THE HOMOPTERA 



219 



October and March. Hydrocyanic acid fumigation has also given satisfactory 

 results, especially with light doses frequently repeated. A number of natural 

 enemies are of some value against this insect. 



The Long-tailed Mealy Bug (Pseudococcus longispinus Targ.). This is 

 often found in greenhouses attacking many kinds of plants. The bodies of adult 

 females vary from yellow to gray, and the young are born alive, there being 

 apparently several generations each year. Hydrocyanic acid fumigation seems 

 to be the most successful treatment for these insects. Nicotine sulfate may 

 also be used. 



The Cottony Cushion Scale or Fluted Scale (Icerya purchasi Mask.). 

 This serious pest of citrus and many other plants, apparently reached 

 California from Australia about 1868 and by 1880 had spread all over 

 the citrus-growing regions of the State and was threatening the destruc- 

 tion of the entire citrus fruit industry. 



FIG. 216. Cottony Cushion Seale (Icerya purchasi Mask.) and its lady beetle enemy, 

 the Vedalia (Novius cardinalis Muls.): a, larvae of the Vedalia feeding on a Seale; b, pupa 

 of the Vedalia; c, adult Vedalia; d, twig with the Scales and lady beetles, a, greatly 

 enlarged; real length of 6 and c shown by hair lines; d about natural size. (From Sanderson 

 and Jackson, Elementary Entmology: after Marlatt, U. S. D. A.) 



Investigation showed that in Australia it had an enemy known as 

 the Vedalia (Novius cardinalis Muls.), a lady beetle, and these were 

 finally brought to California and colonized in the orange groves, where 

 they attacked the scales so effectively that in the course of a few years 

 these were brought under control, and now only an occasional local 

 outbreak makes the scale of importance. When this happens, the in- 

 troduction of the lady beetles to that region is soon sufficient to check 

 all injury. In later years the scale has appeared in Portugal, South 

 Africa and elsewhere, and when the introduction of the Vedalia into those 

 regions has successfully followed, the scale has soon become relatively 

 unimportant. 



The female scale has a red, yellow or brown body. It lays its 400 



