Habits, etc., of the " Walking-Stick " {Aplopus mayeri) . 55 



This insect suggests to one a papier-mache imitation with wire legs 

 which may be bent or twisted in almost any manner and put in any position. 

 It could scarcely be more stick-like. 



When walking, Aplopus often stops and waves its antennas about in a 

 circle, apparently feeling for some object in front of it. If the antennae 

 strike an object, a stick or a leaf, the first pair of legs reach forward 

 and attempt to grasp it and pull the body of the insect up to it. When 

 the insects have climbed to the top of a branch they usually wave their anten- 

 nae, trying to find some object on which to continue their upward journey. 

 The antennae of several individuals were cut away close to their proximal 

 joints. The insects were slightly excited by the operation, but soon moved 

 off, using their first pair of legs as feelers, stopping at intervals and waving 

 either the right or left leg and at times circling both legs in front of the head, 

 just as if the legs were efficient antennae. One of the first pair of legs was 

 removed, and the remaining one then served the purpose of a feeler. The 

 other first leg was then removed, leaving the animal without antennae or 

 either first leg. The insect now progressed in a slower but surprisingly 

 normal fashion upon only four legs. The point of especial interest is that 

 first the one and then the other of the second pair of legs was raised and 

 circled about as an antenna or feeler. Both of these legs could not be so 

 used at any one time, since the insect is unable to stand on less than three 

 legs. Normal insects were never observed to use either of the second pair 

 of legs as feelers. 



The eyes of such a four-legged, antennaless animal were blackened so 

 that it was unable to see. This confused the subject considerably and it 

 turned several times in a circle before being able to progress straight for- 

 ward. The progress was then slow and cautious. Such an Aplopus often 

 turned its head from side to side, as if attempting to see; it also moved the 

 stumps of its antennae and legs. It was able to climb among the branches 

 and feed in a typical manner. On the following day it showed marked im- 

 provement in its ability to progress. When at rest these crippled individuals 

 directed the remaining proximal portions of their antennae and first legs 

 forward, just as though they were assuming the attitude with legs and 

 antennae pointing straight out in front of the head, which is so typical for 

 normal individuals. 



A strong electric current causes Aplopus to move actively and may often 

 cause its legs to kick violently for some seconds. 



MATING OF MALES WITH A PORTION OF A FEMALE ABDOMEN ATTACHED TO 



A STICK. 



Many experimenters have attempted in various ways to determine 

 through what senses the male insect locates and mates with the female. 

 Among the moths and butterflies the sexes are sometimes differently colored 



