An experimental study of the functions of the different spiracles in certain Orthoptera

✍ Scribed by McArthur, James M.

• Publisher: John Wiley and Sons
• Year: 1929
• Tongue: English
• Weight: 578 KB
• Volume: 53
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1400530108

✦ Synopsis

Until recent years, most students of insect respiration seem to have assumed that all the spiracles of terrestrial insects are both inspiratory and expiratory in function. Opposed to this view are the results obtained by Lee ('25, '27 a, '27 b), who experimented on several species of Orthoptera and concluded that the first four spiracles are normally inspiratory and that the last six are expiratory in function. On the other hand, MacKay ( '27) , working on grasshoppers, supports the older view that the air moves in and out through each spiracle. In the experiments which are reported in the present paper, an attempt has been made to test the two conflicting opinions which have just been cited, methods of Lee and MacKay being used in part of the work.

The work was done during the months of June, July, and August, 1927, in the Zoological Laboratory of Tulane University. Thanks are due to Dr. E. S. Hathaway, under whose direction the work was undertaken, for guidance in making the investigation, and to Mr. Joseph T. Brierre for assistance in the study of the action of the spiracular valves.

The species of grasshoppers used were Romalea microptera, var. marci (Loding), Schistocerca obscura (Fabricius), Schistocerca americana (Drury) , and Melanoplus differentialis (Thomas). Fresh specimens were caught about once a week during the course of the experiments, and were kept alive in screen-wire cages and were given food and water.