•->G 



JOl'RNAL OF AURICULTURE OF P. K. 



A Summary of rosults from all the boxes follows; 

 Infection of May-Beetles by Mitarrhi:ium. 



Box 

 No. 



Iiioc'iiIaU'il will) 



Metnrrhi/imii. . . 



Pteriginatoi^yslis 

 Sporotvicliiim. . . 



<heck 



Supply 



Isarla 



Botrytis 



Supply 



I'or cent infection 



38 

 19 

 35 

 17 

 29 

 14 

 33 

 27 

 16 



It eaii very clearly be seen from these results tliat the fungus 

 was, first of all, not especially virulent toward the May-beetles and 

 that above all it oceuri-ed independent of inoeulatons. 



In order that thorough field trials might be carried out, there 

 was eonstrueted at the Station an apparatus (see Fig. 1) consisting 

 of two cabinets and a five-horse-power ui)right boiler, following the- 

 plans of Ror( r (27. '■)()). The medium used was rice, spread (mt in 

 thin layers on the shelves and cooked /// sllii. No particular diffi- 

 culties other than mechanical ones were encoiinlered, and the first 

 batch of spore material was taken off by Mr. .lohnstoii in August, 

 1913. A low-grade fiour was used to (liliite the spore mass and t(v I 

 make removal fi"om the rice media more easy. \ 



The resulting mateiiid consisting of about lil'ly poiiiuls of thc' ] 

 flour-spore mixture and a similar amount of the rice residue was^ 

 taken to Yauco on the soutii coast, and ap])lied to one (jf the fields 

 of the Guanica Central. About an acre of young plant cane was , 

 dusted, using two tyy)es of hantl dusters, the Furet and the (Jyclone. 

 The foniiei- was the more convenient and serviceable. The rice resi- 

 due material was applied by hand around stools of cane adjoining 

 the dusted area. 



In October a <-onsidei'able numbei- of adults were collected from 

 the dusted area hy .Mi-. Siii\tli and confined to Santa Rita. Only 

 one of file entire number showed at any time signs of Mrfarrhiziimi. 



The following year another lot of spore material was prepared 

 by the writei' and again api)lied to tiie field previously dusted at | 

 Yauco and in the same manner, it has nevei- heen apparent that ' 

 any infection resulted among the beetles in this field. A third lot 



