PAGE. 



THE OLFACTORY SENSE OF COLEOPTERA 



N. E. McINDOO, Ph.D., 



Bureau of Entomology, Washington, D. C. 



Contents. 



Introduction and methods 



Morphology of the ohactory pores 4io 



„. . . 410 



Disposition 



(a) Epilachna borealis 4 



(&) Other species 



(c) Individual and sexual variations 4i8 



420 

 Structure 



(a) External structure ^20 



(6) Internal structure 42 



Experiments to determine the location of the olfactory organs 426 



The olfactory sense of Harpalus pennsylvanica 428 



(a) Effects with antenna pulled off 43° 



(&) Effects with elytra and wings pulled off ■ • 43i 



(c) Effects with elytra and wings pulled off and pores on legs covered with 



vaseline 4o 



The olfactory sense of Harpalus caliginosus 433 



(a) Effects with antennee pulled off 433 



The olfactory sense of Epilachna borealis 434 



(a) Effects with antennae pulled off 434 



(&) Effects with elytra and wings pulled off 435 



The olfactory sense of Chaulcognathus pennsylvanica 436 



(a) Effects with antennae pulled off 43 



The olfactory sense of Passalus cornutus 43 



(a) Effects with antennae pulled off 437 



The olfactory sense of Cotinis nitida 437 



(a) Effects with antennae pulled off 437 



The olfactory sense of Euphoria sepulchralis 437 



(a) Effects with antennae pulled off 43 



The olfactory sense of Cyllene rohinice 438 



(a) Effects with antennae pulled off 438 



(&) Effects with elytra and wings pulled off 438 



The olfactory sense of Leptinotarsa lO-Uneaia 439 



(a) Effects with antenna pulled off 440 



{h) Effects with elytra pulled off and wings cut off 440 



(c) Effects- with elytra pulled off, bases of wings glued and pores on legs 



covered with vaseline 44i 



The olfactory sense of Epicauta marginata 442 



(a) Effects with antennae cut off 443 



{h) Effects with antennae pulled off 443 



407 



