206 INDIRECT INJURIES CAUSED BY INSECTS. 



attack upon our dead stock. Ulloa mentions one peculiar to 

 Carthagena, called there the comegen, which he describes as a 

 kind of moth or maggot so minute as to be scarcely visible to 

 the naked eye.^ This destroys, says he, the furniture of 

 houses, particularly all kinds of hangings, v/hether of cloth, 

 linen or silk, gold or silver stuffs, or lace; in short, every 

 thing except solid metal. It will in a single night ruin 

 all the goods of a warehouse in which it has got footing, re- 

 ducing bales of merchandise to dust without altering their 

 appearance, so that the mischief is not perceived till they 

 come to be handled.^ If we make some deduction from this 

 account for exaggeration, still the amount of damage will be 

 very considerable. 



There are three kinds of insects better known, to whose 

 ravages, as most prominent and celebrated, I shall last call 

 your attention. The insects I mean are the cock-roach 

 ( Blatta orientalis)i the house-cricket ( Gryllus domesticus), and 

 the various species of white ants ( Termes). The last of these, 

 most fortunately for us, are not yet naturalised. 



The cock-roaches hate the light, at least the kind that is 

 most abundant in Britain (for B. germanica, which abounds 

 in some houses, is bolder, making its appearance in the day, 

 and running up the walls and over the tables, to the great 

 annoyance of the inhabitants), and never come forth from 

 their hiding-places till the lights are removed or extinguished. 

 In the London houses, especially on the ground-floor, they 

 are most abundant, and consume every thing they can find, 

 flour, bread, meat, clothes, and even shoes. ^ As soon as light^ 

 natural or artificial, reappears, they all scamper off as fast as 

 they can, and vanish in an instant. These pests are not in- 

 digenous here, and perhaps no where in Europe, but are one 

 of the evils which commerce has imported ; and we may 

 think ourselves well off that others of the larger species of 

 the genus have not been introduced in the same way — as, 

 for instance, Blatta gigantea, a native of Asia, Africa, and 

 America, many times the size of the common one, which, 



1 It appears from Humboldt {Personal Narrative, E. T. v. 116.) that the 

 destructive insects called by this name are Termites. 



2 Ulloa, i. 67. 3 Amcen. Acad. in. 345- 



