ALMONDS— APHIDS 



45 



First, to select varieties that are pro- 

 lific bearers, for some varieties will not 

 bear fruit enough to pay the cost of cul- 

 tivation. 



Second, to select varieties that cross pol- 

 linate, for most varieties of the almond 

 will not pollinate from the same tree. 



Third, to select a site for the almond 

 orchard that is as nearly as possible free 

 from frost, because the tree is an early 

 bloomer and the fruit buds are tender. 



There are about 25 varieties grown in 

 California and the general treatment and 

 cultivation given to them is similar to 

 that given to the peach. 



The almond is propagated by budding 

 on seedling stock, and at maturity the 

 nuts are gathered some time in the au- 

 tumn. The kernels should be smooth, 

 plump and symmetrical in order to bring 

 the highest price in the market. 



Almonds Produced in the United States 



There are but few states in the Union 

 which produce almonds for commercial 

 purposes. The number of bearing trees 

 by states, as reported in the census of 

 1910, gives California 1,166,730; Arizona, 

 6,639; Utah, 1,408; Nevada, 13. We per- 

 son,ally know of a few trees in Washing- 

 ton, and doubtless there are in many other 

 states a few grown for home use. The in- 

 dustry in the other states, however, has 

 not assumed commercial importance. 



Varieties 



The more important varieties are as 

 follows: 



California, California Jordan. Chilinese, 

 Commercial, Drake, Eureka Jordan, Gol- 

 den State, I. X. L., Languedoc, Lassen, 

 Nonpareil, Prolific. St. Joseph, Texas. 



Gr.^x^tlle Lowther 



Altitude. See Apple Orchard. Select- 

 ing Site For. 



Anthe.icxose, Time to Spr.^y for. See 

 San Jose Scale on Apple, under General 

 Recommendations. See also Black Spot 

 Canker. 



Aphids 



The Aphididae or plant-lice are among 

 the largest families in the great Order 

 Hemiptera. Economically they rank 

 among the groups of the higher impor- 

 tance and few indeed of the higher plants 

 there are that are not subject to their 

 attack. Many of our most injurious forms 

 on fruit trees and truck crops were im- 

 ported from Europe, while indigenous 

 species include the grape Phylloxera, first 

 imported from wild American vines into 

 France and later from that country into 

 the grape regions of California. Aphids 

 feed solely by means of a stout beak 

 which they thrust Into the plant tissue 

 and through which the juices of the plant 

 are sucked up. In certain species this 

 sucking mode of feeding causes the plant 

 tissue to form galls or pseudo-galls In 

 which the lice continue to dwell pro- 

 tected from their foes. Certain other 

 species live on the roots of trees or small 

 plants, but the great majority exist un- 

 protected on the leaves, stems or flower- 

 heads of their food-plants. Many aphids 

 — and among these are a number of very 

 injurious forms — migrate at certain 

 periods from one host plant to another 

 and such hosts may be widely separated 

 botanically. Our knowledge of these 

 migrations and the causes which pro- 

 duce them is as yet far from complete. 

 Most aphids are confined to one host or 

 to several closely related plant species, 

 but a few forms, as for example the 

 Green Peach Aphis (Myzus persicae 

 Sulz.), attack a large number and variety 

 of plants. Parthenogenetic reproduction 

 occurs In the vast majority of aphids, al- 

 though true sexual forms are produced in 

 most species once a year, the sexual fe- 

 male after copulation with the male de- 

 positing winter eggs. In some species, 

 especially those inhabiting evergreen 

 plants, it is thought that two or more 

 years may elapse between appearances of 

 the sexed forms, as these forms have 

 failed to appear when expected. Parthen- 

 ogenetic females are winged and wing- 

 less, in some species only the former. 

 Sexed males and females may be winged 

 or wingless, according to species. Lab- 



