CONTENTS. 
Page. 
Introduction 7 
Parasitic and predatory enemies of white flies 8 
Snails that feed on sooty mold 9 
Climatic conditions 10 
Unexplained mortality 11 
Dropping from leaves 18 
Mortality due to overcrowding 18 
Effect of curling and dropping of leaves from drought 19 
Bacterial diseases 19 
Fungous diseases 20 
The red fungus 20 
The yellow fungus 26 
The brown fungus 28 
Fungi of little or no value as white-fly parasites 32 
Natural efficacy of fungous parasites 39 
Artificial means of spreading fungous diseases 47 
Length of vitality of spores 56 
Relation of weather conditions to fungous infections 57 
Relation between abundance of white flies and success in spreading fun- 
gous infections 58 
Susceptibility of different stages of host insects 58 
Cost of introducing and spreading parasitic fungi 58 
Degree of infection obtainable 59 
Practicability of increasing the efficacy of fungous parasites 60 
The disadvantages accruing to citrus trees through the use of parasitic 
fungi 69 
Summary and conclusions 70 
Index 75 
5 
