£° CALIFORNIA STATE HORTICULTURAL COMMISSION. 



PARASITIC HYMENOPTERA, DIPTERA, ETC. 



Beneficial Insects. Host Insects. 



Scutellista cyanea Black Scale (Saisseta olese). 



Dilophogaster californica . - . Black Scale (Saisseta oleae). 



Hymencyrtus crawii . - Black Scale (Saisseta olese). 



Aphelinus mytilaspidis Black Scale (Saisseta olese). 



Aphelinus fuscipennis -.--San Jose" Scale (Aspidiotus perniciosus). 



Aspidiotophagus citrinus ....Yellow Scale (Chrysomphalus [AspidiotusJ citrinus) and 



San Jose' Scale (Aspidiotus perniciosus). 



Pteromalus puparum Internal parasite of the Cabbage Butterfly (Pieris rapa>). 



Comys fusca Brown Apricot Scale (Eulecanium armeniacum). 



Encyrtus flavus Soft Brown Scale (Lecanium [CoccusJ hesperidum). 



Coccophagus lecani Soft Brown Scale (Lecanium [Coccus] hesperidum). 



Coccophoctonus sp. Yellow and Red scales. 



Eupelmus mirabilis Internal parasite of the Katydid (Microcentrum retinervis). 



Braconid sp _ ..Parasite of Cutworm. 



Anastatus sp - Egg parasite of Tent Caterpillar. 



Tachnia fly.: --- -- Internal parasite of Cabbage Butterfly (Pieris rapte). 



Internal parasite of Lecanium robinarum. 



Aphelinus sp. — -- Internal parasite of Aphis. 



Somewhere about the year 1868, a California nurseryman in San 

 Mateo County, not far from San Francisco, imported some lemon trees 

 from Australia. There was nothing unusual about this, nor was there 

 apparently anything unusual on the trees themselves; nevertheless 

 that importation cost the State of California millions of dollars and 

 came near destroying one of the most important of its fruit industries, 

 for on those trees, unseen and unnoticed by any one, were some of the 

 young of the now well-known cottony cushion scale (Icerya purchasi). 

 These soon reached their mature stage, and still no notice was taken of 

 them ; they were regarded merely as a curious object when noticed, and 

 it was never dreamed that they were the commencement of one of the 

 most terrible pests that California fruit-growers have ever known. The 

 insects increased in numbers, but not being in a fruit section, and their 

 depredations being confined largely to ornamental stuff, they were dis- 

 regarded. Soon afterwards a Los Angeles nurseryman and florist 

 secured some of the imported stock, with the imported pest, and so it 

 was introduced into Southern California. Here conditions were better 

 suited to it than even in the section where it had first obtained a foot- 

 ing in the State, and it spread much more rapidly. Soon it got into 

 the orange orchards. Here conditions seemed perfect, and in a very 

 short time it had spread to an alarming extent. Orchards in which it 

 had become firmly established were covered with it until they looked 

 as though they had been exposed to a severe snowstorm. It was soon 

 found in remote sections, and in a short time appeared to have taken 

 possession of the whole country. Nor did it confine itself to the orange 

 trees; many varieties of fruit' and a great quantity of ornamental 

 plants fell beneath its attacks. It even found its way to forest trees, 

 and for some time it looked as though it would reduce the whole country 



