As global warming becomes more and more felt worldwide, we are observing its effects on plant pests. TSSM (T. urticae) is highly resistant to warm temperatures and show improved fitness in temperatures over 35ﹾC. We are interested to study the effect heat exposures (short or long) may have on physiological fitness traits in TSSM, that is on its ability to be pesticides resistant. To this end, we subject TSSM females from different genetic backgrounds to various heat and pesticide regimes and record their life history traits for possible changes.