UPON SCALE-INSECTS 63 



doubtfully parasitic and the identity of the latter is un- 

 certain. They are black fungi and one of them is known to 

 follow " honey dew." 



8. The forms placed amongst the Fungi imperfecti are 

 probably in the main conidial stages of the Hypocrealess. 

 Microcera is known to belong to Sphserostilbe, and Ascher- 

 sonia to Hypocrella. 



9. Some of these fungi appear to be restricted to definite 

 kinds of scale-insects. Nectria and Microcera are confined 

 to the sub-family Diaspidinae; Cephalosporium to species of 

 Lecanium ; one type of Aschersonia to the Aleurodida 3 

 (Aleurodes spp.) ; and another to Lecanium. 



10. So far fungi have been found on ten distinct genera, 

 and thirty species at least of Coccidae and Aleurodidae. 



11. The interesting genus Torrubiella has only been 

 found on spiders and coccids. It has not been so fre- 

 quently met with in Ceylon as some of the others, e.g. 

 Nectria. 



12. Several of these fungi that have been tried grow well 

 on various artificial media. 



13. Inoculating experiments attempted by the applica- 

 tion of watery decoctions of spores to healthy scales have 

 not met with the success expected. The conditions favouring 

 infection are evidently somewhat peculiar and require 

 thorough investigation. 



14. The conidia of many of these fungi are probably dis- 

 tributed by rain and ants, and not by wind. 



15. The economic importance of these fungi must be 

 kept in view. Some of them have been successfully em- 

 ployed in the United States against noted scale-pests, render- 

 ing ordinary insecticides unnecessary. As moisture and 

 warmth naturally favour their growth, Ceylon should be a 

 suitable country for testing their efficacy as a remedy for 

 scale-attacks. 



In conclusion, my thanks are due especially to Mr. E. E. 

 Green for much assistance in many ways, and also to Mr. T. 

 Petch for some useful criticism. 



