COCKROACHES 129 



Brazilians very properly encourage the large house spiders, 

 because they tend to rid the house of other insect pests." 



METHODS OF DISSEMINATION 



The foreign species of roaches, the German roach, 

 Australian roach, and Oriental roach were brought here 

 on ships from the various countries in which these insects 

 were native. 



The German roach, now so well known by the name of 

 croton-bug, is gradually spreading all over this country. 

 It is called croton-bug because it was first associated with 

 the water system of New York City supplied through the 

 great Croton aqueduct. Very likely this cockroach had 

 been in this country long before, but the water pipes gave 

 opportunity for entrance to the houses and the accom- 

 panying dampness was much liked by the insects. It is a 

 fact that these insects become numerous and greatly 

 troublesome in dwellings as soon as a system of water- 

 works is installed. It is evident that these roaches demand 

 a certain measure of dampness for their successful increase 

 and continued existence. There is no reason to suppose 

 they are brought to a town with the iron pipes ; but the 

 dampness attracts them and affords favorable conditions 

 for their increase. 



Roaches are often carried from town to town in ship- 

 ments of grain, groceries, and other foods. The author 

 once saw two cockroaches in a tight box containing 

 groceries that had been shipped from Chicago to Missis- 

 sippi. Undoubtedly roaches are carried from one house 

 to another with furniture and supplies. 



We have, at least, one recorded instance of the un- 



