Summary: We give a short proof of the Cushing-Henson conjecture [cf. J. M. Cushing
and S. M. Henson
, J. Difference Equ. Appl. 8, No. 12, 1119–1120 (2002; Zbl 1023.39013
)] concerning the Beverton-Holt difference equation [cf. R. J. Beverton
and S. J. Holt
, On the dynamics of exploited fish populations. Fish. Invest. 19, HM50, London (1957)] which is important in theoretical ecology. The main result shows that a periodic environment is always deleterious for populations modeled by the Beverton-Holt difference equation.