The top half and the bottom half are on two rotating systems.
When they move round they will realign so that four associated words are read downwards.
What are they?
M-F-G-W O-L-N-A T-E-A-S H-A-T-P Moth- Flea- Gnat- Wasp all are insects
Place the two words together and rearrange them to give two 8-letter words.
SAD + STORE =
When each word is rearranged, one of them will suffix the others, to give two longer words.
GOY HUN RUT