294 PROCEEDINGS OF THE ACADEMY OF [Apr., 



the olfactory sense of hymenoptera. 



by n. e. mcindoo, ph.d. 



Contents. 



PAGE 



Introduction and Methods 294 



A. The Olfactory Sense of Ants and Hornets 296 



I. Experiments on Normal Ants and Hornets 297 



1. Winged females of Formica 299 



2. Winged males of Formica 300 



3. Winged males of Carnponotus 301 



4. Major workers of Carnponotus •. .303 



5. Minor workers of Carnponotus 304 



6. Females of Vespula maculata .304 



II. Experiments on Ants and Hornets with Mutilated Antennae 30.5 



1. Funiculi of Ants cut off 30.5 



2. Funiculi of Ants covered with glue..... 307 



3. Flagella of Hornets cut off 307 



III. Summary 308 



IV. Morphology of the Olfactory Pores 309 



1. Disposition 309 



(a) Winged female of Formica 310 



(6) Other Ants and Hornets examined 312 



2. Structure 312 



(a) External structure.: 312 



(b) Internal structure 313 



V. Physiology of the Olfactory Pores 316 



1. Dealated females of Formica : 317 



2. Wings of females of Formica pulled off 317 



3. Wings of males of Formica pulled off 31S 



4. Bases of wings glued and legs of females of Formica covered 



with vaseline 319 



5. Dealated females of Camponotus 320 



6. Glue in wing niches and legs of dealated females of Carnponotus 



covered with vaseline 321 



7. Wings of males of Camponotus pulled off 321 



8. Wings of Vespula maculata pulled off 322 



9. Summary 323 



B. "Disposition of the Olfactory Pores of other Hymenoptera 325 



I. Distribution 325 



II. Number 325 



III. Relative Sensitiveness of Species examined to Odors 326 



Discussion 334 



Literature Cited .' 338 



E.xplanation of Plates XI and XII 339 



Introduction and Methods. 



In the investigation here recorded three objects have been kept 



in view: (1) To determine physiohjgically the relative sensitiveness 



of ants and liornets to different odors, so that it may be expressed 



numerically for comparison under different conditions; (2) to locate 



