JS PARKIN* : FUNGI PARASITIC 



Cultural and Infection Experiments. 



Such of the fungi as have been used for experiment are 

 easily cultivated on artificial media, showing that they have 

 not become so specialized as to need their own particular 

 insect as food. The spores of several kinds tried by the 

 author germinated readily in water. 



Roll's has succeeded in cultivating Sphaerostilbe (Micro- 

 cera) on. bread, agar, gelatin, &c. He finds slightly acid 

 bread a very useful material. 



Zimmermann has shown that the Java Cephalosporium 

 grows readily on agar substratum, provided with various 

 nutrients. By this means crops of conidia can be obtained. 



Guegnen found he could cultivate Acrostalagmns on a 

 variety of substances. 



The ease whereby these fungi can apparently be artificially 

 cultivated is a point in their favour for their possible use as 

 checks to scale-insects. 



Infection experiments have not so far been extensively 

 tried, but such as have been attempted have often been 

 failures, except those with Microcera in the United 

 States. 



As regards the Aschersonia aleyrodis of Florida, Webber 

 reports that orange trees infested with mealy wing, but 

 possessing no fungus upon them, have been sprayed with a 

 mixture of conidia and water on several occasions with no 

 result. Another method attempted was to hang orange 

 branches containing Aschersonia pustules over trees posses- 

 sing healthy mealy wing larva 1 . In this waj it was thought 

 that the conidia would be washed down by the rain and 

 infect the insects. Only in one out of several trials did the 

 Aschersonia make its appearance. Hence he goes on to say 

 that the most satisfactory way of introducing the Ascher- 

 sonia into orange groves is to transplant into them small 

 trees containing the fungus, allowingthe foliage to inter- 

 mingle freely. Several experiments of this kind have given 

 satisfactory results with the Aschersonia as well as with the 

 •• brown mealy wing fungus." 



