BEHAVIOR OF SPIDERS AND OTHER INSECTS 413 



According to Wodsedalek (108), rough handling of the ephe- 

 meridae nymphs Heptogenia inter punctata Say produces leti- 

 simulation. The time of the feint varies from a fraction of a 

 minute to fifteen minutes. The average is between two and 

 three minutes. Prolonged stroking of the nymph on the sternum 

 or on the ventral side of the abdomen will prolong the feint. 

 By such means a feint has been prolonged for an hour. A touch 

 with a smooth object tends to prolong the spell; a tap with a 

 sharp one arouses the insect. 



Gee and Lathrop (31) describe three methods of inducing 

 this form of behavior in Contrachelus nenuphar Herbst: (1) 

 dropping them from a height in the air; (2) compressing, at 

 short intervals, the lateral surfaces of the abdomen and thorax; 

 (3) grasping the insect between the thumb and forefinger and 

 suddenly blowing upon the ventral surface of the abdomen. 

 Two distinct postures are assumed by the letisimulating indi- 

 viduals. In one type the individual draws the thoracic appen- 

 dages closely against the ventral surface of the body. The first 

 pair of legs extend forwards and are pressed against each side 

 of the proboscis. The closely flexed second and third pairs of 

 legs are held securely against the ventral side of the abdomen. 

 In the other type the legs are folded closely together and held 

 somewhat at right angles to the line of the body. The tarsi of 

 the first and of the second pairs of legs are drawn tightly against 

 the tibia; but, in the third pair, they aie held approximately 

 parallel to the ventral surface of the thorax. In the first type 

 the pose resembles the attitude of insects that have been starved 

 to death or killed by slow poison. These investigators suc- 

 ceeded in causing one indi\ r idual to letisimulate fifty-three times ; 

 but, after the first few times, the duration of each successive 

 feint was gradually reduced until the animal would not leti- 

 simulate at all. To test the influence of temperature, letisimu- 

 lating individuals were placed in a glass and held over a flame. 

 In every case the individual quickly recovered. This is unlike 

 DeGeer's experience with the beetle Anobrium pertinax; which, 

 he claims, could be roasted over a slow fire without recovering. 

 Gee and Lathrop find that a low temperature increases the 

 duration of the death feint, thus agreeing with Fabre's work on 

 Caponoides tenebrinicnis and Holmes' work on Ranatra. It was 

 found that letisimulating individuals, when placed in an atmos- 



