Tag Archives: caterpillar


Viruses are weird – they are non-living, yet still contain genetic information and are dependent on a live host to actually replicate and survive. Unlike many other parasites, since viruses are basically just a string of DNA or RNA, they actually need to actually get inside the cells of their host and hijack some of the components of these cells to allow them to replicate. After infection they are (at least partially) in the driving seat and can control and manipulate how some cells behave.

This means that viruses often have the capacity to also alter the behaviour of their host – which can be particularly beneficial to help ensure that the virus can also spread from one host to another. A good example is rabies, whereby the virus triggers infected individuals to become exceptionally aggressive – a surefire way to probably lead to them biting another individual and allowing infection to occur via the bite wound.

Sometimes the behavioural changes can be more nuanced – in this case caterpillars infected by a baculovirus start perceiving then sun in a positive light (pun definitely intended). Infected caterpillars become attracted to sunlight and feel compelled to move towards it (this process is known as phototaxis). Unfortunately in this case is is drawing them to an untimely death. Having the caterpillars die near the tree canopy is beneficial for the virus, as its a better scouting ground for newer hosts.

Read more: Baculoviruses hijack the visual perception of their caterpillar hosts to induce climbing behaviour thus promoting virus dispersal

Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Helping the Little Guy

Animals often compete with one another for food, but sometimes their actions can actually help other animals (Image Credit: Dennis Jarvis, CC BY-SA 3.0, Image Cropped)

Food and habitat provisions jointly determine competitive and facilitative interactions among distantly related herbivores (2019) Pan et al., Ecology Letters, https://doi.org/10.1111/1365-2435.13456

The Crux

Community structure, or the makeup of species within a given habitat, is largely determined by the interactions between the organisms that feed on plants. As such, the effects that different herbivores have on one another may impact how they feed, which would then feed back into which plants that are consumed, which would impact community structure. When one herbivore has a positive effect on the feeding of another, this is called facilitation.

Classically, facilitation has been studied as a one-way interaction (Species A facilitating Species B), but this ignores the reality of natural systems, where any interaction between species has the potential to act both ways. Today’s study investigated three different herbivores to investigate how they may interact with and/or facilitate one another.

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