BUG VS. BUG. %& 



hesperidum) . This scale was another of the very serious pests which the 

 orange-growers of California had to contend with and from which they 

 have been relieved by insect aids. When orange-growing was in its 

 infancy, the soft brown scale obtained a foothold in the orchards, and 

 without any check soon spread. In a short time the trees were covered 

 with it and were suffering greatly from its depredations. In a compara- 

 tively short time, however, it began to disappear, and investigation 

 showed that several internal parasites, among which the Encyrtus flaviis 

 was one of the most important, were actively at work upon it. and 

 reducing it below the danger limit. 



Coeeophagus leeani. (Plate II, Figs. 2, 2a.) This is another of the 

 internal parasites of the soft brown scale (Coccus hesperidum). It is 

 found in several of the Lecaniums, but its best work in this State lias 

 been on the soft brown scale of the orange, which, in connection with 

 Encyrtus flavus, it has kept below the danger limit. 



Coeeophoetonus sp. This is an internal parasite of both the yellow 

 and red scales, and while it has not done as extensive work as some of 

 the other parasites above described, it is none the less an important 

 addition to our list of friendly insects. 



Eupelmus mirabilis, Walsh. This is an egg parasite of the katydid 

 (Microcentrim retinervis, Scudder). The female insect lays her eggs 

 within those of the katydid. The young parasite is hatched and at 

 once proceeds to eat the eggs of the host insect. The Eupelmus mirabilis 

 has been an invaluable friend to the orchardists of California and 

 especially to those engaged in orange-growing, where at one time the 

 katydid was an annoying and destructive pest. It is now rather a rare 

 insect in those sections where it was once so common, and it is difficult 

 to find its eggs without observing that they have been perforated and 

 destroyed by this parasite. 



Besides the above-named insects which are common in California, 

 and to which without doubt we owe our position as a fruit-producing 

 State, there are a number of others of greater or less importance, among 

 them a species of Braconid, parasitic on cutworms; Anastatus, an egg 

 parasite of the tent caterpillar, and another parasite of the tent cater- 

 pillar eggs. There is also a Tachnid fly which destroys the cabbage 

 butterfly by laying its eggs on the victim, the young larva hatched 

 from which eats up the caterpillar and destroys it. There is also an 

 internal parasite of the Eulecanium (Lecanium) robinarum. Douglas, 

 and a species of Aphelinus working as an internal parasite of the aphis. 



