1904] BENNETT:— EARWIGS 49 



Adults. 



The females, after they have shed their skins for the last time, have only eight 

 plates on the upper side of the abdomen. The easiest way, therefore, to distinguish 

 the adult female from the young is to count the number of its plates ; for the 

 general shape both of the body and of the forceps is essentially the same in both. 

 The case of the males is different. Although until the last change of skin their 

 forceps were not distinguishable from those of the adult females or the young of 

 either sex, after that the forceps were much more curved. (See Figure i, a, b, and 

 c ; a and c are adult males, and b is an adult female.) Their plates also, after this 

 last moult, seemed to overlap each other along the sides of the abdomen to a 

 greater extent than did those of either the females or the young. The posterior 

 end of the abdomen seemed broader in proportion to the size in the male adults 

 than in the other sex or in the younger earwigs. The abdominal plates also 

 remained ten in number, as in the nymph stage. The legs of both male and 

 female adults were of a uniform tan color, while those of the young were generally 

 more or less dotted with black. Female adults are, as a rule, longer and otherwise 

 larger than the males. The size of the full-grown insects which I have seen varied 

 from almost sixteen millimeters (five-eighths of an inch) to nearly thirty-five milli- 

 meters (about one and three-eighths inches), not in either case including the length 

 of the antennae. I have not been able to ascertain the length of life of earwigs 

 when wild, but one which I still have in confinement has lived about twenty-one 

 months. The females were three or four times as numerous as the males. 



Hardiness. 



Earwigs seem to be capable of great endurance. They are accustomed to 

 live near water, and when disturbed they frequently enter the water. One of them 

 remained under water for an hour and five minutes or more when disturbed above 

 water. It showed little sign of being weakened by its experience. They are 

 capable of recovery from quite serious injuries. Once when an earwig was by 

 accident nearly torn in two just below the last pair of legs, and was consequently 

 paralyzed for a while in one leg and most of its abdomen, I pushed in all the 

 viscera as far as possible with a wooden toothpick, and then closed the opening. 

 In a short time it seemed to be as well and as able-bodied as ever. They easily 

 succumb to lack of water ; if kept in a dry place they soon die. 



