333 



Watson (J. R.). Insect Damage to Crops in Florida. — Qtrly. Bull. 

 Florida State PI. Bd., {Gainesville, v, no. 3, April 1921, pp. 138-140. 



Besides the direct loss of crops due to insect attack in Florida, there 

 is a good deal of indirect loss caused by hindrance to the development 

 of industries from fear of insect pests. It is thought that the average 

 loss, as estimated for the United States — about 42s. per year for each 

 individual — is too low for Florida, where growth continues all the year 

 round without any prolonged and severe winter to kill off insects. 

 The average plantations of Citrus probably jdeld onl}' one-half of 

 what they might produce if freed from insect pests ; only in the best- 

 cared-for groves is the loss nmch less. Winter vegetables do not 

 suffer very severely, as many insects are hibernating during the peiiod 

 of their growth, but vegetables grown in autumn and spring are often 

 badly attacked. Late-planted maize frequently fails owing to insect 

 attacks. Some instances are given of the control of insect pests by 

 entomogenous fungi and by introduced parasites, and the importance 

 of discovering and propagating fresh natural enemies is emphasised. 



Berger (E. W.). Natural Enemies of Scale Insects and Whiteflies 



in Florida. — Qrtly. Bull. Florida State PI. Bd., Gainesville, 

 V, no. 3, April 1921, pp. 141-154, 10 figs. 



The climate of Florida is very favourable to the development of 

 certain fungi, which are of great assistance in keeping down the scale- 

 insects that infest Citrus. The Plant Board of Florida grows and 

 supplies pure cultures of these fungi with instructions for applying 

 them to the trees. Their importance is soon apparent if a tree is 

 sprayed with a fungicide, such as Bordeaux mixture ; this destroys the 

 fungi, and the scale-insects rapidly increase in consequence. Artificial 

 dissemination is best carried out during the summer rains, but the use 

 of fungi is not recommended for trees less than three years' old. These 

 are better sprayed with oil, and a spray of oil emulsion, miscible oil 

 or soap solution is recommended towards the end of September on 

 all trees where scales seem to be increasing. The fungi may be applied 

 by spraying a mixture of the spores in water into the trees. For 

 whiteflies this must be applied to the lower side of the leaves. About 

 100 heads of fungus should be used to one gallon of water. Fungi 

 not obtainable in pure cultures should be collected from deciduous 

 trees when wanted for use on Citrus, or vice versa. 



These beneficial fungi include the red-headed scale-fungus, Sphaeros- 

 tilbe coccophila, which infests Lepidosaphes beckii (purple scale) on 

 Citrus, Aspidiotus perniciosus (San Jose scale) chiefly on peach, 

 plum and pear, L. glover i (long scale) on Citrus, A. hederae chiefly 

 on chinaberry, and Parlatoria pergandei (chaff scale) mainly on Citrus. 

 The pink scale-fungus, Microcera fujikuroi , greatly resembles the above 

 and has long been confused with it. It attacks ChrysotnpJialus 

 aonidum (Florida red scale) mainly on Citrus, C. obscurus (water-oak 

 scale) and C. tenebricosus (red maple scale) on their respective food- 

 plants, and C. aurantii (California red scale) and L. beckii on Citrus. 

 The white- or grey-headed scale-fungus, Ophionectria coccicola, is ver}' 

 commonly found on L. gloveri, L. beckii and P. pergandei. The black 

 scale-fungus, Myriangium duriaei, which probably occurs throughout 

 Florida, but is more abundant in the north, kills L. beckii, L. gloveri. 



