122 First Report on Economic Zoology. 



more or less soft, not a hard, rigid shell. The egg gives rise to the 

 so-called larval stage, which resembles the adult, except that it has 

 six instead of eight legs, and they are usually colouiiess and semi- 

 transparent. This larval stage does not last long, a single ecdysis 

 bringing it to the thu-d or nymph condition. 



The nymph resembles the adult when nearing maturity, but when 

 young it has the appearance of the larva. This is the period when 

 the mite grows, and it assumes its fourth pair of legs. The nymph 

 casts its skin twice. Another curious stage exists in these acari, 

 namely, the hypopial stage, in which the mite assumes a different 

 appearance — a stage in which it can more easily be distributed from 

 place to place by becoming attached to flying insects, etc., but in the 

 two furniture pests this stage is rudimentary; in G. domesticus it 

 never emerges from the young nymphal skin, and in G. sjjinipes it 

 seldom does so. This " skin-like " case protects the mite and so 

 enables it to withstand heat, moisture, etc., and in this stage it may 

 very easily be distributed from place to place by the wind. The 

 wind may also spread these minute creatures in other stages as well. 



The " feather-bristle " mites, or Glyciphagi, may often be noticed 

 in houses suffering from dry rot. They do not seem to do any 

 material damage in a house except to stored goods, unless it is by 

 carrying the spores of dry rot fungus about. Mr. White stated in 

 one of his communications, "the white insects give considerable 

 trouble on my furniture ; perfectly harmless, but unpleasant." They 

 may also be noticed in abundance in furniture attacked by the furni- 

 ture pest — the Death Watch {Anohiuni tessallatum) — living amongst 

 the dust and debris these pests produce. 



Teeatment. 



Washing well all likely corners where they may shelter with a 

 strong solution of " Chinosol " was recommended. Failing this, 

 fumigation with hydi'ocyanic acid gas or disulphide of carbon might 

 be tried. These, of com'se, are poisonous, also the fumes, and bisid- 

 phide of carbon is also inflammable, so must be used with care 

 (^vide p. 126). 



A further letter regarding fumigation for this pest was received 

 from Mr. Howard White, to wliich the following answer was sent : — 



Your letter has not been answered because I was waiting the result 

 of some experiments Prof. Hall was making for me re bisulphide of 

 carbon. He finds it will not hurt gold picture frames, etc., unless there 

 are impurities in the gold. Nor will it hurt furniture, foods or draperies 



