The control group would be the biodiversity of the trees without the fire
The control group in the experiment would center on the biodiversity of the trees without the fire. Ideally, both the control group and the experimental groups are usually identical in every way except that the experimental group would receive the treatment that is believed to have an effect on the biodiversity of trees.
Pesticides used in mosquito control can contribute to immune suppression in humans. A report from the World Resources Institute notes, "Impairment of the immune system by chemical pesticides can lead to allergies, auto immune disorders such as lupus, and cancer.