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Bulletin 396 



EXPERIMENTS IN PRODUCING SCARS BY PIN PUNCTURES 



In making feeding punctures, Lygidea mendax may inject into the wound 

 a poison which affects the fruit differently from ordinary punctures. 

 The peculiar festering noted in the wounds made by feeding redbugs, 

 and their subsequent development, are so characteristic that it seems very 

 probable that some secretion of the bug plays an important part. The 

 writer made dissections of nymph and adult heads of L. mendax in an 

 effort to locate poison glands, but if such were present they were so small 

 that he failed to find them. 



The bug when feeding will at intervals raise and lower its proboscis 

 in the wound, evidently lacerating the pulp cells in order to obtain a 

 greater flow of sap. Experiments were made in imitating redbug wounds 

 by using a No. insect pin to make the punctures. On June 7, when 

 the young apples were not more than a half inch in diameter, a great many 



§ 



Fig. 58. RHODE ISLAND GREENING APPLE, AND TWO SLICES FROM OTHER APPLES, 

 SHOWING THE SCARS " RESULTING FROM PUNCTURES BY A NO. O INSECT PIN 



fruits were treated in this way. The mature result of some of these pin 

 punctures on Rhode Island Greening apples is shown in figure 58. The pin 

 punctures did not produce the characteristic festered wound made b)^ red- 

 bugs, with the subsequent splitting of the adjacent skin and development 

 of russet scars. 



NOTES ON THE CONTROL OF LYGIDEA MENDAX 



Observations on the control of Lygidea mendax by spraying were made 

 in 191 5 in one of the orchards of R. E. Chapin & Son, at Batavia, New 

 York. In 19 14 this orchard was found to be badly infested with L. 

 mendax, and at picking time fifteen per cent of the fruit had to be dis- 

 carded due to the injuries of these bugs. It was decided to spray with 

 Black-leaf-40 in the following spring, and the results of the spraying in 

 19 1 5 are here given. 



The writer examined the unfolding buds dail\' for the hatching insects, 

 and it was found that the first nymi)hs hatched on April 26. On the 



316 



