18 JhiUeliiì (le la Sociélc lìnloniologiqiie d'E(jij])l('. 



Coltoli Bollwonn and on Ihe pupae of Ilio Collon 

 Worm Prodcnia lilloralis. 



In America in addition to being recorded as a l)e- 

 neficial species, feeding on llie immature stages of the 

 Mexican Cotton hoWwQeyii.Anllioiioiiiiisi/rdndis.Bruclins 

 ihineììsis etc., it lias also proved itself (t j)c\sl to m(ui. 



During the Spring and Suinnier of 1907 and HI09 

 in Philadelpiiia and neighbouring towns, a peculiar 

 eruptive skin disease became prevalent. This com- 

 plaint took the form of numerous small lesions 

 over j)art or the whole of the body. A ver}^ curious 

 fact was established namely that all the sulTerers had 

 slept on or handled newly made straw mattresses. 

 The explanation of the disease was as follows. The 

 straw of the mattresses had come from localities in 

 which there had been a severe attack of the Angoumois 

 grain moth Silotroga ccrcdlclla and the Joint Worm 

 Isosoiud sp., a small Hymenopterous pest of wheat 

 straw. On the immature stages of these two 

 insects the mite Pidiciiloidcs ncììtricosiis had bred in 

 enormous numbers. The straw swarmed with them 

 and their natural food supply linally giving out they 

 made their way through the covering of the mattresses 

 and attacked the persons sleeping on them, their 

 bites causing the curious skin eruption. 



The (juestion of this mite as a pest of man is fully 

 dealt with in Circular 118 of the Bureau of Entomology. 

 U.S.A. written by Mr. F. M. Webster under the title: 

 " A Predaceous Mite Proves Noxious to Man. " 



In conclusion I would like to express my thanks 

 to Monsieur E. Trussart and D' A. C. Oudemans for 

 very kindly examining the majority of the mites 

 mentioned above. 



