48 Notes on a Plague of Psocids in a Factory 



the large double doors of part of the building, referred to below as the 

 " loft," were opened in the morning, they could be seen flying out in 

 thick clouds. When, further, complaints began to be made by customers 

 about large numbers of insects appearing in bedrooms where newly 

 purchased mattresses were being used, tiie manager of the factory 

 recognised the seriousness of the outbreak, and wrote a letter to the 

 writer, requestiiig advice as to how to get rid of the pest. 



In order to ascertain the nature of the buildings and the manner 

 in which the straw for making the mattresses was being stored, a visit 

 was paid to the factory, when it was found that three buildings were 

 involved, viz. 



{a) the loft, in which the straw was stored, 



[b) the making-room, in which the mattresses were made, 



(c) the store-room, where the finished mattresses were stored. 

 The insects were most numerous in the loft, which measured 18| feet 



high, by 28 feet long, by 15 feet wide, the other rooms being slightly 

 less. No fresh straw had been brought in after the old had been used 

 up, so that the nature of the flooring could be easily examined. It was 

 of concrete, and there were a few fairly wide cracks running across the 

 whole width. In these cracks immature forms of Psocidae were 

 observed. 



The measures successfully adopted to get rid of the pest may be 

 put briefly as follows : 



(1) The ventilators in the loft were closed, and all crevices (round 

 the doors, etc.) were covered over with paper carefully pasted on — the 

 door through which the fumigant was admitted being dealt with im- 

 mediately after being closed. 



Ten pounds of rock sulphur (previously broken up in a sack by means 

 of a mallet) were placed in an iron pot, and some hot cinders thrown 

 on top. The pot was placed in the middle of the room, and instructions 

 were given not to open the doors until twenty-four hours had elapsed. 

 The other rooms received similar treatment. 



(2) The loft having been thoroughly ventilated after fumigation, 

 the walls were then carefully whitewashed (tlie whitewash containing 

 some carbolic acid) and the floors of all the rooms were washed out 

 with water aiid carbolic soap. 



(3) It seemed probable that a few Psocids might appear in a week 

 or two, seeing that the eggs might not be affected by the treatment, and, 

 indeed, six days after the fumigation, a report was received stating that 

 the insects were beginning to reappear. The writer accordingly visited 



