OLFACTORY ORGANS OF LEPIDOPTERA 



51 



seems to be the latest and perhaps the best, most of the preceding 

 discussion will be taken from his paper. 



Disposition 



Schenk has carefully studied the antennal organs in both sexes 

 of the following moths: One geometrid (Fidonia piniaria), two 

 bombycids (Org>da antiqua and Psyche unicolor), and one 

 zygaenid (Ino (Atychia) pruni). He found the following five 

 sense organs on the antennae of both sexes: (1) Pit pegs (Sen- 

 silla coeloconica), (2) pegs (S. basiconica), (3) end pegs (S. stylo- 

 conica), (4) bristle-like hairs (S. saetica) and (5) ordinary hairs 

 (S. trichodea). In regard to the disposition of the above five 

 types of sense hairs on the feathered antennae of the males and 

 on the non-feathered ones of the females, the following maj^ be 

 said : These sense organs not only he on the shafts of both types 

 of antennae, but also on all the barbs of the male antennae. 

 The total number of sense hairs of each type found on the an- 

 tennae of the four moths examined by Schenk is tabulated as 

 follows : 



Number of sense organs on antennae of moths (after Schenk) 



Hicks ('59) and Hauser ('80) saw the same organs, particularly 

 the pit pegs, in the antennae of the butterflies, Argynnis and 

 Vanessa. Hauser says that each segment of the antennal knob 

 of Vanessa carries about 50 pits bearing pegs. 



