264 DISEASES OF TROPICAL PLANTS CH.VIH 



Microcera, sp., is a fungus belonging to the 

 Hyphomycetes which has been reported as attacking the 

 Aleyrodes citri in Florida. It appears to be of con- 

 siderable importance, but has not been fully studied. 



Aegeritia Webberi, Fawcett, which is commonly 

 known as brown fungus has been reported from Florida 

 as important in the control of the Aleyrodis citri. It 

 was first reported by Webber, and later described by 

 Fawcett, who says that " it sends out long, straight, 

 colourless hyphae, which grow not only over the under 

 surface of the leaf, but around the edges and upon 

 the upper surface." It is brownish in colour and of 

 considerable importance. 



Ophionectria cocicola, E. & E., which is commonly 

 known as the white-headed fungus, belongs to the 

 Hypocreales. It has been reported from Florida and 

 Dominica, where it is said to be very efficient in its 

 work on Mytilaspis citricola and Chionaspis citri. It 

 forms white knob-like outgrowths on the dead insects, 

 on the surface of which numerous conidia are borne. 



Myriangium duriaci, Mont, is a fungus belonging 

 to the Plectascineae which is commonly known as the 

 black fungus. It has been reported on Mytalaspis 

 citricola and Chionaspis citri from Florida, St. Lucia, 

 St. Vincent, Barbadoes, and Dominica. When the 

 insects are very abundant and the weather favourable, 

 the fungus spreads from insect to insect, forming a black 

 crust containing softer areas in which the asci are borne. 

 This disease should not be confused with the black 

 blight disease of the lime and other citrus trees. 



The Shield Scale Fungus, so far as the writer knows, 

 has not been determined, but is said to attack Lecanium 

 hemisphericum, L. hesperidium, L. viride, L. nigrum, 

 and L. oleae, and has been reported from Barbadoes, 

 St. Vincent, Grenada, Antigua, Dominica. The dead 

 insects become dry and papery, and covered with a 

 buff-coloured fungal growth which produces numerous 

 spores. 



