CALIFORNIA AVOCADO ASSOCIATION 



17 



INSECT PESTS 



The nuni1)er of insect pests attacking avocado trees so far in 

 California is small. The list includes the mealybug, greedy and black 

 scales in A'entura and the southern coast counties; the omnivorous 

 looper on seedlings at Berkeley ; the twig borer, Polycaon con- 

 fertus, and a chafer, Serica alternata, on nursery trees in A^entura 

 County, and an unidentified miner, the galleries of which have been 

 noticed in the bark of tender branches in various parts of Southern 

 California. According to the horticultural commissioner of Ven- 

 tura County, the Avork of the twig borer was similar to that on 

 other trees, namely, boring into the tree at the forks of the branches. 

 In some cases Avhere the trees were small the cavities made were 

 equal to about half the diameter of the limbs on which the insects 

 were working. In such cases the trees were so weakened that a 

 heavy wind would break them off. Digging out the beetles by hand 

 proved the surest remedy. The Serica was found working on avo- 

 cado foliage in the Fillmore section, where it is found very com- 

 monly on walnut trees. It feeds only at night, burying itself in the 

 ground during the daytime. Some of the avocado trees were almost 

 defoliated. Arsenical sprays did not proA'e effective as a remedy, so 

 the young trees were coA'ered with muslin as a temporary protec- 

 tion. On large trees the damage done by these chafers would 

 seldom be appreciated. 



In all countries where the avocado is produced its principal use 

 is as a fresh fruit. A few recipes are given in which the pulp is 

 cooked Avith vegetables ; it is also commonly used to flavor soups. 

 The subject of by-products has receiA'ed some attention in other 

 countries, and recently experiments ha^-e been made at the Uni- 

 versity of California to see it some methods could be worked out 

 by which the pulp and seeds of the small seedling could be utilized. 

 Naturally the possibilities of producing a commercial oil from the 

 fruit have been first considered. 



The Florida Experiment Station in 1902 made some prelim- 

 inary investigations of avocado oil, but owing to a change in the 

 station staff about 1903. the Avork Avas dropped and has never been 

 taken up since. Brant, in his "Animal and A'egetable Fats and 

 Oils," 1897, states that the oil is of a slightly dark greenish-broAvn 

 color and consists of 30 parts of olein and 70 parts of lauro-stearin 

 and palmitin. Olein is licjuid and the other tAvo fats are solids, 



