20 POMONA JOURNAL OF ENTOMOLOGY 



PARASITES AND PREDACEOUS INSECTS. 



As yet no parasitic or predaceous insect has served to appreciably lessen 

 the number or work of the red scale in our orchards of Southern California. 

 This is not true of the yellow scale, as the golden Chalcid has in many places 

 seemed sufficient to hold that species in check. As suggested above, the yellow 

 scale about Claremont is not controlled by its insect enemies. This greater 

 freedom from attack by parasites of the red scale, is another important differ- 

 ence between these two species, which in general are so closely similar. While 

 we should strive to secure parasites that would be as efficient to destroy this 

 red scale as is Noz'ins (rcdaHa) cardinalis to combat the cottony cushion 

 scale, yet we must not withhold fumigation until some enemy is found that 

 will control the scale. We can never afford to allow our orchards to be 

 victimized by these devitahzing sappers. 



PRACTICAL SUGGESTIONS. 



The fact that the red scale is armored, and exists at all times, and in all 

 stages of growth, makes its destruction very difficult. It requires nearly or 

 quite double the black scale dosage and about as much cyanide as does the 

 purple scale, if we would secure complete extermination. At times, even 

 when we are so thorough, it may be wise, to give a second fumigation as soon 

 as we can learn, by examination, that the first fumigation was not entirely 

 effective. The tents must be gas proof, and should remain over the trees for 

 a full hour. They should also in all cases of fumigation, be marked as directed 

 by the Department of Agriculture, that there may be no guess work, and so 

 no possible mistake in determining the amount of cyanide to be used in each 

 case. 



As is true of all scale insects, all weeds that may harbor the scale should 

 be kept entirely from the precincts or neighborhood of the orchard. Clean 

 culture, except in winter, when the best success demands that a good cover 

 crop of legumes be grown, must be practiced. In case of red and purple scale, 

 it is wise to gather and burn the fallen fruit. On fallen leaves scale insects 

 soon die, but they live a long time on fruit. 



HINTS ON Fumigation. 



Fumigation for black scale may best be done, when all the scale are 

 hatched and still quite young. For our locality this is October and November, 

 though when necessary this may extend from September 1st to February 1st. 

 As there are more or less black scale in all our citrus and deciduous orchards, 

 this is a good time to treat any scale, as we then kill both the black and the 

 other as well. It is not wise, however, in case the red scale, the ])urplc scale, 

 or the mealy bug are found to be introduced into any region, to wait for autuinn, 

 but to fumigate at once. They are all very prolific, and are easily scattered by 

 wind, bird or insect, so immediate extermination should be the watchword, 

 as soon as their presence is discovered. To delay treatment is costly and 

 dangerous, and makes the orchard a menace to all others in the region. For 

 the red, the yellow, and the purple scale, it is fortunate if we can fumigate in 



