Homework Writing Help on Parasites

Parasites

Knight, K. (2013). How parasites turn victims into zombies. The Journal of experimental biology, 216(1).

In one of the experiments conducted to understand the molecular mechanisms used by the Ophiocordyceps to control the mind of their hosts, Knight (2013) wrote in support of previous studies indicating that these parasites are species-specific. According to this article, the characteristics exhibited by Ophiocordyceps could be because of overproduction of specific arrays of reactant chemical compounds that affect the functionality of the host brain. In other words, Knight (2013) in the above article believes that Ophiocordyceps, unlike other mind-controlling parasites, adaptively manipulate the behavior of their ant hosts in order to increase parasitic fitness for future regeneration. This article, therefore, identifies factors like parasite encounter rate, host defense mechanisms and abiotic factors as considerably important towards determining which ant specie becomes a host for the Ophiocordyceps.

The discussions presented in the above article are important to this study because they will help the researcher to discover the candidate compounds involved in behavioral manipulation of ant hosts. The article also provides an advance understanding of the molecular mechanisms through which Ophiocordyceps control the minds of their hosts, which could be applied in other areas of investigation. By understanding the factors that lead to the death grip in ants infected by Ophiocordyceps, the researcher can perform an experiment to determine the exact phenotypic changes that make ant hosts weak and vulnerable to these groups of parasites. The information retrieved from this article can also be used by the researcher to investigate species-specificity beyond the mentioned factors with particular focus on Ophiocordyceps life history, environmental controls and cuticle compatibility.

Andersen, S. B., Gerritsma, S., Yusah, K. M., Mayntz, D., Hywel‐Jones, N. L., Billen, J., & Hughes, D. P. (2009). The life of a dead ant: the expression of an adaptive extended phenotype. The American Naturalist, 174(3).

This article is developed from a worldwide survey that assesses the overall taxonomy and ecology of the brain manipulating Ophiocordyceps. According to this article, Ophiocordyceps are fungal pathogens with pan-tropical distributions and specific to ant hosts of the tribe Camponotini. In their research, Andersen, Gerritsma, Yusah, Mayntz, Hywel‐Jones, Billen and Hughes (2009) believe that the behavioral manipulation of the Ophiocordyceps provide a base for acknowledging the taxonomy and ecology of a group of parasites known as carpenter ants. With the single stalk arising from the dorsal neck region of the carpenter ant, the researchers were able to demonstrate that carpenter ants provide a conducive environment for the Ophiocordyceps to grow and regenerate.

The above article is important for this study because it provides information about the taxonomy and ecology of Ophiocordyceps, which are important concepts when it comes to understanding the relationships between parasites and their host. The article also provides information about the specific specie of ants (carpenter ants) as the main target. With this information, the researcher is in a position to eliminate errors that may arise when deciding on the right sampling groups or study population. Similarly, the researcher gets the opportunity to determine the appropriate conditions that will facilitate the growth of Ophiocordyceps for other control experiments.

Janssen, A., De Brito, E. F., Cordeiro, E. G., Colares, F., Fonseca, J. O., & Sabelis, M. W. (2008). Parasitoid increases survival of its pupae by inducing hosts to fight predators. PLoS One, 3(6), e2276.

According to this article, Glyptapanteles parasites operate as bodyguards of the parasitoid pupae by inducing protective layers on caterpillar hosts. This behavior of Glyptapanteles parasites according to this article is unique and disturbing because most parasites are known to manipulate their hosts in order to derive benefits from them. In addition to discussing the mutual relationship between parasitoid pupae and Glyptapanteles parasites, the article also shows that the behavioral manipulation of Glyptapanteles parasite may at times not result into parasitoid survival as always expected. According to this article, the effects of behavioral manipulation of the Glyptapanteles parasites on the host depend highly on ecological factors.

The above article is relevant to this investigation because it will allow the researcher to determine Glyptapanteles response to the different species or community of predators. This means that the researcher can demonstrate by setting up all the relevant components of food web and how they result into growth of Glyptapanteles parasites. In addition to determining the mentioned relationships, the researcher will be able to measure the mortality of caterpillar based on other causes apart from predation and hyper-parasitism.

