February, '22] frost: apple red-bug 103 



Seasonal Activities of the False Red-bug 



The n3nTiphs hatch shortly after the time that the color is showing 

 in the cluster buds. From records taken during the years 1917 to 1921, 

 it appears that in Pennsylvania the hatching of the red-bug eggs occurs 

 after the pink condition of the buds. No nymphs were observed 

 during these years before the blossom pink. During the unusually early 

 spring of 1921, the relation of the hatching of the nymphs and the 

 development of the buds remained the same and the eggs did not hatch 

 until a considerable time after the pink condition of the flower buds. 



The investigations of five consecutive years have been summarized 

 on the following chart. During this period there were four normal 

 years. In 1921 conditions as legards the bud development were ex- 

 tremely early. The data secured during this abnormal year add con- 



Il93ll 



BLOSSOM 

 PINK 



^^^ 



CLUSTER 

 APPLE 



Jl 9l9) 



ll'saol 



- ^ APRILS 



-£miI- 



■ <a JUNEg - 



Fig. 2 Apple red-bug, Lygidea mendax Reut. ; chart showing length of nymph- 

 al stage dviring five successive years. 



siderably to the value of the chart as it shows very clearly that the same 

 relation of bud development and insect activities exists even under 

 extreme conditigns. The horizontal broad, black lines indicate the 

 length of the nymphal stage of the false red-bugs from the hatching of 

 the first nymphs to the transformation of the first adults. The activities 

 of the nymphs would therefore extend over a longer period than indi- 

 cated by a single line for any particular year. The nymphal periods 

 are based entirelv on field conditions in a number of orchards. No 



