Expression of ftz^{hs.T:Hsim\VP16} during embryogenesis using heat shock results in a decrease in the number of wild-type cuticles, with the maximum decrease centered at a time of heat shock of about 2.5 hours after egg laying (AEL). ftz^{hs.T:Hsim\VP16} is able to induce patterning defects with a modest increase in efficiency at both earlier and later stages of development compared to ftz^3-413.hs. The most common phenotype induced by ftz^{hs.T:Hsim\VP16} is the "anti-ftz" pair rule phenotype; deletion of ftz-independent parasegments. ftz^{hs.T:Hsim\VP16} also induces other cuticle phenotypes. The first is characterised by fusions between alternate denticle belts. Most of these fusions (approximately 80%) occur in posterior regions. Disruptions of terminal structures are also seen in these cuticles. This phenotype peaks when heat pulses are given between 1 hour 40 minutes and 2 hours 20 minutes AEL. The second cuticle phenotype is an extreme pair-wise fusion of denticle belts with the remaining denticles arranged in mirror-image symmetry. This phenotype peaks with a frequency of about 15% when heat pulses are given between 2 hours 40 minutes to 3 hours 10 minutes AEL. The third phenotype is deletions of both naked and denticle-belt containing portions of each segment. The remaining portions of each denticle belt appear to be duplicated with mirror image symmetry. This phenotype is prevalent when heat pulses are given between 3 hours to 3 hours 30 minutes AEL. The final phenotype is a deletion of all denticle belts. This occurs when heat pulses are given between 3 hours 30 minutes to 4 hours AEL.