144 



ance to the adults. The flattened body and spiny legs of 

 cockroaches make it possible for them to penetrate 

 into very narrow cracks and crevices, where they hide 

 during the day. 



A small cockroach often occurs in the living rooms of 

 houses, hiding by day behind pictures and ornaments, and 

 inside presses, chests of drawers, under tables and in like 

 situations. The bright-brown egg-capsules may often be 

 found in the hiding places of these insects ; from such places 

 these forms sally forth at night, committing depredations 

 similar to those of the larger species. They are related to, 

 if not the same as, the German cockroach Ectobia ger- 

 manica, shown in Fig. 153. 



Fig. 153. The German cockroach. 



(a. b,c, d} four stages of growth ; (e), adult; (/), adult female with 



egg case ; <#), eog-case enlarged ; (h). adult with ivings spread. 



All natural size except (g), (From U, S, Dept. Agric.) 



Control. A mixture of boracic acid and sweet choco- 

 late or molasses, in equal parts, placed where these insects 

 are abundant serves as a very efficient check. A mixture 

 of flour and plaster of Paris is also said to be useful in 

 this connexion. If the supply of these mixtures is re- 

 peated at intervals of six weeks or two months, or when- 

 ever it is noticed that cockroaches are on the increase, it 

 should be possible to keep them reduced to very small 

 numbers all the time. Cleanliness in kitchens and store- 

 rooms, and the careful removal of all pieces of food, will 

 also be found to help in reducing the numbers of these 

 disagreeable pests. 



Natural Enemies. The egg masses of cockroaches are 

 attacked by hymenopterous parasites of the genus Evania. 



