L. Heong ◽  
J.C. van Lenteren ◽  
R. Rabbinge
Keyword(s):  
Population Dynamics ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Survival Rates ◽  
The Philippines ◽  
Cnaphalocrocis Medinalis ◽  
Irrigated Rice ◽  
Larval Stages ◽  
Ovipositional Preference ◽  
Rice Leaffolders

AbstractPopulations of rice leaffolders and their natural enemies were studied in eight crops of irrigated rice in Laguna Province, the Philippines. The rice leaffolder complex consisted of three species: Cnaphalocrocis medinalis (Guenée), Marasmia patnalis Bradley and M. exigua Butler. Leaffolder population dynamics were characterized by an egg peak at maximum tillering and a broad larval peak around booting stage. Peak densities ranged from 0.2 to 2.0 larvae per hill. Most larvae originated from immigrant moths and there was no substantial second generation. The seasonal percentage egg parasitism by Trichogramma sp. ranged from 0 to 27%, and percentage larval parasitism from 14 to 56%. The braconid Macrocentrus philippinensis Ashmead was the most commonly reared larval parasitoid. Forty natural enemy taxa that may attack rice leaffolders were identified from suction and sweepnet samples: 24 predator taxa and 16 parasitoid taxa. The estimated survival rates from leaffolder egg to larval stages and between larval stages showed large variation between rice crops, but were not clearly correlated with observed levels of parasitism, natural enemy abundance, or natural enemy to leaffolder ratios. It is suggested that the generally low densities of rice leaffolders in Philippine transplanted rice are caused by their ovipositional preference for crops at the maximum tillering stage, allowing for only one generation, and by high immature mortality caused by the abundant and diverse complex of natural enemies.

scholarly journals A novel metric reveals biotic resistance potential and informs predictions of invasion success

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ross N. Cuthbert ◽  
Amanda Callaghan ◽  
Jaimie T. A. Dick
Keyword(s):  
Biotic Resistance ◽  
Global Scale ◽  
Invasion Success ◽  
Feeding Rates ◽  
Functional Responses ◽  
Predictive Capacity ◽  
Prey Switching ◽  
Prey Preferences ◽  
Ecological Concepts ◽  
Frequency Independent

Abstract Invasive species continue to proliferate and detrimentally impact ecosystems on a global scale. Whilst impacts are well-documented for many invaders, we lack tools to predict biotic resistance and invasion success. Biotic resistance from communities may be a particularly important determinant of the success of invaders. The present study develops traditional ecological concepts to better understand and quantify biotic resistance. We quantified predation towards the highly invasive Asian tiger mosquito Aedes albopictus and a representative native mosquito Culex pipiens by three native and widespread cyclopoid copepods, using functional response and prey switching experiments. All copepods demonstrated higher magnitude type II functional responses towards the invasive prey over the analogous native prey, aligned with higher attack and maximum feeding rates. All predators exhibited significant, frequency-independent prey preferences for the invader. With these results, we developed a novel metric for biotic resistance which integrates predator numerical response proxies, revealing differential biotic resistance potential among predators. Our results are consistent with field patterns of biotic resistance and invasion success, illustrating the predictive capacity of our methods. We thus propose the further development of traditional ecological concepts, such as functional responses, numerical responses and prey switching, in the evaluation of biotic resistance and invasion success.

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.

Effects of an Experimental Lake Acidification on Zooplankton Feeding Rates and Selectivity

1990 ◽  
Vol 47 (4) ◽  
pp. 772-779 ◽  
Author(s):  
Michael E. Sierszen ◽  
Thomas M. Frost
Keyword(s):  
Population Level ◽  
Plankton Community ◽  
Lake Acidification ◽  
System Level ◽  
Phytoplankton Species ◽  
Fine Scale ◽  
Important Process ◽  
Selective Feeding ◽  
Feeding Rates ◽  
Integrative System

Although the changes in plankton community composition that result from lake acidification have been documented, little is known about processes that accompany these changes. Here we report investigations on an important process, zooplankton herbivory, in an experimentally acidified lake. Acidification from pH 6.2 to 5.2 has not directly impaired the ability of several major taxa to gather food. Acidification may indirectly affect selective feeding behavior, through changes in the relative abundance of phytoplankton species. Dramatic shifts in population-level grazing were not reflected in overall community herbivory, because of complementary changes in populations in the reference and treatment lake basins. Hence, integrative system-level functions may be poorer indicators of perturbation than specific, fine-scale processes.

