76 



THE REPORT OF THE 



[19 



Smithsonian Institution, United States National Museum. 



May 18th, 1899. 



Dear Sir : — Your favor of the 8th inst.. together with the wasp came promptly to hand. 

 The specimen you sent me is the male of Polistes lineatus Fabr. a species widely distributed 

 throughout the West Indies and South America. By some it is considered only a variety of 

 orinitus Felton, but so far as I can see it is a good species and ought to be kept separated. 



Yours very truly, 



Wm. H. Ashmead. 



Vegetal parasitism, in one form or another is not an unusual 

 occurrence in insect life. The Silk Industry of France was at one time 

 threatened with complete destruction, by a form of it attacking the 

 Mulberry Silk- worm, Bomby xmori. Illustrations of the effect of one 

 form may be seen in specimens of our common housefly. Another 

 form is known as the white-grub fungus ; this white grub being the 

 larval stage of the common May-beetle, Lachnosterna Sp. An interest- 

 ing account of that form is given in the "American Entomologist," Vol. 

 1, page 92. In a letter from Mr. S. H, Y. Early given there, I quote 

 the following particulars. *' In the spring of 1842 I observed in what 

 is called "New Ground" in Virginia a great quantity of these mush- 

 rooms, and in reply to some remarks I made about them, some of my 

 father's negroes who were then making hills with hoes for planting 

 tobacco, enquired of me if I knew what produced these mushrooms. 

 On my replying in the negative, I was informed that they grew from 

 the white grub worm (Fig. 31). I think there were some twelve or 

 fifteen negroes present, all of whom concurred in the statement, and 

 said it was no new thing to them. They had no difficulty in establish- 

 ing the truth of what they stated, because they dug them up in all 

 their stages of germination and growth before my eyes. In a very 

 short time they had furnished me with a large number of the worms in 

 their original shape, features and size, and as distinct to the eyes as if 

 they had been alive, but having the consistency, color and smell of a 

 mushroom ; and I actually broke them up, just as a mushroom breaks 

 in one's hands, snapping them crosswise and squarely off." At one 

 time it was hoped that this fungus disease might b° propagated at 

 pleasure, for the destruction of the white grub in meadows, but so far 

 it has not proved to be practical. 



One can easily conceive of fungus spores vegetating on the soft 

 body of a grub, but it is difficult to understand how they could obtain 

 a foothold on the hard chitinous covering of these wasps. In another 

 letter Mr. Ramsden informed me that they suspend their nests on a 

 branch of a bush, so they cannot be specially exposed to contact with 

 moisture ; and yet they seem to be specially liable to this fungus attack, 

 as shown by the following quotation from the paper previously men- 

 tioned : " According to Dr. Carpenter, it is not at all unusual in the 

 West Indies to see wasps (genus Polistes) flying about with plants of 

 their own length, projecting from their bodies." And again, in " The 

 American Entomologist," vol. 3, page 138, when speaking of the species 

 Fig, 31— White oi fungus of the genus Torrubia which affects tbe white grub, Prof. Riley 

 grub fungus Cordy- said " We have in our cabinet some interesting specimens of this stage 

 ceps melolonthas. a ff ec ting wasps of the genus Polistes, originating just as the White grub 

 fungus does, from the base of the mandibles." In those received from Mr. Ramsden, the 

 fungus had its origin in the immediate vicinity of the front pair of legs. With regard to 

 the scientific name of the fungus affecting the wasps, Mr. Dearness did not find any of them 



