The apical band of segment II is often in the form of a pad, band or row of strong hooks (hook row II - Fig.3a.jpg) by which the pupa is attached to the silk tube in which it lies, using it as a pivot for the undulations it performs to drive water through the tube to supply its respiratory needs. Similar bands or rows of hooks occasionally occur on other segments. Structurally the apical band may belong intersegmentally as it can often be folded under the posterior edge of the tergite, in which case its armament invariably opposes that of the posterior band and it is possible that they can be used to grip the tube so as to release the hooks of the hook row prior to changing position or leaving the tube for eclosion.

Alternative forms for apical band : apical bands, apical point band, apical point bands, apical row, apical toothed band, apical toothed bands, apical transverse point band, apical transverse point bands, apical transverse row, hook row, hook row II.