Harvey, J. A., Kos, M., Nakamatsu, Y., Tanaka, T., Dicke, M., Vet, L. E., … & Bezemer, T. M. (2008). Do parasitized caterpillars protect their parasitoids from hyperparasitoids? A test of the ‘usurpation hypothesis’. Animal Behaviour, 76(3), 701-708.

According to this article, the altered behaviors of caterpillar hosts may not be necessarily as a result of the direct effect of parasites. In this article, the authors argue that the traumatic side effects of parasitism may even cause extreme changes in the usual behavior of the hosts. According to this article, most studies discriminate the cause-and-effect relationship between direct manipulation by the parasites and traumatic side effects, most caterpillar pupae experience in their entire life cycle. In general, the article agrees to the common understanding that while Glyptapanteles parasites provide protection to their host caterpillar pupae, they cause traumatic side effects that are worse than parasitoid effects. 

This article is important to this study because it provides explanations that do not only focus on the direct links between parasites and their hosts. From the article above, the researcher is able to conduct further investigations to understand the level of damage Glyptapanteles parasites have on their hosts. Based on the explanations about the host-parasitoid relationship, the researcher may have the opportunity to determine whether without the traumatic side effects, the host pupae may withstand the pervasive effects of Glyptapanteles parasites. This article, therefore, leaves the researcher with two alternative areas to study, which are all relevant towards understanding the means through which Glyptapanteles parasites control their hosts.

William G. E. (2000). “Spider manipulation by a wasp larva” Nature 406 (6793): 255-256. doi:10.1038/35018636 PMID 10917517.

According to this article, parasites manipulate their hosts in two main ways; either partially or totally, but at the molecular scale. In his article, William (2000) wrote about Hymenoepimecis argyraphaga as one of the few parasites that solely manipulate their hosts by injecting a chemical compound that alters the behavior of the spider host. The fact that female Hymenoepimecis argyraphaga uses spiders for regeneration means that there is a durable interaction that will finally result in the death of the spider host. This relationship according to the above article only ends when the spider is dead or when the wasp has created a balance that will allow the spider to procreate while at the same time making its own offspring.

The article above is important for this study because it provides information that will allow the researcher to understand how the chemicals produced by the parasite can make the spider change its behavior to an extent of constructing a web it has never woven before. on the same note, the information provided by the article can be used by the researcher to conduct studies at two distinct levels. The first study will aim at determining the partial relationships between Hymenoepimecis argyraphaga and its spider hosts while the second study will aim at determining the total relationship between the parasite and its host. With good understanding about such relationships, it will be possible for the researcher to understand why Hymenoepimecis argyraphaga is specific to spiders and their webs.

William G. E. (2001). Under the influence: Webs and building behavior of Plesiometa argyra (araneae, tetra-gnathidae) when parasitized by Hymenoepimecis argyraphaga (hymenoptera, ichneumonidae). Journal of Arachnology, 29(3), 354-366.

According to this article, Hymenoepimecis argyraphaga control the behavior of the host spider by blocking the ability of the host to construct the usual multi-step web, which is more durable. In the article, the authors discuss how the chemical cocktail induced by the Hymenoepimecis argyraphaga reduce spiders to repeatedly construct a two-step web, which is unusual and more likely to be damaged by debris. For the Hymenoepimecis argyraphaga, the two step web is strong and able to create an environment that favors the growth of larva. Before turning into a cocoon in the two step custom-web, the larva molts, kills and sucks nutrients from the spider and finally discards the corpse. According to this article, the spider host provides both shelter and food for the Hymenoepimecis argyraphaga, which exhibits a specific parasitic relationship with its hosts.

The above article is important to this study because it introduces another dimension; foods and shelter, which shows pure parasitic relationship between Hymenoepimecis argyraphaga and its host. From the article, the feeding habit shown by the parasite is an illustration of complete control the parasite has over its hosts, which is also an area of interests for this study. This article also provides sufficient information about the response behaviors of spiders and how such responses lead to manipulation and control by the parasite. In other words, the article reflects upon Hymenoepimecis argyraphaga and its control mechanisms that have significant effect on spiders and what they enjoy doing most; building a web.

