26 Arachnida and Myriopoda 



and ankles, or into the underclothes and stockings from the knees 

 downwards. A bath in hot water, or water containing salt or 

 strong soap, should be taken within a few hours after walking in 

 places likely to be infested with the mites. Chittenden, from 

 whose pamphlet the advice given above is taken, has pointed 

 out that sheep grazing in infested tracts of land destroy the 

 harvest bugs. 



The earliest known of these harvest bugs attacking man is the 

 Acarus batatas of Linnaeus, the habitat of which is Surinam, 

 Dutch Guiana. Dr. Oudemans has given the name Microtrombidium 

 wichmanni to the larval form assailing human beings in New 

 Guinea and Celebes, and he has described another form with 

 similar habits also occurring in New Guinea under the name 

 Schongastia vandersandei. Harvest bugs occur in practically 

 every part of the world, and the more annoying kinds have been 

 given popular names ; for instance, the " Bete Eouge " of some 

 parts of South America, the " Bicho Colorado " {Microtrombidium ? 

 molestissimum, Weyenberg) of the Argentine Bepublic, the 

 Mexican " Tlalzahuatl," the " Gonone " of Celebes and neigh- 

 bouring islands, and others. The following extracts from 

 various sources will serve to give an idea of the trouble caused 

 by these Acari in tropical regions. 



In their well-known Introduction to Entomology Kirby and 

 Spence quote the following observation by Lindley : "A similar 

 insect is found in Brazil, abounding in the rainy season, 

 particularly during the gleams of sunshine, or fine days that 

 intervene, as small as a point, and moving very fast. These 

 animals get upon the linen and cover it in a moment ; afterwards 

 they insinuate themselves into the skin and occasion a most 

 intolerable itching. They are with difficulty extracted, and leave 

 behind them large livid tumours, which subside in a day or two. 

 An insect very tormenting to the wood- cutters and the settlers on 

 the Mosquito shore and the bay of Honduras, and called by them 

 the doctor, is thought to be synonymous with this." 



Alfred Russel Wallace makes the following remarks about one 

 of these harvest bugs in his work on the Malay Archipelago : 

 " All the time I had been in Ceram I had suffered much from the 

 irritating bites of an invisible acarus, which is worse than 

 mosquitoes, ants, and every other pest, because it is impossible to 

 guard against them. This last journey in the forest left me 

 covered from head to foot with inflamed lumps, which, after my 

 return to Amboyna, produced a serious disease, confining me to 



