BEHAVIOR OF SPIDERS AND OTHER INSECTS 439 



Samia cecropia. They tested both mated and unmated indi- 

 viduals. In all they studied 3,569 individuals. The following 

 are some of their conclusions: (1) mating does not significantly 

 shorten or lengthen the life of the male ; (2) the unmated female 

 lives longer than the mated: (3) a low temperature lengthens 

 the life of 5. cecropia and of T. polyphemus. 



MISCELLANEOUS 

 Shelf ord (81) discusses the importance of evaporation in 

 insect behavior. 



1. Migration. Lillie (48) records the well known fact that 

 the monarch butterflies of Minnesota and of New York migrate 

 southward in vast swarms each fall; and Davidson (19) discusses 

 the migration of certain plant lice. 



See Becker under locomotion. 



2. Pain. Weiss (97) reviews the arguments that have been 

 produced as proof that insects do not feel pain and concludes 

 that " The evidence for assuming that insects do not suffer 

 acute pain is not by any means complete. We simply do not 

 know and have no reliable means at present of finding out." 



3. Pollenization. Mrs. Howard (38) has experimentally proven 

 that bees are needed to pollenize certain plants. She covered 

 100 clover blossoms with netting and left 100 exposed to the 

 bees. From the uncovered blossoms she obtained 2,720 seed; 

 none of the covered blossoms produced seed. Of 2,586 covered 

 apple blossoms only three matured. 



4. Sleeping habits. According to Beutel-Reepen (7) the males 

 of several species of solitary bees spend the night congregated 

 in large clusters. 



Williams (102) states that large groups of the males of the 

 wasp Priononyx tkomae spend the nights and unfavorable weather 

 on the weeds. 



Frohawk (24) describes the sleeping habits of the butterflies 

 of the family Lyncaenidae. 



5. Temperature. In an extended study of the temperature 

 of the bee-hive, Gates (25) discovered that, even in cold weather, 

 the bees are neither torpid nor semi-quiescent. There is a 

 constant interchange of individuals between the outside and 

 the inside of the cluster. Even in the coldest weather, they 

 groom and comb one another. 



