416 



NATURE SKETCHES IX TEMPERATE AMERICA 



vatioii of llie ground whicli ctfectually destroyed their eggs 

 has gradually controlled ihesc enormous swarms of locusts, 

 so we rarely witness the clouds of these insects seen some years 



ago. 



TuK Pennsylvania Cockroach 



Few of us realize the great abimdance of insect life that can 

 be found in old stumps. I recall my surprise at pulling off 

 some bark of an old tree stump one day to discover a horde of 

 cockroaches secreted there. But so c^uick were they in their 

 movements to escape that I could hardly get a satisfactory 

 glimpse of one of them. At this time the tjuestion arose as to 

 whether these insects were simply our common household 

 pest, Blatta orientalis, or a wild species. More recently, 



The Pennsylvania Coclcroarh (Ischnoptera pennsylvanica) , 



one of tlic most common of our roaches, living under 



loose hark. Male, female, and cast skin. 



June 1, 1905, an opportunity came again to look into this 

 question and I satisfied myself that what I formerly saw on 

 the old tree stumps was the wild species, the Pennsylvania 

 cockroach, which in scientific terms is known as Lschnoptera 

 fennsylvanica. I have depicted the male, female, and a nymph 

 cuticle in the accompanying photographic illustration. On 

 the day mentioned I was in an open wood at Flossmoor, Illi- 

 nois, when I noticed a number of oak stumy)s. Here under 

 the loose bark that peeled off cjuite easily, I encountered a large 

 number of these cockroaches. 



