Amplexiform: It is the simplest form of wing coupling. A linking structure is absent. Coupling
is achieved by broad overlapping of adjacent margins. Eg: Butterflies.
3. Frenate: There are two sub types. Eg: Fruit sucking moth.
(1) Male frenate: Hindwing bears near the base of the costal margin a stout bristle called
frenulum which is normally held by a curved process, retinaculum arising from the subcostal
vein found on the under surface of the forewing.
(2) Female frenate: Hindwing bears near the base of the costal margin a group of stout bristle
(frenulum) which lies beneath extended forewing and engages there in a retinaculum formed by
a patch of hairs near cubitus.