THE GROSS AND CELLULAR MORPHOLOGY OF WING DEVELOPMENT IN THE GRASSHOPPER,MELANOPLUS LAKINUS, SCUDDER (ORTHOPTERA, ACRIDIDAE) Item Type text; Dissertation-Reproduction (electronic) Authors Bland, Roger G. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 01/10/2021 18:24:26 Link to Item http://hdl.handle.net/10150/284888 This dissertation has been microfilmed exactly as received 67-12,193 BLAND, Roger Gladwin, 1939- THE GROSS AND CELLULAR MORPHOLOGY OF WING DEVELOPMENT IN THE GRASSHOPPER MELANOPLUS LAKINUS SCUDDER (ORTHOPTERA, ACRIDIDAE). University of Arizona, Ph.D., 1967 Entomology University Microfilms, Inc., Ann Arbor, Michigan THE GROSS AND CELLULAR MORPHOLOGY OF WING DEVELOPMENT IN THE GRASSHOPPER MELANOPLUS LAKINUS SCUDDER (ORTHOPTERA, ACRIDIDAE) by Roger Gladwin Bland A Dissertation Submitted to the Faculty of the DEPARTMENT OF ENTOMOLOGY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 1967 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE I hereby recommend that this dissertation prepared under my direction by ROGER GLADWIN BLAND ~ entitled THE GROSS AND CELLULAR MORPHOLOGY OF WING DEVELOPMENT IN THE GRASSHOPPER MELANOPLUS LAKINUS SCUPPER (ORTHOPTERA. ACRIDIDAE) be accepted as fulfilling the dissertation requirement of the degree of DOCTOR OF PHILOSOPHY /yd '/ Dissertation Director Date After inspection of the dissertation, the following members of the Final Examination Committee concur in its approval and recommend its acceptance:* 3 A • £7 /?6>7 37 /f?/7 y- - <>7 *This approval and acceptance is contingent on the candidate's adequate performance and defense of this dissertation at the final oral examination* The inclusion of this sheet bound into the library copy of the dissertation is evidence of satisfactory performance at the final examination. STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library, Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or re­ production of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the in­ terests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED ACKNOWLEDGMENTS X wish, to thank my research director, Dr. William L, Nutting, for his advice, guidance and the time and effort expended in reading and offering suggestions for strengthening the revisions. In addition, the critical review of the manuscript made by Dr. Floyd G. Werner is greatly appreciated. This investigation was supported through the University of Arizona Agricultural Experiment Station Projects 564 and 624 which have also contributed to the Western Regional Research Projects W-37 and W-92, respectively. X am indebted to Drs. Laurence A. Carruth and William L. Nutting for their role in obtaining these grants. I am also grateful to my wife, Kathryn, for her encouragement and for the thankless job of typing the manuscript during its for­ mative stages. iii TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS V LIST OF TABLES vii ABSTRACT viii INTRODUCTION 1 MATERIALS AND METHODS 3 Rearing methods 3 Histological Procedures 4 Measurement of Growth 6 RESULTS 9 Duration of Instars 9 Occurrence of Macropterism 9 Histology of Wing Development 10 Third Ins tar 10 Fourth Ins tar 12 Fifth Instar 15 Adult 21 Modifications of the Cuticular Surface 25 Mitotic Activity 27 Increase in Cell Number 31 Morphometries of Wing Growth 35 DISCUSSION 50 SUMMARY AND CONCLUSIONS 56 LITERATURE CITED 59 iv LIST OF ILLUSTRATIONS Figure Page 1. Notal plates on the first day of the third instar .... 11 2. Transverse section of the inesonotum along line e-f of fig. 1 on the first day of the third instar showing cells with a minimum of cytoplasm at the apex of the wing 11 3. Posterolateral elongation of the meso- and metanotum on the second day of the third instar 11 4. Reversal of wing pads at ecdysis in the fourth instar 11 5. Transverse section of the forewing pad on the second day of the fourth instar showing the migration of several nuclei toward the middle membrane ...... 14 6. Transverse section of the hindwing pad on the fourth day of the fourth instar showing closely apposed epidermal cells and nuclei 14 7. Transverse section of the forewing pad on the fourth day of the fourth instar showing the laminated endocuticle and unidentified large particles in the granular molting fluid 14 8. Transverse section of the forewing pad on the third day of the fifth instar showing the elongated cells and nuclei 17 9. Transverse section of the hindwing pad on the fourth day of the fifth instar showing the separation of the epidermis from the cuticle 17 10. Transverse section of the forewing pad on the fifth day of the fifth instar illustrating the pro- cuticle, attenuated epidermal cells and dis­ placed nuclei 19 11. Transverse section of the forewing pad on the sixth day of the fifth instar showing the attenuated cells of the folded epidermis. v vi Figure Page 12. Transverse section of the hindwing pad on the sixth day of the fifth instar showing the columnar and cuboidal cells in the folded epidermis ........ 