There are very few supporting studies on the beneficial effect of comb replacement; this one was done more than ten years ago, pre-CCD

Effects of comb age on honey bee colony growth and brood survivorship
Jennifer A Berry; Keith Delaplane

Abstract
This research examined the effects of comb age on honey bee colony growth and brood survivorship. Experimental old combs were of an unknown age, but were dark and heavy as typical of combs one or more years old. New combs were produced just prior to the beginning of the experiment and had never had brood previously reared in them. Either old or new combs were installed into each of 21-24 nucleus colonies each year over a three-year period. On average, colonies with new comb produced a greater area (cm2) of brood, a greater area (cm2) of sealed brood, and a higher weight of individual young bees (mg). Brood survivorship was the only variable significantly higher in old comb.

Journal of Apicultural Research
Vol. 40 (1) pp. 3 - 8


More recent work was done in Iran

Effects of Comb Wax Age on the Brood and Honey Product Performance in Honey Bee

Old combs also have increased disease problems due to accumulations of microorganisms, such as fungi, bacteria, protozoa (Nosema Apis Zander) and viruses (Bailey and Ball, 1991). 
AsianJ.Anim. Vet. Adv., 3 (1): 51-53, 2008 



Peter L Borst
128 Lieb Road
Spencer, NY  14883
42.35°N 76.50°W

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