Adamo, S. A., & Webster, J. P. (2013). Neural parasitology: how parasites manipulate host behavior. The Journal of experimental biology, 216(1), 1-2.

According to this article, Ophiocordyceps unilateralis, Glyptapanteles, and Hymenoepimecis argyraphaga are mind controlling parasites that have the ability to manipulate the minds of their hosts from within. By manipulating the minds of their respective hosts, the three parasites not only make their hosts to act in self-destructive ways, but also in ways that benefit the parasites. According to the article, Ophiocordyceps unilateralis, Glyptapanteles, and Hymenoepimecis argyraphaga other than being species-specific have the ability to alter the behavior of their hosts in order to obtain a better home, supply more nutrients or create a conducive environment for reproduction and regeneration. The article also states that while the parasites retain all the benefits resulting from the exhibited relationships, the host always suffer losses and ultimately meet their untimely death. In general, this article recognizes that there is no benefit that can emerge from a parasitic relationship and in most cases the host is sacrificed so that the parasite can survive.

This article is important to this type of study because it reveals other important similarities among the three parasites that should be investigated by the researcher. Apart from being species-specific, the characteristics held by this article could form a foundation for understanding the relationships between the parasites and their hosts and how such relationships affect the behavior of the hosts. By illustration, the fact that the hosts provide food shelter and better breeding grounds for the parasites means that without the hosts, the parasites cannot survive. This statement has its scientific foundations and the researcher can develop a hypothesis to either prove or dispute the mentioned relationships.     

Cézilly, F., & Thomas, F. (2012). Behavioral manipulation outside the world of parasites. Host Manipulation by Parasites, 198-212.

This article also connects to the general fact that Ophiocordyceps unilateralis, Glyptapanteles, and Hymenoepimecis argyraphaga are species-specific. However, the article acknowledges the notion that each parasite develops a separate relationship with its hosts and the mechanisms of manipulation also differ. From example, other parasites control the mind of their hosts to obtain access to better breading grounds while other parasites control the minds of their hosts only to see them suffer and finally die. This means that the behaviors of these parasites are diverse just like the different types of host species they control.

The differences in behavior and control mechanisms used by the parasites on their hosts can be explored by the researcher to understand the motives behind these parasitic relationships. At the same time, the researcher can use these differences to determine if in case there is any benefit, however little, the host derives from the parasite. By studying the relationships as outlined in this article, the researcher may also have the opportunity to determine if at any point it will be possible for the parasites to control the minds of other hosts apart from the usual ones.

References

Adamo, S. A., & Webster, J. P. (2013). Neural parasitology: how parasites manipulate host behavior. The Journal of experimental biology, 216(1), 1-2.

Andersen, S. B., Gerritsma, S., Yusah, K. M., Mayntz, D., Hywel‐Jones, N. L., Billen, J., & Hughes, D. P. (2009). The life of a dead ant: the expression of an adaptive extended phenotype. The American Naturalist, 174(3).

Cézilly, F., & Thomas, F. (2012). Behavioral manipulation outside the world of parasites. Host Manipulation by Parasites, 198-212.

Harvey, J. A., Kos, M., Nakamatsu, Y., Tanaka, T., Dicke, M., Vet, L. E., … & Bezemer, T. M. (2008). Do parasitized caterpillars protect their parasitoids from hyperparasitoids? A test of the ‘usurpation hypothesis’. Animal Behaviour, 76(3), 701-708.

Janssen, A., De Brito, E. F., Cordeiro, E. G., Colares, F., Fonseca, J. O., & Sabelis, M. W. (2008). Parasitoid increases survival of its pupae by inducing hosts to fight predators. PLoS One, 3(6), e2276.

Knight, K. (2013). How parasites turn victims into zombies. The Journal of experimental biology, 216(1).

William G. E. (2000). “Spider manipulation by a wasp larva” Nature 406 (6793): 255-256. doi:10.1038/35018636 PMID 10917517.

William G. E. (2001). Under the influence: Webs and building behavior of Plesiometa argyra (araneae, tetra-gnathidae) when parasitized by Hymenoepimecis argyraphaga (hymenoptera, ichneumonidae). Journal of Arachnology, 29(3), 354-366.