  A part of Grothendieck's program for studying the Galois group $G_{\mathbb
Q}$ of the field of all algebraic numbers $\overline{\mathbb Q}$ emerged from
his insight that one should lift its action upon $\overline{\mathbb Q}$ to the
action of $G_{\mathbb Q}$ upon the (appropriately defined) profinite completion
of $\pi_1({\mathbb P}^1 \setminus \{0,1, \infty\})$. The latter admits a good
combinatorial encoding via finite graphs "dessins d'enfant". This part was
actively developing during the last decades, starting with foundational works
of A. Belyi, V. Drinfeld and Y. Ihara. Our brief note concerns another part of
Grothendieck program, in which its geometric environment is extended to moduli
spaces of algebraic curves, more specifically, stable curves of genus zero with
marked/labelled points. Our main goal is to show that dual graphs of such
curves may play the role of "modular dessins" in an appropriate operadic
context.
