CATALEPSY IN PHASMIDAE.^ 



By P. Schmidt. 



In the spring of 1912 the author obtained eggs of Carausius {Dixi2>- 

 piis) nwrosus Br. \. W. which was imported from abroad and bred 

 by amateurs in Petrograd nurseries. After hatching, he fed the 

 gi-owing material mainly on parsley. During the rearing he has made 

 some observations and experiments which led him to conclude that 

 these insects are subject to catalepsy. 



Never very active, the young of Catriuslus are the most mobile. 

 The adults, on the other hand, spend nine-tenths of their lives in a 

 state of perfect stilbiess, as if transfixed. When at rest the four hind 

 legs are extended, while the front legs are extended forward w^here 

 their tarsi meet the ends of the antennaa, which are also extended 

 forward. The abdomen is also perfectly straig'ht, the end alone 

 being occasionally raised upward. This is the pose the adult insect 

 maintains for hours, frequently a whole day without stirring leg or 

 antenna. Only after long intei*vals of such quiescence, particularly 

 at night, do some of them stir in search of food. 



The transition from the state of rest into activity is accompanied 

 by very rapid lateral swinging on its legs. Its active existence is 

 always preceded by such vibration. This swinging frequently pre- 

 cedes also the transition into the resting state. The swinging, he be- 

 lieves, is for the purpose of starting circulation in its limbs which 

 " go to sleep " during the extended quiescence. 



A very few experiments sufficed to convince the author that the 

 state of rest in Carmisius is a state of catalepsy. Following are some 

 of the observations the author records. 



By carefully placing a forceps under the head of a resting speci- 

 men and raising it so that the portion composed of the head, pro 

 and mesothorax forms an angle of 40° to 45° with the metathorax 

 and then removing the forceps the insect remains in this position for 

 hours. By aid of the forceps the folded front legs may be pried apart 

 and placed at any angle to the body. Carausius retains this Mantis- 

 like pose of prayer for hours. A specimen resting on the side of the 

 jar may be flung to the bottom without provoking a change of the 

 posture of rest. However, on falling, it often assumes another pose; 



» Abstract from Rev. Russ. d' Ent., Vol. 18, No. 1, pp. 44-GO HfilS). 

 (35133°— SM 1917 ^33* .501 



