PLANT LICE— NATURAL ENEMIES 



1689 



In the state of California tliis species 

 has become a very important factor in the 

 control of aphids of various kinds, and 

 especially the melon aphis in the south- 

 ern part of the state. The superintend- 

 ent of the state insectary sends his men 

 up into the mountains where the lady- 

 birds gather in the autumn for their 

 winter sleep to locate the colonies as 

 they begin to assemble. Later when the 

 snow has covered them up these colonies 

 are dug out, the beetles are sifted out of 

 the pine needles and other rubbish and 

 sacked up. They are then carried out on 

 the shoulders of men to some central 

 point where they are loaded upon pack 

 animals and transported, literally by the 

 ton, to the state insectary and put in cold 

 storage to await the spring. From the 

 insectary they are sent out at call all 

 over the state to hold in check the rising 

 horde of plant lice. 



Ashy Gray Ladybird 



Coccinella dbdominalis Say. 



This ladybird gets its common name 

 from its color, which is gray with eight 

 black spots on each wing cover and 

 seven on the thorax. The larvae resemble 

 those of the red spotted ladybird, Hippo- 

 damia convergens. but are a little larger 

 with light or yellow spots on the back 

 instead of orange. 



This insect is an enemy of the various 

 plant lice which are pests of the orange, 

 but is of special value as a control for 

 the walnut louse, which It prefers to all 

 other species of aphids for food. Its im- 

 portance can hardly be overestimated. 

 Scymnus sordidus Horn 



This is one of the smallest of the aphid 

 feeders. The larva is considerably larger 

 than the adult, being nearly a quarter of 

 an inch long and half as wide. It is 

 easily recognized by the heavy coating 

 of rather long white, cottony wax and is 

 often mistaken for the mealy bug. The 

 adult is scarcely more than an eighth of 

 an inch long and two-thirds as wide; 

 light brown to very dark brown in color 

 and with elongated body. 



This insect is a native of California 

 and is especially abundant in the south- 



ern citrus counties, where it also does 

 good work on the citrus mealy bug. 



Syrphus Flies 



Common names: Flower flies, honey 

 flies, sweat flies. 



Always among the plant lice are to 

 be found greenish, fiat, sticky-looking 

 "worms" which are decidedly pointed at 

 one end and which do not have distinct 

 head, eyes or legs. These so-called 

 "worms" are the larvae or maggots of 

 a two-winged insect or fly of the order 

 Diptera and the family Syrphidae. The 

 larvae vary from the minutest first- 

 hatched maggot to nearly an inch in 

 length, according to the species to which 

 it belongs. They are usually light or 

 dark green, but some may be brown, 

 orange, very light or nearly black. The 

 mouth is situated at the small end and 

 all of the food is obtained by puncturing 

 the body walls of the lice and then smok- 

 ing out the contents. This operation is 

 easily observed in the field. The maggot, 

 firmly supported by the large posterior 

 end, raises itself up and begins to blindly 

 move its mouth-end about in quest of 



The Lar^e Syrphid Fly 



.\. larvae; B, puparlum. from which adult has 



emerged ; C, adult. 



— After Essig 