19 13. Transverse section of the hindwing pad on the eighth day of the fifth instar showing the presumed chromatolysis 22 14. Transverse section of the forewing pad on the eighth day of the fifth instar showing both the cuboidal and elongated epidermal cells 22 15. Transverse section of the tegmen just after ecdysis and before sclerotization and tanning have occurred 24 16. Longitudinal section of the tegmen one day after ecdysis showing the cuboidal epidermal cells and occasional processes . 24 17. Cuticular plaques in the third, fourth and fifth instars 24 18. Average mitotic activity observed during development of wing pads 29 19. The average number of mitoses observed every 2 hr in the fore- and hindwings of the third, fourth and fifth instars is summed for consecutive 24-hr periods after ecdysis. The increase in the number of nuclei recorded in the forewing at the same 24r-hr intervals is also plotted for comparison .... 36 20. Left tegmina and hindwings of brachypterous and macropterous adults 37 21. Average length and width of the forewing, hindwing and metathoiracic femur just after ecdysis in the third, fourth and fifth instars and in the adult ... 38 22.. Regression lines of the growth in length of the fore- and hindwing pads on the length of the metathoracic femur 47 23. Change in the coefficient of allometry of the fore- and hindwing pads of the third, fourth and fifth instars 48. LIST OF TABLES Table Page 1. Sum of the average number of mitoses observed In squashes of wing pads of the third, fourth and fifth instars during consecutive 24-hr periods after ecdysis 32 2. Total number, increase in number and percent increase of nuclei in the forewing pads of the third, fourth and fifth instars 33 3. Percent increase in relative area of the wing pads of the fourth and fifth instars and of the adult wings when measured immediately after ecdysis .... 42 4. Statistical analysis of growth in length of the - - forewing pad on the inetathoracic femur 43 5. Statistical analysis of growth in length of the hindwing pad on the metathoracic femur 44 vii ABSTRACT Melanoplus lakinus ia a brachypterous grasshopper of Arizona rangeland that occasionally shows macropterism. Wing development is similar histologically to that in holometabolans, although the epidermal cells are less attenuated in this species. The cells extend to the middle membrane and generally are hot continuous with opposing cells. After the procuticle is secreted, they become extremely distorted. The middle membrane may be as much as 3g wide. Granular molting fluid occurs in large quantity and is prevalent during the last half of each instar. Chromatolysis may occur in the last stage of growth in the hindwing. On the surface of the wing pads, the polygonal cuticular plaques change to "shingled" rows in the last two instars. Two characteristics of mitotic activity in wing pads are re­ vealed: (1) mitoses occur in distinct bursts and at fluctuating low levels, and (2) mitosis begins while the epidermis is still attached to the endocuticle and continues at low levels after the deposition of the procuticle. Mitotic activity corresponds well with the increase in nuclei during each instar. The regression coefficient of wing length on hind femur length increases significantly during most instars. The large increase in wing length of the macropterous form occurs in the last instar and deviates greatly from simple allometric growth. viii INTRODUCTION An extensive literature deals with the morphology and genetics of wing development in insects. However, the studies have primarily involved holometabolous insects, perhaps due to their complex and more cryptic mode of growth, and relatively minor attention has been allotted to hemimetabolous forms. The present investigation describes the morpho­ genesis of wings in a hemimetabolan, Melanoplus lakinus Scudder, a normally brachypterous species of grasshopper. The section on histol­ ogy supports previous observations and adds new information involving epidermal activity. In addition, previously unreported characteristics of mitotic activity are described. Macropterous forms of this grass­ hopper are occasionally found and these variants facilitated comparisons between the growth of short and long wings.