Answer
The angle $\theta$ is measured from horizontal, so as the insect "straightens out the legs" $\theta$ $\left.\text { will increase (getting closer to } 90^{\circ}\right), \text { which causes } \sin \theta $ to increase (getting closer to $ 1$ and consequently (since $\sin \theta$ is in the denominator) causes $T$ to decrease.
Work Step by Step
The angle $\theta$ is measured from horizontal, so as the insect "straightens out the legs" $\theta$ $\left.\text { will increase (getting closer to } 90^{\circ}\right), \text { which causes } \sin \theta $ to increase (getting closer to $ 1$ and consequently (since $\sin \theta$ is in the denominator) causes $T$ to decrease.
