OF WASHINGTON, VOLUME XVII, 1915 151 



At the close of the regular program Mr. Burgess, being called 

 upon told in detail of the methods used and the success attained 

 in the colonization of the egg-parasite of the gypsy-moth, Anas- 

 tatus bifasciatus, in Massachusetts. 



Mr. L. H. Worthley and Mr. I. W. Davis, visitors, were in turn 

 called upon by the President and responded briefly. 



THE USES OF CERTAIN WEEVILS AND WEEVIL PRODUCTS 

 IN FOOD AND MEDICINE. 



BY W. DWIGHT PIERCE. 



Large quantities of pupal cocoons of a weevil were recently 

 received by the Bureau of Chemistry from the American Consul 

 at Constantinople under the name of trehala manna, an edible 

 substance. Although there is some little literature on the sub- 

 ject it is mostly very inaccessible and practically unknown to Amer- 

 ican entomologists. A complete bibliography of the chemical 

 phases of trehala has been prepared in the Bureau of Chemistry 

 and was very kindly loaned the writer by Mr. C. S. 'Hudson. 



It is not common for an insect to produce a substance which 

 is edible for man, and that ;i weevil should be the maker is a 

 matter of especial interest. 



The first reference in literature properly classifying the maker 

 of this substance is contained in a note by Guibourt (Revue et 

 Magasin de Zoologie, 1858, ser. 2, vol. 10, p. 276) entitled "Notice 

 sur une matiere pharmaceutique nominee la Trehala, produite 

 par un Insecte de la famille des Charangons." He states that 

 the cocoon is used for food in the Orient as commonly as salep 

 and tapioca are used in France. His material was received from 

 Roumelia and probably originated in Syria. Guibourt names the 

 producer of these amylaceous cocoons Larimis nidificans, but 

 does not supply any further description. 



About the same time as the publication of Guibourt's note, 

 M. Berthelot made a chemical study of the product and pub- 

 lished an article entitled "Sur le trehalose, nouvelle espece de 

 sucre" (Comptes Rendus de rAcadcmie des Sciences, vol. 46, 

 June 1858, pp. 1276-1279). This substance trehalose is analogous 

 to cane sugar, with the formula CiJIa-jOn as indicated by modern 

 chemistry. At ordinary temperatures il retains two molecules of 

 water of crystallization. The proper! ies are quite fully discussed. 



It is interesting to note that trehalose was first obtained from 

 the ergot of rye, that it is derived from many species of mushrooms, 

 from Aspergillus nujer, and also from the resurrection plant 

 (SelagineUa lepidophylla) . 



