  Given a real polynomial $p$ with only real zeroes, we find upper and lower
bounds for the number of non-real zeroes of the differential polynomial $$
F_{\varkappa}[p](z):= p(z)p''(z)-\varkappa[p'(z)]^2,$$ where $\varkappa$ is a
real number.
  We also construct a counterexample to a conjecture by B. Shapiro on the
number of real zeroes of the polynomial $F_{\tfrac{n-1}{n}}[p](z)$ in the case
when the real polynomial $p$ of degree $n$ has non-real zeroes. We formulate
some new conjectures generalising the Hawaii conjecture.
