f7 



BUG VS. BUG. -21~ 



Aphelinus fuseipennis, Howard. (Plate III, Figs. 2, 2a.) It is well 

 withiu the memory of the fruit-growers of California when the San Jose 

 scale was the most terrihle of our pests. It antedated the appearance of 

 the cottony cushion scale and attacked nearly all of our deciduous fruit 

 trees. For some time it seemed as though the fruit industry of our State 

 was doomed, at least such varieties as were attacked by this pest, .and 

 orchardists were digging out and destroying their trees by thousands in 

 order to stay its ravages. Various compounds were devised to fight it; 

 among them the now celebrated wash of salt, sulphur, and lime was dis- 

 covered as most effective. This wash is still the best known artificial 

 remedy for San Jose and kindred scales on deciduous trees; but it is 

 impossible with the greatest care to destroy any kind of pest by artificial 

 means. There are always solitary trees which will be neglected, careless 

 people who refuse to spray, wild shrubbery out of reach of the operators, 

 and all of these become sources of infection. While active and efficient 

 work was being done by artificial means against this pest, it was discov- 

 ered to be disappearing in sections where no spraying was done, and 

 investigation showed that one of our native parasites, the Aphelinus fus- 

 eipennis, had adapted its taste to it and was rapidly getting it under. 

 To-day, wherever the San Jose scale is found we also find its parasite, 

 and while the pest has not, and never will disappear, it is entirely con- 

 trolled by its little enemy until we pay no further attention to it. 

 Spraying is still carried on, however, as it has been found beneficial to 

 our fruit trees in killing other pests, preventing fungous diseases, 

 and keeping the trees healthy: but so far as the San Jose scale is con- 

 cerned, there is no further need of artificial remedies. 



This same parasite is generally distributed all over the United States 

 and is undoubtedly doing good work, as shown in our quotation from 

 Prof. W. G. Johnson of Maryland, but the long winters and compara- 

 tively short summers there may check its spread. In the mild winters 

 and long summers of California it probably has more broods than there, 

 and, increasing in greater quantity, it is enabled to do more effective work. 



Pteromalus puparum. This is a very common enemy of the cabbage 

 butterfly (Pieris rapae) in this State, and undoubtedly to its work is 

 due the fact that this pest is not more common than it is. This parasite 

 has a wide range and is found over the greater part of the United States. 

 It is parasitic upon the pupa of the butterfly, upon which it lays a 

 number of its eggs, which, hatching out in its unfortunate victim, puts 

 an end to its career. Prof. F. M. Webster in "Insect Life" gives an 

 interesting account of the operations of this insect, as follows : 



On the morning of August IJth, we observed a larva of Pieris protoMce, Boisd., in 

 the act of transformation to the chrysalis. Near by, and very evidently watching this 

 transformation, were a male and female of this parasite. The trio were ohserved 

 several times during the early part of the day, the parasites always on guard, as it 



