No interactions present.
The main feature for separating these two seems to be the the length and shape of the scale tooth on the trailing edge of the third lobe of the hindwing.
In acanthadactlya it is long and narrow and in punctidactyla it is short and broad.
This is illustrated well in Colin Hart's "British Plume Moths".
An illustration of this for A acanthadctyla (assuming my ID is right) is here http://www.ispot.org.uk/node/250147
Lat/Lng: 54.07768, -0.84853
OS grid ref: SE754652