VI 



Wing. Carlton. Wabasha, Fillmore, Redwood, Blue Earth and 

 Lyon. 



Four houses in the Twin Cities, to our certain knowledge, and 

 there were doubtless others, have been over-run with the so-called 

 "book louse." Troctcs diz'iiiatoria, which, by the way, is by no means 

 always confined to books. In these particular cases these tiny 

 pests swarmed in bureau drawers and closets, over clothing, on 

 walls and the backs of pictures, and in fact in every place likely 

 to disgust a sensitive house-keeper. An efifort was made by this 

 department to free two houses of this unwelcome guest, and partial 

 success was attained by the use of hydrocyanic acid gas, the fam- 

 ilies vacating the premises in question for about thirty hours. We 

 were vmable to locate the starting point or breeding place of the 

 insects in these two cases. It is a significant fact, however, that 

 all of these residences known to be infested are new houses, built 

 within a year, the present occupants being the first to use them. 

 Serious outbreaks of Psocids are unusual, though some are on rec- 

 ord, starting from straw or husk fillings of mattresses, in which 

 they find a congenial breeding place. No such chances were offered 

 the insects in the cases above referred to, and we are constrained 

 to believe, from our observations, that they came from the space 

 betwen the walls, or under the floors, or both. Another family, 

 which, for a year or more, has been troubled by that very common 

 household pest, the little red ant, has appealed to the entomologist 

 for relief, and at date of writing, believe they have been practically 

 conquered by the use of bisulphide of carbon, after they had been 

 traced to their retreat, evidently the walls of the furnace room. 

 Our object in this case, of course, is to kill the queen or queens in 

 the nest or nests thus preventing increase, as well as killing all 

 worker ants in the nest at time of treatment. 



In a special report on the Flour Moth, issued in February, 1904, 

 we counselled great care in the use of hydrocyanic acid gas against 

 this pest, and on account of the danger of its application, unless 

 in the hands of experienced parties, it was placed among remedies 

 which were regarded as undesirable for any cause. Personal work 

 with this agent since that date, as well as work done by others in 

 the East, convinces us that it is the most effective and useful of 

 all known remedies when intelligently used. It is absolutely sure 

 death to all eggs, which cannot always be claimed for the freezing 



