Tag Archives: insects

Like a House of Cards

An empirical attack tolerance test alters the structure and species richness of plant–pollinator networks (2020) Biella et al., Functional Ecology, https://doi.org/10.1111/1365-2435.13642

Image Credit: Adamantios, CC BY-SA 3.0, Image Cropped

The Crux

Put simply, ecosystem function is the process that control how nutrients, energy, and organic matter move through an environment. Think about a forest. You have small plants that are eaten by small animals, small animals that are eaten by larger animals, and those larger animals are eaten by even larger animals. When those animals die, they are broken down and consumed by scavengers, fungi, and bacteria. These processes result in a continuous flow of nutrients and energy through the ecosystem. However, if one link (organism) in this chain breaks (goes extinct), the ecosystem could lose its function, and other species that depend on this cycle could go extinct as well.

The way in which a given ecosystem reacts to or recovers from any negative impact that it sustains is key to understanding how ecosystems function. Classically, this is tested with attack tolerance tests, in which all species on a given trophic level are removed and the ecosystem is then monitored to see how/if it maintains its function. In studies of plant-pollinator networks, this is usually modeled with computers, but studies which use natural systems are lacking. Today’s authors wanted to use a natural plant-pollinator system to see what happens.

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It’s What and Where You Eat

Animals depend on consumable energy to live, and that energy can come from a variety of places. If the energy that animals get from their food varies in quality depending on where the animals get their food, what does this mean for birds like the Eastern Phoebe (Sayornis phoebe) that consumes both terrestrial and aquatic food? (Image Credit: Andrew CannizzaroCC BY 2.0, Image Cropped).

Aquatic and terrestrial resources are not nutritionally reciprocal for consumers (2019) Twining et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13401

The Crux

In the natural world, ecological subsidies, or the influx of sustenance from one habitat type to another, connect a variety of environments. While research has been conducted on this topic in the past, most of it has dealt with the quantity of energy moving between habitats, but not the quality of the resource itself.

When one habitat (such as an aquatic habitat) is rich in a specific resource that is hard to find in other habitats, subsidies of these resources play a unique role by providing animals and plants with food or energy that they could otherwise not get. The authors of today’s paper wanted to investigate if subsidies from aquatic habitats and terrestrial habitats contain the same amount of that hard to find, valuable resource: highly unsaturated omega-3 fatty acids (HUFAs). Read more

Changing with the Climate

An immature female blue-tailed damselfly (Ischnura elegans)

An immature female blue-tailed damselfly (Ischnura elegans) (Image Credit: Charles J Sharp, CC BY-SA 4.0, Image Cropped)

Signatures of local adaptation along environmental gradients in a range-expanding damselfly (Ischnura elegans) (2018) Dudaniec et al., Molecular Ecology http://doi:10.1111/mec.14709

The Crux

Terrestrial organisms aren’t always stationary entities, they often move around the landscape searching for food, potential mates, or more ideal environments. Over time, these movements may introduce the species into new environments, as some change allows the species to expand their historical range.

An interesting aspect of this shifting of the species range is how the organisms at the edge of the distribution are maladapted to the novel environments, as most of the species will be adapted to conditions at the core of the species range. To overcome this, they must adapt to the new conditions. Successful adaptation is dependent on changes in gene frequencies away from the historical genotypes, with an increase in genes that promote survival in the new habitats. The authors in this study used molecular techniques to identify genes that new environments might select for.

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Taken For a Ride

This parasitic fungus takes over the brain and then ejects its spores out of the ant’s head (Image Credit: Erich G. Vallery, USDA Forest Service – SRS-4552, Bugwood.org, CC BY 3.0 US)

Mind Control: How Parasites Manipulate Cognitive Functions in Their Insect Hosts (2018) Libersat et al., Frontiers in Psychology, https://doi.org/10.3389/fpsyg.2018.00572

The Crux

The field of neuro-parasitology is a relatively new field in biology and deals with the study of parasites that manipulate the nervous system of their hosts for their own gain (usually at the expense of the host). The authors of this review focused on host-parasite interactions between insect hosts and their myriad of parasites, due not only to most studies in this field being done with insects, but also the fact that most animals on the planet are in fact insects.

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