Colony Collapse Disorder in relation to human-produced toxins: What’s the buzz all about?

Dijk, S. van (2017) Colony Collapse Disorder in relation to human-produced toxins: What’s the buzz all about? Master's Thesis / Essay, Marine Biology.

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Abstract

In recent years, the global population of pollinating animals has been in decline. The honey bee in particular is one of the most important and well known pollinators and is no exception.The Western honey bee Apis mellifera, the most globally spread honey bee species suffers from one problem in particular. Colony Collapse Disorder (CCD), which causes the almost all the worker bees to abandon a seemingly healthy and food rich hive during the winter. One possible explanation for this disorder is that it is because of the several human produced toxins, such as insecticides, herbicides, fungicides and miticides. So the main question is: Are human-produced toxins the primary cause of CCD? It seems that insecticides and, in particular, neonicotinoid insecticides caused increased mortality and even recreated CCD-like symptoms by feeding the bees with neonicotinoids. Herbicides seem relatively safe for bees, though they do indirectly reduce the pollen diversity, which can cause the hive to suffer from malnutrition. Fungicides are more dangerous, causing several sublethal effects, including a reduced immune response and changing the bacterial gut community. The levels of one fungicide in particular, chlorothalonil, tends to be high in hives. Miticides levels tend to be high in treated hives and can cause result in bees having a reduced lifespan. Antimicrobial drugs are relatively safe, as long as they are not applied in a too low dose, as this will increase the chance of the parasites becoming immune. Adjuvants are supposedly biologically inactive ingredients that are added to pesticide mixtures in order to make them more effective without increasing the toxicity. However, recent studies suggest that they might be even more dangerous than the toxins themselves. Toxins can also cause synergistic effects when mixed, becoming even more dangerous than you would expect from the ingredients alone. In conclusion, although there are many negative effects that A. mellifera will suffer from due to exposure to pesticides, there is no significant evidence that pesticide exposure is the main factor for causing CCD, although it does seem that is an important exacerbating factor for triggering CCD.

Item Type:	Thesis (Master's Thesis / Essay)
Degree programme:	Marine Biology
Thesis type:	Master's Thesis / Essay
Language:	English
Date Deposited:	15 Feb 2018 08:27
Last Modified:	15 Feb 2018 08:27
URI:	https://fse.studenttheses.ub.rug.nl/id/eprint/15096

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