150 PROCEEDINGS OF TWENTY-SIXTH FRUIT-GROWERS' CONVENTION. 



destructive insect enemies, and at times very much more than their 

 share. The tsetze-fiy and bot-fly kill thousands of cattle annually. 

 Thousands of sheep succumb to the ravages of the gadfly, scab-mite, 

 and lung parasite. Tens of thousands of acres of grain are annually 

 destroyed by the Hessian-fly, chinch-bug, and innumerable other 

 pests; and we fruit-growers have pests without number infesting our trees 

 and vines, in every part and at all periods. We find them attacking 

 the plant from the minute rootlets to the uppermost twigs, on trunk and 

 branch, on twig, leaf, and fruit. There is no part immune from their 

 attack, or that does not sutler from their presence. Minute as these 

 pests are, microscopic even, they are sufficient to reduce our profits, 

 largely increase our labors, and give us infinite worry and anxiety. 



Probably the most persistent, annoying, and destructive group of 

 insects with which the fruit-grower has to contend is the scale insects or 

 Coccidse, and the object of this paper is to discuss this particular group 

 more in detail. 



Scale insects (Coccidse) belong to the order Homoptera, and are 

 closely allied to the Aphis, or plant-lice, family in their habits, but 

 differ greatly in appearance. Some confine themselves to a single genus 

 of plant, while others attack a great variety, and, when present in great 

 numbers, soon cause the plant to lose its vitality, and if not checked in 

 time, will soon kill it. 



Scale insects have been known from time immemorial. The beautiful 

 and impressive color of the curtains of the tabernacle and of the robes 

 of the priests, which brought awe and inspiration to the tribes of Judah, 

 is said to have been obtained from a scale insect (Kermes ilicis). This 

 insect is still used as a dye in some remote parts of Europe, and in some 

 parts of Spain the inhabitants, mostly women, help support their fami- 

 lies by collecting Kermes. The cochineal insect ( Coccus cacti, Linn.) has 

 been used as a dyestuff for a very long period. Our shellac of com- 

 merce is the product of a scale insect ( Tachardia lacca), and was known 

 in 1781. There are many other species whose usefulness was well 

 known, and it shows that in olden times scale insects were mostly 

 considered beneficial, and although one or two are still so regarded, yet, 

 as a whole, they are very injurious. 



Horticulture has made such rapid strides within the last fifty years, 

 and the orchard area has increased to such an extent, that scale insects 

 have, so to speak, found themselves in clover, and many species have 

 taken hold of the new food which man has seen fit to propagate. Very few 

 of our native species have changed their habits or their food plants, and 

 most of the troublesome species we have to do battle with are imported 

 from foreign countries. The orchards of California have been troubled 

 by these pests for more than thirty years, and some species which once 

 threatened our industry, especially the cottony-cushion scale [leery a 



