Household Pests and Their Treatment. 81 



it becomes very numerous. It is uncertain why this is so, and 

 an explanation of this feature of its prevalence might help us 

 to get rid of it everywhere. For there must be some good reason 

 for its absence from one place and its constant presence in an- 

 other seemingly similar place of resort. Dr. L. 0. Howard, 

 some years ago, observed a migration in large numbers of this 

 roach from a restaurant in Washington. The restaurant peo- 

 ple were not at the time making war on roaches, so it is not 

 unlikely that some insect or other predatory enemy drove 

 them out. The life-history of this roach is briefly the follow- 

 ing: 



The eggs are produced within a brown rather firm capsule 

 or case and may be carried about by the parent for some time 

 before being dropped in some nook or crevice, behind base- 

 boards or other woodwork, when the young hatch and at once 

 begin an active life of foraging in the neighborhood, especially 

 at night. As they increase in size the skin is molted from time 

 to time until finally wings are acquired, when they are adult 

 and ready to produce a new generation. It is believed that the 

 entire development of an individual is accomplished in six 

 months in the case of this species, which thus breeds more 

 rapidly than the other domestic species. There is no quiescent 

 pupa stage, such as is undergone by bees, butterflies and some 

 other highly organized insects. 



The Croton-bug thrives in some dwellings in a most exas- 

 perating way, not entirely because of its great capacity for in- 

 crease, but because it keeps close to the artificially warmed 

 parts of households and thus escapes the severity of winter. 

 Brick or stone buildings kept well warmed in winter are, 

 therefore, favorite haunts for the pest, and some of the very 

 best and most carefully constructed buildings thus become in- 

 fested ; while more open frame buildings, not well warmed in 

 winter, may be less often invaded. 



TREATMENT FOR ROACHES. 



The use of insecticides against roaches is a satisfactory 

 of suppressing them if it is persisted in, and especially 



