14 



BULLETIN" 838, U. S. DEPARTMENT OF AGRICULTURE. 



Larvae isolated in rials, immediately after hatching, lived for two 

 and three days. Living for this length of time and traveling at the* 

 above rate of speed during only the warmer parts of the day, larvae 

 could go considerable distances in search of proper food. In this way 

 larva? are able to migrate from one tree to another in closely planted 

 hedges or windbreaks. During this migratory period, larvae are also 

 likely to be transported short distances by dropping from high 



Fig. 2. — Tracings of five first-instar larvae of the cypress bark scale during migration. 

 Reduced 5i times. All were started from the same center. 



branches and being carried by the wind, and for longer distances by 

 animate agencies, such as insects, birds, and animals. 



ATTACHMENT. 



As soon as a larva finds a suitable crevice or a protected area in the 

 bark, it thrusts its proboscis into the bark tissues, where it remains 

 permanently. Larvae have not been known to remove themselves 

 from this first location to another after once becoming attached. 

 Larvae which have become detached somewhat later in life are able 

 to crawl about feebly, but finally die without being able to attach 



