STATE AGRICULTURAL SOCIETY. 461 



Article VIII. — Diseases. 



My attention was called, as early as 1874, to the condition of the trees 

 in and around Santa Barbara from the ravages of the " Coccus olece" com- 

 monly known as the "black scale," and which was always followed by the 

 black fungus. In 1875 I visited the orchards of San Diego, San Gabriel, 

 San Buenaventura, and Santa Barbara, and in 1876 San Luis Obispo. At 

 the latter place I learned from the mission fathers, through the late Hon. 

 Judge Murray, that the disease had appeared about fourteen years before 

 that date, fixing the date of its appearance in California at about 1862. 

 Prior to that time they had had uninterrupted success with their olive 

 trees. These examinations, very carefully made, determined in my mind 

 one of two alternatives, either to keep the trees free from the scale bug, or 

 root them out. I chose the former, and have been fighting it without any 

 cessation ever since. I believe all my olive trees are clean, and are, at this 

 writing, loaded with a beautiful fruit crop. 



An olive tree once attacked with the scale bug, unless cleaned, will soon 

 be infested so that it cannot bear fruit. Such fruit as is borne during the 

 period of rapid increase of the insect will not make oil. There are trees 

 enough in the southern part of the State, if properly cleaned and cared 

 for, to produce many thousands of gallons of oil, while, with a few excep- 

 tional orchards, I do not believe one single gallon could be made. This is 

 the condition everywhere where the insect is prevalent. The attack is 

 fatal, unless it is at once destroyed, and it is useless for any orchardist to 

 fortify himself behind theories that something will turn up to counteract 

 the ravages, or that the ants will destroy them, or that some enemy or 

 parasite will appear to do the work which he cannot escape. The whole 

 business will be bankrupted by anything short of total annihilation of the 

 insect. In some districts on the northern coast of the Mediterranean the 

 spread of this insect has become so alarming that the question of aban- 

 donment is contemplated. The ravages have baffled the efforts of their 

 wisest men. To give some idea of the rapidity with which it will spread, 

 I quote from a very interesting treatise — a pamphlet of ninety pages, written 

 by Alfred Lejourdan, agricultural engineer — published in Marseilles, in 

 1864, title " Maladie Noire." It is, in this work, estimated that one female 

 " Coccus " will produce from two thousand to four thousand eggs. By one 

 autbpr, that one " Coccus" in five generations, will produce five billions 

 ninety-four millions. By another, that ten generations are produced in 

 one year, and allowing only one hundred as the reproduction of each, w-e 

 will have at the end of the year, from one single female, one billion billion — 

 fortunately for us, there are too many things contingent that prevents the 

 possibility of such increase — high winds, birds, and insects of various kinds 

 destroy the greater number ; still, in favorable years, the rapidity with 

 which they will spread will require our greatest energies and intelligence 

 to counteract. 



In a very exhaustive work on the olive, compiled by A. Coutance, Pro- 

 fessor of Natural Science in the schools of medicine, published in Paris in 

 1877, it is claimed that the silenoe of authors on this malady, caused dur- 

 ing a period of twenty years, great ravages. Let us not commit the same 

 blunder, and if we are to foster the culture of the olive in this country, the 

 valuable portions of such works as above mentioned, and of other books 

 on the subject, should be translated into English and made accessible to 

 all the cultivators where the olive can be grown. 



The ravages of this insect are of quite recent date; Lejourdan states 



