|Last year while the gooseberries were developing they turned brown (a cocoa color) and fell off. The same thing is starting to happen now. The bush does not look diseased to me. The berries that fall off are not shriveled up, they are very plump.|
|Based on your description I suspect the problem is the gooseberry maggot, which is the larval stage of the currant fruit fly. The adult flies emerge in mid spring and are yellow or orange, about 1/5" long, and have dark bands across the wings. The female flies lay eggs just under the skin of the gooseberries. When the maggots hatch, they burrow in and feed on the berries. This causes the berries to turn reddish and sometimes drop; a severe infestation can cause significant fruit drop. The maggots move from the fruit to the soil and overwinter there to emerge the following spring as adult flies.|
To control them, you can place tarps under the bushes to prevent the larvae from entering the soil to pupate, or you can remove and destroy all of the infested fruit each day. There is no chemical control for this.