THE OLIVE INSECTS OF CALIFORNIA 45 



eggs are laid till scarcely more than a thin shell remains. Upon 

 hatching, the young, which have much endurance for such small 

 creatures, crawl from beneath the bodies of the parents and seek suit- 

 able feeding places. The majority first settle on the undersides of 

 the leaves along the midribs while the remainder seek the smaller 

 twigs. Many, of course, perish during the winter, but by spring there 

 are still great numbers remaining, and chiefly those which settled on 

 the twigs. Those on the leaves also move to the twigs and remain 

 there during the rest of their existence or until the old dead bodies 

 fall off. The cold winter months are not conducive to growth, but 

 with the coming of the warm spring days, development is rapid and 

 the excrement, known as honeydew, begins to appear in quantities over 

 the trees. This sweet excrement is the food of a black smut fungus, 

 which, though an after-effect, is the most serious feature about this 

 and many other scale insects. It is the prevention of the smut fungus 

 that most often prompts the control of the black scale. The fungus 

 serves as a good index to the time for spraying. 



The black scale is a general feeder and attacks a large and ever- 

 increasing number of plants, the known list for all countries including : 

 almond, Antidesma, apple, apricot, mountain ash, aster, beech, buck- 

 thorn, camellia, California nutmeg, deodar cedar, Oestrum, chrysan- 

 themum, citron, Duranta, eucalyptus, fig, fuchsia, geranium, grape, 

 grapefruit, Grevillea, Grewia, groundsel tree, guava, English holly, 

 mountain holly or Christmas berry, St. John's wort, jasmine, Irish 

 juniper, laurel, lemon, black locust, honey locust, magnolia, mahogany, 

 maple, Maytenus, Melaleuca, Myoporum, nightshade, oleander, olive, 

 orange, trifoliate orange, orchids, palms, periwinkle, pigeon pea, pear, 

 pepper tree, phlox, plum, pomegranate, poplar, privet, prune, rose 

 rubber, sage, sumach, sycamore, tangerine, sago palm, strawberry 

 tree, Thespesia, Veronica, and watermelon. 



Considering the whole state, very little has been done towards the 

 control of the black scale on olive trees. In a few of the large com- 

 mercial plantings, particularly along the coast regions, some attention 

 is given to the insect and control measures are employed whenever 

 necessary. These control measures have been well worked out and 

 have given very satisfactory results. In a few instances fumigation 

 has been used in the citrus districts with marked success, but the cost 

 as compared with spraying is so much greater that the latter practice 

 is now almost universally followed where treatments are advantageous. 

 The hardiness and resistance of the olive trees are remarkably great, 

 making it possible to apply very strong sprays without injury to 

 the fruit or foliage. Normally, the dormant sprays for deciduous 



