88 PRINCIPAL HOUSEHOLD INSECTS. 



tea, will be noticed to have a peculiar, disgustiug, foreign taste and 

 odor, the source of which may be a puzzle and will naturally be sup- 

 posed to come from the food rather than from the dish. 



The roaches are normally scavengers in habit and may at times be of 

 actual service in this direction by eating up and removing any dead 

 animal material. 



One other redeeming trait has been recorded of them, namely, that 

 they will prey upon that other grievous pest of houses which are not 

 subjected to careful supervision, the bedbug. Their habits in this direc- 

 tion have been recorded scA-eral times. One writer, in a narrative of a 

 voyage (Foster's Voyage, Vol. I, j). 373), makes the following statement 

 in this connection: 



CockroacLes, those uuisances to sliips, are plentiful at St. Helena, and yet, bad as 

 they are, they are more endurable than bugs. Previous to our arrival here in the 

 Chanticleer, we had suifered great inconvenience from the latter, but the cockroaches 

 no sooner made their appearance than the bugs entirely disappeared. The fact is 

 that the cockroach preys upon them and leaves no sign or vestige of where they have 

 been. So that it is a most valuable insect. ^ 



The cockroach is, however, far too much of a nuisance itself to war- 

 rant its being recommended as a means of eradicating even the much 

 more disagreeable insect referred to.^ 



The local si)read of roaches from house to house is undoubtedly 

 often effected by their being Introduced with supplies, furniture^ goods, 

 etc. That the Croton bug, or German roach, and probably the other 

 species also, may develop a migratory instinct has been witnessed by 

 Dr. Howard and the writer in Washington. (See Insect Life, Vol. 

 VII, p. 349.) 



This very interesting instance of what seems to have been a true 

 migration, in which an army of thousands of roaches by one common 

 impulse abandoned their old quarters and started on a search for a more 

 favorable location, illustrates, as pointed out by Dr. Howard, what is 

 probably of frequent occurrence under the cover of darkness, and 

 accounts for the way in which new houses frequently become suddenly 

 overrun with these vermin. 



iProc. Ent. Soc. Lond., 1855, N. S. 3, p. 77. 



^The following interesting letter from Mr. Herbert H. Smith, the collector and 

 naturalist, gives a vivid picture of the roach nuisance in the Tropics: 



''Cockroaches are so common in Brazilian country houses that nobody pays any 

 attention to them. They have an unpleasant way of getting into provision boxes, 

 and they deface books, shoes, and sometimes clothing. Where wall paper is used 

 they soon eat it off in unsightly patches, no doubt seeking the paste beneath. But at 

 Corumba, on the upper Paraguay, I came across the cockroach in anew role. In the 

 house where we were staying there were nearly a dozen children, and every one of 

 them had their eyelashes more or less eaten off by cockroaches — a large brown spe- 

 cies, one of the commonest kind throughout Brazil. The eyelashes were bitten off 

 irregularly, in some places quite close to the lid. Like most Brazilians, these chil- 

 dren had very long, black eyelashes, and their appearance thus defaced was odd 

 enough. The trouble was confined to children, I suppose because they are heavy 

 sleepers and do not disturb the insects at work. My wife and I sometimes brushed 

 cockroaches from our faces at night, but thought nothing more of the matter. The 

 roaches also bite off bits of the toe nails. Brazilians very properly encourage the 

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