Selective predation on cladocerans by common pond insects

1983 ◽  
Vol 61 (4) ◽  
pp. 879-886 ◽  
Author(s):  
Scott D. Cooper
Keyword(s):  
Light Conditions ◽  
Selective Feeding ◽  
Feeding Rates ◽  
Selective Predation ◽  
Anax Junius ◽  
First Instar ◽  
Chaoborus Americanus ◽  
Late Instar ◽  
Insect Predators ◽  
Predation Rates

A variety of common pond insects was presented with a mixture of different size classes of Daphnia magna or different sizes of Daphia pulex, Moina affinis, and Ceriodaphnia sp. in predation trials. Juvenile Belostoma flumineum and most instars of Notonecta undulata and Anax Junius fed at the highest rates on the largest available cladoceran prey, and late-instar Buenoa corfusa fed at the highest rates on prey between 0.8 and 2.0 mm in length. Predation rates of instar IV Chaoborus americanus larvae were highest on Daphnia < 1 mm in length, and lowest on Daphnia > 2 mm in length. First-instar Chaoborus larvae did not eat cladocerans in these trials. The size-selective feeding patterns exhibited by Notonecta adults and late-instar Anax were similar in the light and dark, although overall feeding rates were depressed in the dark. Buenoa, on the other hand, only exhibited size-selective feeding in the light. The results indicate, however, that all of these insect predators can feed in the dark. Predation rates for late-instar Chaoborus larvae were unaffected by light conditions or the presence of filamentous algae. Chaoborus larvae were readily eaten by late-instar Notonecta and Anax.

Lethal and Sublethal Toxicity of Drilling Fluids to Larvae of the American Lobster, Homarus americanus

1984 ◽  
Vol 41 (9) ◽  
pp. 1334-1340 ◽  
Author(s):  
Jennifer G. Smith Derby ◽  
Judith M. Capuzzo
Keyword(s):  
Sublethal Effects ◽  
Drilling Fluid ◽  
Homarus Americanus ◽  
Diesel Oil ◽  
Chemical Components ◽  
American Lobster ◽  
Drilling Fluids ◽  
Feeding Rates ◽  
Fine Grained ◽  
Larval Stages

The lethal and sublethal effects of five used, whole drilling fluids on the larval stages of the American lobster (Homarus americanus) were assessed in laboratory experiments using a continuous-flow bioassay. Although the five tested drilling fluids varied markedly in their toxicity, some were highly toxic, with LC50 values as low as 74 mg/L. Sublethal exposures to drilling fluids at concentrations as low as 10–50 mg/L resulted in reduced respiration rates, reduced O:N ratios, and increased protein:lipid ratios, demonstrating a change in energetics of the larval lobsters. Growth and development of the larvae were seriously impaired by exposure to three of the five drilling fluids at concentrations of 50 and 100 mg/L. The feeding rates were also significantly reduced after a 24-h exposure to 50 mg/L drilling fluid. Exposure of larvae to barite (a major component of drilling fluids) and to a field-collected, fine-grained sediment did not result in deleterious effects. We suggest that the chemical components and not the physical properties of the drilling fluids are primarily responsible for detrimental effects. From results of the chemical analyses of the tested drilling fluids, we consider that the adverse effects of these drilling fluids cannot be attributed to any one group of chemicals. For example, diesel oil, a known toxicant, was present in the more toxic drilling fluids; however, there was no direct correlation between the toxicity of a drilling fluid and diesel oil concentration. Phenolic compounds, various metals, and other components probably also contributed to the toxicity of these drilling fluids.

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