82 



AN ECONOMIC ENTOMOLOGY. 



convenient crevice, and very soon thereafter the young issue. 

 Modifications of this habit occur, and in some cases the eggs act- 

 ually hatch within the body of the mother, 

 ■ ^'' who thus becomes viviparous. 



I am not aware that roaches ever become 

 injurious to growing crops in our country ; 

 but two species are certainly great nuisances 

 in houses, — the " Croton bug," Phyllo- 

 dromia germanica, and the " black beetle," 

 Periplaneta orientalis. Both are introduced 

 and almost cosmopolitan forms. The former 

 is small, averaging about half an inch in 

 length, and is winged in both sexes. The 

 latter is larger, varying between three- 

 fourths and one and one-fourth inches, with 

 short wings in the male and mere rudiments 

 in the female. 



The most satisfactory way of dealing with these insects is by 

 means of a phosphorus paste, spread upon bits of soft bread 

 and placed near their haunts, all other food particles being care- 

 fully put out of reach. A short period of such treatment will 

 usually prove effective. Almost as good is a mixture of equal 



Fig. 48. 



Forficiila tcEuiata, male 

 and female. 



The Croton bug, Phyllodromia germanica. — a, first stage ; b, second stage ; c, third 

 stage ; d, fourth stage ; e, adult ; /, adult female with egg-case ; g, egg-case, enlarged ; 

 A, adult with wings spread. All natural size except^. 



parts of finely powdered chocolate and borax, dusted into the 

 crevices where the insects hide. The mixture should be inti- 

 mate, and is best made in a mortar, so that with each part of 



