3.3.4. Co-Exposures

Only 20% of the publications investigated interactions between stressors. The most studied were interactions between different pesticides followed by pesticide–PIAs interactions. Other co-exposures included PIAs–nutrition or pesticide–nutrition interactions. The combinations of exposures to be studied is infinite, therefore to help in the decision making process, Henry et al. [35] proposed a procedure to narrow down the panel of options.

#### *3.4. What Methods Were Used in the Articles to Measure Various Endpoints?*

Different techniques were used to study the impact of stressors on *A. mellifera* according to the level of biological organization of the measured endpoint: colony, individual, cellular, molecular or genetic endpoints. Individual endpoints were by far the most studied (53%), followed by colony endpoints (21%) and molecular endpoints (14%). Only 8% and 4% of the endpoints were genetic and cellular endpoints, respectively. As colony and individual are the most prevalent endpoints in terms of their relative proportion, we will describe in detail below how these endpoints were produced.
