294 



FRUIT INSECTS 



sooty black fungus that renders the fruit practically unsalable. 

 The winter is passed by the fertiUzed females on the smaller 

 branches. These scales are about yV inch in length, nearly 

 circular in outline and very convex with an elongate reddish 

 area on the back and radiating black Hues along the margin. 

 ■S} The edge of the scale is sHghtly ridged 

 (Fig. 250). Individuals vary greatly in 

 color from nearly pure black to orange- 

 red. Growth is resumed in early spring, 

 and by the last of May the females are 

 about J- inch in length. Eggs are formed, 

 and the minute straw-colored flattened young 

 escape from beneath the old scale and es- 

 tabUsh themselves on the leaves. Hatch- 

 ing continues for a period of about 6 weeks 

 during June and July. Winged males ap- 

 pear during August and fertilize the females ; 

 the latter soon migrate to the bark of the 

 smaller branches, where the winter is spent. There is only one 

 generation a year. 

 Treatment. 



Recent experiments in Maryland have shown that this scale 

 may be readily controlled by thorough spraying with miscible 

 oils at the usual dilution for dormant trees. When used in the 

 fall there is danger of kiUing the fruit-buds, but if the treatment 

 is deferred until spring, when the tree has r(»sumed its ac'tivities, 

 this difficulty can be in grc^at measure obviat(Hl. Th(^ use of 

 Hme-sulfur for this scale is of little or no vakie. Summer appli- 

 cations directed against the n(^wly hatched active young hav(; 

 been found impracticable in commc^rcial practice. Although the 

 young are easily killed by apphcations of kerosene emulsion 

 or nicotine extracts, so many sprayings are necessary to cover 

 the long hatching period of at least six weeks that the expense 

 becomes prohibitive in large orchards. 



Fio. 250.- 

 terrapin scale on a 

 peach branch. En- 

 larged. 



