Brown rot pattern on quince fruit (Cydia pomonella). In the centre of the bullseye pattern is a small hole caused by the caterpillar of the codling moth (Cydia pomonella). Damage like this introduces the fungus (Monilinia fructigena), a plant pathogen, into the fruit. The brown rot bruise spreads across the fruit as it ripens and sporing bodies, often in concentric rings, cover the surface. Quince, apple, pear, plum, cherry, peach, nectarine or apricot can all be affected and with favourable warm and humid weather it is able to destroy a very significant proportion of the fruit crop.