rro>- SCALE-INSECTS. 59 



Zimmermann records in a footnote to his pamphlet (loc. 

 tit.) a case of successful infection of the green-bug 

 (Lecanium viride) on the Java coffee by an artificial culture 

 of Cephalosporium. The conidia were apparently applied to 

 the bugs with a damp brush. 



Green has tried inoculating Lecanium psidii with an 

 artificial culture of the Aschersonia found growing on it 

 without success. In a letter he writes, "All endeavours to 

 communicate tbe disease by these means to healthy indivi- 

 duals completely failed. I tried it under different conditions, 

 but with equally negative results." 



Attempts made by the author at Peradeniya to infect scales 

 of Lecanium viride with Cephalosporium were also failures. 

 The conidia were painted over the scales with a damp brush, 

 but no development of the fungus upon them was shown after 

 the lapse of several days. 



Guegnen has tried inoculating coccids with the Acrostal- 

 agmns discovered by him without success, but it is not clear 

 from his account as to whether the insect upon which 

 he experimented was the same as the one upon which 

 he found the fungus growing naturally. 



The conditions for successful inoculation are, therefore, 

 somewhat obscure. Possibly the fungus-spore has to exist 

 previously on the area of the leaf upon which the coccid fixes 

 itself. It then germinates beneath the young scale, pene- 

 trating the soft parts. Spraying with decoctions may 

 not succeed owing to the germinating spores merely alighting 

 on the hard external shell of the coccid where, unable to pene- 

 trate, they dry up, and die, before they can produce sufficient 

 hyphse to effect an entrance below the scale. It has 

 been pointed out that many of these spores germinate readily 

 in water, and of course once sprouted easily die if the con- 

 ditions for growth are unfavourable. 



Careful investigation is required to ascertain how the 

 germinating tube of the spore first gains access to the interior 

 of the scale-insect, as well as to follow out the early develop- 

 ment of the fungus in the host. Perhaps these fungi chiefly 



