Related Experiment Video
Updated: Apr 2, 2026
09:23
Methodology for Developing Life Tables for Sessile Insects in the Field Using the Whitefly, Bemisia tabaci, in Cotton As a Model System
Published on: November 1, 2017
12.7K
Population dynamics of apparent competition in a host-parasitoid assemblage
1Department of Biology and NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire, SL5 7PY, UK.
The Journal of Animal Ecology
|September 29, 2015
Summary
Apparent competition dynamics were studied in a lab insect assemblage. The parasitoid Venturia canescens eliminated Ephestia kuehniella, while Plodia interpunctella persisted, showing delayed density dependence.
Area of Science:
- Ecology
- Population Dynamics
- Insect Ecology
Background:
- Apparent competition occurs when two species interact indirectly through a shared enemy.
- Understanding these indirect interactions is crucial for predicting community dynamics.
- Laboratory insect assemblages provide controlled environments to study ecological interactions.
Purpose of the Study:
- To investigate the population dynamics of two moth species, Plodia interpunctella and Ephestia kuehniella, under apparent competition with a shared parasitoid, Venturia canescens.
- To analyze the consequences of indirect interactions on the stability and persistence of the insect populations.
- To quantify the strength and nature of the apparent competition between the two moth species.
Main Methods:
- Conducting well-replicated time series experiments with controlled laboratory conditions.
- Utilizing time series analysis to examine population fluctuations and identify density dependence.
- Employing repeated-measures analysis to assess the strength of indirect interactions.
Main Results:
- Ephestia kuehniella populations were eliminated in all replicates due to the presence of the shared parasitoid, Venturia canescens.
- Plodia interpunctella and Venturia canescens populations persisted, exhibiting delayed density dependence.
- Time series analysis indicated stable equilibrium or damped oscillations in the persistent populations.
- The indirect interaction between E. kuehniella and P. interpunctella was characterized as amensal ([-, 0]) before E. kuehniella extinction.
Conclusions:
- Apparent competition can lead to the exclusion of one species (E. kuehniella) when interacting with a shared parasitoid.
- The dynamics of apparent competition can result in persistent populations of the other species (P. interpunctella) with delayed density dependence.
- This study highlights the significant impact of indirect interactions on structuring ecological communities.
More Related Videos
Related Concept Videos
02:34Competition
25.4K
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.
25.4K
00:57Population Growth
29.5K
Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.
29.5K
01:22Microbial Interactions: Parasitism
55
Parasitism is a form of microbial interaction in which parasitic microbes exploit a host organism for nutrients and shelter, often at the host's expense. Unlike mutualistic relationships, where both organisms benefit, parasitism benefits only the parasite and harms the host.Classification of ParasitesMicrobial parasites are broadly classified based on their location relative to the host.Ectoparasites remain on the host’s surface, such as the skin or outer tissues, drawing nutrients...
55
01:26Microbial Interactions: Competition
54
Microbial competition is an ecological interaction in which microorganisms vie for limited resources within shared environments. These resources may include nutrients, space, or light, depending on the system. The intensity and outcome of competition are influenced by the environmental context, such as nutrient availability, spatial constraints, and the diversity of microbial species present. These competitive interactions significantly influence the structure, function, and resilience of...
54
02:39Predator-Prey Interactions
22.3K
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.
22.3K
00:30What are Populations and Communities?
38.6K
Overview
38.6K