1) Balancer 2) Halter 3) Wing 
Modified hind wing in flies (Diptera).
(from the article `dipteran`) Adult flies have only one pair of wings, on the mesothorax or second thoracic segment. The hind wings, modified into halteres, have a stalk and a ... ...campaniform organs detect bending strains in the integument. Such organs exist in the wings and enable the insect to control flight movements. ... [2 re...
One of the club-shaped 'balancers' found on each side of the metathorax among the true flies (Diptera)
One of the club-shaped 'balancers' found on each side of the metathorax among the true flies (Diptera)
a modified wing that is reduced to form a 'drum stick' shaped balance organ.