Insect Wing Coupling
In primitive Pterygota fore and hind pair of wings moved independently of each other e.g. Isoptera and Odonata. Higher pterygotes have attained virtual dipterous by coordinated wing movements. Both the pairs of wings move synchronously.
1. Hamulate: A row of small hooks called hamuli are present on the costal margin of the hindwings. These hooks catch the folded posterior edge of fore wings e.g. Honey bee.
2. Amplexiform: A linking structure is absent. Coupling is achieved by broad overlapping of adjacent margins e.g. Butterflies.
3. Frenate: e.g. Fruit sucking moth.
i. Male Frenate: Hindwing bears near the base of the costal margin a group of shout bristles called frenulum which is held by a curved process, retinaculum arising from sub-costal vein found on the under surface of the forewing.
ii. Female Frenate: Hindwing bears near the base of costal margin a group of stout bristles (frenulum) which lies beneath the extended forewing and engages there in a retinaculum formed by a patch of hairs near the cubitus.
In Aphids various small hooks present at margins of forewing and hind wind.