We have all learned so much together about this marvel of the world of animal biology. While that is all good and fun it’s important to know that these insects don’t just exist by themselves, but they also interact with the human animal world. (yes humans are animals too). When we think of bugs we think of them as pests, at least I do. But some of the insects in our world are like a miniature pest control service, pretty cool huh? When it comes to the C. carnea, they are very important in the upkeep of many crops; in this specific case the sunflower. Although the C. carnea is very helpful, farmers often need to employ the help of chemical insecticides to keep the invaders at bay.
Today we will deep dive into the world of scientific literature, specifically research composed by Pablo C. Gontijo, Valeria F. Moscardini, J. P. Michaud, and Geraldo A. Carvalho investigating “non-target effects of chlorantraniliprole and thiamethoxam on Chrysoperla carnea when employed as sunflower seed treatments” seems like a mouth full but don’t worry, we are in this together.
The overall purpose of this research is to instigate the effects of adding chemical insecticide treatments to sunflower seeds on the C. carnea. The researchers want to assess whether either material would affect key life history parameters of C. carnea when both larvae and adults were exposed to sunflower seedlings grown from treated seed.
- Chlorantraniliprole: A human made pesticide. It controls moth and butterfly caterpillars or larvae, as well as some beetles and “true” bugs like aphids and spittlebugs.
- Thiamethoxam: Thiamethoxam is used as a systemic insecticide of the neonicotinoid class. It has a broad spectrum of activity against many types of insects and can be used as a seed dressing.
- Fecundity: the ability to produce an abundance of new offspring
- Sublethal effects: effects (either physiological or behavioral) on individuals that survive exposure to a pesticide.
- Bonferroni test: a type of multiple comparison test used in statistical analysis.
- One way ANOVA test: a statistical analysis tool used to study variability.
Given the potential for contamination of sunflower extrafloral nectar with chlorantraniliprole and thiamethoxam when applied as seed treatments, the researcher’s hypothesis that there will be some effect on the C. carnea from exposure to the chemical seed treatments.
In this experiment, there were four experimental groups and two control groups: Larvae control, adult control, and an adult and larvae group for each of the two chemicals being tested. All these groups were assessed in two parameters, survival rate and sex ratio. A one-way ANOVA and Bonferroni test were used to interpret the results. The results of this experiment show in larvae, a reduced female sex ratio with no significant survival rate impact. In adults, there was a significant decrease in survival compared to that of the control in the presence of both chemical pesticides.
This research demonstrates the negative impact that these chemical seed treatments have in the C. carnea. The most likely reason for the contamination of C. carnea from these chemicals is their tendency to consume the nectar of sunflowers. This is especially important when it comes to non-target organism during the summer obtaining the hydration they need from this nectar. Although this form of treatment is cost effective and convenient for farmers, this form of control does not align with the basic principles of Integrated Pest Management (IMP). This study and other like it all boils down to the same conclusion that systematic insecticides used for seed treatments are harmful and potentially will disrupt population dynamics even though their application limits direct exposure of non-target insects.
These findings are unique and unusual because they contradict what is “fiscally” correct from an economic standpoint. The struggle to maintain our ethics in the world of biology is harder and harder to do in a world that has become all about money. This is so important to discover because this cheaper and faster alternative is slowly chipping away at the populations well-being.
Further research on this topic is necessary to determine at what life stage of the sunflower does the insecticide presence become an issue, what impact does the presence of predators and prey have,as well as the ongoing compatibility of this with biological standards.
Gontijo, P.C. et al. (2014) Non-target effects of chlorantraniliprole and thiamethoxam on CHRYSOPERLA carnea when employed as sunflower seed treatments – Journal of Pest Science, SpringerLink. Springer Berlin Heidelberg. Available at: https://link.springer.com/article/10.1007/s10340-014-0611-5 (Accessed: April 22, 2023).