Local dynamics of the Hutchinson equation with two delays in a critical case of a resonance 1:2

A differential-difference equation arising at the description of dynamics of a population is considered. It is supposed that the parameters are chosen so that characteristic quasipolinom has two pairs of imaginary roots which are in resonance 1:2. The normal form of the equation, when the parameters are close to the critical values, is constructed. Phase reorganizations of a normal form under changes of parameters are studied.