Fundamentals of Entomology

Wing coupling

• Wing coupling: Among the insects with two pairs of wings, the wings may work separately as in the dragonflies and damselflies. But in higher pterygote insects, fore and hind wings are coupled together as a unit, so that both pairs move synchronously. By coupling the wings the insects become functionally two winged.

Types of wing coupling
Hamulate : A row of small hooks is present on the coastal margin of the hind wing which is known as hamuli. These engage the folded posterior edge of fore wing. e.g. bees.
Amplexiform : It is the simplest form of wing coupling. A linking structure is absent. Coupling is achieved by broad overlapping of adjacent margins. e.g. butterflies.
Frenate : There are two sub types. e.g. Fruit sucking moth.
i. Male frenate : Hindwing bears near the base of the coastal margin a stout bristle called frenulum which is normally held by a curved process, retinaculum arising from the subcostal vein found on the surface of the forewing.
ii. 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.
Jugate : Jugam of the forewings are lobe like and it is locked to the coastalmargin of the hindwings. e.g. Hepialid moths.