308 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



part of or even the entire exuvium, and it may be possible that Riley 

 overlooked some of the molts on this account. If Thomson did not 

 fall into this same error, it is difficult to explain why all of his walk- 

 ing-sticks should have molted four times. He writes, ''the first speci- 

 men emerged on the 11th of June, and others from time to time dur- 

 ing the summer. They changed their 'skins' four times before reach- 

 ing maturity." In Wisconsin, the walking-sticks hatch in June also, 

 but we noticed, as Riley (63, 73 and 74) also describes, that "some 

 of them, however, continue hatching much later, so that all through 

 the summer and even into fall, young individuals may be found.'" ^ 

 In their natural habitat in Wisconsin, the walking-sticks feed most 

 abundantly upon the leaves of the hazel-nut shrubs (Coryhis americana 

 Walt.) and to some extent upon the leaves of the linden (Tilia amer- 

 icana L.). 



The following table shows the number of male and female Avalking- 

 sticks which molted four, five or six times. All of these specimens 

 were reared from fertilized eggs under normal conditions. 



TABLE I 



NUMBER OF MALB AND FEMALE DIAPHEROMERA FEMORATA WHICH MOLTED FOUR, FIVE OR Sit TIMES. 



Number of walking-sticks which molted four times. 

 Number of walking-sticks which molted five times. . 

 Number of walking-sticks which molted six times. . . 



It is evident from this table, that in those specimens which molted 

 four times, the males greatly outnumbered the females. 



The interval or periods between the molts (stages or stadia) and the 

 total duration of these periods (or the post-embryonic development) 

 in Diapheromera reared under normal conditions during June 

 July and August, which time corresponds to the normal period of 

 development of this Phasmid in its natural habitat in Wisconsin, is 

 shown in the following table. In this table the specimens are arranged 



iThe development of Diapheromera femorata, however, is often retarded by parasit- 

 ism, which fact may account for some of theimmature walking-sticks being found late 

 in autumn in Wisconsin. We have reared a leaf-ovipositing Tachinid, which Town- 

 send (98) has recently described as Phasmophaga antennalis for us. This year (1910), 

 a large number of walking-sticks parasitized by a host-ovipositing Tachinid were 

 found. We succeeded in obtaining the egg, larval and pupal stages of this parasite 

 but at the present writing the imago has not yet been bred. 



