DEATH FEIGNING REACTIONS IN TYCHI US 



PICIROSTRIS 



E. MELVILLE DuPORTE 



Biological Laboratories, Macdonald College (McGill University), Canada 



The behavior of the lower organisms is of importance, not 

 only for the intrinsic interest attached to the study of the 

 subject but also for the light which it may throw on the more 

 complicated reactions of the higher organisms. Any contribu- 

 tions, therefore, which will add to our knowledge of any phase 

 of animal behavior or confirm results already obtained in this 

 field, which has not been greatly exploited, will be of some 

 interest to the student of comparative psychology; and for this 

 reason the writer is publishing the following brief notes on 

 observations incidentally made while studying the habits of 

 Tychius picirostris, an European weevil observed this year for 

 the first time in this country doing appreciable injury to clover. 



The habit of feigning death is found in a large number of 

 animals but is most marked in certain insects. This habit 

 among insects is of interest not only to the student of behavior 

 but also to the collector and to the applied entomologist. The 

 entomological collector often takes advantage of this reaction 

 in collecting beetles and other insects which fall to the ground 

 in a death feint when a sudden jar is given to the plant on 

 which they are feeding, and this practice of jarring has been 

 used effectively in the control of certain insect pests such as 

 the May beetles {Lachno sterna spp.) and the plum curculio 

 (Conotrachelus nenuphar Herbst), especially prior to the advent 

 of arsenical sprays. 



Methods of Producing the Feint. The weevils congregate in 

 large numbers on the leaves of the clover in the spring, and 

 on the flower heads later in the season. If a plant attacked 

 by these weevils is jarred, the majority of the insects will fall 

 to the ground. Their action upon falling shows considerable 

 individual variation; most of those which fall on their backs 



