246 STATE BOARD OF HORTICULTURE. 



" Male pupse apterous, naked or covered. Adult males with two wings and 

 two halteres ; metamorphosis complete ; rostrum present in larva and pupa, 

 always absent in adult; tarsi monomerous, feet ending in a single claw; 

 abdomen terminating in a spike which forms the sheath of the penis ; eyes 

 present in adult; ocelli often large, sometimes exceeding three in number." 

 W. M. MASKELL, F.R.M.S., "The Scale Insects," New Zealand, p. 37. 



This group of insects is of the utmost importance to horticul- 

 turists, as but few trees are exempt from its attacks. While the 

 study of economic entomology is comparatively new in Califor- 

 nia, its incipiency dating back but a few years, these insects 

 have attracted wide attention, as nearly every branch of the fruit 

 industry has felt their effects more or less. In this State there 

 is a great diversity of industries in the fruit line, and trees and 

 plants have been imported from almost every country. Upon 

 them many injurious species of insects have been brought in. 



The pernicious scale, or "San Jose" so called, which does not 

 affect the citrus, but deciduous trees principally, was the first 

 species of this group which gave this important study its 

 incentive. It made its presence felt in Santa Clara County 

 as early as 1878. Whence it came is not definitely known, 

 but was no doubt brought here on cuttings or trees. As very 

 little was then known of this species, effective measures were 

 not adopted for its suppression, and it spread to adjoining 

 orchards and was afterward taken to other counties on nursery 

 trees. For a time it threatened to be a menace to the deciduous 

 fruit industry, and it appeared as if its progress could not be 

 checked; but effective measures were discovered for its suppres- 

 sion in the way of insecticides, and lately, beneficial insects 

 have accomplished great good in practically exterminating it 

 throughout the State. 



In 1868 another species, the cottony cushion scale, was 

 brought into our State on plants from Australia, its natural 

 home. This species played great havoc in many sections, 

 especially to orange and lemon orchards. Every means pos- 

 sible were applied, and for a time it baffled the combined wisdom 

 of scientists and fruit-growers. It was not that the insecticides 

 applied did not kill the pest, but because all insects could not 

 be reached, enough escaping to reinfest the tree. Here again 

 nature came to our relief. The Vedalia cardinalis, Mulsant, 

 in one season reduced it to such an extent that it can no longer 

 do injury. Where this scale appears in isolated localities 



