120 THE PHYSIOLOGY OF INSECT SENSES 



must hit a given number of receptors and that the probabihty of a 

 response can be increased by increasing either the concentration or the 

 number of receptors. 



Table 3 

 (From Dethier, 1952 b) 



Effects of unilateral and bilateral operations in the responses of beetles 



given a choice between 0% and 100% R.H. at 27°C. 



(Data from Roth and Willis, 1951b) 



Species 



Receptor areas remaining on 

 Antenna 



% Response 



Rhyzopertha dominica 

 (thin-walled sensilla 

 present on segments 

 8-10) 



Latheticus oryzae (thin- 

 walled sensilla present 

 on segments 7-11) 



Tribolium castaneum 

 (thin-walled sensilla 

 present on segments 

 9-11) 



Tribolium confusum 

 (thin-walled sensilla 

 present on segments 

 7-11) 



Segments 

 Segments 

 Segments 

 Segments 

 Segments 

 Segments 

 Segments 



Segments 

 Segments 

 Segments 

 Segments 



Segments 

 Segments 

 Segments 

 Segments 

 Segments 



Segments 



Segments 



segments 



antennae 



Segments 



Segments 



Segments 



Segments 



Segments 



Segments 



Segments 



-10 on both (normal) 



-10 on one 



-9 on other 



-9 on both 



-10 on one 



-7 on other 



-7 on both 



-1 1 on both (normal) 

 -1 1 on one 1 

 -10 on other/ 

 -10 on both 



-1 1 on both (normal) 

 -9 on both 

 -9 on one 

 -8 on other 

 -8 on both 



1 1 on both (normal) 

 -11 on one 

 on other 



-7 on both 

 -7 on one 

 -6 on other 

 -6 on both 

 -11 on one 

 -6 on other 

 -6 on both 



76±2-7 

 69±30 

 56±3-4 

 61±2-9 

 01±7-0 



87±3-l 

 73±3-2 

 46d=2-7 



80±10 



75±2-9 



78di3-6 

 31±5-4 



86±l-7 



76±30 



-0-2±2-2 

 23±l-6 



12±3-9 



5±4-l 



75±2-l 

 5±4-l 



A more detailed investigation of this phenomenon has been made 

 by Dostal (1958), who studied the response of honeybees to the sub- 

 stance Nerol R (CjoHigO), a synthetic constituent of rose oil. She 

 showed that with successive amputation of one to six antennal seg- 



